Dosing and Using Ivermectin to Treat My Dog's Cancer (Current Research)
Ivermectin can be an effective alternative treatment for cancer in dogs.
Should I Treat My Old Dog for Cancer?
"My dog has breast cancer, and I do not want to watch her have surgery at her age nor suffer with chemotherapy in the few months she has left.
A guy at the dog show was telling me about this new cancer medication that used to be sold as a dewormer. Is ivermectin really an alternative to treat her cancer?"—Gina
Does Ivermectin Help With Mammary Cancer?
Yes, ivermectin has been shown to work to treat mammary cancer in dogs. There are several good alternative treatments for cancer, and as you already know, some of the newest treatments available use dewormers with success. Diet is also important, as a low-carbohydrate diet does not support the tumor growth.
This podcast video discusses some of the advantages of treating cancer when on a low-carbohydrate diet:
How Does Ivermectin Work on Tumors?
Mammary gland cancer is the most common tumor in intact female dogs, and figuring out how to handle it in a senior dog is sometimes a problem. Conventional therapy involves surgery to remove the tumor and sometimes chemotherapy to destroy the metastasis. As you already know, there are all sorts of negatives with chemotherapy, and dogs suffer during their remaining life.
Ivermectin is an alternative that does not cause all of those negative side effects. It works by inhibiting the growth of new cancer cells by several means, one of which is stopping the cell cycle, and another is interfering with the signaling pattern that tumors use to grow. (1)
Besides stopping cancer cell growth, some new research has shown that ivermectin also creates an environment in which tumor cells are less likely to survive. In this study, the researchers decided that it was also cytotoxic. (2)
Dosing Ivermectin for Cancer
If you want to try this alternative therapy, giving ivermectin for your dog's cancer can be done at home. The dose of ivermectin to treat your dog for cancer is given orally, just like the monthly heartworm preventative, and it does NOT need to be injected.
The toxic dose of ivermectin is quite high—about 2mg per kilogram of body weight—and although you can give the 1% cattle solution (available at your local feed store), I would still recommend you purchase the sheep formula if you have a tiny or small dog since it is more dilute and does not taste as bad. If you have a medium-sized or large dog, you can use the cattle formula, but never use the horse paste as it is too strong for most dogs, and a small dose cannot be given accurately.
In some rodent studies, the amount of ivermectin used effectively is quite high (about 5 mg per kilogram of body weight, but when used on humans or dogs, those doses are a lot lower, and they can be used safely. (3)
The most common canine dose that has been recommended by many of the veterinary researchers is 200 micrograms per kilogram of body weight. There are 800 micrograms in each milliliter of the sheep drench, so since the dose is 200 micrograms per kilogram, a dog needs 0.25 ml per kilogram of body weight (see the chart below for dosing guidelines based on body weight).
If you have a Maltese, for example, and he only weighs 6.5 pounds (about 3 kilos), he should be getting 600 micrograms, or about 0.75 cc of the sheep oral formula. I recommend that you use a tuberculin syringe to get an accurate dose for a small dog, but a regular larger syringe is okay for a larger pet.
Ivermectin Dose by Weight
| Body Weight (lbs) | Body Weight (kg) | Dose (mcg) | Sheep Drench (ml) |
|---|---|---|---|
5 | 2.3 | 460 | 0.6 |
10 | 4.5 | 900 | 1.1 |
20 | 9 | 1800 | 2.3 |
25 | 11 | 2200 | 2.8 |
30 | 14 | 2800 | 3.5 |
35 | 16 | 3200 | 4 |
40 | 18 | 3600 | 4.5 |
45 | 20 | 4100 | 5 |
50 | 23 | 4600 | 5.8 |
75 | 34 | 6800 | 8.5 |
100 | 45 | 9000 | 11 |
Frequency
The researchers who have used ivermectin to treat mammary cancer in dogs have not published their frequency dose, but since ivermectin has been used every day for at least 2 months in dogs with generalized demodex mange we know that it can be used safely every day for at least that long.
Since the half life of ivermectin in 2 days in dogs, however, I recommend it only be given every other day so the amount will not build up to dangerous levels. After 3 months, dogs can be given a rest of 15 days before resuming therapy.
The veterinarian in this video discusses the dose and shows how to give it orally using the cattle preparation and an insulin syringe. This is fine for a larger dog, but I do not recommend giving a large dose to a small dog in that way.
The vet in the video gives the ivermectin directly into his dog's mouth, but I have found that many dogs grow to hate the taste. If you are using this solution, it is much easier to put this on a piece of kibble, bread, or some other food the dog likes and let him eat that instead.
If you are using the sheep drench formula, it does not taste as bad—at least according to my dogs—and you should be able to give it without disguising it in kibble or bread. The vet in the video also discusses the genetic sensitivity that very few types of dogs have that prevents them from taking ivermectin.
Research Is Ongoing
If you decide later on that you want to treat your dog with conventional therapy, there is also some evidence that ivermectin will work with some of the normal chemotherapy drugs.
Ivermectin is probably also useful in a lot of other types of cancer in dogs, but we need more research to prove how useful it is. In people, (4) we already know that ivermectin is good for:
- Breast cancer
- Colon cancer
- Ovarian cancer
- Skin cancer (melanoma)
- Leukemia
If you are going to use ivermectin to treat her cancer, be sure to change her diet too.
Any Questions?
If you have any questions about this article or other questions about your dogs cancer diagnosis please let me know at my Ask a Vet column at Pethelpful.com.
Sources
- Diao H, Cheng N, Zhao Y, Xu H, Dong H, Thamm DH, Zhang D, Lin D. Ivermectin inhibits canine mammary tumor growth by regulating cell cycle progression and WNT signaling. BMC Vet Res. 2019 Aug 2;15(1):276. https://pubmed.ncbi.nlm.nih.gov/31375107/
- Tang M, Hu X, Wang Y, Yao X, Zhang W, Yu C, Cheng F, Li J, Fang Q. Ivermectin, a potential anticancer drug derived from an antiparasitic drug. Pharmacol Res. 2021 Jan;163:105207. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7505114/
- Juarez M, Schcolnik-Cabrera A, Dueñas-Gonzalez A. The multitargeted drug ivermectin: from an antiparasitic agent to a repositioned cancer drug. Am J Cancer Res. 2018 Feb 1;8(2):317-331. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5835698/
- Lee DE, Kang HW, Kim SY, Kim MJ, Jeong JW, Hong WC, Fang S, Kim HS, Lee YS, Kim HJ, Park JS. Ivermectin and gemcitabine combination treatment induces apoptosis of pancreatic cancer cells via mitochondrial dysfunction. Front Pharmacol. 2022 Aug 26;13:934746. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9459089/
This article is not meant to substitute for diagnosis, prognosis, treatment, prescription, or formal and individualized advice from your veterinarian. Animals exhibiting signs and symptoms of distress should be seen by a veterinarian immediately.
© 2024 Mark dos Anjos, DVM
