Pet Care Articles
Back to main articles list...
Cancer in Cats
While I don't regularly see cancer in cats as much as I do in dogs, cats certainly can and do develop various forms of cancer. In my integrative medicine practice, the three most common types of cancer I see are squamous cell carcinoma (SCC,) lymphoma (LSA,) and vaccine associated sarcoma (VAS.) This article will discuss these three types of cancer as well as offer some tips on treatment and prevention.
Squamous cell carcinoma (SCC)
Squamous cell carcinoma is the most common feline skin cancer that 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 on the tips of the ears. Because it is a cancer that can be induced and exacerbated by ultraviolet light, light haired outdoor cats are more commonly affected with involvement of the tips of the ears and the nose.
Squamous cell carcinoma occurring in the mouth of cats is easy to diagnose but is often not found until later in the course of the disease when they cancer has become more aggressive and more difficult to treat or cure. I have found his cancer in the oral cavity of cats who were acting normally but presented for a routine dental cleaning; the tumor was found on the gums, palate, or tongue when the teeth were being cleaned.
Clinical signs of SCC include any be erosive or ulcerative skin disease, especially an erosion are all server that does not heal within a few weeks despite proper therapy. Lesions of the well-known eosinophilic granuloma complex may be mistaken for SCC; any eosinophilic lesions which do not resolve proper therapy should be biopsied to rule out the presence of SCC.
Clinical signs of SCC in the oral cavity can include reduced appetite, reluctance to eat on the affected side of the mouth, drooling, bloody discharge in the mouth, and they foul odor from the mouth. As previously mentioned, this form of SCC is often not diagnosed until the oral cavity is examined for another reason such as a dental cleaning.
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 of the oral cavity that are small and caught early might also be cured surgically or with radiation therapy. However, since most of these lesions are not diagnosed until they become aggressive, treatment is often palliative until the cat is euthanized due to a poor quality of life.
Integrative therapy using specific herbs and homeopathics may also help to control SCC. I have the best results when treating pets with cancer by combining both alternative therapies and conventional therapies.
Lymphoma occurs when normal lymphocytes, white blood cells important in the immune system, become cancerous. There are several forms of lymphoma, and each form refers to the body system affected. In kittens and young cats, mediastinal lymphoma is more common. Cats with this form of lymphoma develop a solid tumor in the chest cavity. Cats with generalized lymphoma can develop tumors anywhere in their bodies; most commonly they developed the kidneys, nervous system (especially spinal cord) and eyes. The alimentary form of lymphosarcoma, the most common that I see in practice, develops in the gastrointestinal system. This form of LSA often develops after chronic and unsuccessfully treated inflammatory bowel disease (IBD,) reinforcing the need for prompt diagnosis and treatment of all cats with IBD.
Clinical signs of LSA depend upon the tissue involved. Cats with mediastinal LSA often develop difficulty breathing due to the presence of the tumor within the chest cavity or fluid developing in the chest cavity. Cats with generalized LSA can develop kidney failure, blindness, or varying degrees of paralysis depending upon which organ system is involved. Cats with alimentary LSA usually develop some combination of vomiting, diarrhea, and or weight loss. It is extremely important that cats which vomit (especially if hairballs are not vomited,) show a change in fecal consistency, or have unexplained weight loss be evaluated for IBD and LSA. Diagnosis involves a variety of best depending upon the form of LSA that is present, and can include a complete blood profile, urinalysis, radiographs, ultrasound, MRI, CT scan, and endoscopic examination and biopsy.
Therapy involves a combination of chemotherapy and herbs, homeopathics, and nutritional supplements. In general, cats do not respond as favorably to treatment of lymphoma as do dogs with the same disease. Complete response rates range from 50 to 70% with combination chemotherapy, and survival is reported to be around six months. However, those cats that do respond to chemotherapy may live one year or longer. The more guarded prognosis in cats compared to dogs may be due to several factors, including: 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 using this drug appears to increase response rates.) Certainly an integrative approach combining alternative therapies with chemotherapy tends to produce a better response than in pets treated 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 (most commonly high doses of corticosteroids such as prednisone) and alternative treatments.
Vaccine associated sarcoma (VAS)
Vaccine associated sarcoma is probably the most common cancer that I see in my feline patients. As the name implies, VAS is a solid tumor of the subcutaneous tissues anywhere on the cat's body caused by vaccination. 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, having first been 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 began as small pea sized lumps usually between his 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 (which is 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: a small lump you feel is the head in the arms containing cancer cells stretch out some distance from the tumor. Preoperative assessment of the spread of the tumor is usually done with an MRI or CT scan.
Many cats with VAS can live for several years following the initial diagnosis when an aggressive protocol of surgery, chemotherapy, radiation therapy, and alternative therapies are used.
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. However, high doses of omega-3 fatty acids, antioxidants such as vitamins A, C, and E, coenzyme Q-10, Echinacea, Astragalus, medicinal mushrooms, DMG, and various homeopathics may all be helpful. Specific therapies targeting affected organs (such as probiotics, enzymes, and the amino acid glutamine for cats with intestinal lymphoma) are also indicated in the integrative treatment of cats with cancer. No cat with cancer should ever receive further immunizations as this may bring the pet out of remission.
Copyright 2007, Paws & Claws Animal Hospital, All Right Reserved