With cancer blamed for as many as half of the canine and feline deaths in the U.S., veterinarians and owners are looking for solutions and are more frequently turning to supplements.
As veterinarians find clinical evidence to support aggressive supplement use, organizations like Morris Animal Foundation and the American Kennel Club are on board as well.
“My colleague Cheryl London is investigating the use of curcumin, a derivative of the popular Indian spice turmeric and has Morris funding,” says Ohio State University professor C. Guillermo Couto, DVM, Dipl. ACVIM. “Her research is separate from mine, but we are both investigating ways supplements can affect osteosarcoma.” London, DVM, Ph.D., Dipl. ACVIM (Oncology), also is an Ohio State professor.
Dr. Couto is clinically evaluating the effects of artemisinin, also known as sweet wormwood, an herb that has killed human and canine cancer cells in the laboratory.
“From what we’ve found with its effectiveness in test tubes, it should be achievable to arrest the cancer cell cycle of dogs with osteosarcomas,” Coutou says. “Incubation with dihydroartemisinin—the active metabolite of all artemisinin compounds—resulted in biological activity against canine osteosarcoma cell lines, which included induction of apoptosis and arrest of the cell cycle.”
In a separate but related study, Couto worked with the AKC in testing artemisinin on dogs diagnosed with cancer.
“We gave 20 dogs two different treatments using artemisinin and only one dog had a modest response,” he says. “We found the animals weren’t achieving the blood levels necessary to make a significant difference in their disease. We essentially were not giving a large enough dose and plan on conducting additional studies.”
Coutou says absorption and metabolism may affect the use of artemisinin and could explain the difference between what was found in osteosarcoma canine cell lines and canine patients.
Osteosarcoma is the most common primary bone tumor in dogs, accounting for about 85 percent of all bone tumors, says Dr. London, who notes that more than 10,000 new canine cases are diagnosed each year.
Osteosarcoma commonly affects Rottweilers, greyhounds, Scottish deerhounds and golden retrievers. London’s research was spurred because traditional treatment hasn’t substantially improved in the past 15 years and involves removal of the tumor, usually through limb amputation, followed by chemotherapy.
Despite this aggressive approach, most patients don’t survive longer than two years after treatment because the tumor metastasizes to the dog’s lungs. However, Ohio State researchers have shown that STAT3, a protein important in a tumor cell’s ability to metastasize and resist chemotherapy, is essential for cancer cell survival. Curcumin, a component of the spice turmeric, inhibits STAT3 but is not well absorbed after ingestion.
According to Morris Animal Foundation, researchers are evaluating a curcumin-derived compound developed at OSU for its ability to kill osteosarcoma cells. The compound and other compounds that target STAT3 represent cutting-edge research that could positively affect disease treatment in the future.
Charles Loops, DVM, of Pittsboro, N.C., says using efficacious, quality supplements is a priority.
“Two-thirds of my practice is consulting with owners of animals with cancer, by veterinary referral or word of mouth,” Dr. Loops says. “I don’t carry a lot of the supplements that I recommend, but I do give clients names of reliable places they can find the supplements.”
Americans spent $1.4 billion in 2008 on supplements for animals.
“Some clients want to purchase supplements from wholesale stores, but there is little regulation and you don’t know what’s in it,” says Carmine Bausone, DVM, of Acacia Animal Health Center in Escondido, Calif.
“It is better to purchase supplements created for animals when that is the patient they are intended for. I carry everything I prescribe to patients or suggest they purchase the supplement carrying the NASC label. Some supplements, especially Chinese herbs, may carry high levels of lead, mercury or other toxins, depending on where they are grown.”
The National Animal Supplement Council (NASC) is a non-profit trade organization comprising companies providing health and nutritional supplements that comply with a set of guidelines set by NASC for good manufacturing practices. While membership and compliance with the organization is optional, creating a regulatory environment that is fair, reasonable, responsible and nationally consistent is the council’s goal.
“When the FDA sends a warning letter to a company, it means business,” says Bill Bookout, president of the NASC. “If a company has false claims on its website or label, the FDA will take action against it to protect consumers and their pets.”
Bookout says a rule of thumb when looking at supplement labels is that if the claims seem to be too good to be true, they probably are; and cheap products are usually cheap for a reason.
Using supplements as part of pharmaceuticals, surgery or chemotherapy is the route many pet owners go, Loops says.
“I treat a lot of animals in conjunction with the use of chemo-therapy,” Loops says. “Radiation is performed by specialists who usually prefer that supplements aren’t given during the treatment. This preference is largely because oncologists don’t understand how to properly use supplements, but that is pretty common even with the American Veterinary Medical Association.”
Loops says cancer is commonly found in older animals, but after 30 years in practice he’s seeing more young patients than ever.
“Many veterinarians who use supplements in practice also push a healthier diet. Lena McCullough, DVM, CVA, of Seattle, helps identify the right diet and supplement combination for her cancer patients.
Dr. McCullough serves as a referral veterinarian to practitioners who make a cancer diagnosis but need diet and supplementation support.
“Some poor dogs come in on 20 supplements because the owner doesn’t realize you can have too much of a good thing,” McCullough says. “I consult with the owner to find what their expectations are with treatment, then go from there to determine the course of action.
“Most of the patients I work with are either also using conventional drugs, had an adverse effect to conventional treatments or aren’t good candidates for harsher treatments. There isn’t one program that fits every cancer patient. Each supplement and treatment plan needs to be individualized.”
Just as many pet owners’ interest in animal supplements stems from their use of supplements, so did veterinarian Melissa Shelton’s decision to incorporate supplements into her practice.
“After veterinary school I practiced traditional medicine for about eight years,” says Shelton, DVM, the owner of Crow River Animal Hospital in Howard Lake, Minn. “I was frustrated with the lack of response patients had to traditional drugs and started thinking, ‘Well, it works for me, why not dogs and cats?’ ”
Shelton recommends glucosamine for puppies to prevent the onset of joint problems later in life. The same theory exists with preventing cancer and other diseases.
“I recommend whole-food supplements and essential oils,” Shelton says. “I’d rather clients put money into disease prevention instead of paying to try to slow it down once the animal has it. There is a role for supplements at every life stage. Even animals in hospice care can benefit. I might add pain medications or something to help reduce stomach upset, but supplements can help an animal have more quality days toward the end, too.”
Alice Villalobos, DVM, PNAP, says most veterinarians who provide supplements for cancer patients aim to temper cancer’s fatal agenda using natural substances that inhibit common cancer pathways.
“Supplements may inhibit angiogenesis, proliferation and metastasis or encourage the destruction of cancer cells by accelerating apoptosis,” Villalobos says. “In addition, some supplements such as beta glucans from mushrooms have been shown to increase the surveillance functions of the immune system to improve recognition and destruction of cancer cells.”
This article first appeared in the July 2010 issue of Veterinary Practice News. Click here to become a subscriber.