Signs of cancer in dogs include lumps, swelling, persistent sores, and abnormal discharge and odors, states the American Society for the Prevention of Cruelty to Animals. Other symptoms are lethargy, weight loss, black stools, and difficulty breathing, urinating or defecating.
Veterinarians diagnose canine cancer by doing a biopsy if a lump is present, as well as by taking X-rays, ultrasounds and blood tests, according to the ASPCA. Treatment options often include surgical removal of the tumor, states DogHealth.com. However, cancer may require chemotherapy or radiation.
Lymphoma is one of the most common types of tumors in dogs, per DogHealth.com. Symptoms of lymphoma in dogs include swelling of the lymph nodes, difficulty breathing, vomiting and diarrhea. Other types of tumors include osteosarcoma, a tumor found in the bones; mast cell tumor, a tumor found on the skin; and mammary carcinoma, a tumor found in the mammary gland.
Cancer is more likely in older dogs than younger ones, states the ASCPA. Large breeds are more likely to develop bone cancers, while boxers, Boston terriers, and golden retrievers are most likely to get mast cell tumors. Golden retrievers are also more prone to canine lymphoma due to their genetics, states DogHealth.com.
Although not all cancers can be prevented, certain measures can reduce the probability of cancer, reports the ASPCA. Having dogs fixed at an early age can help prevent canine breast and testicular cancer. In fact, having a female dog spayed before her first heat cycle can almost eliminate the risk of developing breast cancer.