Cancer: The #1 killer of dogs | Dr. Justine Lee

Posted by justinelee in Animal Safety, Blog, Pet Health, Pet Help

One of the toughest parts of working in the ER is the constant barrage of bad news that one has to deliver. Unfortunately, cancer is one of the top causes for presentation to the veterinary ER, and the leading cause of death in dogs in the United States.

Having lost my own beloved pit bull, JP, to a brain tumor, my heart now breaks whenever I tell pet owners that their dog or cat has cancer.

In the emergency room, the most common type of cancer that I see is hemangiosarcoma. This is a very aggressive type of cancer that loves bloody organs: the spleen, liver, heart, and blood vessels. This vascular tumor often results in acute internal bleeding in popular, large breed dogs like Golden retrievers, Labrador retrievers, German shepherd dogs, and mixed breed dogs.

Unfortunately, hemangiosarcoma is a type of cancer that manifests acutely. In other words, one day your dog is normal, and the next day he may present acutely collapsed and be diagnosed with metastatic cancer.

When cancer invades normal tissue, it destroys the blood flow to that area, and can result in necrosis. This may result in rupture of the tumor. With hemangiosarcoma, rupture of the tumor results in severe internal bleeding secondary to a ruptured organ (typically on the spleen). Clinical signs of internal bleeding include:

• Panting excessively
• Acute collapse/generalized malaise
• Weakness/inability to get up
• Pale gums
• Vomiting
• Signs of shock (e.g., elevated heart rate, pale gums, a low blood pressure)
• Increased thirst
• Inappetance/anorexia
• A distended abdomen
• Acute death

When this occurs, an emergency trip to the veterinarian is imperative. Immediate treatment and stabilization is necessary, including IV fluids, IV protein, and blood transfusions. Once a patient is stabilized, surgical removal of the bleeding tumor can be performed. However, the prognosis – even with surgery and chemotherapy – is quite poor, with the average survival being days to months (typically 1-6 months).

So what can a pet owner do? While it may be very difficult, one can arm themselves by trying to pick up on the warning signs of cancer earlier. Colorado State University Animal Cancer Center provides some clues to watch for when it comes to early cancer detection:

• Weight loss
• Not eating
• Generalized malaise/lethargy
• Abnormal swelling that persists or continue to grow
• Sores that do not heal
• Offensive odor (which may be due to a tumor in the nose, mouth, or rectal area)
• Difficulty eating or swallowing
• Bleeding or discharge from any body opening
• Exercise intolerance, hesitation to exercise, or loss of stamina
• Persistent lameness (which may be due to bone, nerve or muscle cancer)
• Difficulty breathing, urinating or defecating
• Constant coughing
• Hiding

As with any disease, the sooner you or your veterinarian pick it up, the sooner you can diagnose and treat it, and the better the potential prognosis. Monitor for these subtle signs of your pet’s illness.

My general advice to pet owners with geriatric pets? Skip the vaccines this year, but still get an annual exam. Instead of the vaccines, I’d talk to your veterinarian about doing baseline geriatric screening blood work once a year instead. Other diagnostics like x-rays and abdominal ultrasound are also possible, but I generally don’t recommend this unless there are clinical signs to worry about. Again, the sooner you diagnose a problem, the sooner it can often times be fixed.

If your pet was just diagnosed with cancer, don’t beat yourself up– dogs and cats are so stoic, that they often don’t show signs of illness until the disease or cancer is quite advanced. That said, be on the look out for these subtle signs as your pet ages.

If your pet was diagnosed with cancer, know that you have many options and factors to consider. Some options include seeking a veterinary oncologist’s opinion (BTW, just because you make an appointment with an oncologist doesn’t commit you to having to do chemotherapy! It just lets you learn about your options, which I always recommend!), doing palliative care, keeping your pet on pain medication, humane euthanasia, or more aggressive in treatment (options like include surgery, chemotherapy, or radiation therapy, etc.). When in doubt, talk to your family, your veterinarian, and your veterinary specialist to find the best option for you and your pet.

Part of this blog was previously published on www.PetHealthNetwork.com.

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