Signs of Canine Cancer: Identifying 10 Common Types (Video)


I had a terrible scare yesterday. Janice is coming into the final days of her pregnancy, and I’ve been checking her breasts every day (okay, sometimes several times a day; what’s it to you?) for any abnormalities.

Yesterday, I found a tiny little lump.

Now, we all know that Ash does not obsess over Janice’s current condition or general health. Ash does not panic. No, Ash is the very picture of calmness, reason and good sense.

All right, regular readers, stop laughing!

I mean it!

Okay, so I panicked. Then I called the veterinary clinic and implored the assistant who answered the phone to tell Stephen that he had to see Janice right away, since I thought I might have found signs of canine cancer in her breasts, and she was due to deliver any day now, and OMG, what if something was horribly wrong!

Canine Cancer

Good News

The good news is that Janice is just fine. Stephen took a look, gave me that “Ash, you’ve done it again” look, and said, “It’s a zit.”

The bad news is, apparently, that I’m no less obsessive over every little thing than I’ve ever been.

In my defense, though, I have to say that I’d rather shell out money for an examination than let things go, and then discover, late in the game, that the tiny little lump I found was actually something pretty bad.

How Common Is Canine Cancer?

If you doubt the importance of identifying signs of canine cancer, think about this – if a dog lives longer than 10 years, there is a 50% chance that he will develop some form of cancer. Now granted, Janice isn’t anywhere near that age, but cancer can occur in young dogs, as well. I still think I did the right thing erring on the side of caution.

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What Causes Canine Cancer?

Truthfully, we really don’t know any more about the causes of canine cancer than we do human cancer. Environment could be a factor, as could diet. Some breeds are simply more predisposed to cancer – it’s genetic.

All that’s really known is that cancer occurs when cells divide more quickly than they should, and then fail to die when they should. The only protection against the disease is to identify canine cancer early on so that the disease can be treated as soon as possible. The best way of doing thisis to know about the different types of tumors, and the various signs of canine cancers that can occur in various parts of the body. Any time you find something unusual on your dog, a trip to the vet is warranted.

So, yes, I suppose I panicked, and ultimately I found out that there was nothing wrong with Janice. What would have been worse, though, would have been if I’d said, “No biggie,” and then let something really bad get to the point where it was incurable.

Most of the time, once the signs of canine cancer are identified, treatment will involve surgery, and/or chemotherapy, and/or radiation.

How Do the Treatments Work?

Once the signs of canine cancer are identified, and a diagnosis confirmed, your veterinarian will recommend a course of treatment. The most common treatment is chemotherapy, in the early stages. This treatment works by administering drugs that attack cancer cells before they can continue to divide. The trouble with this treatment is that the drugs can also, to some extent, affect healthy cells in the hair, intestine and bone marrow. This often causes owners of dogs that have cancer to resist treatment – they know how hard these side effects are on humans.

The fact is, though, most veterinary oncologists will tell you that the side effects in dogs don’t even begin to compare with those in humans. This is because the chemotherapy doses needed for dogs are a lot lower than those that humans require, and consequently, the side effects are fewer and less severe. If your dog needs chemotherapy to combat cancer, you can be assured that your veterinarian will be very alert to any potential side effects, and will lower the dose of the chemotherapy drugs in order to reduce the side effects.

Types of Canine Cancer

Now that you know the basics, let’s move on to talking about specific types of canine cancer, how to identify these cancers, and how to treat them. There are ten types of cancer that are most common.

1. Lymphoma

This is by far the most common type of cancer that you will see in dogs. In fact, it accounts for about 20% of all canine cancers, and it can affect a dog of any age, and any breed.

The signs of canine cancer as they relate to lymphoma are pretty obvious. You might notice that your dog’s jaw is swelling. You might also notice swelling in the chest (just in front of the dog’s shoulders) or in his knees. Other signs might include lethargy or loss of appetite.

There is another type of lymphoma, internal lymphosarcoma,that affects the dog’s lymph nodes and other organs that are made of comparable material, like the spleen and liver. Symptoms can include diarrhea, vomiting, trouble breathing, or abdominal discomfort. If the condition is not treated, the dog could die in less than a month.

The preferred treatment for both types of lymphoma is chemotherapy. Assuming that the treatment is successful (and it usually is), the dog will usually recover significantly within a few months. This isn’t always a “new lease on life” scenario, though. Most of the time, you’re buying your dog an extra year to year and a half of life. The quality of life during that period will be good, though.

2. Hemangiosarcoma

This is a type of cancer that occurs in the blood cells, and is most common in dogs that have reached at least middle age. With this type of cancer, you won’t likely notice symptoms early on, and that’s what can make it particularly deadly.

The most common of the early signs of this canine cancer is lethargy – and let’s be honest, who among us doesn’t get a bit lazier as we age? Obsessive as I am, I doubt if I’d have the presence of mind to take a dog to the vet simply because he was slowing down.

Usually, you really know that you’re in trouble when the dog goes into shock due to blood loss thanks to a tumor rupturing internally. Then you’ll see pale gums, weakness and difficulty breathing. By this point, though, the disease has well and truly taken hold. Since hemangiosarcoma most often affects the spleen, a splenectomy (surgical removal of the spleen) can be performed, but realistically, it’s probably too late. Even if the dog survives the operation, the very best you can hope for is about seven months of life, assuming that you follow up the operation with chemotherapy. Often, the prognosis is as little as two months.

Realistically, if your dog is diagnosed with hemangiosarcoma, the kinder course of action would be to have him put to sleep.

3. Osteosarcoma

You probably know this type of cancer by its more common name – bone cancer. It’s most common in large breeds. In fact, I think that my friend Neila, who breeds and owns Rottweilers, has probably lost track of how many dogs she has lost to osteosarcoma.

This is a very aggressive type of cancer, and you’ll know the signs of this canine cancer very early on. The first sign is that the dog begins to limp. Now, given that I’ve just said that it’s common in large breeds, one of the reasons that it’s not all that commonly diagnosed is that large dogs are often very active. So, what happens is, the owner assumes that the dog sprained his leg while running, or jumping, or doing any of the other things that really active dogs like to do. By the time the owner gets around to thinking, “Maybe there’s something else going on here,” it’s already too late.

By the time the signs of this canine cancer become apparent, the cancer will have already spread, and probably invaded other parts of the body. The affected limb can be amputated, which might buy the dog four to six additional months of life. If chemotherapy is included in the treatment, the best case scenario will probably be that the dog will live for a year following diagnosis.

4. Mast Cell Cancer

Mast cells work to suppress allergic reactions. So, as you might expect, mast cell tumors are usually found on the skin. In retrospect, this is probably the type of tumor that, if I had been right in panicking over Janice, would have been found – they’re little, grainy things.

Treatment will depend on where the tumor is located. Sometimes, surgery gets the job done. Other times, it needs to be followed with chemotherapy.

The nasty thing about mast cell tumors is the way that they grow – they tend to spread out, kind of like a spider web, and that means that a good deal of the surrounding tissue has to be removed along with the tumor.

5. Melanoma

You’ve probably heard of this type of cancer in the way that it relates to humans – it’s skin cancer, pure and simple. And it happens in dogs the same way that it does in humans – the cells that make up the skin pigmentation go nuts and grow in ways that are harmful.

Your veterinarian will proceed in the same way that a human doctor would – by removing some of the growth and sending it off for a biopsy. If the growth is determined to be malignant, then surgery will be the best option.

6. Squamous Cell Carcinoma

This is another type of cancer that can occur on the skin, but can also affect the mouth. With this disease, identifying the early signs of canine cancer is critical. If these tumors are found and removed early on, the chances of recovery are very good. In fact, there’s less than a 20% chance that they’ll spread to other parts of the body.

Now, having said that, these tumors can be hard to find. Be honest – how often do you open your dog’s mouth up and check to see if there’s anything unusual in there? Squamous cell carcinoma most often affects the tongue, tonsils and other parts of the mouth. If they’re not found, they can be very aggressive, and there’s less than a 10% chance of survival within a year of diagnosis.

What I’m saying here is simply this – when you’re grooming or otherwise caring for your dog, take a look inside his mouth. Your dog will probably never develop squamous cell carcinoma, but if he does, early diagnosis is what will save him. It only takes a few seconds, so do it.

7. Mammary Cancer

Okay, you don’t have to rush out and buy a pink ribbon. Mammary cancer is pretty common in dogs (females, obviously, more than males), but it usually grows slowly and is not all that invasive. It’s also very curable – all you need to do, usually, is get your dog spayed.

Once spayed, there is a chance that the mammary cancer will recur, but it will not usually come back for many, many years. In fact, the chances are that your dog will die with mammary cancer – not of it.

Of course, the best way of preventing mammary cancer in your female dog is to spay her early on. Despite what you might have heard to the contrary, there is no reason why a bitch should have to have one litter before she’s spayed. Trust me, she doesn’t care if she breeds. And if she doesn’t, she’ll probably never develop mammary cancer.

8. Apocrine Gland Carcinoma

This is butt cancer, plain and simple. Usually, apocrine gland carcinoma is identified when your vet is doing a routine rectal exam. Then he or she identifies a mass, and goes, “Uh oh!”

This can be a hard type of cancer to deal with, since it invades the tissues that surround the anal glands, and can be difficult to remove. The first course of action is surgery, assuming that it’s possible. Then, chemotherapy is the next step.

If the tumor has grown very large, radiation might be used to shrink it. If it’s gotten to that point, though, it’s sad to say that further treatments might not be the best course of action. Dogs that have surgery for this type of cancer usually don’t live for much more than a year. If radiation treatment or chemotherapy are added, you might have your dog for a year and a half.

9. Transitional Cell Carcinoma

This is a cancer of the lower urinary tract. The first signs of this canine cancer will include blood in the urine. Sadly, this is another very invasive type of cancer, and it’s very likely to move into other parts of the body. As is the case with anal tumors, bladder tumors are often hard to remove without causing damage to other areas. With transitional cell carcinoma, if surgery isn’t practical, then radiation or chemotherapy might be recommended. The prognosis isn’t good, though.

10. Soft Tissue Sarcoma

This is another “spidery” type of cancer that invades your dog’s body by spreading out little tendrils of cancer cells into normal tissue. They can be removed, but they are likely to spread to other parts of your dog’s body. As is the case with mast cell tumors, how successful the treatment will be will depend on where the tumors are located, and whether they have moved to other parts of the body.

The usual course of treatment for soft tissue sarcoma is surgery, followed by radiation and/or chemotherapy.

Those are the 10 most common types of canine cancer, and the symptoms that can help you to identify them.

Related Content:

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The Final Word

There you have it – Signs of Canine Cancer 101. I hope you never have any need for this information. For sure I’m glad that I didn’t need it, and I’ll keep you updated on Janice!

If you ever do suspect cancer in your dog, though, and if you notice any of these symptoms, please don’t waste time. Take your dog to the vet. There’s nothing sadder in the life of a “dog person” than having to use the phrase, “I wish I’d gotten him looked at.” Don’t be that person.