* Petmoo is reader-supported. When you buy products via links on our site, we may earn an affiliate commission at no cost to you.

Rectal Tumors In Dogs – Symptoms, Treatment & Prevention

Rectal Tumors In Dogs

Colon and rectal tumors are usually grouped under ‘colorectal tumors’ as they both have many features in common.

Tumors that originate in the rectum are called rectal tumors. Colorectal tumors are the second most common tumors of large intestine - the first one is proximal colon cancer. The rectum is the terminal section of the large intestine from the sigmoid colon to the anus. This section is where wastes from the colon accumulate just prior to discharge through the anus.

Most colorectal tumors gradually develop from benign polyps (adenomas), sessile serrated lesions, or abscesses in that region. colorectal Hyperplastic polyps are benign protrusions that are often small and found in the rectum and are not a cause for concern.

Most Hyperplastic polyps will not become malignant (in almost 90% of the cases), but some can gradually into cancer over a period of time due to unknown reasons.

Rectal cancer has no sex disposition and occurs in both males as well as females. This uncommon cancer tends to be locally invasive in the surrounding tissues and has a high rate of metastasis (spread to distant tissues).

Symptoms Of Rectal Tumors

General Symptoms of tumors in the rectal region may include:

  • Diarrhea or constipation
  • Change in bowel habits/consistency of stool
  • Narrow or ribbon-like Stools or bloody/black/ tarry stools
  • Inflammation or external swelling in the perianal region
  • Unexplained weight loss.
  • Polyuria, polydipsia

Treatment Options For Rectal Tumors

  • Surgical options, radiation, chemotherapy, or a combination of these modalities may be tried.
  • Colonoscopy (polypectomy) is used to remove polyps.
  • Endoscopic mucosal resection - for larger polyps.
  • Partial colectomy - part of your colon that contains the cancer is removed.
  • For advanced cancers, surgery is the only option followed by chemotherapy.
  • Radiotherapy may be used to shrink cancerous cells prior to surgery or used post-op to reduce the duration of the resulting remission.
  • Newer treatment protocols such as immunotherapy, Targeted drug therapy, and monoclonal antibodies are also available.

Home Remedies For Rectal Tumors

  • After surgery, Dog activities should be restricted activity for about 2 weeks to allow recovery and incision healing.
  • A restrictive collar usage is recommended for 10-14 days. This prevents the natural tendency of dogs to lick and chew at a wound.
  • A diet of roughly 50% meat and 40–50% whole grains or non-starchy vegetables is optimal.
  • A homemade balanced diet is an alternative to commercial diets.
  • Fish oils or fish meals, or whole fish are rich in omega-3 fatty acids.

Prevention Of Rectal Tumors

When dogs are diagnosed with inherited types of colorectal cancer, it is important to take measures to avoid breeding or neutering the dogs (if they does survive to adulthood) to remove affected dogs from the gene pool.

Affected Breeds Of Rectal Tumors

There is no breed disposition.

Springer Spaniel, Cavalier King Charles Spaniel, German Shepherd, Beagle, Bulldog, Samoyed, Fox Terrier, Siberian Husky

Additional Facts For Rectal Tumors

1. Causes

  • Hereditary
  • Overweight dogs
  • Rectal infection
  • Anal or rectal tears
  • Presence of colorectal polyps
  • Irritation from constant diarrhea
  • Entamoeba histolytica infection
  • Inflammatory bowel disease (IBD)


Primary rectal tumor: Cancer that originates in the colorectal region itself is called primary prostate cancer. Most primary rectal cancers are destructive and with high metastatic potential. For example, colorectal Adenocarcinomas (95 %).

Secondary rectal tumor:Cancer that spreads from another organ or metastasized to the colorectal region.

3. Mortality:

The mortality rate of benign types of rectal cancer is almost zero. Colorectal Adenocarcinoma is highly aggressive and it should be diagnosed early as well as treated promptly. Sadly less than 50% of dogs live more than 10- 12 months from the time of diagnosis of malignant colorectal tumors.

4. Diagnosis:

  • Complete blood count (CBC), blood chemistry profile
  • Electrolyte panel
  • Urinalysis/ Faecal analysis
  • Guaiac-based fecal occult blood test (gFOBT)
  • Gut biopsies: include mucosal biopsies of the stomach, duodenum, and/or ileal mucosa (ileostomy)

5. Prognosis:

Prognosis can differ based on the time of diagnosis and aggressiveness of the tumor. When the cancer is detected early, before any metastasis, radiation and chemotherapy treatment may be effective. When there is the presence of significant metastasis, vets may recommend against conventional treatment and will treat your dog’s clinical signs to make them comfortable.

When To See A Vet

Contact your vet right away, if you notice any of the following:

  • Narrow or ribbon-like Stools or bloody/black/ tarry stools
  • Chronic constipation or diarrhea

Food Suggestions For Rectal Tumors

  • High Protein, Good Fats and Low Carbs, antioxidants, and cancer-fighting nutrients.
  • Dogs: 50% veggies (dark leafy greens, carrots, broccoli, green beans, etc are good choices) + 50% protein (chicken or beef is best).
  • Fresh, lean protein (Lean ground beef, White-meat skinless chicken, or turkey).
  • Vitamin-rich fruits and veggies: legumes, such as lentils, peas or beans, cauliflower, cabbage, broccoli, tomatoes, and citruses, such as oranges and limes.


The most favorable prognosis can be expected with early detection and appropriate treatment. This emphasizes the significance of a rectal examination as part of a routine physical examination in all dogs.

For benign tumors, recovery is very good. Proper post-operative care should be provided for 3 months to monitor tumor regression. Malignant rectal tumor recovery is poor. Many dogs can die within a year from diagnosis or are sometimes euthanized.

dog care
dog health
dog breeds
dog food
dog training
dog insurance
Petmoo Tools
Essential Tools for Pet Owners
Top Rated Services In Your Neighborhood