Signs Of Cancer In Dogs (13 Cancers Type)

Signs Of Cancer In Dogs- It is sad when you don’t know that your dog has cancer and even more terrifying when you find out. That’s because you were ignorant of Signs of Cancer in Dogs.

You don’t have to beat yourself because generally, it is difficult to detect cancer early in pets. For this reason, we have decided to help you detect cancer in dogs early by providing you with signs and symptoms you can observe in your dog portraying that it has developed cancer. To get all the information you need, take time to read from beginning to end.

15 Signs Of Cancer In Dogs (What You Need  To Know).

The essence of compiling the top 15 common Signs of Cancer in Dogs is to help dog owners detect the disease at a very early stage in their dog. Also, cancer is best treated with a favourable outcome when it is treated early when it is yet to be malignant and metastasize (spread) to other body parts.

That is why dog owners should not overlook any health change they perceive in their dog and should immediately visit their veterinarian for proper examination to come up with a definitive diagnosis to either confirm or overrule the presence of the disease. Likewise, to formulate an advantageous treatment plan that can arrest the situation before it progresses.

With that been said, below is the highlight of the top 15 signs of cancer in dogs covering different types of cancer cases that affect dogs.


Signs Of Cancer In Dogs include the following:

  1. The appearance of Lump or a Bump
  2. Ulceration (open)
  3. Abnormal Bleeding and Fluid Discharge
  4. Enlarged Lymph Nodes
  5. Seizure
  6. Lameness, Swelling, and Stiffness in the Bone
  7. Lethargy
  8. Change of Appetite and Difficulty in Swallowing
  9. Difficulty in Breathing
  10. Halitosis (Bad Breath)
  11. Non-healing wounds or sores
  12. Evidence of Pain
  13. Irreversible Weight Loss
  14. Unwillingness to Exercise and Play
  15. Difficulty in Urination, Excess urination, and Inability to Urinate

#1. Appearance Of A Lump Or A Bump.

The appearance of singular or multiple mass, lump or bumps commonly referred to as tumor is the primary sign of cancer in dogs. You will find this growth developing under the skin.

It is often recommended that the tumor be removed through surgery and biopsy examination be carried out.

Also, if the mass is benign, there is high hope, but if it turns out to be malignant or cancerous, there is a slim chance of recovery.

#2. Ulceration (open).

A typical Cancer in Dogs Symptoms is ulceration. This often happens when cancer has progressed to a severe stage. This refers to the formation of a break or opening on the skin or on the surface of an organ and it forms when the surface cells die and are cast off.

Normally, bleeding or fluid discharge occurs immediately after the body site affected is ulcerated. This is a common symptom that is evident in all forms of cancer.

#3. Abnormal Bleeding And Fluid Discharge.

The next sign of canine carcinoma in dogs involves abnormal bleeding and fluid discharge such as blood, vomiting, and diarrhea shows a severe sign of cancer in dogs.

Discharge occurs in almost every orifice (opening) in the body such as the nostrils, mouth, or anus. This is common with dogs suffering from gastrointestinal cancer.

#4. Enlarged Lymph Nodes.

There are varying reasons why the lymph nodes are enlarged. Sometimes it signifies that the lymph node is working hard, and as a result, more immune cells are transported there and more waste are produced and may pile up there.

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On the other hand, lymph node swelling can occur due to metastasis of cancer to the lymph node.

#5. Seizure.

Seizure is a common Cancer in Dogs Symptoms especially when the dog is diagnosed with brain cancer, spine, or lung cancer. Also, breast, skin, and colon cancers can cause seizures in your dog.

It occurs due to the presence of mass or growth putting pressure on the brain or spine, or any of the initially mentioned organs.

#6. Lameness, Swelling, And Stiffness In The Bone.

Lameness, swelling, and stiffness in the bone are among the common Signs of Cancer in Dogs. These conditions tend to progress just as the disease continues to advance in your dog.

You will find your dog limping or experience difficulty in movement. Also, it can lead to lameness. This mostly is as a result of bone cancer effect in your dog.

#7. Lethargy.

Lethargy, weakness, weariness, and a lack of energy and enthusiasm to do anything is a common sign of cancer. Although, other sicknesses can show the same sign.

Also, it is a common sign of every cancer type in dogs and when you observe your dog displaying a lethargy attitude, waste no time visiting your veterinarian.

#8. Change Of Appetite And Difficulty In Swallowing.

Poor or total loss of appetite, as well as dysphagia (difficulty in swallowing), is another common sign that points out your dog has cancer.

Change in appetite can occur as a result of oral cancers on especially on the gum, labia (lip), or tongue, making chewing difficult thereby leading to loss of appetite.

The sign of dysphagia can occur as a result of a lump in the neck that could be putting pressure on the esophagus, thereby making it difficult for your dog to swallow food.

In addition, gastrointestinal cancer can lead to stomach upset and loss of appetite, and dysphagia.

#9. Difficulty In Breathing.

Difficulty in breathing is common in dogs when cancer has affected the respiratory system.

When there is a mass putting pressure on the windpipe or lung, breathing becomes difficult.

The symptom is common in most cancer cases that occur in dogs especially when it has metastasized.

#10. Halitosis (Bad Breath).

When halitosis (bad breath or odor) occurs in your dog, it can be a Cancer in Dogs Symptoms.

Halitosis is a common sign of cancer and it occurs due to a mass or multiple growths in the mouth, nose, or anus which can cause offensive smells.

#11. Non-Healing Wounds Or Sores.

When you observe skin lacerations, wounds, and sores that seem never to heal, there is no doubt that cancer has occurred.

The signs that indicate that your dog has developed particularly skin cancer is the appearance of never healing sores and wounds despite the use of antibiotics applied locally or used orally.

#12. Evidence Of Pain.

Most cancer cases are very painful and it takes many forms. most cancers are aggressive and pains can be dull, achy, sharp, or burning.

Also, the pain caused by cancer can be constant, intermittent, mild, moderate or severe.

The amount of pain you feel depends on different factors such as the type of cancer, the degree of the case, the site of cancer, and the level of pain tolerance.

#13. Irreversible Weight Loss.

This symptom is a predominant Sign of Cancer in Dogs. When you observe that your dog losses weight despite been fed properly and adequately, illness could be causing your dog’s weight loss including a tumor that develops along the intestine.

#14. Unwillingness To Exercise And Play.

Dogs that are energetic and playful do not just lose interest in exercise and play. It is a sign of sickness and it is also a common sign of cancer in dogs.

In most cases, it serves as the first sign that your dog is sick. Typically, unwillingness to exercise is a common sign of most cancers in dogs.

#15. Difficulty In Urination, Excess Urination, And Inability To Urinate.

The last  sign common to Cancer in Dogs Symptoms includes difficulty in passing urine, excess urination, and inability to urinate.

This sign becomes evident when the urinary system made up of the bladder, and urethra is affected by cancer.

Difficulty in urination describes the pain experienced in the process of passing urine. Excess urination describes frequent urination and the inability of the bladder to hold urine.

Inability to urinate is referred to as failure to pass urine. These symptoms are consistent in dogs diagnosed with cancer of the prostate.


Types Of Cancer And Its Clinical Signs/Symptoms.

We will be writing on different types of Cancer and its various signs, follow us as we ride on this horse.

Signs Of Skin Cancer In Dogs.

Following are the common signs of Skin Cancers in Dogs (Tumour).

  • #1. Lesions that look like warts but are actually raised bumps (squamous cell carcinomas).
  • #2. Sores that are inflamed and rubber-like in texture (mast cell tumors).
  • #3. Lumpy or bumpy skin on lips, mouth, footpads, or toenail beds (melanomas).
  • #4. Your dog’s limp is an indication that he is in pain.

Signs Of Bone Cancer In Dogs.

Following are the common signs of Bone Cancers in Dogs (Tumour).

  • #1. Appetite loss and lethargy.
  • #2. Such as an unsteady gait are neurological indicators.
  • #3. Evidence of significant pain
  • #4. There is a discharge from the nose.
  • #5. Asthma or other breathing problems.
  • #6. Swelling of the ribs, spine, legs, or jaws, as well as other areas.
  • #7. Hemiplegia, sometimes known as limping or lameness.
  • #8. On the dog’s body, there is an increase in mass.

Signs Of Lung Cancer In Dogs.

These are the common symptoms that are peculiar to Lung Cancers in Dogs;

  • Lethargy.
  • Coughing.
  • Loss of weight.
  • Breathing/wheezing that is rapid.
  • Vomiting.
  • Excessive effort in breathing
  • Lameness.
  • Tolerance to exercise has been reduced.
  • Hair loss is a common problem that many people face.
  • Appetite loss.
  • Fever.
  • Ulcers of the digestive tract.

Signs Of Stomach Cancer In Dogs.

These signs are peculiar to Stomach Cancer in Dogs and they are;

  • Vomiting.
  • Drooling/salivation that is profuse (a symptom of nausea).
  • Overall decrease inactivity.
  • A hunger that has waned.
  • There is a reduction in weight.
  • Inflammation of the abdomen.
  • Activity and socializing decline.
  • A hunger that has waned.
  • Unwillingness to move, or lethargy.
  • Vibratory amplification (whining, growling, etc).
  • Respiratory rate increase.
  • Indoor urinating or defecating.
  • When touched, people may yell, snap, or run away.
  • Licking or scratching in excess.

Signs Of Bladder Cancer In Dogs.

Following are the common signs of Bladder Cancer in Dogs, include;

  • A small volume of urine is urinated quite frequently.
  • Urination problems.
  • Accidents happen in the house all the time.
  • Urine that is discolored or crimson.
  • Infections of the urinary tract that persist despite treatment.
  • Lameness can occur in dogs with bladder cancer in its later stages when cancer has progressed to the bones or lungs.

Signs Of Liver Cancer In Dogs.

These signs are common with Dogs with Cancer in the Liver;

  • Loss of weight.
  • Jaundice is a condition in which the body (Yellowing of eyes, skin, and gums).
  • Weight loss and loss of appetite.
  • Fever.
  • Lethargy.
  • Weakness.
  • There is a great deal of thirst.
  • Urination has increased.
  • Diarrhea.
  • Vomiting.

Signs Of Prostate Cancer In Dogs.

Here are the signs associated with Prostate Cancer in Dogs;

  • urinary incontinence, with numerous attempts to urinate.
  • Feces/ribbon-like feces must be passed with effort.
  • Haematuria.
  • Gait abnormalities/lameness of the hind legs.
  • Fatigue.
  • There is a reduction in weight.
  • Fever.

Signs Of Breast Cancer In Dogs.

Following are the signs of Breast Cancer in Dogs;

  • Nipple discharge that is either bloody or pussy.
  • Several bumps.
  • Breasts that are inflamed or in pain.
  • Lumps that are singular.
  • Ulceration.
  • Nipple discharge or pus is yellow in color.
  • Inability to breathe.
  • Lameness.
  • Lethargy.
  • There is a decrease in appetite.
  • Weakness.
  • There is a reduction in weight.

Signs Of Testicular Cancer In Dogs.

Here the common symptoms associated with Testicular Cancer in Dogs;

The testis of a dog with testicular cancer may appear or feel odd. Symptoms include enlarged testicles or testicular masses that are hard and occasionally painful to the touch.

They may appear larger than normal, be inflamed, or have lumps if both testicles have cancer.

In certain dogs, it appears like there is just one testicle present. One testicle descended or dropped naturally throughout puppyhood, but the other testicle was left in his abdomen or belly.

Cryptorchidism is the name given to this type of occurrence. Your pet’s undescended or cryptorchid testicle is prone to cancer, but it won’t be immediately apparent from a quick glance. In an undescended testicle, sertoli cell tumors and seminomas are the most common kinds of malignancy.

In addition to weight loss, cancer can cause an inability to eat or a lump in the abdomen.

Estrogen is more usually connected with female dogs than male dogs in certain testicular malignancies, such as Sertoli cell tumors (SCT).

As well as mammary gland or breast tissue enlargement, hair loss on the dog’s trunk and dark staining of the skin may be signs of a tumor.

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Leydig cell cancers can create an excessive amount of testosterone, according to the American Cancer Society.

As a result of a hernia or an enlargement of the perianal glands surrounding the anus, your dog may have swelling on his rear near his anus.

Bone marrow can be impacted by severe kinds of testicular cancer. Blood cell abnormalities can result in anemia (a decrease in red blood cells), insufficient platelets, bruising, or white blood cell abnormalities.

To begin with, many dogs will not exhibit noticeable signs. The fact that some of the symptoms discussed are not exclusively related to testicular cancer is also important to keep in mind.

Further tests may be required to discover the source of your dog’s strange behavior.

Signs Of Brain Cancer In Dogs.

Following are common symptoms associated with Brain Cancer in Dogs;

  • Seizures.
  • Abnormal mental activity or conduct.
  • A vision that is abnormal.
  • Circling.
  • Walking with a shaky stride.
  • The head is tilted to the side.
  • Intolerance for neck pain.

Signs Of Pancreatic Cancer In Dogs.

Following are clinical signs associated with Pancreatic Cancer In Dogs;

  • Changes in their food or water consumption.
  • Appetite loss is common.
  • Weight loss of a significant amount.
  • Pain in the abdomen or sensitivity to touch.
  • Distension of the abdomen (swollen tummy).
  • Fieber ranges from mild to extremely high temperatures.
  • Limping and wobbling are common symptoms of aging.
  • Normal activities are not appealing to them.
  • Anxiety or high amounts of stress are symptoms of depression.
  • A lack of coordination in the movement of the body parts.
  • Convulsions, seizures, and fainting spells (can be caused by low blood sugar).
  • Tremors and spasms are common symptoms.
  • The mood is gloomy.
  • There is little to no energy available.
  • Weakness.
  • Vomiting.
  • Diarrhea.
  • The skin is discolored.
  • Signs of jaundice are getting worse.

Signs Of Anal Cancer In Dogs.

Here are the signs associated with Anal Cancer in Dogs;

  • The perianal area develops an outward enlargement.
  • During a regular rectal check, you may feel a lump.
  • constipation.
  • Pain or straining to excrete are symptoms of constipation.
  • Stools with blood in them are a medical emergency.
  • If you have kidney failure due to high calcium levels, you may have excessive thirst and urine.
  • Defecation symptoms from even a large tumor are usually mild if there are no swollen lymph nodes (in the belly).
  • Owners may notice signs of kidney failure as a result of elevated calcium levels (referred to as hypercalcemia or malignancy).
  • Increased thirst is the result of this.
  • An increase in urination has been observed.
  • vomiting.
  • Appetite loss.
  • Lethargic (weak/tired) behavior.

Signs Of Bone Marrow Cancer In Dogs.

Following are the observed signs of Bone Marrow Cancer In Dogs;

  • Sluggishness, a lack of energy (lethargy).
  • 47 percent of affected canines show signs of lameness.
  • Bone discomfort and weakness are present in 60 percent of the dogs who are affected, and bone destruction is also present.
  • Fever.
  • Unconsciousness in some parts of the body
  • 11 percent of affected canines have dementia with generalized discomfort or unease.
  • Breathing that is labored.
  • Dogs with elevated calcium levels in the blood or kidney failure show increased thirst and urine in 25 percent of cases.
  • Incontinence of the urinary tract.
  • Inflammation of the liver and the spleen.
  • As a result of blood collection or intravenous medicine and/or fluid administration, needle punctures result in excessive bleeding.
  • Stomachic bleeding.
  • 36 percent of infected dogs experience bleeding, particularly from the nose or mucous membranes (the moist tissues of the mouth, eyes, and other parts of the body).
  • As much as 35 percent of affected canines suffer from retinal hemorrhage or dilated retinal arteries.
  • Mouth and body tissues that are wet and pale (mucous membranes).
  • Retina that is detached.
  • Glaucoma.
  • Ocular inflammation includes inflammation of the cornea and iris.
  • A state of Coma (rare).

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Cancer is a severe illness in dogs just as it is in humans. There are numerous Signs of Cancer in Dogs because there are different types of cancers discovered with most presenting their unique symptoms.

However, the cancer symptoms listed here are peculiar to almost all cancer forms.

When one or more of these symptoms are discovered, pet owners should waste no time in getting it investigated by a veterinarian for a definite diagnosis and favorable treatment options employed.


Author: David Arthur

David's lifelong passion for animals blossomed into a dream profession in 2020. He founded Petscareway Inc., a professional pet care company situated in the Texas. Several veterinarians have educated him in Pet First Aid and CPR since 2003. David decided to become a certified Pet First Aid and CPR instructor in 2011 after completing an instructor training course. David decided he had to be a part of ProPetHero when he discovered them in 2016 and saw how they were offering ER veterinarian-led training to everyone. As a result, he became a member of the ProTrainings family, the designers of ProPetHero. He volunteers and fosters for The Boxer Rescue Inc in his spare time, is a health-conscious Boxer breeder, and is a member of the Middlesex Boxer Club and Wachusett Kennel Club. David has served as a mentor to many people in the pet industry and in the small company world. When he's not working or helping, he's competing with his dogs in agility, lure coursing, and conformation trials across the country. David can be seen training with his puppies, hiking with them on trails, or playing in his backyard when he is not at a trial or trying to find a nice home for a Boxer through the rescue.

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