Novartis Temporarily Halts Production on Heartworm Drugs

Here’s one that slipped under my radar last month:

Novartis Animal Health has ceased production of Interceptor, Sentinel and several other drugs manufactured in its plant in Lincoln, Neb., while the facility undergoes “process and compliance improvement activities,” a spokesman for the company confirmed today.

I buy Interceptor for Mulder, my CHD (Compulsive Herding Dog) since she has white feet.  As far as I know, there is no other product on the market that contains only the active ingredient in Interceptor (milbemycin oxime).  I hope the stoppage will be short-lived.


15 thoughts on “Novartis Temporarily Halts Production on Heartworm Drugs

    1. I was referring to the old veterinary adage regarding the administration of ivermectin to herding breeds and mixes: “White feet, don’t treat”. Veterinarians generally recommend these dogs be given heartworm meds which do not contain ivermectin due to a historical sensitivity to the drug.

  1. Okay, are we in 1950? “White-footed dogs can’t use heartguard?” Is your vet still living there?

    1. Dogs with the MDR1 mutation are equally sensitive to the active ingredients in all heartworm preventatives. They are all the same class of drugs.

    2. Dogs with the MDR1 mutation can take any of the commercial heartworm preventatives, because the doses are so low that reactions are not a concern. You can give heartguard to MDR1 mutant dogs.

    3. Dogs with the MDR1 mutation occur in at various rates in the collie-family breeds. A black and tan English shepherd or collie mix, with no white on him, is just as likely to have this mutation as his sable and white brother.

    4. There are many other drugs that, given at therapeutic doses for whatever condition, are a concern for MDR1 mutant dogs. Therefore, it is prudent to know what is going on in your dog’s chromosomes, so that you know *before* the dog gets sick that some drugs are contraindicated.

    5. Fortunately, there is a cheap genetic test for the MDR1 mutation that will tell you whether the dog is normal/normal, mutant/normal, or mutant/mutant. If there’s any reason to suspect collie ancestry in a dog, just get the test.

    6. If you have normal/normal dogs, you can learn to titrate doses of livestock ivermectin for monthly heartworm prevention. This is INSANELY more cost-effective, especially if one has a lot of dogs. It is too risky for dogs with one or more mutant genes.

    1. Thanks for the detailed explanation Heather. I would hazard a guess that your explanation goes above and beyond what many vets tell their clients in the exam room and what many clients have the interest in researching. I believe, perhaps wrongly, that Joe Average vet and Jane Average pet owner still fall under the “white feet, don’t treat” category.

      Also meant to add that, while I would hardly characterize my vet as living in the 1950s, she is old school. She still very much believes that annual revax has a value for pets and she sells Science Diet. We don’t agree on everything but that’s been true with my previous vets as well. The main thing for me is that I trust her with my pets. I actually travel a long way to get to her for that reason.

      1. Many vets are still old school and do not have a clue about the many DNA tests for genetic illnesses in breeds. Some are done with just a cheek swab-extremely easy and some tests are not that expensive.

    1. Thank you Roo. The test can be conducted via a visit to a vet’s office (they will send off the sample for testing) or owners can send off a sample for testing themselves. It costs $70 for a test. Your vet will likely add on additional charges for collecting the sample and whatever else they deem fitting.

  2. Milbemax is manufactured by Novartis in Australia. It contains milbemycin oxime and praziquantel for heartworm protection with intestinal dewormer. I alternate Milbemax with Interceptor as I do not believe my dogs need deworming every month. My source ships from Australia without a prescription:

    PS. Of course My vet is not thrilled for obvious $$$ reasons. I do HW testing with my annual vax, boloodwork & urine and have never had a dog test positive… double digit dogs x five years with no problems.

      1. I work for a vet and have known about this for over a month. Basically, Novartis sent us a letter telling us that they had shut down production to make improvements and had no estimate of when they would be back up and running. No estimate at all. We have already been out of the 11-25lb size of Interceptor of several weeks now.

        My advise is that if you are currently on Interceptor or Sentinel and wish to stay on it, buy a year’s supply now while you can. The current stock isn’t going to last long.

        p.s. BOTH Milbemax and Interceptor deworm your pet monthly. In addition to heartworm prevention, they also get hook worms, round worms, and whip worms. The difference is that Milbemax contains praziquantel, a drug which treats an additional worm, tape worms.

  3. Trifexis contains milbemycin oxime but also spinosad for fleas. Not sure about your pup’s sensitivity to spinosad. Generally this product is very safe and we recommend it to all our clients (I’m a vet tech) except for those with epilepsy or sensitivity to comfortis (spinosad).

    If your not concerned about spinosad I would recommend using trifexis for an interceptor replacement. But then you won’t need flea control as it already contains it (if you were using flea control).

  4. I heard that Novartis had various compliant problems with the quality of their human drugs and possible contamination with other drugs. But I can’t find this with their canine drugs, but worry about my mutant MDR1 bitch’s sudden neurological state, wondering if there is any correlation. Has anyone heard anything?

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