Heartworm preventative-questions

[Mara]

I miscounted the number of doses of Interceptor I had left for my dog Lance and nearly missed the scheduled day’s dose. Thankfully, I did get to the vet’s office, as they are open late on Mondays, and got a 6 month supply and a script for an online purchase for another 6 months’ worth.

This near-miss made me wonder, though. How late is too late to safely give a missed dose of monthly heartworm preventative? When would the situation dictate getting another occult test for microfilariae?

Also, my other dog has several doses remaining. He weighs 52 pounds, so he gets a larger dose, obviously, than the 49 lb dog. Could I, in a pinch, give the larger dose to the 49 lb dog? I realize that question can enter dangerous (for the dog) territory - i.e., someone says, “well, if the 49 lb. dog can take it, then it should be OK for the 46 lb. dog”. Dogs do gain and lose, though (in fact, the 49 pounder used to be the 52 pounder and vice versa). What are safe parameters?

[MikeP]

Ivermectin has been tested up to ten times the recommended rate without any negative effects. I wouldn’t worry about a few pounds difference in dog weight.

I also wouldn’t worry about a few days. We routinely skip December, January and February heart worm treatments since we don’t have mosquitoes at that time of year. Some months have 30 days, some 31…a few days here or there is not that big a deal.

Somebody will probably get all uptite and say otherwise, but 20 years of dog treatments following the above has resulted on no heartworms and no overdoses.

[dalpal]

Yep, few days doesn’t really matter…that’s what a vet told me.

Someone else pointed out that even if you missed a dose…the next month’s pill would kill any larvae from the missed dosage.

We go 12 months here, just to be safe.

[Mara]

[QUOTE=dalpal;4154358]
Yep, few days doesn’t really matter…that’s what a vet told me.

Someone else pointed out that even if you missed a dose…the next month’s pill would kill any larvae from the missed dosage.

We go 12 months here, just to be safe.[/QUOTE]

I’m in Georgia, where it isn’t at all uncommon to have a few warm spells in the dead of winter, so yes, we go 12 months as well. And my dogs seem to be mosquito magnets. The mosquitoes leave me alone when we’re out walking, but I can see clouds of them, literally, around the dogs’ ears and bellies. So I don’t dare miss a dose.

[Horsegal984]

Here in NC we reccomend year round, as we don’t go long enough with true cold spells to make sure all the ‘skeeters’ are dead. Same with fleas really, if it’s over 60 degrees they’re going to be active.

To answer your questions, you can be up to 2 weeks late before we really consider it a ‘missed’ dose. And you usually have to miss 2 doses in a row before we really worry about testing.
However with that said, even if you miss one or two or 5 doses, start back on preventative as soon as you can/remember. The new AVMA(American Veterinary Medical Assoc.) resomendations now are to treat with preventative for a period of time as the first step in treating an infected dog.
If you’re not sure of the dogs exact weight, or you have a dog on the cut off point for a weight class we always reccomend going up. They’re all so safe now a days that better to air on the side of caution than risk being underdosed. It’s so safe and easy to prevent, and so dangerous and expensive to treat, why chance it?? So yes, your 49#er could very safely take the larger dogs size. As a matter of fact to help out my very well meaning but not always accurate DH I have both my 48# female ACD and my 55# male on the 51-100 Heartgard Plus. It’s way easier for him to remember to give them both one of these than “Oz gets this one, Eclipse gets the other one…”

Katherine
Vet Tech

[Mara]

Thanks everyone. I’m thinking I may put them both on the larger dose, to allow for fluctuations in weight.
I worked at a vet’s office for a couple of years after college, when I didn’t really know what I wanted to do. During that time I remember having three dogs in for treatment for heartworms. All of them lived, thankfully, but it wasn’t fun for anyone. (A fourth client with a positive dog refused to treat the dog, since “he isn’t showing any symptoms”. Wouldn’t listen to the vet’s explanation that it would likely be too late for her dog when he DID start showing symptoms, such as possibly dropping dead. ARRRGGHHH.)

[wendy]

the dose ranges on the packages are immense. Mine say “for dogs 51 to 100 pounds” so clearly the exact dose isn’t all that important. I give them every 45 days and skip them during the winter but heartworm is really not a big problem in this area. They aren’t actually a preventative- if the dog got infected before you gave the pill it kills the larvae the dog picked up.

[dalpal]

[QUOTE=Mara;4154898]
Thanks everyone. I’m thinking I may put them both on the larger dose, to allow for fluctuations in weight.
I worked at a vet’s office for a couple of years after college, when I didn’t really know what I wanted to do. During that time I remember having three dogs in for treatment for heartworms. All of them lived, thankfully, but it wasn’t fun for anyone. (A fourth client with a positive dog refused to treat the dog, since “he isn’t showing any symptoms”. Wouldn’t listen to the vet’s explanation that it would likely be too late for her dog when he DID start showing symptoms, such as possibly dropping dead. ARRRGGHHH.)[/QUOTE]

I have a dog that came to me HW positive four years ago…still have her. I opted for the slow kill of just giving HG Plus. I personally don’t believe in loading a dog’s system full of poision and crating them for three months. I know many dogs who have died from the treatment and I wasn’t about to go there. She’s healthy, happy and has shown absolutely no signs of being sick in four years. BTW…the slow kill method was recommended by my equine vet (who also owns a small animal practice)…the small animal clinic had a fit and fell in it over the thought of slow killing heartworms. I’m just not going to put a dog through that hell for three months.

I don’t know if your vet’s client opted to do no heartworm meds at all, but there are risks to doing the quick kill treatment as well. My vet’s staff probably thinks I’m an ass too, because many times I will say no to all the wonderful drug, vaccine suggestions that they have.

The other issue with HW pills…I just bought a box of 12 for 92.00 at the vet’s office. That’s 7.66 per pill. The average joe who just lost his job or has a minimum wage job may very well not be able to afford a box of Heartworm meds. Don’t get me wrong, I’m a big believer of…if you can’t afford it, dont’ have it…but that doesn’t change the reality of things.
I can get the same box online for 69.00…still 5.75 per pill. If these meds were made more affordable, more people would probably buy them for their dogs. I hate it that so many dogs are HW positive, but I do somewhat understand WHY that is the case.

[wendy]

actually, I think the biggest barrier is that they require a vet’s prescription for some reason. So in order to get them you have to go to the vet, which costs more than the pills.

[Nes]

Don’t want to steal, but: does anyone know a non-ivermectin based horse wormer that would prevent heartworms?
(we have collie crosses, so ivermectin would probably be ok, but I still worry!)

Our vet strongly suggested we buy a tube of horse wormer to split amonst the dogs & cats to do them regularily (we have GREAT vets who actually care about saving poor people money! GO THEM! :D); but the original concern was more about roundworms, which our kitten did have.

[Sing_Mia_Song]

@wendy;4155441

actually, I think the biggest barrier is that they require a vet’s prescription for some reason. So in order to get them you have to go to the vet, which costs more than the pills.

They require a vet’s prescription because of the potential side effects of giving them to a positive dog with a heavy heartworm load. They need to test out negative before they can start on it (though, as mentioned above, some vets do opt to treat mild cases with Heartgard).

Heartgard only kills circulating microfilarae. Once the worms have grown to adult size and taken up residence in the heart, Heartgard will not affect them, but will prevent infestation from subsequent microfilarae.

The adult heartworms don’t live forever, so it’s possible that by stopping the influx of additional circulating microfilarae, the dog will eventually test negative. The SNAP test can catch adult worms, but I think it needs something like three to read positive and won’t catch just one or two.

In a HW+ dog who has other issues, such as malnutrition, I can see putting it on Heartgard and hoping for the best. But in a young, healthy dog (like the Beagles in my region positive that are the usual victims), I’d go to the immiticide.

Don’t want to steal, but: does anyone know a non-ivermectin based horse wormer that would prevent heartworms?
(we have collie crosses, so ivermectin would probably be ok, but I still worry!)

Nes, you can do a test for the MDR-1 gene mutation that allows ivermectin to cross the blood-brain barrier. It’s a good idea to do, because there are lots and lots of other commonly used drugs (i.e., dexamethasone, loperamide, digoxin, erythromycin,) that are also contraindicated in dogs with the mutation.

And no, sorry, there’s no horse wormer that you could use that would affect heartworms and not affect dogs with the MDR-1 mutation. Moxidectin (Quest) is actually more dangerous than plain old ivermectin.

[FatPalomino]

[QUOTE=Nes;4156762]

Our vet strongly suggested we buy a tube of horse wormer to split amonst the dogs & cats to do them regularily (we have GREAT vets who actually care about saving poor people money! GO THEM! :D); but the original concern was more about roundworms, which our kitten did have.[/QUOTE]

One of my good friends strongly does NOT suggest doing this, because their may not be an equal concentration of the medication in, say, every ounce of the paste. We did use liquid ivermectrin, which was more reliable in terms of concentration.

[Nes]

We bought a dose from the vet for the kitten so admittedly I havn’t really looked into anything for the dogs. Quest, however is moxidectin which would treat HW. That is a very good point FP I’ll look into the matter further :).

Sorry totally skipped over SMS post. I just did some preliminary research and will certainly discuss this with my vet. From what little I’ve read Quest (avermectin) is safe for dogs & will kill heartworms. Unfortunately it was hubby who did the kitten’s vet appointment (conflicting baby appointment).

[Ben_and_Me]

That’s 7.66 per pill. The average joe who just lost his job or has a minimum wage job may very well not be able to afford a box of Heartworm meds. Don’t get me wrong, I’m a big believer of…if you can’t afford it, dont’ have it…but that doesn’t change the reality of things.

$7.66/month to prevent a life-threatening disease? That doesn’t seem over-the-top expensive to me. The IverHart (generic) which is available through several online pharmacies is even cheaper.

http://www.kvvet.com/KVVet/product_family.asp?family_id=1237&gift=False&0=dept.asp%2Cdept_id%3D197%26Tree%3D%2CMost%20Popular&1=dept.asp%2Cdept_id%3D982%26menu_id%3D%26Tree%3D0%2CHeartworm%20Medication&mscssid=EDC5FC40357F4CE2A5B368EC91E18D91

Check it out. $22 for 6 months worth. Money should NOT be an excuse.

[dalpal]

[QUOTE=Ben and Me;4156976]
$7.66/month to prevent a life-threatening disease? That doesn’t seem over-the-top expensive to me. The IverHart (generic) which is available through several online pharmacies is even cheaper.

http://www.kvvet.com/KVVet/product_family.asp?family_id=1237&gift=False&0=dept.asp%2Cdept_id%3D197%26Tree%3D%2CMost%20Popular&1=dept.asp%2Cdept_id%3D982%26menu_id%3D%26Tree%3D0%2CHeartworm%20Medication&mscssid=EDC5FC40357F4CE2A5B368EC91E18D91

Check it out. $22 for 6 months worth. Money should NOT be an excuse.[/QUOTE]

Really? Might sound much more to you if you just lost your job. :mad: Good for you that you are in a situation that money is never an excuse…we should all be so darn lucky, huh?

I wasn’t talking about ME personally, btw…I know about all the online deals, generics…etc…but not everyone does…so no need to snipe off some condenscending post.

And just an FYI…I pay the 7.66 x3 because this is one instance where I don’t trust generic drugs…so need to preach to me about what’s important…but price is a big reason that so many dogs in this country go without heartworm medication.

[dalpal]

As far as the mention of Quest…I thought it could kill a dog?? Someone correct me if I’m wrong.

[McVillesMom]

Wow, I am amazed that a veterinarian would suggest using horse dewormer on your dogs. That’s a good way to lose your license and get sued.

To answer the original question, 45 days is the cutoff. After that, you can consider it a missed dose.

Moxidectin, the active ingredient in Quest, is not toxic to dogs per se (well, unless you’re a collie). The problem with giving any equine dewormer to a dog is the dosing. As FP said, the problem is that you can’t guarantee that there’s an equal concentration in every ounce of the paste. For the same reason, I’ve been taught you shouldn’t take a large dog Heartgard and break it into two pieces for a smaller dog.

[SonnysMom]

wendy- I am roughly in your area (Pottstown) and heartworm is a problem around here. My GSD as a child had it when we found her and I have known 3 other people that have gotten rescues from this area that have had to go thru the HW treatment. Most vets in this area do recommend year round treatment.
After seeing what my dog went thru for HW treatment I would give it every 30 days as recommended by the vet and by the manufacturer.

[Ben_and_Me]

[QUOTE=dalpal;4157082]
Really? Might sound much more to you if you just lost your job. :mad: Good for you that you are in a situation that money is never an excuse…we should all be so darn lucky, huh?

I wasn’t talking about ME personally, btw…I know about all the online deals, generics…etc…but not everyone does…so no need to snipe off some condenscending post.

And just an FYI…I pay the 7.66 x3 because this is one instance where I don’t trust generic drugs…so need to preach to me about what’s important…but price is a big reason that so many dogs in this country go without heartworm medication.[/QUOTE]

I make $9 an hour. It’s all about priorities. I don’t consider $3-$4 a month to be cost prohibitive.

[Canopach01]

AHHHHHHHHH

Do not ever ever ever under any circumstance give a Collie or Collie cross an Ivermectin Drug. Collie dogs are to use milbemycin oxime (interceptor), revolution, sentinel for heartworm prevention. The ivermectin dose for a dog being used for heartworm prevention is such a micro dose that most people do not have small enough syringes to measure it. Large dogs dont even get more than 0.1ml - can get exact calculation tomorrow.

It is not safe to use interceptor if you have missed more than 4 weeks. It can have serious adverse effects if your dog has been infected with heartworms!

Slave to the pet world

No No Quest