Find out which forms of this disease are most prevalent in felines, and how you can protect your own kitty.

Let’s start with the good news. Cancer isn’t as common in cats as it is in dogs. But they certainly can and do develop various forms of the disease. In my own integrative medicine practice, the three most common cancers I see in felines are squamous cell carcinoma, lymphoma, and vaccine associated sarcoma. In this article, I’ll discuss these three types and offer some tips on treatment and prevention.

1. Squamous cell carcinoma (SCC)

This is the most common feline skin cancer I see in practice. It can occur anywhere on the body (as skin cells are squamous cells) but is usually found in the mouth, on the nose and the tips of the ears. Because it can be induced and exacerbated by ultraviolet light, light-haired outdoor cats are more commonly affected, with involvement of the ear tips and the nose.

Squamous cell carcinoma in the mouth is easy to diagnose but is often not found until later in the course of the disease, when the cancer has become more aggressive and difficult to treat or cure. I have found this cancer in the mouths of cats who were acting normally and just in for a routine dental cleaning; the tumors were found on the gums, palate or tongue during the cleaning procedure.

Clinical signs of SCC include any erosive or ulcerative skin lesions, especially those that do not heal within a few weeks despite proper therapy. Other symptoms can include reduced appetite, reluctance to eat on the affected side of the mouth, drooling, bloody discharge in the mouth, and a foul odor. Lesions of the well-known eosinophilic granuloma complex may be mistaken for SCC; any eosinophilic lesions that do not resolve with treatment should be biopsied to rule out SCC.

If diagnosed early, squamous cell carcinoma can be cured. Small lesions on the tips of the ears can be removed surgically. Lesions on the nose might be cured with surgery if they are not too large. Larger lesions might be controlled or even cured with  radiation therapy or cryotherapy (freezing the lesion). Lesions in the oral cavity that are small and caught early might also be cured surgically or with radiation therapy. However, since most oral lesions are not diagnosed until they become aggressive, treatment is often palliative until the cat is euthanized due to a poor quality of life.

2. Lymphoma (LSA)

This form of cancer occurs when normal lymphocytes, white blood cells important in the immune system, become cancerous. There are several forms of lymphoma, and each refers to the body system affected.

  • In kittens and young cats, mediastinal lymphoma is more common. Cats with this form develop a solid tumor in the chest cavity. Symptoms may include difficulty breathing due to the tumor or fluid developing in the chest cavity.
  • Cats with generalized lymphoma can develop tumors anywhere in their bodies, most commonly in the kidneys, nervous system (especially spinal cord) and eyes. Depending on which organ system is involved, symptoms can include kidney failure, blindness or varying degrees of paralysis.
  • The alimentary form of lymphosarcoma develops in the gastrointestinal system and is the most common I see in practice. It often develops after chronic and unsuccessfully treated inflammatory bowel disease (IBD). Cats with alimentary LSA usually develop some combination of vomiting, diarrhea and/or weight loss. It is extremely important that cats who vomit (especially without hairballs), show a change in fecal consistency, or have unexplained weight loss be evaluated for IBD and LSA.

Diagnosis involves a variety of tests depending on the form of LSA, and can include a complete blood profile, urinalysis, radiographs, ultrasound, MRI, CT scan, and en- doscopic examination and biopsy.

Therapy involves a combination of chemotherapy and herbs, homeopathics, and nutritional supplements. In general, cats do not respond as favorably to lymphoma treatment as do dogs. This more guarded prognosis may be due to several fac- tors: many cats are diagnosed later in the course of the disease; many cats with lymphoma test positive for feline leukemia virus; anatomic location of the disease; and whether or not the chemotherapy drug doxorubicin is used (this drug appears to increase response rates).

In cats, complete response rates range from 50% to 70% with combination chemotherapy, and survival is around six months. Cats that do respond to chemotherapy may live one year or longer. An integrative approach combining alternative therapies with chemotherapy tends to produce a better response than with chemotherapy alone.

Since improperly treated IBD can progress to intestinal LSA, all cats with IBD must be treated aggressively with a combination of conventional medications and alternative treatments.

3. Vaccine associated sarcoma (VAS)

This is probably the most common cancer I see in my feline patients. As the name implies, VAS is caused by vaccination and presents as a solid tumor of the subcutaneous tissues anywhere on the cat’s body. While any injection has the potential to induce a VAS, this type of sarcoma is usually linked to a prior vaccination at the site of the tumor.

VAS is a relatively new cancer. It was first discovered about 15 years ago as increasing numbers of cats received annual vaccinations for rabies and feline leukemia virus. The exact cause is not known, and certainly most cats that receive vaccinations do not develop VAS. It is theorized that VAS develops in genetically predisposed cats that develop chronic inflammation which becomes neoplastic (cancerous) after immunization. These tumors begin as small pea sized lumps usually between the shoulder blades or over the round, common sites for vaccination. If not diagnosed and treated early, they can become quite large, making successful treatment difficult if not impossible.

Conventional treatment involves a combination of surgery (both diagnostic and therapeutic), radiation therapy, and chemotherapy. Aggressive surgery is necessary to remove as much of the tumor as possible. This type of cancer is known for spreading out some distance from the initial tumor. In effect, a VAS is like an octopus: the small lump is the head but the arms containing cancer cells stretch out some distance from the tumor. Preoperative assessment of the tumor’s spread is usually done with an MRI or CT scan.

Many cats with VAS can live several years following the initial diagnosis when an aggressive protocol of surgery, chemotherapy, radiation therapy, and alternative therapies is used.

Integrative therapies

Integrative therapy for any of these cancers involves judicious use of immune-enhancing herbs, homeopathics, and nutritional supplements. It is beyond the scope of this article to detail every type of alternative therapy but the following may all be helpful:

  • high doses of omega-3 fatty acids
  • antioxidants such as vitamins A, C and E
  • coenzyme Q10
  • Echinacea
  • astragalus
  • medicinal mushrooms
  • DMG
  • various homeopathics

Specific therapies targeting affected organs (such as probiotics, enzymes, and the amino acid glutamine for intestinal lymphoma) are also indicated in the integrative treatment of cats with cancer. And no cat with cancer should ever receive further immunizations, as this may bring him out of remission.

Cancer is a scary disease, but a healthy lifestyle and early diagnosis can greatly reduce your feline friend’s chances of getting sick.

Prevention points

To help prevent your cat from developing cancer, follow these seven steps.

  1. Feed him a high quality, natural whole foods diet free of artificial additives and by-products.
  2. Give him only pure, filtered water.
  3. Minimize vaccines.
  4. Prevent exposure to pesticides and as many other environmental toxins as possible.
  5. Reduce stress.
  6. Schedule regular veterinary checkups.
  7. Make sure he gets adequate exercise.