Causes of Lymphosarcoma in Dogs
Vets don't really understand what causes canine lymphosarcoma. Some breeds, such as Boxers, appear to be more prone to lymphosarcoma than others. Some vets think that excessive exposure to UV rays can contribute to lymphosarcoma. Long term exposure to second hand cigarette smoke, exposure to environmental toxins or infection by certain viruses or bacteria may all play a role in the development of lymphosarcoma in dogs. Most dogs develop this type of cancer at the age of eight to ten years.
Lymphosarcoma Symptoms
Since this type of cancer can affect different parts of your dog's body, his symptoms may vary depending on where the cancer is located. General symptoms of canine lymphosarcoma include:
- Lethargy
- Weight loss
- Decreased appetite
- Swelling of the lymph nodes in the groin, neck, chest and armpit
More specific symptoms include diarrhea and vomiting in the case of gastrointestinal tumors. If tumors are located in your dog's stomach, he may become short of breath. Tumors of the skin can cause excessive itching.
Diagnosing Lymphosarcoma in Dogs
Your vet will need a complete medical history and a thorough physical exam in order to diagnose canine lymphosarcoma. Your vet may be able to feel your dog's cancerous tumors during a physical exam. If your dog's lymph nodes are swollen, your vet may remove cells for biopsy via a fine needle aspiration. Because the symptoms of lymphosarcoma can be so vague, your vet will almost certainly need to take tissue samples in order to diagnose your dog's cancer.
Treating Canine Lymphosarcoma
The most popular treatment for canine lymphosarcoma is chemotherapy. Most dogs do well on chemotherapy, and don't experience very many side effects. Less than ten percent of dogs require medical treatment for the side effects of chemotherapy, and most continue to enjoy a good quality of life. Your vet may prescribe multiple chemotherapy drugs to help drive your dog's cancer into remission.
Popular drugs used in the treatment of lymphosarcoma include prednisone, doxorubicin, cyclophosphamide and vincristine. Vets use a number of different chemotherapy treatments against canine lymphosarcoma; remission rates can vary widely and each drug protocol carries its own risks. However, on average, about 75% of dogs with lymphosarcoma achieve temporary or permanent remission no matter what drug protocol the dog's vet and owner decide to use. Some treatment plans may last for as long as one year.
Canine Lymphosarcoma Prognosis
Many dogs respond well to chemotherapy treatment and go into remission. On average, 65 to 95% of dogs experience a remission of about six months, depending on the combination of drugs your vet has prescribed, the length of chemotherapy and the progress of your dog's cancer. Lymphosarcoma may come back, but dogs who have experienced a first remission are more likely to experience a second remission. A second remission typically lasts for 10 to 12 months.