I have a rough coated collie, and my vet said they will not be making the product anymore, in fact it hasn't been manufactured since January.
In discussing this with my vet, I am right now trying to decide between a product called Trifexis (sp?) which includes an anti flea component, or my vet said the amount of ivermectin in Heartguard is so tiny he should be OK with that. (I should add, she herself has smooth coated collies, and tells me she's given them Heartguard all along).
Not sure what I'm going to do. The rescue I got my collie from equated Heartguard with death, basically, but my vet is, well, a vet. What to do?
I use Trifexis for my Australian Shepherd puppy. My vet also said the amount in heartguard would probably be ok. But why risk it? I've heard of dogs dying from just licking up a little bit after the horses get wormed. The Trifexis is more expensive but I think it's about the same as if you bought topical flea preventative and I love not having an oily spot on my dog from topical flea preventative.
I also have used Interceptor for years. Last week I was at my vet's and we were talking about it. She didn't say anything about it not being made anymore, just that the whole plant was shut down because of a problem with another drug (forget which one) but since Interceptor was made there too, it was suspended. She also said that herding breed dogs (or mixes) would be OK with Ivermectin since the amount in the heartworm meds is so small. I remember years ago when we got our Australian Shepherd, my vet at the time said herding/Collie related dogs should never be given Ivermectin. That was about 18 years ago so I guess research has advanced and veterinarians aren't as conservative about this anymore.
However, if anyone is really worried about it, there is a DNA test to see whether dogs carry the mutant MDR1 gene (the gene that makes them sensitive to certain drugs, including Ivermectin). The test is thru Washington State University but is available to vets anywhere. Not expensive, about $70.
from Washington State College of Veterinary Medicine website:
"My dog has tested positive for the MDR1 mutation. Now that Interceptor is no longer available, what heartworm preventive product should I use for my dog?
Any of the monthly heartworm preventives (administered at the label dose) can be used in dogs with the MDR1 mutation. We recommend avoiding the 6-month or 12-month injectable products and we prefer the single-ingredient products to the multiple ingredient products."
Although none of our dogs are of herding breeding, I do like Interceptor and hope that they resume production of it. I've used it for all of our dogs ever since we started using it for our late Aussie.
I can't give Ivermectin because my dog already has seizures... Vet put him on Trifexis (which I have now read can cause seizures... Sigh.) He is also now on Phenobarbital as the seizures have progressed to more than every few months, so I guess that is why vet was OK with Trifexis. But did say specifically not to use Heartguard.
If you have one of the breeds affected by the MDR1 mutation, it's best to have them tested. Ivermectin is not the only drug that can cause a problem.
"Approximately three of every four Collies in the United States have the mutant MDR1 gene. The frequency is about the same in France and Australia, so it is likely that most Collies worldwide have the mutation. The MDR1 mutation has also been found in Shetland Sheepdogs (Shelties). Australian Shepherds, Old English Sheepdogs, English Shepherds, German Shepherds, Long-haired Whippets, Silken Windhounds, and a variety of mixed breed dogs."
"Drugs that have been documented to cause problems in dogs with the MDR1 mutation include: Acepromazine (tranquilizer and pre-anesthetic agent). In dogs with the MDR1 mutation, acepromazine tends to cause more profound and prolonged sedation. We recommend reducing the dose by 25% in dogs heterozygous for the MDR1 mutation (mutant/normal) and by 30-50% in dogs homozygous for the MDR1 mutation (mutant/mutant). Butorphanol (analgesic and pre-anesthetic agent). Similar to acepromazine, butorphanol tends to cause more profound and prolonged sedation in dogs with the MDR1 mutation.We recommend reducing the dose by 25% in dogs heterozygous for the MDR1 mutation (mutant/normal) and by 30-50% in dogs homozygous for the MDR1 mutation (mutant/mutant).
Emodepside (Profender�)-is a deworming drug approved for use in cats only in the U.S., but is approved for use in dogs in some other countries. Use of this drug in dogs with the MDR1 mutation has resulted in neurological toxicity. Erythromycin. Erythromycin may cause neurological signs in dogs with the MDR1 mutation. A mutant/mutant collie exhibited signs of neurological toxicity after receiving erythromycin. After withdrawal of the drug, the dogs neurological signs resolved. There were no other potential causes of neurological toxicity identified in the dog.
Ivermectin (antiparasitic agent). While the dose of ivermectin used to prevent heartworm infection is SAFE in dogs with the mutation (6 micrograms per kilogram), higher doses, such as those used for treating mange (300-600 micrograms per kilogram) will cause neurological toxicity in dogs that are homozygous for the MDR1 mutation (mutant/mutant) and can cause toxicity in dogs that are heterozygous for the mutation (mutant/normal). Loperamide (ImodiumTM; antidiarrheal agent). At doses used to treat diarrhea, this drug will cause neurological toxicity in dogs with the MDR1 mutation. This drug should be avoided in all dogs with the MDR1 mutation. Selamectin, milbemycin, and moxidectin (antaparasitic agents). Similar to ivermectin, these drugs are safe in dogs with the mutation if used for heartworm prevention at the manufacturer's recommended dose. Higher doses (generally 10-20 times higher than the heartworm prevention dose) have been documented to cause neurological toxicity in dogs with the MDR1 mutation. Vincristine, Vinblastine, Doxorubicin (chemotherapy agents). Based on some published and ongoing research, it appears that dogs with the MDR1 mutation are more sensitive to these drugs with regard to their likelihood of having an adverse drug reaction. Bone marrow suppression (decreased blood cell counts, particulary neutrophils) and GI toxicity (anorexia, vomiting, diarrhea) are more likely to occur at normal doses in dogs with the MDR1 mutation. To reduce the likelihood of severe toxicity in these dogs, MDR1 mutant/normal dogs should have their dose reduced by 25% while MDR1 mutant/mutant dogs should have their dose reduced by a full 50%. These patients should be closely monitored for adverse effects. "
Umm.... I've never heard a vet say you cannot do Ivermectin with a seizure pet, but I do know they generally would not reccomend Trifexis because of the proven seizure risk. It does not cause seizures directly, but lowers the threshold, making them far more likely to have breakthroughs.
Bold- Ivermectin IS deadly to all dogs, in the higher exposure they would get from horse dewormers etc. The amount in heartworm preventative products is so incredibly low that it does not pose a threat. There is less active product in a Heartgard chew than in a BB sized drop of paste dewormer. The concern for herding breeds is that some of them carry a genetic mutation that allows the drug to cross the blood-brain barrier(which it should not) and then the body cannot flush it back out. So over time the levels continue building up and become toxic. Thankfully there is now a test to check for this genetic defect, so it is easier now to decide what to use(and hopefully who to breed). Beats the old way, "White feet don't treat" rule......
I'm hoarding mine for the collie. Switched the others to Heartguard but I prefer Interceptor. I've heard that Target Pharmacies still have some, you might want to make some calls. Vet can call in a prescription.
We switched our Springer spaniel to trifexis, and have had no problems. I like the added flea protection as I hated the spot on the neck types - our kitty likes to groom 'her' dog, so I was always afraid she would ingest doggie flea treatment.
Bringing this back up since I have finally run out of Interceptor. I've tried Trifexis for my smooth collie, but it makes him sick (was feeding it with his meal- read stuffing it down his throat since he won't eat it- but made him puke within a half hour or so. No good on an empty stomach either.) and now my vet has recommended Advantage. Upon reading the insert, there is no way I would give it to my dog (4 of 5 Ivermectin-sensitive collies treated with it had to be PTS due to neural problems). I suppose I should have him tested for the genetic mutation, but he is 12 years old. I'm wondering if it's honestly worth treating him for heart worm at all at this point
I was inquring about using Ivermection for a friend and her BC. The Neurologist I worked for (he has been around a long time) said there is not enough ivermection in Heartguard to worry about it. He even showed me some research papers. Trifexis also lowers the threashold to tolerate Ivermectin. We had a dog come in in a coma after the owners administered the dog's Trifexis then the Ivermectin it was taking to treat some form of mange.
My older dachshund got sick after giving her Trifexis, but the vet tech had given us a dosage for dogs 20-40 lbs (she's 16 lbs) and I didn't notice until I went back and read the package insert, so it was probably more from that than the drug itself. After getting the correct weight dosage I have been giving it to my other dachshund, who's been fine, but just in case I've been giving the older dachsie Iverhart.
Either way, really hope Interceptor is back again soon! My vet also thought it would be back in production in a few months.