Don't Risk It: The Ultimate Guide to Heartworm Prevention!

Episode Transcript
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Dr. Tyler Sugerman (00:00):
Today on Vetsplanation, we are tackling a
silent threat lurking in theshadows for our pets.
It's called heartworm disease.
It's an often overlooked, butunfortunately, potentially
deadly disease for our pets.
Heartworm prevention is reallythe key cornerstone to trying to
help prevent this disease forour cats and our dogs.
Join us as we dissect the dangerthis parasite poses and arm

(00:23):
yourself with the knowledge tobe able to protect your beloved
companion.
From the life cycle of theheartworm, to the latest
prevention strategies, we arecovering it all.
So welcome to Vetsplanation, thevet podcast for your pet.
I'm Dr.
Sugerman and we're gonna bejoined today by Dr.
Z.
So tune in to learn whypreventing heartworm isn't just

(00:43):
a recommendation.
It is a necessity.
This episode could be thedifference between a healthy pet
and a heartbreak.
So don't miss it.
And don't forget, if you likeour content and want to hear
more of it, make sure tosubscribe and leave us a five
star review.
Hey everybody, welcome back toanother episode of
Vetsplanation.
I have our pretty much residentexpert here now, Dr.

(01:04):
Z with me again, and I am yourhost, Dr.
Sugerman.
So today I'm really excited,we're going to be talking about
something that's apparently beena hot topic in our office, at
least.
We're going to be talking aboutheartworms.

Dr. Xenia Zawadzkas (01:17):
Yes.
Heartworm disease.
Another fun parasite to talkabout in detail.

Let's start off, what is heartworm?

So heartworm is a, it's a worm.
The Latin name is Dirofilariaimmitis.
If we break that down,'diro'means it's like dire, terrible,
fearful, dreadful, formidable,that's what diro means.
So it's a nasty one.

Yeah, it has to be terrible.
Yeah.

And then filaria means like a thread-like
worm, like filament.
It's like a thread.
And then immitis actually meansharsh and cruel.
So it's a very negatively namedworm.

It sounds terrible.
I don't think I've ever heardany other worm named something
like that.

Yeah.
I don't know if I've broken downthe names of other words, but
like I looked this one up, I'mlike, Oh yeah, that makes sense.
Not a nice worm.
Yeah.
So adult heartworms, they areskinny about a foot long when
they're adults.
So about the size of yourforearm, usually length, I
should say.

Yeah.
That's long.

Yes, they're very long when they're
adults.
And they live in the heart andthe lungs and the associated
blood vessels.
They infect many differentanimals.
The big ones is dogs, of course.
But they can also get into cats,ferrets, wolves, coyotes, foxes,
sea lions, harbor seals, bears,muskrats, raccoons, red pandas,

(02:42):
leopards, and wolverines.
We've found them in all thosekinds of animals.
And those wildlife carriers areimportant, unfortunately they
keep the parasite going.
So they can get into these otherspecies.
Even they've been into humansbefore, too.
Like people have found themincidentally.
An x-ray of their chest andthere's like a spot in their
lungs and then they biopsy andthey find like heartworms.

(03:04):
It's like a granuloma that wasjust subclinical hanging out in
there.
So pretty nasty.
Even can get in people.
But that's not the main host sothey don't really do much else
besides make a small littlespot.
That's not a big deal.
So don't worry too much.

Good.
Good.

For people.
Let's see.
They really prefer the canidsthough.
That's their definitive host,and that's when they can
complete their full life cycle,as we'll go into.
But since they're in all thesewildlife species, and they can
get into other animals, it'sjust impossible to eradicate
them, probably.
We will always be dealing withthem, and it's important to
continue to protect our pets andourselves from these kinds of

(03:38):
parasites.

And the wildlife.

Yes.

I actually have seen a harbor seal that had
heartworm.

Did you?
See?
Interesting.
I've heard about the sealsgetting it because they sun
themselves and I'm sure themosquitoes are out there.

Exactly.
I mean, they're just so far outthough, like it is interesting
like how, but I guess they docome closer and closer,
especially when people startfeeding them fish.

Yeah.
The city harbors, there's sealseverywhere.

Exactly.
Exactly.

So because the wildlife are harboring these
worms.
And keeping them around.
It's very similar to rabies.
Like that's a virus.
It's not a parasite.
But it's because it's in thefoxes and the bats and the
wolves and other places it'sconstantly a threat and there's
probably no way we're ever gonnabe rid of it.
Yeah, we just can't get it outof those wildlife populations.
So yeah, the companion pets thatwe have are like our buffer from

(04:23):
rabies.
So if we keep them vaccinated,then we won't ever get rabies.
Hopefully it happens sometimes,that's the idea.
And that's why rabies is soimportant to like, that the
governments are like, you haveto vaccinate.
It's required by law.
It's not like similar forheartworm because it doesn't
kill people like rabies does,but my point is that the

(04:43):
wildlife harbors it, and we justcan't ever be rid of it, and
it's always a threat.

That makes a lot of sense.

Yeah.

So I know you always have like fun facts
for us.
Do you have any fun facts for usabout heartworm?

Yeah, just some historical things.
I was trying to look up thehistory of heartworm, and
there's not a lot out there, butapparently in 1586, there was
some person, I forgot his name,but I tried to look him up and I
couldn't find anything on him.
But apparently he drew a pictureof a monster worm.
Like it was a worm that was likea monster, had a monster face on
it.

(05:12):
And it was in the heart of ahorse.
And so that was like the firstdocumented possibility of
heartworms being found.
But really they pop up more inSouth America.
They were documented in the1800s and then by 1856 they were
found on the southeast coast ofthe U.
S.
area.
And then almost a century later,1974, is when the American

(05:36):
Heartworm Society wasestablished.
Those are my little historicalfactoids about Heartworm.

I will say, so my daughter came home the
other day and she was talkingabout how there's this crazy
blood death worm.
And I thought about yourHeartworm stuff, and I was like,
I wonder if that was the samething that they were writing
about.
But I don't know.

You should ask.

Yeah she had it in a book at school, so I'd
have to ask her to, to whichbook it was.

I'm curious which worm it was.

Yeah

Blood death worm?

A blood death worm.
I don't think it's a real thingfrom what I looked up, because
it she said the title was, like,the very true story of, so I
feel like it maybe is not a truestory,

Yeah, I think there's a lot of myth
around worms in general and,monsters.

Exactly.
They're creepy.

They are super scary.

Exactly.

It makes everybody's skin crawl.

Yes, exactly.
So how does a pet get heartworm?

So they are transmitted by mosquitoes.
Straightforward, they get bit bya mosquito.
That's how they get it.
And we'll go into the whole lifecycle, but to answer that
simply.

Perfect.
And then I think you mentionedthis before both dogs and cats
get heartworm, is that correct?

Correct?
Yeah, so dogs again are theirnatural host, but the parasite
can complete its life cycle bestin those species.
Cats can get them too, they justdon't usually get very far,
because the cat's immune systemis just better at killing the
baby heartworms on its own.
And occasionally one adult willmake it to the heart, but
usually it's just one worm thatwe find incidentally.

(07:01):
Or up to three, I think has beenreported.
There are like three total adultworms, but in dogs on the other
hand, hundreds of them can getinto their heart eventually.

Wow.

Yeah.
Cats also, they can't toleratethe adulticide treatment, like
to kill the adult worms.
Like it will kill the cat.
So you just, there's notreatment for it in cats.
So your best bet is to justprevent it.
And when cats get the babyheartworms circulating around
usually they just get into theirlungs, the baby heart worms, and
then they get coughing is thebig symptoms.
So they look like they'reasthmatic.

Asthmatic, yeah.

They like just have a cough.
And that's usually, we justtreat'em the same.
We just give them steroids andstuff to get the inflammation
down and get them to cough less.
But you can't really treat theworms themselves, unfortunately,
in, in cats.
You can kill the baby ones withthe preventatives, but you can't
kill the adults.
So it's a bum deal if a cat getsthem.

I know, right?

Yeah.

Poor cats.

It's bad for the dogs too, obviously, but
at least we can do something ortry to do something for them.

So how do the heartworms actually get into
the heart then?
You have to be bit by themosquito, but then how does that
go to the heart?

Yes.
Let's review the anatomy of theheart, if you don't mind, real
quick, for people that don'treally know.
I think most people know there'sfour chambers in the heart two
ventricles and two atriums, oratria.
So the ventricles are on thebottom, and then the atriums are
on the top.
So there's the right side andthe left side.
Blood travels from the bodythrough the veins, back into the

(08:27):
right side of the heart.
First it goes into the rightatrium, and then from there it
goes down into the rightventricle, and then that
ventricle is very, the muscular,big muscular part.
So that pumps it right from theright ventricle up into the
lungs.
That's where the right side ofthe heart is going.
In the lungs is where webreathe, we get oxygen, and then
the blood is oxygenated.
And then it goes right back tothe heart.

(08:48):
the left side, and to the leftatrium, and then the left
ventricle, and then that leftventricle is even more strong,
and it pumps the blood all theway to the rest of the body
again.
So we then get our fresh,oxygenated blood for the rest of
the body.
So that's the path of the blood.
So when these little baby wormsare traveling, And migrating
through the body of the dog,they are making their way into

(09:10):
the veins and back into theheart.
So eventually they'll get intothe right side of the heart and
that's where they love to be.
That's where the adults end upmaturing.
So they're mostly in the rightventricle and up into the
pulmonary artery that goes upinto the lungs.
Yeah.
So they're actually mostly inthe lungs rather than in the

(09:30):
heart.

Yeah.
You think it'd be called thelung worm but that's a totally
different thing.

Totally different.
Yeah, those are actually in theairways whereas the heartworms
are in the blood that's going tothe lung.
So it's a little different, alot different, but just so
people know that's where they'rehanging out.
They like, actually, the lessoxygenated blood and they like
to stay right there in thepulmonary arteries.

It's so weird that they want to go into
a less oxygenated thing.

Yeah.
I think they just evolved thatway because they're pumped that
way towards the heart once theystart migrating.

Yeah.

I don't know.
Let's go through the whole lifecycle.
It's a pretty crazy life cycleand it's pretty impressive.
When I first learned about ityears ago, I was like, wow, this
is just nuts.
How they developed to do allthese things and the fact that
it works, that they can completea life cycle in this way.
It's just blows my mind.

It reminds me of the salmon poisoning, like
that life cycle.

Yes.
With the fluke, and therickettsial..
And yeah, that's another'Wow, somany things have to come
together for this to actuallywork.'

Yet we see it so often.

Yeah, but it's somehow very successful.

Yeah, exactly.

So if the conditions are right, and we'll
talk about the conditions, butthe whole life cycle takes
around seven to nine months tocomplete, to go from the baby to
an adult heartworm.
And if we understand this lifecycle, I call it know thy enemy,
just like with any parasite, ifyou know their life cycle,
again, that's the best way thento fight them and to prevent the
problem.

(10:56):
So let's start with the adults.
They are in the heart and thepulmonary arteries they mate
there's males and females andthey mate and they produce
little babies and then thefemales give birth to these
millions of them.
They're called microfilaria.
So micro just means tiny, right?
Microscopic.
And filaria, again, is likelittle thread.
So there's high numbers of thesecirculating in the blood.

(11:18):
And I really have to think abouthow tiny they are.
Like, you can't see them unlessyou look on a microscope.
Not much longer than a few redblood cells put together.
So they're really tiny.
And these are compared to theadult heartworms and the other
stages, they're actuallyrelatively harmless to the dog.
Like they're circulating in theblood and the dogs, I think
that's why they're a definitivehosts.
They don't really have aresponse to them normally, like

(11:41):
they don't mind them being intheir bloodstream.
So they're just circulating inhigh numbers all the time and
the dogs are okay with this.
And these actually they can bepassed through the placenta to
unborn puppies.
So puppies can actually be bornwith these microfilaria.

Okay.

But it's important to note that these
microfilaria will never turninto adult heartworms.
They have to go through amosquito first.
So even though puppies may beborn with microfilaria they're
not gonna get adults from that.
So they're just having them intheir blood.
These microfilaria before I moveon they can live for about two
years in the bloodstream beforethey die of like old age yeah,

(12:19):
so..

That's a long time.

Yeah, they're there.
They're a problem.
And when they're circulating,that dog is infectious then.
It's going to be able to exposeother dogs to heartworms by a
mosquito.
So that's the next step.
So the mosquitoes come along andthey bite the dog and they suck
up some of these babymicrofilarias because there's

(12:41):
tons of them in there andthey're just sucking them up
right with the blood thatthey're getting.
Inside the mosquito, over abouttwo weeks is how long it takes,
these microfilaria start to moltand grow up.
And they go through twodifferent molts.
So they start, they go to L1 andthen L2, actually three molts,
and then L3.

Okay.

We don't call the microfilaria L1s.
The microfilaria are their ownthing.

Just your own thing.

Yeah.
And then it goes L1, L2, L3.
So once they become L3s insidethe mosquito, then they can go
back into the next dog.
Which is crazy, I know.
But then the mosquito will biteanother dog and it's carrying
the L3s.
They don't just inject the L3s.
It's interesting, there's videoson YouTube like really, yeah,
you can see the mosquito biteand it makes a hole where it's

(13:25):
sucking blood and it also spits.
Mosquitoes spit a little bit..

Gross.

Yeah, so there's like a little bubble of
spit, like next to where they'rebiting.
And in that spit is where thoseL3s go, and they're just like
swirling around in this mosquitospit.
And then the mosquito leaves,but that bleb of spit is still
there with the baby worms, onthe skin, yeah, on the surface
of the skin.
And they're just swimming aroundand then they're like, Oh look,
there's that hole that themosquito just made.

(13:52):
And then they like swim downinto the hole that the mosquito
made with his bite.

Yeah.

And so then those L3s get into the dog.
And that's when they cancontinue along their life cycle.
Over the next six months abouttake six months for these L3s to
continue growing up.
I call them teenagers Teenagerheartworms.

Yeah.

They are L3s and then they go to L4s.
So then they're like tweens,right?
And they migrate through thisskin and the muscle and then
they finally get into the biggerveins and blood vessels, and
then they find their way to theheart and the pulmonary
arteries, and that's where theyfinally become adults.

(14:36):
And do a final molt and become,we used to call them L5s, but I
was told, nope, now they're justadult.
Yeah, there's no L5.
They're no longer a larva.
They are an adult.
Yeah, so it goes microfilaria,L1, L2, L3 in the mosquito, L3,
L4 in the dog.
The next dog.
And then not L5, but adultsbecome into the heart.

Okay.

So then they breed and produce new
microfilaria and the whole thingstarts all over again.
And one other note I wanna makeis that those adults if they're
not killed by a treatment, theylive five to seven years before
they die of old age.
In a cat, they don't live quiteas long, two to three years has
been documented.

When they're an adult, then they go back to
making more microfilaria, right?
And then we're just doing thiswhole process all over again.

You got it.
Yep.

Okay.
Sheesh.

I know, it's a nutsy.

It is crazy.
From a dog, back to a mosquito,back to a dog.

You can imagine that they need to have
high populations of dogs andhigh populations of mosquitoes
to establish themselves and keepgoing with this life cycle

Yeah, well then where are these heartworm
found?

Yeah, so warm climates are the big ones
especially near water riverbasins.
And that's where mosquitoes tendto be happiest And again, where
there's large populations ofdogs and mosquitoes.
But they can establishthemselves in less desirable
areas.
If some of these conditions aremet, at least part of the year.
They're found all over theworld, especially the tropics

(16:08):
and the warmer climates.
But besides the US, they arefound in Africa, Europe, Asia,
Australia, and New Zealand wherethey haven't been found is like
the colder areas.
So like Antarctica, Greenland,yeah.
Also, I noticed on the maps Iwas looking at, Sweden, Norway,
and Finland don't haveheartworm.
Too cold there, I think.

(16:29):
In the U.
S.
they're very stronglyestablished in the southeast.
Especially where the MississippiRiver basin is.
Louisiana, Alabama, Georgia andareas of Texas as well.
That's where some of theresistant strains too, which
I'll talk about a little bit.
There's some resistant,unfortunately heartworms out
there and they're coming fromthat area, the Mississippi River

(16:50):
area.
But really they're in all thesouthern states, including Texas
and the southern coastlines.
The American Heartworm Societyhas amazing maps and they count
every year or two and they put anew map out showing where they
are in the country.

How they've moved.

How they've moved.
Yes, that's a big point.

So do we have it here in the Pacific
Northwest?

Yes.
So they're not as establishedhere as they are elsewhere, but
they are here.
They're being documented moreall the time.
And they've detected theheartworms actually in all 50
states of the U.
S.
One way or another, they havebeen documented.
Since 2018 the Washington StateDepartment of Agriculture did
actually have 418 cases reportedjust for Washington since 2018.

(17:34):
But I think that's underreportedbecause I've actually diagnosed
quite a lot of heartworm thepast few years.

Or we've given you quite a lot of
heartworm cases.
Yes.

And I didn't know that I was supposed
to report it, honestly.
Like I didn't, I don't think Ireported any of those.
And I imagine there's a lot ofother vets like that too, that
just, don't think to do it.

Exactly.

So I feel like there's probably more than
418 since the last few years.
Interestingly, the WashingtonState Department of Agriculture
is considering calling itendemic here now, too, because
they've noticed that it's underreported.
And that people aren't reallyfollowing reporting directions.

Yeah.
They're like, oh, I'm supposedto do that?

Testing directions and everything, yeah.
But I actually had Jackie pullsome reports for our hospital
and there was an 18 total counthere in the hospital.
Nine of these we treated here.
Two of them were also, thesewere ones that I saw, they were
positive for microfilaria, whichwas shocking to me, because that
was the first time.
here in this very hospital thatI saw an infectious dog.

(18:32):
And I was like, wow, this doghas baby heartworms.
A mosquito is going to bite thisdog and then bite another dog
and infect that dog withheartworms.
So I was at that point likeshocked and convinced that it's
a problem here too.
And that we should, it's an easyway to keep our dogs healthy.
Just put them on a preventative.
So I'll get into that more.
All of these dogs though thatwe've documented anyway, came

(18:55):
from outside the Washington.
So most of them were from Texas.
I had one from Mexico and therewas one from Georgia.
So I haven't yet seen any thatgot it here.
Or, were documented you haveactually been infected here.
It's just a matter of time Ithink, but I haven't actually
seen one.

(19:15):
However, I am on a Facebookgroup for DVM moms, and there's
a subgroup for Washington, likejust here, and we talk on
Facebook occasionally, and Ijust asked them recently, I'm
like, have any of you seenheartworm positive dogs that
didn't travel?
And a few of them said yes,there was probably four or five
that had said, absolute.
Yep.

Yeah.

They were born and raised here.
Heartworm positive.
Yeah, so that's just anotherthing that's telling me, oh
shoot it's here now.
Yeah.
And the big problem is justgenerally though, I think it's
happening because there's thishuge business to rescue dogs
from elsewhere and bring themhere.
It's very lucrative for theserescue operations.
Unfortunately, people have softhearts and they, you know, they

(19:56):
always have pictures of thesepoor dogs on the street and
they're like, will you save thisdog?
Of course, I'll save it and thenit takes a long time to treat a
heartworm positive dog and to doit right.
And some of these rescueoperations just don't have the
funding..

Or if they have a test for it I just found
out we had one that came from Ithink I remember correctly from
the Czech Republic to Germanyand then Germany to here.
It was heartworm positive.
And we, I was like it has to beon, it has to have been negative
because it travels, right?
And they're like no, you don'thave to have that to travel
here.

Yeah.
It's more about rabies.
Yeah.
But maybe we should also betesting for heartworm.
I think a lot of the rescueoperations are aware and are
doing it, but they're not alwaysfully treating them.
And then I think it's hard forthe owners too, because it's
such a crazy life cycle and it'sinvolved and detailed trying to
treat them, they just don'tunderstand the importance of

(20:50):
taking them right away to a vetwhen they get here and test them
and be like, okay, is thereanything else we need to do?
Like some of them, it's like awhole year, Oh, we've been here
for 18 months we're from Texas.
I'm like, Oh, did you get testedfor heartworm?
Yeah.
Oh yeah.
They said they treated.
And I'm like let's take a lookand see if they're still
heartworm positive or not.
Cause it's, it takes forever.

(21:10):
And a lot of them were actuallypositive and then we're like
shoot, this dog's been here for18 months and microfilaria
positive.
And then we're just now gettingon treatment.
So that's why it's becoming aspreading.
This huge movement of dogs andthe ignorance around heartworm,
I think is a uphill battle.

Yeah.
Which is funny because like inTexas, like they're, they are
very used to heartworm.
And just don't think about itwhen you move somewhere else,
like to Washington, where itreally wasn't endemic before.

Yeah.
And a lot of the vets here just.
Oh, we don't see it.
We don't care about this.
And you don't need to worryabout heartworm preventative.
And then a lot of the times theydon't even ask where the dog
came from.
We don't think to ask the travelhistory or the owner moved here
3 years ago and they forgotabout it, yeah, it's just a lot
of that kind of is making itdifficult and making it possible

(21:57):
for these heartworms to spreadhere.

It makes a lot of sense.

Yeah.

Then how do you test for heartworms then?

Yeah, so blood tests we do.
The first one is just ascreening heartworm antigen
test.
It's quick blood draw.
It's very specific to femaleadult worms, especially pregnant
ones.
It'll come up positive on thattest if there's adult female
worms.
There's also an antibody test,which detects the body's
response to heartworms.
Not necessarily an active orcurrent infection though.

(22:26):
I think this would be moreuseful for cats if you really
wanted to know if they hadheartworm because they will
produce an antibody to them.

And if they just have one worm to get like
the antigen from that.

They might be negative for the antigen test
unless they have an adult worm.
And they might not have one atall.
Or the one adult that they havecould be a male.
And then it's just secretlyhiding there.
So I think antibody is somethingwe'll do more often in a kitty.
There is a microfilaria test toothat tests for those babies.
You basically just look underthe microscope.
And there's ways to concentratethem.

(22:58):
It's called a Knott's test whereyou look harder for those
babies.
And you can get different countsof, how many per field there are
and see how many arecirculating.
But basically it's a positive ora negative if they got the
babies or not.

You still send that out?

Yes.

Do you usually look on the microscope
here?

You can.
I remembered learning in vetschool.

Yeah.
I was like, I did it too.

Yeah.
Yeah.
I think I did too.
It was so long ago though.
And honestly, I wouldn't knowhow to do it now, other than
looking at a blood smear and belike,

So true.
I know.
I think I did it on this lastone.
The one that I had that waspositive and I was like, I'm not
really sure if it was likelooking at it.
I'm like, I know what it lookslike.
I've seen one before in school,but

Yeah.

I didn't see any.

I think it's just like a little tiny
worm right next to the redcells.
Like you have to not stain it.
Maybe you'll see a dead one, butyou can see the live ones like
on a wet mount.
I think that's how they do it atthe lab.
But I, yeah, I just send thoseout.

Yeah, exactly.

Because I would be worried I would miss
them.
Yeah, so there is one other testtoo, blood wise occasionally
dogs that have had heartworm fora long time, they will produce
antibodies to them, and thenthose antibodies stick to the
antigens and hide them from thetest.
It's called an antigen antibodyimmune complex.
So if you heat the blood sampleup, it'll break up that bond of

(24:17):
the antibody and antigen andthen it'll show up positive.

Okay.

So we don't have to do that much here
because we don't see a ton ofheartworm.
But like in the south, that'slike a big thing that they'll
do, especially if they'reconfused, like they suspect
heartworm and it comes upnegative.
You can do the heat test to justdouble check.

So it sounds like if they do come from the
south, that's definitelysomething we should do here
though, right?

Maybe if you're suspicious for heartworm
and, or like they're positivefor microfilaria, but negative
for the antigen, like that makeszero sense, right?
Like how can they have babies ifthey don't have adults like
giving birth to them?
So then they probably have justthe complexes that are hiding
the antigen.
Yeah, there's just a way todouble check that if you're

(24:58):
suspicious.
As far as further testingthough, we can also take x-rays
and look at the heart.
There is, if they have reallybad heartworm, they can have
physical changes to their heart,like the right side gets really
big, full of worms.
And then you can see the wormson an echo, on an ultrasound of
the heart.
The cardiologist can actuallylook and see adult worms.

Yeah, they're real creepy.

Have you seen them?

Yeah.
Yeah, in California actually.
It was a dog that traveledthere.
Yeah, we saw the littleheartworms in the heart.

Wow.

Weird.

Yeah.
Yeah.
So that's, that can be done.
Those are all the tests that wehave.

Yeah.
So how is heartworm treatedthen?

It's a lengthy treatment.
I always follow the AmericanHeartworm Society protocol.
They have one.

Luckily they have one.
Otherwise I think all of uswould be like, what do I do?

Yes, I always just, they tell you step
by step and it's fantastic.
Because it's complicated.
I would just refer you there ifyou ever wanted to know.
They do what's called anadulticide treatment.
Adult meaning the adult wormsand cide is killing.
So you kill those adultheartworms in a predictable
manner so you can know what toexpect.
So the goal is to kill theadults in a predictable manner

(26:07):
but also kill and prevent allthe babies and the larval stages
too so that they don't get newadults.
So you have to hit all the lifecycles, unfortunately.
You can't do much for what'shappening in the mosquito, but
you can try and repel mosquitoestoo.
That can help, that can be partof the treatment.
And you want to do all of thiswhile minimizing the deleterious

(26:28):
effects, right?
These adult worms are dying.
You can imagine if they're afoot long and dying, they're
going to let go and startshooting around the dog's lungs
and body, and it's just, you canimagine the reactions from that.
Yeah, they get lodged in thereand clog up things and they can
get embolisms from that.
So a pulmonary thromboembolismor a PTE, we call it is when

(26:51):
like something, it doesn't haveto be a worm, it could be a
blood clot or whatever blocks upthose little arteries in the
lungs and then you get anassociated inflammatory response
and you can sometimes notbreathe in that area and it can
be fatal.
You can die from that and youcan have lasting scarring and
fibrosis and like changes inyour lungs that are chronic and

(27:13):
never going to go away.
Even after the worms are deadand gone, you can have these
chronic lesions in your lungsfrom it.
So you have to try and deal withthat and treat that as you go
through this treatment.
There's also, I have to mentionbefore I go into the treatment
protocol, there is a bacteriathat lives inside of these

(27:35):
heartworms.
They're called Wolbachia.
And they are pretty fascinating.
They are what we callendosymbiotic to the worms,
meaning endo is inside so theylive inside the heartworms and
symbo is like together, and thenbio is life.
So they're living inside themand helping each other.

(27:56):
They both like the Wolbachiaobviously needs to live inside
the heartworm and then theheartworm does a lot better when
they have Wolbachias inside ofthem.
They help them live longer.
They help them just be robustand healthy.
It's like a probiotic for aheartworm.
It's the good bacteria for theheartworm.
But so if we kill thoseWolbachia, then we are putting a

(28:20):
big dent into those heartwormslives, and helping them wither
and not live as long.
And then also they don't reactas much when they die.
The dog is more reactive tothose Wolbachia when they expose
themselves after a heartwormdies and they get a bigger
inflammatory response to them.
So if the Wolbachia aren'tthere, the dogs don't react

(28:40):
quite as much to the dead worms.
Yeah.
So really helps prevent theanaphylaxis and allergic
reactions that we see if wedon't pre treat with the
antibiotic first.
And that antibiotic is of coursedoxycycline.
Our favorite.
Helps with so many parasiteproblems.

Exactly.

Yeah.
So doxycycline kills theWolbachia and all of these
protocols, they recommend doinga month of doxycycline before
you even think about killing theadult worms, and that just helps
those heartworms wither andweaken.
Their lifespans are shortenedand it also prevents the L3s in
the mosquito, if a mosquitosucks up microflaria from a dog,

(29:22):
and then they change into theL3s inside the mosquito, but
then they are just unable to gopast that.
Like they aren't able to matureinto adults eventually.
So even though a mosquito mightinfect an L3 into the dog, or
the dog is on doxycycline thenthose L3s don't turn into the
adults.
Yeah.
Yeah.
So it really helps in many areasof the life cycle if we have

(29:45):
doxycycline on board.
Yeah.

Is that like because that's where the
Wolbachia is getting..

I mean,there must be something
about Wolbachia that helps thoseL3s turn into adults eventually.
Yeah, like really helps withtheir maturation.

Yeah.
Interesting.
Okay.

Yeah.
That's just when I researchedit, it's one of the things that
Doxycycline does for us.
Yeah.
If we get the Wolbachia out ofthere, that helps.
We also want to before we starttreatment, we want to look at
the dog and see how far alongthey are with their heartworm,
like how many how many wormsthey have, if we can figure that
out, but just like how what thesymptoms are for their worm

(30:23):
load.
So what I've only seen areusually the asymptomatic ones.
And I've only again seen five orsix cases ever.
And so they were maybe had acough, but maybe it was also
just a kennel cough or somethingnot related to their heart
worms.
But that's what we consider mildsymptoms, either no symptoms or
just a little bit of a cough.
When it becomes moderate,besides a cough, they also have

(30:45):
exercise intolerance andabnormal lung sounds.
You can hear crackles andwheezes, and they're coughing
all the time, and they can't runaround very much, they just get
tired quickly.

Okay.

That's called moderate heartworm
symptoms.
Severe is when they have all theabove, plus they just can't
breathe very well.
You can hear a murmur usually atthat point.
And they can have faintingspells, where they just don't
pump blood well enough and theycan just collapse.
And they end up usually goinginto right sided heart failure,
because the worms again are onthe right side of the heart.

Yeah.

So when they have right sided heart
failure, blood kind of backs upinto the right side of the body.
And so you can get like a bigliver, because the liver is
right there, and it will fill upwith extra blood.
And then because the pressuresare so high in those veins, like
fluid starts to seep out ofthose bloods and they can get
ascites or fluid building up intheir belly and they have these
big bellies full of fluid.

(31:38):
You can imagine if this goes on,they'll eventually die from the
heartworm.
But this is really severe andI've never seen one that bad.
When you were in California, didyou ever see such a bad
heartworm?

Never.
Yeah.
Like even the one that we hadseen, we were doing an echo on.
It never got that bad.
It was like literally there fora cough.
Somebody thought it had heartfailure.
They sent it to thecardiologist.

Okay.

And ended up having heartworm.

Oh, interesting.

So it wasn't even sent there for it.

Okay.

Because even then, that cardiologist said
that she didn't see very many ofthem in California.

Yeah.
Yeah.
So I think if you're notpracticed at looking for them,
you miss them easily.

Yeah.
Yeah.
Exactly.

Crazy.
But I think like in down southwhere there's a lot of untreated
dogs, Mexico, those sort ofplaces.
They probably have dogs likethis with severe heartworm
disease.

Exactly.

There is one further step past the severe
category called caval syndromeand this is when there's so many
worms, like this is the one dogthat has hundreds of worms in
his heart, they actually startto block the tricuspid valve
from actually being able toclose at all.

So that's the first valve between the
right atria and right ventricle.

Correct.
It's usually closed so that theright ventricle can then pump
blood to the lungs.
So if that valve can't close,it's like that blood isn't
getting into the lungs anymore.
Not very well anyway.

Yeah, it just pushes right back up to the
right atria.

Yeah, so it just the heart stops doing its
thing.
So with the caval syndrome,there's just like a sudden onset
of lethargy and they also gethemoglobin building up in their
blood, in their urine.
I'm not sure why..

It's'cause all the red blood cells are
lysing.
So the hemoglobin builds up inthere.

That makes sense.
Just'cause it's so turbulentinside the..

Yeah.
All the turbulence plus tryingto go back to the tricuspid.
Trying to go back through all ofthose worms.
It'll just break all the redblood cells down.

Okay.
So they get the hemoglobinbuilding up everywhere.
And then, the other big symptomfor caval syndrome is they'll
get pulses visible in theirjugular vein.
Normally the veins don't have apulse because the blood's just
slowly going back to the heart.
And we see pulses in ourarteries, because that's where
it's being pumped out from theheart.
But if we start seeing bloodpulses going the wrong way,

(33:41):
that's because the blood is notpumping the right way anymore.
And so that's like the keysymptom with caval syndrome is
they'll get the jugular pulses.
And then usually if that goesuntreated and you don't take
those worms out surgically, andthey will die within two days,
if not sooner, once you startseeing that.
So super severe.
And yes, it can kill a dog.

Yeah.
Yeah.

It takes a long time, I think, to get to
that point, but that's certainlythe end stage heartworm disease.
Unfortunately.

It's terrible.

I've never seen that either, but I've heard
about it.

Yeah, I've seen videos of it like I'm
removing it from the vene cava.

Yeah, so I've never referred anybody for
that kind of a treatment butthat's another way to treat is
to, you know have a specialistgo in.
I think they go in through theveins right and

To the jugular vein.

Yeah.
And then into the heart throughthere.
And physically pull out adultheartworms.
Like in bunches.

Yeah.

I've seen videos of it.

It's so crazy.

Yeah.
I doubt they could get all ofthem but they'd probably get a
lot of them so that the valvecan actually close again.
Yeah.
And we can save them that way.
Yeah.
So let's go into now that weknow that background let's go
into the actual AmericanHeartworm Society treatment
protocol.
It's about a year long protocoland they have it, they go month

(35:00):
by month on it.
So the 1st step is to confirmthat the dog's positive.
So say we're just screening andthe antigen surprise comes up
positive.
You want to test again to makesure before we go through all of
this.
So you test one more time, andon that second test, you should
do a microfilaria test as wellif you haven't already, just to
see are they infectious or not,and do we need to deal with

(35:21):
those microfilaria first or not.
And then they also recommend atthat point putting a mosquito
repellent on, which is new, andsince I just went through this
again, they didn't say thatbefore, but they're saying that
now.
It totally makes sense, right?
You want to try and keep themosquito bites down.
While you're treating all this.
There's a few different justover the counter flea medicines
that also cover mosquitoes.
So these would be like Frontlineor Advantage or Vectra, which we

(35:45):
have in the hospital.
They're actually pretty good atrepelling mosquitoes.
So I would double up on that.
Double up with your heartwormpreventative plus add on a
topical mosquito repellent atthis point.
Yeah.
And then, at this point, you'regoing to also determine the
severity of the disease, are wemild, moderate, severe, or caval
syndrome?

Yeah, or terrible.

And yeah, slash terrible, yes.
Again, all the ones I've seenhave always been mild, so I
didn't have to do a whole lotmore at that point.
But, assuming they are, like, inheart failure or something,
you've got to take measures totry and stabilize that.
Heart medications, diuretics,whatever it takes to get their
heart working better as it can.
And then you want to start yourdoxycycline like right away.

(36:26):
Basically day one you're gonnastart your doxycycline for four
weeks course is recommended tohelp those Wolbachia die and it
starts those worms to witheringand all of that.
If they have symptoms likethey're coughing or if they're
positive for microfilaria, youwant to start steroids at this
point too.
It'll help with reactions todying baby heartworms and help

(36:49):
with the coughing and theinflammation in the lungs.
So you do doxycycline andprednisone usually right in the
beginning.
Also it says if they havemicrofilaria, you could do some
Benadryl as well.
Just get them on Benadryl too.
Why not?
Yeah.
And then you give your firstheartworm preventative, and I
always use Simparica Trio, butthere's a bunch of them out
there, and I will go throughthose later.

(37:09):
And then at this point, you'regoing to start exercise
restriction, which is one of thehardest things with these
heartworm treatments.
You can imagine if the dog'srunning around and his heart's
beating really fast, and westart having baby worms dying
and everything, they're justshooting around even faster.
And more likely to haveanaphylaxis problems and
pulmonary thromboembolisms andall of that.

(37:31):
So you have to, through all ofthis, restrict their activity.
You don't have to be superstrict at this point, but you're
going to start thinking aboutit, and you're not going to go
on runs and play with your dogand have them fetch the ball and
stuff.
You have to just walk and yeah,walk everywhere.
Yeah.
Okay.
Then on day 30, so a month afterstarting all that you give your
second monthly preventative.

(37:51):
So another dose of SimparicaTrio.
And they say here you put onanother mosquito repellent.
So another dose of Frontline.

Okay.

And then you're just gonna wait the next
month.
Don't do anything after thatbecause if you give a month
after the doxycycline finishesthen for sure all those
Wolbachia bacteria are gonna dieand it just helps in the studies
that they've done over timethere's a lot less reactions to
everything if you just give agood month after the doxycycline
to just help those worms wither.

(38:20):
Okay, then on day 61 you giveanother dose of Simparica Trio.
Because we're on the third monthnow and then you do your first
big adulticide treatment.
And this is the only way to killthose adult worms is basically a
big arsenic shot.
It's a poison.
It's called melarsomine, butit's like similar to arsenic.

Right.

And we have to do a big shot in the muscles
in the back.
And it seems like best toleratedby the dogs in that spot.
That's still very painful.
Some dogs, I've been able to doawake.
Other ones are crazy and moving.
And I've actually just sedatedthem so that they're quiet while
I give the giant shot.

Not so painful.

Yeah, it's not a giant shot.
It's usually a mL or two, butit's just creepy.
I'm always like shaking when I'mdoing it.
I don't like it.
And I've noticed on some of thefirst ones I treated they were
like Nicole's dog, actually.
He was positive.
And so he was very drooly andlike shifting after I gave it
and like nauseous.
And so I started treating him onthe future shots with Cerenia

(39:18):
and Gabapentin and it totallychanged and made it all much
better.
So now I just do that for all ofthem.
They get Cerenia and they getGabapentin.
So Cerenia, for those that don'tknow, treats nausea, makes them
less nauseous.
And then Gabapentin is a nicepainkiller.
It's also sedating, which isnice because we want them to be
real quiet when we're doing allof this.
I might just give a few weeks ofgabapentin.

(39:38):
You can just keep using it ifyou need it.
At this point also, when youstart the melarsomine shots, you
want to do pred again.
So another whole tapering courseof it to help prevent reactions
to the dying worms.
And then this is where you startyour strict exercise
restriction.
So you basically have them in acrate all day.
And you take them out on aleash.

(39:58):
Don't let them run out in thebackyard to poop and pee.
You go out there on a leash,poop and pee, come back and get
in the crate.
So you basically have to bequiet for a good couple of
months at this point.
You know, cage restrictionunfortunately.
The American Heartworm Societyhas some really nice links and
tips to keeping your dogentertained while they're caged,
just food puzzles and, toys andstuff that they can chew on in

(40:22):
the crate, to keep their mindfrom going bonkers.
Yeah, and we can certainly helpwith drugs like Gabapentin and
Trazodone and just keeping themsleepy most of the time.
It'll help them get through thiswithout trouble.

Yeah.

Also, prednisone causes weight gain
and it has side effects, theydrink a lot, they pee a lot, and
then they're not moving, and soyou can expect some weight gain
at this point, which is likealmost impossible to prevent.
Although I did have one pugowner that her little positive
pug, she was really good aboutrestricting food and he didn't,
I'm sure she was miserable.

(40:56):
But she didn't gain weight.
She stayed steady.
I was very proud of thoseowners.

Nice.
Especially for a pug.

Yeah, I know.
Must've been awful at home,but..
Yeah, the inactivity and thepred, it's usually, it's not fun
but you got to do it, you got tocrate them.

Yeah.

Day 90 another dose of Simparica Trio,
and then we give the secondmelarsomine injection.
We give another course of pred,if we tapered it off, we have to
restart it again the next month.
And then day 91, so the verynext day, we do the third and
final melarsomine shot.

Oh wow, that's real fast.

Yeah.
So basically there's threemelarsomine shots, to recap.
You give one, and then you waita month, and then you give two
more a day apart.

Okay.

So there's three total.
And then after that thirdmelarsomine shot, so day 91, you
have to continue the strictexercise restriction for another
six to eight weeks following thelast injection.
So basically those first three,four months, you're keeping your
dog super quiet.

Yeah.

Yep.
And then you just keep goingafter that with the monthly
preventative.
So keep going every month,Simparica Trio afterwards, you
can let the pred wear off atthat point.
And hopefully the weight gainisn't so bad after that.

Hopefully.

Yeah.
And then on day 120, it says totest for microfilaria.
You just want to see, have wecleared microfilaria or not.
The two positive dogs that I hadthat were positive for
microfilaria, they were negativeat that point.
So I was like, Simparica Trioworks.
We're no longer infectious.
And then after that you justwait till the year mark.

(42:34):
So this would be about ninemonths after the final
melarsomine shot.
If you test before then, you'reprobably still going to be
antigen positive because, again,it's just detecting those adult
heartworms.
They're probably not completelydissolved and absorbed by the
dog at that point.
Even though they're dead,they're probably still there and
hanging out in the lungs inbits.

(42:55):
And coming up positive on thetest.
So they say after the nine monthmark, though, if you killed them
all, they should be negative atthat point for the antigen test.
And the few that I've done werenegative at the year mark.
Thank goodness.
So I did see it all work.

Yeah, this does work.

Yeah.
If they're still positivethough, then there's directions
on the American HeartwormSociety.
You're supposed to retreat withanother month of doxycycline and
then do two more melarsomineshots 24 hours apart.
So basically you repeat it alland keep testing.
And I would say.
I'm wondering why, what thescenario would be, why they

(43:31):
would still be positive.
I guess the melarsomine justfailed and didn't kill all of
them.
Yeah.
Or they got infected again.

Yeah, I was gonna say, maybe they just got
infected again.
Especially in that one monthwhen they're not on anything.

Yeah.
If they didn't give theSimparica Trio every month, they
could have a window whereanother mosquito bit them.
Yep.

Then so there's been a slow kill method
now that I've heard talkedabout.
Can you tell me about that?

So yeah, the slow kill method doesn't
involve the melarsomineinjections because it's horrible
to go through that.
And then a lot of people justdon't want to do that to their
dog.
And a lot of the shelters, not alot, but there's been a couple
of the rescue operations,they're like, Oh, we just do the
slow kill here.
And that's what we're givingyour dog as we ship it to you in
Washington.
But it's a misnomer cause you'renot actually killing the adult

(44:17):
worms at all.
So the preventatives, likeivermectin..
I'll just go into it.
So there's the macrocycliclactones are all the options for
heartworm prevention.
Those include ivermectin,selamectin, milbemycin oxime,
and then moxidectin.
So those are the four options.
The brand names for those, likethe ivermectin is in Heartgard

(44:39):
Plus, or Iverhart, there's a lotof them out there, and then
selamectin is in Revolution,that's the topical prescription
one, and then we have milbemycinoxime, which is in Interceptor
and Sentinel, I believe, andTrifexis has milbemycin.
And then there's NexgardSpectra, which I don't think
they make anymore.
That had milbemycin oxime in it,but now they have Nexgard Plus,

(44:59):
which has the moxidectin in it.
And so does Simparica Trio.
Simparica Trio has moxidectin.
And I think of all of them,moxidectin is the best from what
I can gather.
But I wanted to point outmoxidectin is the one that does
actually get the resistantstrains of heartworm that are
emerging from like theMississippi river basin.
That's where these resistantheartworm worms are.

(45:21):
That's where they're showing up.
And so the milbemycin, andselenamtin, and ivermectin, the
older heartworm preventatives,they don't touch those resistant
heartworms at all.
They just don't work at all.

So would it be fair to say you could use one
of those other ones first, andif that doesn't work, then you
have to go to the..

Dr. Xenia Zawadzka (45:41):
Moxiedectin.
Yeah, I mean you can.
They're still available and theystill work great on most of the
other heartworms.
Yeah, there's a very smallamount of these resistant ones
they don't seem to be thankfullythat prevalent.
Yeah, so I think any heartwormpreventative is better than none
but it seems like the moxidectinworks the best against these

(46:01):
resistant ones, so maybe thoseare the ones we really should be
using, just so we don't have toworry about resistance strains.

Great.

Simparica Trio has moxidectin.
Advantage Multi has a topicalwith moxidectin in it, those
work for resistance strains too.
And then the ProHeart injectionsthat's really a high dose of
moxidectin is in that one.

Okay,

So yeah I just wanted to make sure I
mentioned that's what covers theresistance

I think it's the newest one as well, if I
remember correctly.

It's actually an old medication.
It's been around a long time.
It's also in Advantage Multi,which is a topical medication.
And it's, yeah, it's beenlabeled for many different
dewormer treatment.
But yeah, so those slow killmethods use just a preventative
with one of those medications init and they just give it every
month.
And they say, okay, eventuallythe adults will die on their

(46:54):
own.
And then we're just..

Five to seven years.

Exactly.
So for five to seven years thesedogs still have adult
heartworms, and so yeah, maybeyou're killing their babies
slowly and preventing any newones from becoming additional
adult heartworms but they're notkilling the adults at all.

Or the Wolbachia.

Yeah.
But there is another slow killmethod that follows that they
call it the Mox-Dox slow killmethod.

Okay.

So they use moxidectin, either in Advantage
Multi or Simparica Trio orNexgard Plus and they give
doxycycline as well for a month.
And then so then the Wolbachiaare withering the adults and
maybe they don't live as long.
So maybe two to three years ifwe're lucky instead of five to
seven.
But still it doesn't kill thoseadults.

(47:39):
So they're still dealing withthose.
Also, I think moxidectin athigher doses has been shown to
kill some of the adult worms ormaybe they die a little bit more
quickly.
Again, because their lifespan isshorter, but we just don't know
when they're going to die.
And so that's another risk forthese types of protocols.
Cause at least with the AmericanHeartworm Society, when we know

(48:00):
when they're dying, we know whenwe have to exercise restrict
them during this eight weekperiod, they have to be cage
rested.
If you're doing slow kill, theycould just randomly have an
adult die whenever.
And then they're like, boom,running around one day and they
die from anaphylaxis, so it'sless predictable.
And less safe, in my opinion.
And it's not recommended by theAmerican Heartworm Society.

(48:22):
It's only, they advise againstit unless it's like a salvage
procedure, which, when they justcan't even consider adulticide
treatment at all for whateverreason.

Costs maybe..

Maybe.
It's not that bad.
I want to say it's a few hundreddollars to buy the melarsomine.

Yeah.

And then there's like the rechecks and
stuff, but it's, I don't know,it's not an extremely expensive
treatment.

Yeah.

So I really see no reason to do the slow
kill method.
You can imagine physically wormsin the heart are just constantly
banging around in there as theheart's beating and causing
damage to the heart and thelungs chronically.

Yeah.

It's good to get them out as soon as
possible.

As soon as possible.
About 5 to 7 years.

Yeah.

Yeah.

Yeah.
So I don't recommend the slowkill method.

Okay.
So then can you recap from likehow you prevent heartworm and so
that we don't have to go throughthis right?
So we don't ever have to gothrough the melarsomine
injections.

Yeah, that's the idea.
It's not have to end up doingany of that.
So back to the macrocyticlactones, those are our big
choices for prevention.
And what they do is kill the,basically all of them kill the
L3s and the L4s.

So before the adult..
Right before then.

So they get bit by a mosquito that has an L3
and those L3s are then capableof turning into adults into the
heart of the dog.
So if we give them a monthlypreventative, they're killing
the L3s and the L4s before theybecome adults.
Some of them will kill themicrofilaria too, but they do it
with different degrees ofeffectiveness, I should say.

(49:54):
A lot of them are combo productstoo.
Like they're just trying to makeit easy because there's more
than heartworm that we need toworry about, right?
Fleas and ticks like we talkedabout before and they bring
their own problems.
And so they've just basicallyadded heartworm preventatives to
those other kind of treatments.
Besides the orals that I alreadymentioned.
There is an injection calledProHeart.

(50:16):
ProHeart is just straightmoxidectin.
And it's a very slow releaseformula.
So you give it a shot under theskin, and it just over six
months slowly dissipates andkills baby heartworms and L3s
and L4s.
There's also a 12 month one,which is crazy, but it lasts for
a whole year, so there's a 6month and a 12 month now.

(50:37):
Yeah, Zoetis came out with it,we don't have that here because
we just don't see a lot ofheartworm, but it's a big
product in the South for vetclinics.
So you could just do that andjust take care of heartworm with
that, but here we see so manyother parasites too that we just
added it to the oral comboproducts and there's always
better ones coming out.
Who knows what I'll berecommending five years from

(50:57):
now?

Or even a year from now.

I know, yeah, it's crazy.
And then adding in the mosquitorepellents seems to be helpful
too, especially in thebeginning, or if you're in an
area with a ton of mosquitoes,you should probably be doing
that on top of the heartwormpreventative.

Right, and that was the Advantage and the
Frontline you were talkingabout.

And Vectra, yeah.
You don't want to put DEET onyour dog like the stuff that we
use when we're hiking.

Yeah

It's just a little more toxic to dogs and
cats, but also they are morelikely to lick themselves like
humans don't usually go aroundlicking our arms after we spray
DEET on there.
But dogs and cats will oftenlick and ingest some of that
DEET and then it's really bad.
Yeah, they have all kinds ofneurologic..
I'm sure you've talked about itor seen it.

I've seen one before.
I haven't talked about it yet,but I've definitely seen one.

Yeah, so it's not good.
I don't recommend the DEETproducts at all.
But the ones that are labeledfor dogs and cats Advantage,
Frontline, and Vectra can berepellent as well.
And also I mentioned I don'tknow if you remember in the flea
one and the tick one, theisoxazolines do actually kill
mosquitoes too.
They kill lots of insects, but..
So after the mosquito bites itwill die, which is nice.

(52:05):
So it won't go on to infectanother dog with, yeah,
heartworm.

Yeah.

But it doesn't prevent it from biting
though.
So if you want to have somerepellent activity, you can
double up with one of thosetopicals.
Yeah.
Seresto collars too will repel.
Yeah.
They have the flumethrin, Ithink, in their collars.
Yeah.
Which helps they don't like thesmell of it.
And they don't land on the dog.
Yeah.

Nice.
And so I remember learning thatall dogs should be tested before
we give heartworm prevention.
Because apparently we could killthe dogs right if we just go
ahead and give it.
So is that true?

Actually it's not true.
It's always a concern, right?
If you have a high burden ofmicrofilaria, baby heartworms,
circulating and then you startkilling them.
Yeah, there's a chance the dog'sgonna have some allergic
reactions to all of those babydying heartworms.
However, it's not as bad as youthink..
You don't need to bother testingpuppies that are less than six
months old.

(52:55):
Because there simply is no waythat an adult worm can develop
that quickly.
It takes about at least sixmonths for a teenager heartworm
to turn into an adult heartwormand get in the heart.
And the tests that we haveunfortunately only test for the
heart adults.
Like you don't, you can't testfor the teenage.
Like L3s and L4s, yeah, you canonly detect the adults once

(53:18):
they're there.
So there's really no reason totest a puppy less than six
months before starting aheartworm preventative.
Just go ahead and start thoseyoung puppies on a preventative
and it'll kill any teenagerheartworms that, you know, even
if they were bit by a mosquitowhen they were first born and
given some teenager heartworms,those aren't going to get into

(53:39):
their heart for six months.
Yeah, just go ahead and startthose puppies on the
preventatives.
They've done some pretty amazingstudies.
Like giving dogs heartworms.
I don't know how they do it.

Infecting them?

They implanted, and I was reading the
study, 24 dogs were implantedwith adult heartworms.
10 females and 10 males.

That's so weird.

I wonder, like, how they actually do it.
Like, where do they get theseadult heartworms?
And then how do they like, theygo in the vein?

Do they do it with a jugular again?
Just, I don't know.

Crazy.

That's weird.

But they do it.
And then they wait for thoseadults to set up house and start
making babies.
And then they documented theywere all microflaria positive.
And then they gave them, I thinkthe specific study I'm thinking
of was on Simparica Trio, andthey gave them one dose and
three times the dose.
And without any pred or benadrylor anything.

(54:29):
And they all were fine.
A couple of them, I think twoout of the 24 dogs had transient
fevers and that was it.
Like a day of a fever and theywere fine.
But there was no anaphylaxis oranything else.
So after reading that, I'm likea lot more comfortable with, oh,
it doesn't really matter ifyou're positive, you're going
to, we're not going to hurt you,but that said, it's always a
good idea to test first, right?

(54:50):
It's always, and it isrecommended by the American
Heartworm Society.
Like we should be checking everyyear, pretty much all dogs for
heartworm, especially beforeputting them on a preventative.
Not just to make sure they'renot positive for microfilaria,
but also to start documentingand not missing so many cases
because we're starting to seemore and more.
So I feel like, yeah, we shouldbe screening for it more in
general.

And if we don't, we're essentially just
doing the slow kill method againand not actually treating them
because we don't know thatthey're positive.

And that's why I think these rescues think,
oh, it's fine we're just givingthem the Simparica Trio or
Heartgard every month andeventually their heartworms will
die and we're not going to hurtthe dog with it.
So yeah, the test is notimperative to do before you
start treating.
And again since we don't see ita lot I don't really harp on it
as much as I probably should andI have enough to talk about

(55:37):
during the appointment but theonly product I think that they
insist on the label testingfirst is the ProHeart 6 and 12
because it's a really high doseof moxidectin and I think you're
probably going to kill thebabies off really quick.

Yeah, that makes sense.

Yeah.
And moxidectin is one of thosedrugs.
Like the more you give it, likethe longer repeating courses of
it, the higher effectiveness itis.
So like it won't kill all thebaby heartworms right away.
It takes a few months for themall to die.
And that's why on the protocol,they recommend not testing for
microfilaria until day 120because by then enough, like
three or four months of theSimparica Trio should have

(56:15):
killed all the baby heartwormsby then.

Right.

Yeah, but it might still be positive a
month or two before that.
Yeah, so..

That's really good to know we actually
had a patient who we weren'tsure their symptoms that..
They were like anaphylacticsymptoms were from them starting
heartworm prevention when weknew now that the dog was
heartworm positive.
So..

Yeah.

It's good to know.

Yeah, it's okay to go ahead and just start
it.

Yeah, okay.
And then so is there any overthe counter heartworm
preventions that we can use?

No.
Simply.

Yeah.

Nope.

Just mosquito repellent.

Yeah.
Yes.
Yeah, you can repel themosquitoes with over the counter
products, but you can't killbaby heartworms or adult
heartworms with over the countermeds.
Nothing works.

Yeah.
All pretty much veterinarydrugs.

Yep.
And it's important to have a vethelp you through it, too,
because it's such a tricky thingand you've got to do it
carefully and keep checking andmonitoring to see how we're
doing.

Yeah.
And also to give as little drugsas possible, so that way you're
giving other drugs for fleas andticks and..

Yeah.

Yep.

Yeah.
There's so many parasites.
That's why I really likeSimparica Trio just because it
makes it so easy.
You just do everything in one.
And the owner doesn't have tothink twice about it.

Exactly.

Yeah.
One thing I'll mention aboutNexgard Plus, because that also
has moxidectin in it and I thinkit would be another good option.
But the moxidectin dose is a lotlower than Simparica Trio, and
so it's actually not as certainthat it'll kill the babies or
microfilaria.
I prefer the Simparica Triobecause it's got a higher dose

(57:43):
of moxidectin.

Yeah, nice.

As far as sources go, I encourage
everybody listening to justcheck out the American Heartworm
Society website.
It's amazing.
They have all kinds ofresources.
They go over the life cycle indetail and they have client
handouts and like easy to readthings that kind of show you why
we recommend this and that, andbusting myths and that kind of
thing.

Yeah.

And then, yeah, I looked at good old
Wikipedia and

I saw that.

Yep.
There's some great info there.
And VeterinaryPartner.com is agood resource.

I love that.

Like for any kind of vet questions.
Yeah.

I will say when you do veterinary partner,
you do have to make sure thatyou've spelled whatever it is
correctly.

Okay.

Like If you accidentally misspell heartworm.
It's spelled H A instead of H EA.
It will not pop up.

Dr. Xenia Zawadzka (58:26):
Interesting.

Yeah.
You do have to actually spell itcorrectly for things to pop up.

That's good to know.
Didn't know that.
Yeah.
And then the American AnimalHospital Association, AAHA.
They had a lot of good info onheartworm as well.
And when I was trying to figureout like the history of
heartworm, I actually ended upat the Encyclopedia of Arkansas.

Of Arkansas.

Yeah, that's where I found like the
years that the monster heartwormwas found.
And then there is one goodarticle about the safety of
moxidectin for microflariapositive dogs that I actually
sourced there for anybody ifthey want to read the whole
study.

Yeah, absolutely.
And we'll post that on there inour links as well too.

Good, good.

Perfect.
Was there anything else that youwanted to add to this?

No, you always ask me a question.

I do always ask you a question.
So my question today is actuallygoing to be like, how did you
get into parasites in general?
What is it about parasites that,that you love so much?

I don't know.
I don't have a good answer.
I'm trying to think.
Like I..

I thought you were going to say it because
you can prevent them, becauseyou can treat them.

Of course.
I was trying to imagine the,like a, something that happened
to me and made me hate parasitesand want to kill them all.
And I can't think of any onething, except like I really hate
mosquito bites.
And I hate flea bites too.
I've been bit by fleas and Ithink I'm allergic to them
because I get like a welt thesize of a quarter.
And it's 20 times as itchy as amosquito bite.

(59:49):
And I'm miserable.

Yeah.

Yeah.
And they're there for a weekbefore they finally go.
It's just, so I really hatefleas like with a passion.

Dr. Tyler Sugerman (01:00:00):
That makes sense.
Yeah.

Dr. Xenia Zawadzkas (01:00:01):
Yeah.
Can I ask you a question?

Oh yeah, sure.

What is your favorite color?

So my favorite color is blue.
It always has been blue.
Like even since I was little,yeah.
I even had a little blueparakeets.
I had..
I don't know, like six of thembecause they kept dying, but all
six of them are named baby blue,which is baby blue one, two,
three, four, five, and six.

That's hilarious.

Yeah, I know it's a really common color for
all boys to like, but yeah,definitely blue is my favorite
color.

That's funny.
Mine's green.
I just like greens.
Peaceful, calming.

Yeah.
I think it's actually toobecause my, so I have the same
eyes as my grandpa and he hadvery blue eyes that turned like
grayish eyes.
And so I always remember likehis very blue eyes.

Oh, that's super nice.

Yeah.

You have blue eyes too, I just noticed.

I do have blue eyes, yes.
They did start to turn gray,just like his, but yeah, they
were like a very bright bluewhen I was little.

Super nice.

Yeah.

Blue's a good color.

Yeah.
Thanks for asking me a question.

Oh, yeah.
I was like, I should ask him aquestion.
I love it.
Keep it simple.
Yeah.

Nobody ever asked me a question.

I'll have to think of a better one next
time.

All right.
Perfect.
Thank you, Dr.
Z I appreciate this so muchcoming on to talk about
heartworm.
I know how much work you putinto this.

Oh, thanks.

To like come up with this today.
So I really do appreciate that'cause it's gonna help us,
especially like us in the clinicsince we don't know a lot about
it too.
A lot of times we just send itover to you,

Yeah.
Which I'm happy to take it, butI think it helps if everybody
knows about it.

Exactly.

And is aware of the increasing numbers.
That this is something we shouldstart really, helping dogs with
and preventing.

And also just to know what we should
start with to give doxycyclineand prednisone before we have an
appointment with you.

Yes, and the other big point I'll make,
if you get a positive on ascreen test, send it out again
and do the microfilaria testtoo.
Do both.
And then start your doxycyclineand then send it over to me.

Perfect.
Alright, thank you again, andthank you to everybody
listening.
As always, make sure to keepyour pets happy, healthy, and
safe.
Thank you guys.
Bye.
I just want to say thank youagain to Dr.
Z for all of this reallyimportant information that she
has given to us about heartwormdisease and heartworm
prevention.
Our goal is to really helppeople to be able to save your

(01:02:11):
pet's life.
Also, thank you to Sumner VetHospital for allowing us the
space to be able to record, toShawn Hyberg for doing our
editing, and for Kelly Dwyer fordoing our website.
In the next coming weeks, we'regoing to be hearing from the
ophthalmologist to learn moreabout how an ophthalmologist
helps our pets.
We'll see you next week.

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