Introduction

• Often included under term inflammatory bowel disease (IBD).
• A common cause of chronic diarrhea in dogs.
• Cause: food hypersensitivity, bacterial infection, parasites, frequently not determined.
• Signs: increased frequency of defecation with fecal tenesmus; feces often with blood and mucus.
• Diagnosis: colonoscopy, histopathology.
• Treatment: depends on causes (dietary modification, sulfasalazine, antibiotics +/- corticosteroids and motility modifiers).
• Prognosis: guarded for resolution (relapses common).
  Print off the owner factsheet on Colitis to give to your client.

Pathogenesis

Etiology

• Unknown - considered to be an immune-mediated response to a luminal antigen such as bacteria or diet.
• Bacterial etiology proposed on basis of response to antibiotics, eg Campylobacter spp Campylobacter jejuni , Salmonella spp Salmonella spp and Clostridium spp.
• Parasitic and infectious causes include whipworm Trichuris vulpis (Trichuris spp), Giardia spp Giardia duodenalis.

Pathophysiology

• Mucosal damage → inflammatory response → abnormal motility and failure to absorb fluid and electrolytes from feces; also decreased intestinal transit time → increased frequency of defecation.
• Inflammation → stimulation of Goblet cells → produce mucus.
• Rectal inflammation → urgency to defecate.
• Vomiting observed in 30% of cases due to colonic inflammation, NOT gastric.

Timecourse

• Variable onset, often no inciting factor recognized.
• Often recurs in bouts lifelong.

Diagnosis

Treatment

Outcomes