Blog

11.16.2010

 

November is Cancer Awareness Month, You CAN make a difference!

Brenda Phillips, DVM, ACVIM (Medical Oncology), Blaise Burke, DVM, ACVR (Radiation Oncology)

Cancer (neoplasia) is reported to be a leading cause of death in dogs and cats. Though cancer can be challenging to treat, early detection can improve the prognosis.

 10 Common Signs of Neoplasia in Small Animals*

1. Abnormal swellings that persist or continue to grow; NOTE: while cancer is often an asymmetrical disease, lymphoma is a cancer that often occurs on both sides of the body. Therefore, even symmetrical swellings should not be ignored.
2. Sores that do not heal
3. Weight loss 
4. Loss of appetite, or increased/decreased water intake
5. Bleeding or discharge from any body opening
6. Offensive odor 
7. Difficulty eating or swallowing
8. Hesitation to exercise or loss of stamina 
9. Persistent lameness or stiffness
10. Abnormal urination (including increased urine volumes), breathing, defecation

Many of the above signs are also seen with non-cancerous medical conditions. Observation of any of these symptoms warrants prompt examination by a veterinarian to determine the cause. 

 Common Types of Neoplasia in Small Animals* 

1. Skin - Skin tumors are very common in older dogs, but much less common in cats. While skin tumors in cats are frequently malignant, in dogs they are often benign. Fine needle aspiration cytology is a simple, non-invasive technique that may be used to differentiate between benign versus malignant skin tumors. Relying on physical examination of skin tumors alone is an imprecise method and unfortunately can allow malignant masses to go undetected. Please see the handout entitled “Fine Needle Aspiration Cytology” available on our website for further information about cytology and cancer diagnosis.
2. Mammary Gland (Breast) - 50% of all breast tumors in dogs and greater than 85% of all breast tumors in cats are malignant. Spaying your female pet before her first heat cycle will greatly reduce the risk of mammary gland cancer.
3. Head & Neck - Neoplasia of the mouth and nose; signs to watch for are a mass or tumor in the oral cavity, bleeding, excess salivation, odor, facial swelling or deformity, or difficulty eating.
4. Lymphoma - Lymphoma is a common type of neoplasia in dogs and cats. It is characterized by enlargement of one or many lymph nodes in the body.
5. Abdominal Tumors - Tumors inside the abdomen are common but their location makes them difficult to diagnose early. Weight loss, loss of stamina, loss of appetite, or abdominal swelling are signs associated with these tumors.
6. Bone - Bone tumors are most often seen in large breed dogs and dogs older than seven years, and rarely in cats. Persistent limb pain, lameness, and swelling in the affected area are signs of the disease.  

* Adapted from the website of the American Veterinary Medical Association

 What else can you do to facilitate early cancer detection?

While the cause of many cancers in pets is unknown, sunlight is a common cause of cancer in dogs and cats in Southern California. Solar-induced cancers, often squamous cell carcinoma or hemangioma/hemangiosarcoma, are commonly noted on the underside and inner limbs of dogs and the nose, lips, eyelids, and ears of cats.  

• These cancers occur in dogs and cats in body regions with limited pigmentation (pink skin) and thin hair. In the early stages, sun-induced cancers can appear as a minor crusting or ulceration, and may look like a simple wound rather than a swelling or nodule.  
• If your dog or cat develops skin lesions as noted above, have a veterinary exam.
• It is recommended that pets with thin hair and light pigment anywhere on their body have extremely limited sun exposure throughout their lifetime to decrease the likelihood of development of this type of cancer.  

Routine veterinary exams are an integral part of general health evaluation and early cancer detection. Your family veterinarian is the best one to recommend the frequency of examinations, but typically this is annually for patients < 7 years of age and may be twice yearly for patients > 7 years. Your veterinarian may also recommend laboratory diagnostics and imaging such as radiography (x-ray) or ultrasonography (sonogram) as regular health monitoring tools for mature veterinary patients.

Examine your pet thoroughly every month, including obtaining a body weight if possible; keep a record of exam notes and body weights for later reference and to identify health trends. If your pet will allow you to safely examine their mouth, this should be done as well. The mouth is a common site of malignant cancers that unfortunately often go undetected until they are very advanced. You know your pet best; take changes in your pet’s health or examination status seriously enough to have an examination performed by your family veterinarian when they are noted.  

Donations to animal health organizations are a direct way to help veterinarians find better ways to detect and treat cancer in our beloved pets.

• American College of Veterinary Internal Medicine Foundation
• Morris Animal Foundation
• Veterinary Cancer Society