Cancer In Dogs: What Are The Types, What Are The Signs, What Can I Do?

Although it’s not a pleasant topic, recognizing the signs of cancer in dogs can make a difference in how quickly you can get your pup to the veterinarian. Pet ownership isn’t only about belly rubs and tossing a tennis ball around; it’s also about helping maintain your dog’s quality of life through the good and the bad. 

Those of us at WINPRO Pet know just how important your pet is to you… because we feel the same way! To help your dog have a long, happy life with you, we wanted to create  this starting resource on cancer in dogs. That way, you can identify potential symptoms so that you can know what you can do and what types are out there. 

The Most Common Types Of Cancer In Dogs

Cancer in dogs is different from the way it happens in a lot of other species, because they are susceptible to many of the same types of cancer that we are. Cancer happens because the normal cells in the body start to grow out of control, due to a variety of potential triggers. 

While we may never know what those triggers actually are, the end result is unfortunately the same… and the word “cancer” is any pet owner's worst nightmare. 


Leukemia is essentially cancer of the blood. Instead of taking over healthy cells, the number of abnormal cells begins to slowly outnumber and take over the healthy ones. Oddly enough, male dogs seem to be more affected than female dogs, but leukemia has no age preference in who it strikes.


If the cancer is located in any of the blood-forming tissues, it is called lymphoma. Just like leukemia, lymphoma doesn’t form tumors. However, one of the most common symptoms is enlargement of the lymph nodes (especially in the neck). Certain breeds, like Golden Retrievers, seem to be more susceptible. 


If cancer occurs on the skin, in the glands, or in any of the hormone producing cells, they are known as carcinomas. Examples of carcinomas are lung, skin (squamous cell, melanoma), colon, thyroid, and mammary gland cancer. Some of these cancers are more serious than others, but there really is no common age or breed to expect them in.


Sarcomas are the name for the type of cancer in dogs that starts in the connective tissues, muscles, or bones (medically, those cells are known as “mesenchymal”). A few of the more common types of sarcomas that can happen in dogs are osteosarcoma (cancer of the bone) and hemangiosarcoma (cancer of the blood vessels). Unfortunately, sarcomas are also not very easy to treat and don’t have a very long survival rate. 

Signs And Symptoms Of Cancer In Dogs

The tricky thing about being able to identify the signs of cancer in dogs is that some of them are fairly subtle. Spending plenty of time with your dog is helpful, so that you are more able to recognize changes before they get out of control. 

Whether that is a small bump or a change in your pup’s activity, there’s really no such thing as overreacting when it comes to your furry family member. With that in mind, here are just a few of the more common signs that your dog may be dealing with cancer:

  • New or growing lumps and bumps
  • Abnormal or foul odors coming from the body (mouth, ears, etc.)
  • Evidence of pain
  • Changes in bathroom habits (more/less often)
  • Difficulty breathing
  • Coughing
  • Abdominal swelling
  • Abdominal discharge (from the eyes, rectum, ears, mouth, etc.)
  • Wounds or sores that don’t seem to heal
  • Sudden, unexplained weight loss
  • Changes in appetite
  • Depression or lethargy (excessive sleepiness)

Because there are two different major sources of cancer in dogs, the kinds that cause tumors and the kinds that happen more silently, every symptom is important to stay vigilant for and have checked out. 

Why Early Detection Of Cancer In Dogs Matters

The earlier you are able to recognize the signs of cancer in dogs, the more likely it is that there are a wider array of treatment options available. Also, just like cancer in humans, cancer in dogs can spread into the circulatory or lymph system, which allows it to impact other areas of the body and tissues.

Cancer in dogs can also be often caught by routine screenings at your pup’s annual wellness exams. This is part of why wellness exams are usually done twice annually once your dog hits his or her senior years. Screening blood work, physical checks where your vet feels for any abnormal lumps or bumps, and just getting a general history of how your dog has been doing for the past year are excellent ways to catch cancer early if it does occur. 

Can Cancer In Dogs Be Treated?

The answer to this question is yes… and no. While we wish there was a one size fits all approach to cancer treatment, there is a lot that goes into making that decision. Your pet’s age and physical health, the type of cancer that they are dealing with and what stage it is in when it was diagnosed all play a role in not only how successful treatment may be but what type of treatment is available. Unfortunately, finances can also play a major role in what pet owners are willing and able to do… cancer treatment has a tendency to get expensive and even cost prohibitive. 

Luckily, there are a lot of alternative sources of payment out there, like Care Credit. It shouldn’t have to come down to being able to afford for your pet to make it through a health scare. 

Treatment options for cancer in dogs are also very similar to those that we may go through, with the only difference being that our pets often don’t really understand what’s happening to them. These include chemotherapy, radiation, surgery, and even alternative therapies. In a lot of cases, people may have to take their pets out of town to a larger hospital or vet school for treatment. 

Prevention Techniques

A lot of loving dog owners often find themselves wondering… is there anyway that I can stop my dog from getting cancer? 

While we wish that we had an answer for that, there really isn’t. However, keeping your dog as happy and healthy as possible can help them live as long of a life as they can. Focusing on making sure that you are feeding your dog the best diet possible and treating any other health conditions that may pop up (like allergies) are all ways to help make your dog’s life the best it can be. 

No one knows how long we will be lucky enough to keep our pups, so why wouldn’t you want to do everything you can to make every day awesome for them?

Spaying and neutering your pets can also drastically reduce your pup’s risk of various cancers, like mammary or testicular.

To Wrap Up

Cancer in dogs isn’t preventable, but it doesn’t have to be something that you worry about constantly. Having a close relationship with your pup, so that you can identify any changes in their appearance or behavior, may be able to help you catch cancer early. 

Focus on making every day your best day.That important relationship between us and our dogs is why we created WINPRO Pet, after all!


Types of Cancer - Special Pet Topics | Merck Veterinary Manual (

VCA Pet Cancer Alliance | VCA Hospitals

Reducing the Risk of Cancer - Special Pet Topics | Merck Veterinary Manual (