Difficult Defecation and Blood in Stool in Dogs

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Dyschezia and Hematochezia in Dogs

Dyschezia and Hematochezia are diseases of the digestive and intestinal system; both are visible presentations of an underlying disease that causes inflammation or irritation of the rectum or anus.

Dyschezia is a condition in which defecation is extremely difficult or painful, and hematochezia is symptomized by bright red blood in the stool. Hematochezia can also be concurrent with diseases of the colon.

Symptoms and Types

  • Crying and whimpering during defecation
  • Straining to defecate
  • Inability to defecate
  • Mucosal, bloody diarrhea
  • Hard feces
  • Diarrhea
  • Lumps around the anus
  • Draining pus tracts around the anus
  • The anus is blocked by mats of hair and/or feces


Rectal/Anal Disease

  • Stricture or spasm
  • Anal sac abscess or inflammation
  • Draining tracts around the anus
  • Rectal or anal foreign body
  • The anus is blocked by mats of hair and feces
  • The rectum is hanging out of the anus
  • Traumas – bite wounds, etc.
  • Cancer
  • Rectal polyps
  • Mucocutaneous lupus erythematosus (an immune disease)

Colonic Disease

  • Cancer
  • Idiopathic megacolon (disease of unknown causes, where the colon expands with feces instead of releasing the feces normally)
  • Inflammation
  • Inflammatory bowel disease
  • Infectious parasitic agents
  • Allergic colitis
  • Constipation

Extra-intestinal Disease (outside of the intestinal tract)

  • Fractured pelvis or hind limb
  • Disease of the prostate
  • Perineal hernia (a hernia around the anus)
  • Cancer


You will need to give a thorough history of your dog's health and onset of symptoms. Your veterinarian will perform a complete physical exam on your dog, including a blood chemical profile, a complete blood count, an electrolyte panel and a urinalysis. If an underlying disease is causing inflammation or infection of any part of the intestinal tract, the complete blood count should show this.

Your doctor may also use x-ray imaging to visually inspect the abdominal space. This diagnostic method can detect many of the disorders that affect the digestive tract, including foreign bodies in the stomach or intestinal tract, or internal fractures. An abdominal ultrasound can deliver even greater visualization than an x-ray, enabling your veterinarian to detect disease of the prostate, or masses in the lower abdomen.

Your veterinarian may also employ another useful diagnostic procedure to visually inspect the internal space and to take a tissue sample for laboratory testing. A colonoscope or proctoscope, both of which are very slender instruments that are designed to be guided into and through the body's internal pathways – in this case the rectum. These instruments have micro cameras attached at the end so that your veterinarian can see the internal space, and that can also be equipped with a tool for taking a tissue samples for biopsy. These tools are especially useful for the diagnosis of inflammatory diseases or cancer.

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