Veterinary Oncology

Oncological diseases in dogs and cats

Oncology in veterinary medicine is a growing field: tumors are very frequent and for their correct diagnosis and treatment it is necessary to have a solid scientific knowledge.

Cancer in dogs and cats: general aspects

Cancer is the most important cause of death in dogs and cats. Oncology is the branch of medicine that deals with the diagnosis and treatment of cancer and, in recent years, has become very important in veterinary medicine; diagnostic techniques have been refined and more specific therapies are now available for both dogs and cats. Furthermore, the awareness of owners for oncological diseases has increased and, consequently, the need for specialized services.

Currently, the most frequent tumors of dogs and cats are those that affect the skin, such as the mastocytoma. Skin tumors, being superficial, are relatively easy to identify: usually the owner notices a lump by visual inspection or palpation. Another very common tumor is the lymphoma, which in dogs often leads to an enlargement of the palpable lymph nodes (such as submandibular). Lymphoma is also the most frequent tumor of the cat, but usually in this species affects the gastrointestinal tract and may be more difficult to diagnose. Unfortunately, many cancers can originate from the internal organs and the owner has just the perception that there is "something wrong" in his pet. For this reason, regular checkups performed by the veterinarian can help to early diagnose the disease. All breeds of dogs and cats can develop any type of cancer, although some breeds are more susceptible to certain cancers. For example, in dogs the Boxer and Pug are predisposed to mastocytoma, Scottish Terrier to bladder cancer and Flat Coated Retriever to histiocytic tumors. As in humans, hereditary and environmental factors contribute to the development of tumors also in dogs and cats.

Clinical signs in dogs and cats with cancer

Cancers can present in many ways: from single and clearly visible masses on the dog’s or cat’s body, to more insidious and less obvious appearance if affecting internal organs. In general, there are 10 clinical signs that owners and veterinarians should take into consideration. They are not specific for cancer, but, if present, certainly deserve attention.

1. Each nodule that was recently observed or that, if present for some time, has changed shape or size; in these cases it is extremely important to perform a cytological or histological examination in order to determine the characteristics of each nodule. Visual inspection and palpation are not able to differentiate between benign and malignant nodules.

2. Any wound or ulcer that does not heal with standard treatments.

3. Changes in urination or defecation habits, such as incontinence or persistent diarrhea.

4. Difficulties during urination or defecation, either with gradual or rapid onset.

5. Chewing and swallowing difficulties.

6. Bleeding without obvious cause from any part of the body (such as from the nose).

7. Loss of appetite and weight loss.

8. Breathing difficulty or persistent cough.

9. Lameness or limb stiffness.

10. Halitosis and loss of saliva or blood from the mouth.

Blood tests can also lead to suspect cancer; for instance, certain leukemias may cause anemia or increase the number of white blood cells.

Treatment options and quality of life

Many treatment options currently available for dogs and cats with cancer are similar to those used in humans. Among the most common therapies to treat cancer are chemotherapy, surgery, radiotherapy and molecular targeted therapy; therapeutic protocols often involve the combination of more approaches (multimodal treatment). Some cancers can be cured, for others palliative treatment is only possible, but the goal is always one: quality of life, either in dogs or cats. This philosophy is the basis for all therapeutic choices made by our oncologist. It is important to realize that what makes our animals with cancer sick is the tumor itself, not therapy; hence, therapies should be given according to the type of patient and his individual needs, but also in light of the economic possibilities of the owner. It is important to stress that if the treatment is effective against the tumor, sick dogs and cats often return to benefit from a good quality of life, as if they were healthy.

Oncology at our Veterinary Clinic

The Istituto Veterinario di Novara offers consultations for the diagnosis, staging and treatment of dogs and cats affected by cancer. The tight collaboration between specialists allows our institution to provide the most suitable and tailored treatment for each individual case.

Responsible of the specialistic department: Dr. Chiara Leo, MSc, FHEA, Dipl. ACVIM (Oncology)  
Collaborators:  Dr. Livia Ferro , Dr. Niccolò Rigon





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