I'm Confused - Why Do We Have To Do A Heartworm Test Every Year?

[Guest Kpparker]

If my dog is on heartworm medication for 6 months out of the year (in Canada) or even full year round (in warmer climates) why do we have to do heartworm testing once a year? Isn't the medication supposed to prevent it? What really are the chances of the dog getting heartworm if on medication?

[zimsmom]

My vet gives me the option to test or not knowing that I give it all year long. She leaves it up to me.

[Saffron]

The heartworm preventative is not 100% effective, and there is always user error. I do 12 months a year Sentinel because I'm always amazed by the fact that I can see 'skeeters in November and on a warm March day -- and I'm in Zone 5!

 

This is my understanding -- The preventative can actually be dangerous if the dog has already got heartworm (if this is a myth I'd really like to know!)

 

Therefore, vets insist on the test before renewing the prescription.

 

Gillian

Catwalk, Pilgrim and Murphy P

[Guest Kpparker]

The heartworm preventative is not 100% effective, and there is always user error. I do 12 months a year Sentinel because I'm always amazed by the fact that I can see 'skeeters in November and on a warm March day -- and I'm in Zone 5!

 

This is my understanding -- The preventative can actually be dangerous if the dog has already got heartworm (if this is a myth I'd really like to know!)

 

Therefore, vets insist on the test before renewing the prescription.

 

Gillian

Catwalk, Pilgrim and Murphy P

 

 

Well according to this guy it is: http://www.oldcountryvet.com/index.html

 

There's a thread on off topic about the costs of veterinary care and someone posted his link and when I read about the heartworm info thats when it got me thinking!

[Guest lotsagreys4me]

Yes, that country vet says you do not need to retest. hum..............My dogs are on preventive year round. I asked my vet about testing them once a year and he did not think it was necessary so I don't....

[Guest GunnyGirl]

My old vet and my new vet both say to test every other year, since Gunny is on year round. Like another poster said, nothing is 100% foolproof, so better to be safe than sorry.

[ShantisMom]

Shanti is on it year round. I don't think we retest, but it could just be lumped in with her thyroid bloodwork.

 

Revolution is one I was told could be taken without the test. But the others I was told was dangerous to take if they were actually positive.

[Guest smarthound]

I took the pups off Heartgard over the winter. My vet said it was okay to start Heartgard again without testing first but she recommends they be tested every year. I'm nervous about starting the medication without testing first because I've heard that it's dangerous for them to take the medication if they're positive. So I'm confused about the best approach.

[Guest LynnM]

Well, nothing is 100% when it comes to prevention, though HW prevention, when given properly, is pretty close.

 

Thecommercially available, made-for-canines (I'm not talking about those that dose their dogs with Ivomec cattle wormer) preventatives that the vast majority of you use are safe, even in HW positive animals. If you are one of the few people that give their dogs Filaribits (yes, they still make them, and a few folks find it easier to remember an every-day pill), then you can mess a dog up if it's HW positive. Sentinel/Interceptor, Heartguard (and generics) and Revolution can be safely administered to a HW positive dog.

 

The main reason for getting your dog tested every year is that IF your dog tests positive for heartworm (and was negative in the previous test), but you've kept your dog on preventative as directed by your vet, the manufacturer of the preventative will generally pay for the cost of treating your dog. Think of it as an "insurance" policy. I know that's not much solace if the preventative fails, but treatment can be expensive.

 

Lynn

[Vertragi]

Starting last year our vet recommended year round protection. We're also in zone5, as well. I forget quite what the deal is, but from what I recall, the manufacturer offers some sort of warranty. Something about how they will pay the costs if your dog is on heartworm preventative, but catch it anyways. Well, the impression I got was that the warranty was recently changed, and that you needed to be on preventative all year round in our area, if you wanted the warranty. The part about the annual testing was in conjunction with the warranty, and I could skip the test, but it might impact our eligibility for the warranty.

 

I've also heard about preventative being dangerous if they are positive, and testing once-a-year for peace of mind is ok by me

 

edited to add: Lol! posted at same time as Lynn, I just type real slow

Edited April 27, 2008 by Vertragi

[PatricksMom]

In part, because I'm not perfect about remembering the dosing (bad mommy, I know). And even if I was, I'd probably check just in case, because I'm a nervous nelly about the animals.

[ahicks51]

There is also the very real risk of the organism developing an immunity to the various prophylaxis available for HW. It would be nice to know ASAP if such resistance were to develop.

 

I suspect the prime reason for it is to keep from killing the animal if for some reason there were HW infection and the preventative were provided without precautionary measures taken.

[Houndmommy03]

My vet in SC did NOT require testing every year but my vet here in PA does. My vet in SC was nice about trying to keep costs down.

 

Kim

[GeorgeofNE]

My vet won't write a new script without a test! And I give it 12 mo. out of the year!

[Guest longdogs]

I think opinions differ. Here in Australia many vets don't think it necessary to test for heartworm if the dogs are constantly on medication, unless they show symptoms.

[Guest KennelMom]

We give ivermectin year round, every 30 days. We don't test yearly...ends up to be...oh...about every 18-24 months.

[fourofem]

Since mine are all on Interceptor year round, my vet only retests every three years...when their rabies shots are due.

[Guest FordRacingRon]

Hmmm..my vet never tests. Leia was tested off the track,,was good, ,and has been on Heartguard plus ever since, non-stop. My vet doesn't see the need for a test since she has been on this stuff non-stop.

[Saffron]

Well, nothing is 100% when it comes to prevention, though HW prevention, when given properly, is pretty close.

 

Thecommercially available, made-for-canines (I'm not talking about those that dose their dogs with Ivomec cattle wormer) preventatives that the vast majority of you use are safe, even in HW positive animals. If you are one of the few people that give their dogs Filaribits (yes, they still make them, and a few folks find it easier to remember an every-day pill), then you can mess a dog up if it's HW positive. Sentinel/Interceptor, Heartguard (and generics) and Revolution can be safely administered to a HW positive dog.

 

The main reason for getting your dog tested every year is that IF your dog tests positive for heartworm (and was negative in the previous test), but you've kept your dog on preventative as directed by your vet, the manufacturer of the preventative will generally pay for the cost of treating your dog. Think of it as an "insurance" policy. I know that's not much solace if the preventative fails, but treatment can be expensive.

 

Lynn

 

Wow! This post pretty much covers it. Thanks, even though I am not the OP.

 

I will continue to test annually. First, the cost of the test is a drop in the bucket of their overall medical costs (I have 3 kind of special needs greys), and second, we will be covered for treatment if we do year round and test annually (I just double-checked) . . .

 

Gillian

Catwalk, Pilgrim and Murphy P

[Guest Luvagrey]

Our Cher is on Heartguard year-round, and the vet only tests every other year.

[NeylasMom]

Only one other thought - these days most vets use the 3D snap test, which tests for Heartworm, Lyme and Ehrlichia. I do also frontline my dogs, but not year round and we hike a lot, which means a LOT of ticks. The test is under $50 I think and my pet insurance covers a small part of it, so I don't mind doing it. That way, I have piece of mind for 3 things, not just one.

[nettles]

 

In order for a preventative to be harmful in a HW positive dog, the heartworm must reach the adult stage in the animals heart. Heartworms do not reach adult stage for 2 years. At this stage, the worms can be quite large and if killed by a preventative can clog the blood vessels when they die. Monthly, or year around administering of a preventative is a waste of money.

 

rich

[Guest LynnM]

In order for a preventative to be harmful in a HW positive dog, the heartworm must reach the adult stage in the animals heart. Heartworms do not reach adult stage for 2 years. At this stage, the worms can be quite large and if killed by a preventative can clog the blood vessels when they die. Monthly, or year around administering of a preventative is a waste of money.

 

rich

 

Be careful of such absolute statements. It varies by geography and what other parasites your dog contacts. In many parts of the country, mosquitoes and heartworms are a year-round threat, and the benefits of preventing other parasites are very real. None of the common, commercially available heartworm preventatives (Heartguard, Sentinel, Revolution, Interceptor) have ANY effect on the adult heartworm, and any possible harm due to other stages of the heartworm's lifecycle are minimized due to the minute dosage of the commercially available preventatives.

 

Lynn

[Greytlady94]

Because nothing is infallible, including preventatives. My dogs have taken HWP the 1st of every month, 12 months a year, year after year, but we still do a heartworm test annually.

[6greyhounds]

I am in a tizzy about the HW testing.

 

When I was first introduce to HW meds 6 months on 6 months off then blood test

 

then they came up with HW meds year round no blood test

 

Now every vet has a different opinion of blood testing from 1 year, 18 months, 2 years. One vet in WV says you do not need the meds but test every year.

 

Which one is right???