Home Forums Birds & Dogs Hunting Dogs BS Heart Worm Test?

Went to get heart worm pills at the vets and was advised they couldn't sell them to me until my dog had a blood draw type heart worm test, $87.00. Been getting the heart worm pills for our dogs from this vet for about 30 years and there was never a test required. If anything they were pushing the pills pretty hard. I was advised the test is now required before pills can be prescribed. Called two other local San Joaquin Valley vets and got the same answer. Anyone else run into this?

Many vets require a test before prescribing because if the dog is infected already it can kill them. Been that way for 50 years at least.

This is the procedure for our vet here in MT, and MT is one of the few US states with hardly any heartworm cases.
BTW, our vet charged us $50 for the heartworm test, and $63 for the "Sentinel Spectrum" meds.
I don't keep our dogs on heartworm Rx drugs all year, thus I believe that's the reason for our vet to require a test before resuming the drugs.
My understanding is that if your dog is on a heartworm drug ALL year long with NO breaks in the treatment, then there is no need for a retest.

I believe heartworm tests are primarily a source of income for the vets that do them, and here's why. Several years ago, when my vet tested my dog, he said the dog had a "light" case of heartworms. I had been giving him heartworm pills (that he sold me) every month and asked how this was possible. He said I may have skipped a month (I hadn't) and that the worms would die within 2-3 years and just continue giving him the pills, which I did. He said he wasn't going to treat them as the treatment could be worse on the dog than the worms. That dog never developed symptoms of heartworms, coughing, lethargy, etc.

It wasn't until several years later when my vet was retiring that he told me to start giving my dogs liquid 1% Ivermectin orally each month at 1/10th of a cc per 10 pounds of body weight. He said commercial Ivermectin medication was reduced to just barely sufficient to kill worms and not the colly breeds, which have a mutation making them susceptible to Ivermectin poisoning. The vet said there was evidence that the worms were developing an immunity to the low level of Ivermectin in the pills. The dosage he recommended has many times more Ivermectin than the pills I had been buying. My dogs are kenneled outside, and I live in the Lower Mississippi River Delta, an area where heart worms are most resistant. None of the dogs have developed heartworms since switching to the liquid Ivermectin. I can buy 50cc of 1% Ivermectin for around $30. Shelf life is two years, and there's enough in one vial to treat four DD and my daughter's 20 pound mutt and still have some left when the shelf life expires. I get superior heartworm prevention for around $4 per dog per year. I'm sure the only reason my vet told me about the liquid Ivermectin was because he wasn't going to be selling the pills after retirement.

Ivermectin kills the young worms (microfilaria) that circulate in the blood for around 45 days after an infected mosquito bite. After that time, they travel to the heart and mature. Ivermectin doesn't kill the adult worms, which is why it should be given monthly. If you miss a monthly dose by a week or so, it's not a problem if you go ahead and administer Ivermectin; the microfilaria haven't matured and will still be killed.

All the vets here require the test every year to keep getting the meds. Heartworms are really bad here.

Thanks to all for the info. Went ahead and got him tested yesterday. Supposed to get results back today. I guess we're lucky this is the first time we've had a dog tested and none of our other dogs ever got heart worm.

flitecontrol, that's interesting info on the Ivermectin, we're giving it some thought.

Here's some advice about heartworm and Invermectin products from a well known hunting dog vet in South Dakota named Joe Spoo, aka Gun Dog Doc. Dr. Spoo has recently started up his own educational series on animal care and I subscribe to updates via email, and watch his videos on You Tube. I have two hard core bird hunting buddies that know Dr. Spoo personally and use/used him for their dog care. Note: the reason Dr. Spoo doesn't recommend the use of Invermectin products in dogs is that there are increasing reports about retinal damage and dogs going blind from its use.

Here's his latest video on Heartworm Prevention:
Here's his latest email from today (4/20/24) on Parasite Prevention: Parasite Prevention - Not All Are Equal
If the above link to Spoo's email message stops working, here's my copy and paste of his message:

"A lot has changed in the world of parasite prevention over the course of my career — some of it for the better and some of it resulting in massive confusion due to the overwhelming number of options currently on the market.

The first thing that I would stress is that our hunting dogs need to be on a heartworm preventative, and for the vast majority this should be a year-round strategy. While we absolutely will not be transmitting heartworms in the fall and winter in most of the country we are still likely exposing our dogs to intestinal parasites and this benefit, alone, should be enough to warrant year round prevention. Early in my career you could be fairly certain that from a climate perspective the transmission season for heartworms was only six months. Now with our later falls, warmer winters and earlier springs that just isn’t the case every year and honestly by administering these medications year-round it takes out the variability and potential for error. There is also evidence that when multiple doses are given consecutively it helps reduce the possibility of resistance or breakthrough. Meaning if you had exposure at the “end” of a typical heartworm season and quit your medication there would be increased risk versus if you continued administering the medications. One point to note here is that heartworm medications kill backwards so while they prevent heartworm disease they don’t prevent the organism from entering the body and each dose essentially kills off the parasites from the previous month.

On the heartworm front I use Interceptor Plus in my dogs and have for at least the last decade. My recommendation is for the milbemycin oxime-based products. As far as the products I avoid, I would no longer consider using the ivermectin-based products in my own dogs. I certainly do not recommend the dosing of the large animal product for dog use and even the heartworm products that contain low-dose ivermectin I no longer recommend. There is concern amongst some ophthalmologists about the possibility of retinal damage due to these drugs in some dogs. We certainly do not have this completely worked out but there is enough of a concern that it has changed my habits. For more information you can see the presentation HERE: Retinal toxicity suspected to Gaba-Ergic anti-parastic drug use

The question I often get asked is about the injectable products like ProHeart 6 and 12. In theory they make a lot of sense, they are a give it and forget it situation. Unfortunately for me there are just too many variables and I just haven’t gotten on the bandwagon with its use. There are a number of steps that need to be taken to mix the product, initially and with each dose, and if done incorrectly the dose administered could be wrong. It also acts as an intestinal dewormer only at the time of the injection and not monthly. In my neck of the woods, I am more apt for my dogs to encounter intestinal parasites than I am heartworm.

Flea and tick prevention has also gotten quite murky with both veterinary and over-the-counter options. For the longest time I was a big fan of Frontline, and I still feel that the original chemical, fipronil, is one of our safest options for fleas and ticks. Unfortunately, we have to make everything bigger and better and finding straight fipronil isn’t always the easiest as it is usually combined with other ingredients, and this many years into its existence it may no longer be the best choice.

The other topical options usually revolve around permethrin-based drugs and they have a lot of potential side effects. Smaller dogs are particularly sensitive to them, and they can be fatal to cats. I’m also not a big fan of tick collars with one exception, the Seresto collar. I think that collar has a lot of potential for people in heavy tick burden areas or if you travel to tick-borne disease country to hunt and you want to double up on your prevention.

In the oral class of flea and tick preventatives there are a number of options and all are relatively similar. I will say that some of them come with more reports of neurologic episodes post administration than others. Since it came on the market, we have used Credelio with good success. Some studies show that its efficacy at the end of the dosing cycle may be better than some of the other products on the market. I’ve also used Nexgard and Brevecto with no issues, for what it’s worth. The big thing to remember with these products is that they are in the blood stream so the flea and ticks will need to bite your pet in order for them to be effective meaning you may still see those pests on your dog.

My take home points would be:
—Have your dog on year-round heartworm prevention.
—Understand the benefits and risks of the product you are using.
—Adequately protect your dog from fleas and ticks, particularly if you live in tick-borne disease country".

That's the first time I've heard of the Ivermectin link to blindness, and its' certainly something to consider. I'm going to continue to give it until I see a problem in my dogs. None of them that have been on it have developed vision problems, and the oldest has been on it for eight years. From what I can glean from the literature, there seems to be a link, but not all dogs on Ivermectin develop vision problems. If they did, it would have been well known by now. Who knows, in ten years we may learn that the medications we're giving today have as-yet-unknown adverse side effects.

If a dog has been on a heartworm preventative all year long, what is the justification for requiring an annual test before continuing to prescribe the same medication? I think I know the answer, but it would take a vet to confirm it.

My guess is litigation, at least partly. Believe it or not, some owners who say they never miss a dose, do.

It's not just that owners miss a dose. Dr. Spoo pointed out two other reasons:
1. Your dog vomits up the Rx med and you don't see it happen, and then the dog is not protected for the next 30 days, or
2. In your dog, the Rx med becomes less effective over time. That can happen with all kinds of meds in all animals and humans.

Pretty sure I haven't missed a dose. It's written on our calendar the first day of each month, and I check it off when I've given it just to be sure. I mix grape juice in the syringe with the Ivermectin. While I suppose it's possible they could vomit the dose, they start licking their chops when they see the syringe and come to me wagging their tails. I often immediately exercise them after giving the medication and haven't seen any of them vomit. Eating grass on the other hand.......

I wasn't aware medicine could become less effective over time in a dog, but that is certainly true for many pests that the medicine targets. It's the case with flies and boll weevils that became DDT resistant. One reason heartworms became resistant to the level of Ivermectin in commercial products is because the dosage is intentionally low. A vet isn't going to have a happy customer if the meds kill a customer's collie.

To keep it in perspective. One spends more per year for oil changes in their vehicles, than a test that ensures the existence or absence of a crippling disease in their Dog

And none have guessed a Vet has the professional responsibility to use the current accepted protocol for practicing his profession.

“A simple test would have prevented my Dog from suffering and dying…but the SOB didn’t do it.. He/She should lose their license.”

In my area of SC we have a mobile Pet-Vac that comes around twice a month. They offer basic services that one would need like vaccinations, tests, etc. at reduced costs. Heartworm test is 18 dollars, and yes, your dog has to be tested for heartworms before they will give you any type of heartworm preventative.

I have my dogs tested, occasionally, never been a positive test. I give my dogs Trifexis. It kill fleas and prevents flea infestations, treats and control hookworms, whipworms and roundworms, and prevents heartworm disease. Its tremendous.

This is so simple to do, a cave man can do it. Buy a vial of Ivermectin, Normectine or any generic. Dose at the above recommended dosage and let it bump. Unless required by law or your own desire, a test is unnecessary.

Your dog either has them or not. If it's too far gone, nothing's gonna help anyway. If it isn't infected or the case is in the early stages, monthly dosages will eventually get your dog worm free in a couple of years. No reason not to treat all year long.

This has worked for over 40 years. I love my dogs but they are tools I hunt with. Some people get guilted into expensive, unnecessary treatments for the sake of profit. Do what allows you to sleep at night.

I get proheart 12 once a year and it has gotten the resistant hooks that are prevalent in Greyhounds

I've used liquid ivermectin for over 35 years and none of my hunting dogs (60+) of various breeds have ever had any eye problems resulting from ivermectin use. Sounds like that vet is pushing another drug which is probably a lot more expensive!

Thought I'd throw in my 2 cents here with regards to some recent experience regarding heartworms, as I had a thread about it sometime back, trying to figure out what to do in a heartworm-positive situation.

I adopted a 1-1.5yr old small dog from the local pound and it was obvious she'd lived outdoors her whole life. All of her canines were flattened off, so she was probably on a chain or in a pen too much. Her heartworm test was negative upon adoption and I put her on the heartworm shots that she'd get once a year. When I brought her back to the vet for her next shot, she tested positive for heartworms. Turns out that only adult worms will make the test indicate a positive and she likely had been recently infected when I adopted her. My vet recommended a slow-kill method of treatment, being a stout round of antibiotics to kill the young worms and monthly Simparica Trio to provide a steady flow of anti-heartworm medication to kill the adults slowly (and prevent ticks). Their office had quit doing the intense heartworm treatment that killed the worms in months because the treatment was often so hard on the dogs, due to the drugs and the fact that you have to keep them immobilized for weeks on end, as to not dislodge the dead worms and cause a stroke or death in the dog. A family member works at a vet office one town over, so I took the pup to get a second test and a consult there. The test was again positive and they wanted to put her on the aggressive treatment, not recommending the slow-kill method, due to lack of data. I did a lot of research on the two methods and came across a detailed study of the slow-kill method that showed it being effective for a large portion of their sample size. Considering that my little girl is a very athletic and high energy dog with an obvious history of problems with previous over-confinement, I elected to go the slow-kill route. I just couldn't crate her for weeks on end, as I've heard of some dogs never being quite the same after going through all that. Many have to be heavily sedated for weeks.

So we completed the antibiotics and a year of Simparica, then recently retested. The test result was extremely faint, not enough to be a true positive, which is what my vet expected. It also aligned with the typical results of the study I read. Little girl has never exhibited any outward signs of infection and continues to be healthy and active. I feel like it was the right choice for her scenario, but I recognize she's an example of one.

Here she is yesterday, going after a mole, flinging dirt like a maniac.