Cancer: The dreaded diagnosis
Cancer.
It’s the word that no pet owner ever wants to hear — but sadly, it’s a word that I’ve just heard about my beloved 13-year-old dog Joey. He’s not alone: over half of dogs over the age of 10 will develop cancer, which is now the leading cause of death in dogs older than 2 years.
That’s the bad news.
The good news is that 50% of all canine cancers are treatable if they’re caught early. (One more reason to make sure your dog has annual veterinary wellness checkups.) So, what exactly is cancer?
Put simply, cancer is a disease in which abnormal cells divide and grow uncontrollably. Cancers can be either malignant (fastgrowing, often invading surrounding tissue and metastasizing — spreading — to other organs) or benign (very slow- growing and non-invasive.).
Dogs can develop many of the same types of cancers as humans: internal cancers such as lung, kidney, liver, bladder and brain, as well as external cancers like melanoma. Interestingly, dogs are the only non-human mammals that can develop aggressive prostate cancer.
While there’s no absolute causal link for every type of cancer, studies have shown exposure to certain environmental toxins such as cigarette smoke, pesticides, insecticides, herbicides, air and water pollution can contribute to the development of cancers in both humans and dogs.
Let’s look at the most common types of cancers in dogs. Lymphoma, often appearing as swollen lymph nodes under the jaw, in front of the shoulders, or behind the knees, although it can also attack lymph nodes in the chest or abdomen. This type of cancer is considered highly treatable.
Mast cell tumors typically form on the skin and can range from benign to very aggressive. Surgical removal is necessary, and unless the cancer has spread to multiple sites, prognosis is excellent.
Osteosarcoma is the most common and most deadly bone cancer in dogs, as it spreads extremely rapidly to the lungs, lymph nodes and other bones.
Amputation of the affected limb followed by chemotherapy is usually recommended; even so, most victims of this cancer seldom live longer than three years.
Mammary gland carcinoma is the most common tumor in unspayed female dogs. While many of these cancers can be cured with surgical removal, half of malignant masses will be fatal.
One of the worst and most-feared types of cancers in dogs is the hemangiosarcoma, which is also the most stealthy when it attacks the spleen. Dogs with splenic hemangiosarcoma rarely show any signs of illness until the tumor ruptures, causing extreme blood loss, collapse, shock and death. This can occur so suddenly that there’s little time to get the dog to emergency care. Golden Retrievers are particularly susceptible to hemangiosarcoma, with one in five goldens having a lifetime risk of developing it.
If your dog has been diagnosed with cancer, ask your vet or oncologist these questions:
• What treatments are available, and which one would you recommend?
• What is the prognosis with this treatment?
• What are the side effects of this treatment, and how will they affect my dog’s quality of life?
• Will this treatment actually cure my dog’s cancer?
• What is the cost of this treatment?
That last question is the one that usually creates the most guilt, as most of us recoil from the idea of making a decision about our beloved dog’s life based on cost — but we live in the real world, where money is a very real issue. Take everything, including your finances, into consideration when deciding on whether treatment makes sense, or if the best course of action is simply making your dog’s last months or years the happiest and most comfortable they can be.
Joan Merriam lives in Nevada County with her golden retriever Joey, her Maine coon cat Indy and the abiding spirit of her beloved golden retriever Casey in whose memory this column is named. You can reach Joan at joan@ joanmerriam.com. And if you’re looking for a golden, be sure to check out Homeward Bound Golden Retriever Rescue.