What Are The Early Signs of Cancer in Dogs?

Hopefully, you’ll never be faced with a cancer diagnosis for your dog, but unfortunately, it is a relatively common situation for many pet parents. So we’re sharing pet cancer signs to help you recognize when something may be amiss with your dog’s health — especially as early detection and treatment gives your dog the best hope for remission or even a cure.

Can Dogs Get Cancer?

Yes, dogs can develop cancer, including bone cancer, skin cancer and lymphoma. While some of the diseases that affect humans are not an issue for our furry friends, unfortunately, cancer affects both. As with humans, some pets have a genetic predisposition, and we have to watch our senior dogs more closely, too. 

Like humans, early diagnosis increases the chances that treatment outcomes will be good. Prevention is also important — like using pet sunscreen when your dog is outside. If you have doubts about the health status of your dog, prompt veterinary evaluation means the team can get the cancer diagnosed early and start helping your dog’s immune system fight as soon as possible.

Symptoms of Cancer in Dogs

Pet owners have a general sense of what’s normal for their animals. Noticing changes such as pain, discomfort, difficulty eating, persistent bad breath, abnormal bleeding, changes in bathroom habits or persistent sores can help with early recognition and lead to a definitive diagnosis.

Is There a Cancer Lump on My Dog?

Not every unusual lump you feel on your dog is cancer, but you should still have them examined by your veterinarian, and you should check for lumps regularly. Run your fingers over your dog’s skin at least once a month so you can identify any skin lumps or bumps that are growing or changing. Female dogs that have not been spayed are at greater risk for mammary cancer, so be sure to check for any unusual growths on their chests and bellies.

The lymphatic system is another area you can monitor with your fingers. The lymph nodes that are the easiest to find are just under the jaw, right below the ear and behind the knees. Normally, the lymph nodes feel like a small, pliable blip between your fingers. But if you feel enlarged lymph nodes, anything firmer or bigger than usual, talk to your veterinarian.

Cysts vs. Tumors in Dogs

Not all lumps indicate cancer! Your dog’s lump might be a cyst: a sac filled with fluid, air or other material. Tumors are abnormal growths of tissue. Your veterinarian can examine the cells to determine whether they are benign or malignant. Benign tumors may not require treatment, but some can become malignant tumors, and the tumor location may mean the dog’s quality of life will be improved by treating it. Cancer care could be in the form of surgery, chemotherapy or radiation.

Other Warning Signs of Cancer in Dogs

Of course, the signs of cancer vary depending on the organs or body parts affected, such as the skin, lungs, blood or bones. These signs can also signal other conditions, so don’t panic. Just see your veterinarian if you find any of the following:

• Unexplained weight loss: If your dog starts looking thinner than usual, has a reduced appetite, and you haven’t started a new diet or exercise routine, it’s time for a checkup.
• Chronic cough or difficulty breathing: Tumors that occur in or around the lungs can cause respiratory problems.
• Lameness or limb swelling: If you run your hands along both of your dog’s front or rear legs at the same time, it’s easy to compare the affected limb with the other side and spot areas with unusual swellings along the bones. If your dog starts limping or is hesitant to bear weight on a limb, talk to your veterinarian.
• Stinky breath or difficulty chewing: These can certainly be signs of periodontal disease, but dogs can get oral tumors, as well. If your dog will allow it, take a peek at the gums and under the tongue, checking for unusual growths.
• Chronic vomiting or diarrhea: Not surprisingly, cancers of the digestive tract can lead to loose stools, upset stomachs and, in some cases, trouble with defecation. If the problem persists, or your dog starts losing weight, make an appointment.
• Circling or seizures: A dog with a potential brain tumor may experience a sudden onset of seizures, especially in the older years, or may pace in circles over and over again. If you notice a change in your dog’s behavior, contact your vet.
• Abdominal distension: Dogs might have swollen bellies from overindulging in the treat jar, but it can also be a sign of enlarged internal organs such as the liver.
• Lethargy or weakness: Any time your dog seems less active than usual, lags behind on walks or just doesn’t want to interact with the family as much, there’s a good chance something’s not right. Again, behavioral changes have many possible causes, so check them out before they become worrisome.

When in doubt, see your veterinarian. It may be nothing. But if it’s something more serious, you want to catch it in the early stages.