Top 10 Warning Signs of Cancer in Dogs and Cats

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May is Pet Cancer Awareness Month, a time to spread awareness of the symptoms of cancer in dogs and cats. As cancer is the leading cause of death in cats and dogs, knowing the symptoms your pets may present if they develop the disease can help you and your vet diagnose and treat your pet sooner. In order to help you protect your pet’s health, petMD.com has pulled together the top 10 warning signs of cancer in dogs and cats.

1. Lumps and Bumps: Not every lump or bump is necessarily cancerous, but consulting with your vet is the only way to be sure. If the lump is growing or not resolving itself, contact your vet and he or she will do a biopsy to determine the contents of the bump.

2. Abnormal Odors: Foul odors from any of your cat or dog’s orifices and/or body parts may be a cause for concern. Cancers of the mouth, nose, or anal regions can cause your pet to emit offensive odors.

3. Abnormal Discharges: Discharges such as blood, pus, vomit, diarrhea, and any other abnormal substance being excreted from your pet’s body should be checked out by a veterinarian immediately. A bloated or distended stomach could also be a sign of internal discharge.

4. NonHealing Wounds: Lacerations or sores that do not heal within a normal time range on the surface of your cat or dog’s body may indicate infection, skin disease, and possibly cancer.

5. Weight Loss: Sudden weight loss in cats and dogs not on a diet can be an indicator of many diseases and illnesses. If coupled with another warning sign of cancer, you should contact your vet right away and inform him or her about your pet’s symptoms.

6. Change in Appetite: While a lack of appetite in dogs and cats can be an indicator of many things, they never stop eating without a cause. Not necessarily a sign of cancer, a decrease in appetite can indicate an oral tumor, which would make it painful and difficult for your pet to eat and swallow.

7. Coughing or Difficulty Breathing: Although symptoms of heart and lung disease, coughing and abnormal breathing can also indicate cancer. This symptom will most likely occur if the cancer in your pet’s body has metastasized into his or her lungs.

8. Lethargy and Depression: If your pet has cancer, there is a chance that he or she will suffer from depression and sleep more, become less playful, and be less willing to go for walks. Although lethargy or depression in dogs and cats can set in with any illness, it is commonly seen in pets that have cancer.

9. Changes in Bathroom Habits: Any changes in your pet’s bathroom habits including difficulty using the bathroom, frequent bathroom use, and blood in urine or stools are potential warning signs that cancer has developed in your pet.

10. Evidence of Pain: Limping or other evidence of your dog or cat in pain when he or she is active, or if the pain is too great for them to be active, can be indications of cancer of the bone.

While no one sign purely indicates cancer, a cat or dog displaying two or more of these symptoms should be taken to the veterinarian for an exam so that he or she can be properly diagnosed and treated accordingly, because early detection can make all of the difference in the case of a positive diagnosis.

46 thoughts on “Top 10 Warning Signs of Cancer in Dogs and Cats”

  1. This is great for people to know, but the one thing I don’t see he is Hair loss. I lost my beagle to Lymphoma and hair loss was the only sign we had.

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    • My cat lost her hair above her eyes n around mouth then on the way to vet lost all hair on nose. She was at vets 2 weeks ago bc of bumps on skin n a croup cough. They gave her a steroid n antibiotic shot. Helped a Lil. But now hair loss n cogh n blood in nose. They want to cut her up. Like do 4 biopsies on her eyes nose mouth tomorrow then have her wear a cone. She has a heart murmur murder to. Am I doing the right thing of putting 11 yr old nervous cat through this. I just don’t know. My heart is broke. Thanks Julie [email protected]

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      • I had two cats with cancer and I knew the pain they would feel with surgery, I couldn’t do that to them,one shot and they were free of pain. Hope this helped

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  2. What kind of hair loss Mina? Patchy? All over? My dog has had hair loss due to staph infections in his later years.

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  3. Hombre and me are fighting together to defeat his bone cancer. We already knocked his liposarcoma into submission.

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  4. You also need to know if your breed, and mixed breeds can be susceptible to the pure breeds, are more likely to develop. For instance GSD, from what I was told by my vet in Massachusetts, are likely to develop spleen cancer, which is what killed my last dog. He showed signs of being sick, took him in, we did a general exam, needle biopsy of a lump, and he was dead before the results were in. He was ill for maybe 2 weeks.

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    • Kirsten I just lost my baby 4 months ago he was with me for9years and 7 month he got bloted I call his vet they not wouldn’t check him out they wanted 300 dollars first I ask they if I could pay per month they wouldn’t see him they let my baby die I call them and told them they lost me as their customer because they let my baby die he was their patient and wouldn’t save him they let him die I know you send this message last year on may21 2012 but I didn’t have a computer the I hope you see this message message I wrote you he passed away 3 18 2013 he was born 8 8 2003 I buried him in my backyard with his blanket wrap around I put a little white fence around his grave with white rocks on top also a white cross that tells his name when he was born he has little angle a dog flowers in a vase ,plastic ones everything I put there with clear bags over them so that the sun won’t get to faded and keep the rain off of them I hope I get a answer back soon Mary

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      • i’m sorry, Mary. life is hard too often, and there is little those of us without power in this life can do sometimes. no matter how much we love.
        and it’s clear how much you loved your baby. i’m sorry you and your baby suffered so much. i hope you’ve been able to find some amount of peace now, although i know you will never forget your baby.

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      • So sorry for your loss, Mary. My grandfather was a veterinarian. He always helped animals no mayter what. If someone had no money to pay, they paod him with a chicken or something. And he was financially fine, even through the great depression. I wish there were more vets like him today…

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  5. We found our dogs thyroid cancer while scratching his neck. Took him to the vet. This is a great article. Thank you

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  6. My Brodie GSP was diagnosed right @ 3 years ago. Vet said he would make it 6 months. I cherish every day with him.

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    • you are right its not us their owners its the vets because they all the time want a lot of money off the animals should have a vet that will take their needs free that loves animals and wants to help low income and poor people that don’t get very much money from mary

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    • I am sry to hear about ur dog .. I love dogs n I knw bout that felling after reading this I got tears In my eyeys:-[ :(:(:(:(

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