Warning Signs of Cancer in Dogs

Posted by Maureen Lake at

Warning Signs of Cancer in Dogs

Warning Signs of Cancer in Dogs

  There are so many things I worry about with my dogs and cancer is definitely one of them. I don't mean to sound like a broken record, but my Keira is turning 10 soon, and I feel this compulsion to learn as much as I can about aging pets. Cancer is the leading cause of death in dogs over 10 years old. If your dog can get an early diagnosis, they might have a better chance of survival with treatment. I need to know the warning signs of cancer-period. I think if I need to know the signs, then maybe you do too. Unfortunately, many dogs won't show any symptoms or the signs may be vague at best. Once a dog is sick enough to show clues, it may be too late. What? I need some look sees now!
  • Weight Loss


  There can be numerous reasons why your dog has lost weight. Sometime dogs lose weight for no reason at all. BUT please talk to your vet if your dog seems to be losing weight without trying. It could be cancer or another disease.
  • Appetite Changes


Warning Signs of Cancer in Dogs

Eating less often goes hand in hand with weight loss. But, there are some dogs that still eat, but have lost interest in food or seem to suddenly become a picky eater. Also, difficulty with swallowing is not normal. Give your vet a call to discuss these habit changes, especially if this is occurring with other changes in behavior.
  • Vomiting or Diarrhea


Of course, there are many reasons why your dog may vomit or have occasional diarrhea. But, if it persists and typical treatments just aren't working, your vet may want to run some test. Also, if your dog is having a problem urinating or pooping be sure and share this info with your vet. This is not normal.
  • Bloated Tummy


If your dogs tummy looks bloated or enlarged go to the vet immediately. Bloat is a life threatening condition, but it could also be a tumor in the stomach. Tumors can cause fluids to build up and swell the tummy. No matter the reason, getting to the vet is an urgent necessary!
  • Lameness | Pain


Of course, this may be related to an injury, but if rest and medication doesn't help, you need to have your vet take x-rays and possibly other tests. Cancer in particular may cause lameness in dogs, so don't hesitate to get this checked out.
  • Depression or Lack of Energy


Warning Signs of Cancer in Dogs

When your dog is just not right in your eyes, it usually means something isn't kosher. If these changes in mood, activity level and behavior last more than a couple of days, it's best to get it checked out. This behavior is not typical.
  • Lumps, Growths, Masses


Warning Signs of Cancer in Dogs

Many lumps and bumps are benign growths or fatty tissue. They can occur anywhere on the body and often our older pets get many bumps. That said, your vet not you, needs to decide which bump or growth is something to be concerned about. Especially go in if any lumps or bumps, change in size, shape or start to discharge. Let your vet determine the best course of action.
  • Stinky Mouth


Bad breath isn't really common in dogs. It may be due to dental disease which is extremely important to get checked out. But, strong odors, especially if they come on suddenly  may mean more serious problems. Also, if there is any swelling of the face or shifting of the teeth be sure to see your vet pronto.
  • Discharge or Bleeding


  Any bleeding or abnormal discharge from any opening (mouth, nose, ears, eyes, anus, genitals) you name it, needs attention right away. There may be many reasons why this is occurring that has nothing to do with cancer, but will certainly need attention!
  • Change in Gum Color


  The gums, tongue, cheeks, inside of the eyelids should all be a beautiful pink. Pale white, blue, gray, or yellow mucous membranes need your vet's attention. Also, take notice if your dog's skin or white of eyes turn yellow. Jaundice is a serious reason to see the vet as well. The 10 symptoms discussed is certainly not a complete list of cancer signs. And, of course these can be symptoms of other diseases as well. The bottom line is not to ignore changes in our pets. If you have a senior dog, make sure they have a well check 2x a year. A diagnosis of cancer in your best friend can be heartbreaking for any owner and something we all want to avoid.

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  • No one wants to think about someone they love getting cancer, but if we recognize the symptoms in time, it could save a life. Thanks for sharing this important information.

    Beth | Daily Dog Tag on
  • Thanks for these signs. Kilo just turned 3 so hopefully we have many years, but my lab Cookie got cancer at 13.5.

    Talent Hounds on
  • Thank you for sharing this post – and I hope everyone who reads it takes it to heart! We’ve lost three dogs to cancer – and each was different. One started to refuse eating, the other became more lethargic and snow, and lastly our sweet girl, she didn’t show any other sign other than becoming ‘nervous.’ We thought she was cold – but, she wasn’t cold. Treatment helps so much – and is much less aggressive in dogs than it is in humans – please keep an eye on your fur babies!

    MattieDog on
  • Cancer is such a scary thing. My first pet was a dog and she passed away from cancer of the uterus at the age of 13. I don’t remember what the first signs were. It is great that you are drawing attention to this because those signs are easy to miss if you don’t know to be looking.

    Robin on
  • Thanks for these signs to watch out for. My girls are not seniors yet, but it is always good to know what to look for.

    Abby Chesnut on


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