Can Cancer in Dogs Be Treated With Ivermectin?
Traditional cancer therapies, which include radiation, surgery to remove most of the tumor, and chemotherapy to kill any rapidly growing cells, are sometimes effective but are both expensive and may reduce the quality of life of your dog for the remainder of his time.
There are hundreds of veterinarians around the world working hard to find better alternatives, and some of them have been working with drugs that we used to think were just for deworming. Fenbendazole and ivermectin are two of those drugs that have been found effective.
There is probably never going to be one cure for cancer. Instead, the best we can hope for is to find several different cures for the cancer cells depending on how the cancer cells grow and what kills them.
Ivermectin works in some cases but is not suitable for all types of cancer cells. Here are a few cancer types that may respond to ivermectin.
Related: Ivermectin and Doxycycline for Cancer in Dogs: Doses & Warnings
Mammary Cancer
This is frequently diagnosed in dogs that were never spayed and the only type of cancer in dogs that has research showing that ivermectin is effective. Over 50% of these cancers end up being malignant, so many of them do need to be treated aggressively.
The conventional therapy for mammary cancer is surgery to reduce the bulk of the tumor, and if it is malignant, the dog is put on chemotherapy. In this type of cancer, ivermectin has been shown to inhibit the growth of new cancer cells by stopping the cell cycle and interfering with the signaling pattern that the tumor uses to grow (1).
Other research on mammary cancer has shown that ivermectin is toxic to the tumor cells and creates an environment where tumor cells are less likely to survive.
It may not be the only answer, but it can keep some dogs from receiving chemotherapy, which diminishes the quality of their life.
Melanoma
This type of cancer is common in some dog breeds. Dogs that only have surgery usually live less than a year, and if the cancer is already advanced at the time of diagnosis, the survival time is only about one month.
Ivermectin has not yet been proven to replace chemotherapy in dogs with melanoma. In humans, however, ivermectin has been found to be effective when used with a melanoma chemotherapy drug called dabrafenib. Ivermectin was also found to significantly reduce lung metastasis from metastatic melanomas in animals.
There is no indication that a dog with this type of cancer could avoid surgery. If the tumor is small and can be removed completely, the dog will have a much better prognosis.
If surgery is not an option, this may be effective.
Related: Can You Treat Skin Cancer in Dogs Naturally?
Intestinal Cancer
Whether or not ivermectin is going to be useful for intestinal cancer depends in part on what type of cancer is involved. The most common is lymphoma, and there is no evidence that ivermectin is going to help. The other types of intestinal tumors are leiomyosarcomas and adenocarcinomas. There are other types, but they are less common.
In humans, it was found that ivermectin inhibits the proliferation of gastric cancer cells. Not all gastric cells were treatable, however, and there is no data available on leiomyosarcomas. There was evidence that ivermectin inhibited several other cancer cell lines in the rectum, so it may be similar in dogs.
The other type of digestive system cancer that can be treated with ivermectin, at least in humans, is hepatocellular carcinoma. There are several different ways that this works, but the researchers found that there was increased cell death in these tumors when the patient was on ivermectin. Some of the tumors that were not treatable with conventional chemotherapies also responded to ivermectin.
Photo by chalabalaphotos, Canva
Urinary System Cancer
Transitional cell carcinoma, a type of cancer most commonly seen in a dog's bladder, may respond to ivermectin in the same way as human renal cell carcinoma. Unfortunately, there is not yet any research proving that.
In humans, renal cell carcinoma cell lines were not able to proliferate when exposed to ivermectin, but the healthy renal cells grew normally. The researchers think that it might be because of the way ivermectin affects the mitochondria of cancer cells. The mitochondria of those cells were unable to produce enough ATP (an energy source).
In dogs with transitional cell carcinomas, surgery is sometimes done when only a single tumor is present in the bladder. Most dogs, however, will need radiation, chemotherapy, and other medications. Even with those therapies, the survival time is short, so ivermectin could help if it proves to be useful.
Related: Can I Give My Dog Human Buprenorphine for Cancer Pain?
Mast Cell Tumors
This type of cancer may not respond to ivermectin, although we do not yet have any evidence of that. It has, however, been shown to respond to a ketogenic diet (3) since that diet produces only ketones and not the glucose that the tumor cells need to thrive. If you want to read more about this subject, I have the proper keto diet for dogs outlined in the linked article. No matter what type of therapy you use to treat, this food should be used.
Pancreatic cancer has also been treated in humans with ivermectin in addition to conventional chemotherapies.
Ivermectin Is Not a Proven Alternative, but It May Help
Lymphoma, osteosarcoma, and hemangiosarcomas are common cancers in dogs but still have no evidence that ivermectin will be effective. It is a good idea to put any dog diagnosed with one of these cancers on conventional treatments and a ketogenic diet so that the tumor cells will not have the type of sugar they need to survive.
I do not want this article to give the impression that ivermectin is a well-accepted and proven alternative. If you want to try ivermectin to treat your dog's cancer, you can find a chart where I list ivermectin doses based on your dog's weight.
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. doi: 10.1186/s12917-019-2026-2. PMID: 31375107; PMCID: PMC6679554. 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. doi: 10.1016/j.phrs.2020.105207. Epub 2020 Sep 21. PMID: 32971268; PMCID: PMC7505114. https://pmc.ncbi.nlm.nih.gov/articles/PMC7505114/
Seyfried TN, Mukherjee P, Lee DC, Ta L, Nations L. Case report: Resolution of malignant canine mast cell tumor using ketogenic metabolic therapy alone. Front Nutr. 2023 Mar 28;10:1157517. doi: 10.3389/fnut.2023.1157517. PMID: 37057065; PMCID: PMC10086349. https://pmc.ncbi.nlm.nih.gov/articles/PMC10086349/
