Overview
Rectal prolapse is the protrusion of rectal tissue through the anus, often due to tenesmus (straining) stemming from underlying conditions like diarrhea, urogenital disorders, or respiratory issues. In cattle, it is most common in calves but also occurs in adults. Clinically, it presents as a cylindrical, moist, reddened mass extending externally from the anus (merckvetmanual.com).
Etiology & Risk Factors
- Enteric causes: coccidiosis, colitis, severe diarrhea
- Urinary causes: cystitis, urolithiasis, dystocia
- Respiratory causes: chronic coughing
- Other factors: rectal neoplasia, excessive riding in bulls, estrogenic diets (e.g., clover, soybean meal), genetic predisposition (cmapspublic3.ihmc.us, pmc.ncbi.nlm.nih.gov).
Classification
Grades range I–IV based on extent of tissue protrusion:
- I: mucosal-only
- II: full-thickness rectum
- III–IV: more severe, may include colon intussusception (skat.ihmc.us, cmapspublic3.ihmc.us).
Clinical Examination
- Visual identification: protruding cylindrical mass
- Palpation: differentiate from ileocolic intussusception by inability to pass a probe between mass and rectal wall (merckvetmanual.com)
- Assess tissue viability: edema, ulcers, necrosis
- Identify and treat primary cause (e.g., diarrhea, obstruction) (open.lib.umn.edu, merckvetmanual.com)
Treatment
- Conservative Tissue Management:
- Clean protruding tissue, apply lubrication
- Warm saline or hypertonic solution for edema
- Gentle manual reduction
- Place a temporary purse-string suture, leaving a small gap for defecation (merckvetmanual.com, pmc.ncbi.nlm.nih.gov)
- Adjunctive Measures:
- Caudal epidural anesthesia to reduce straining
- NSAIDs for pain relief
- Stool softeners and fluid support
- Address the underlying disease (antibiotics, antiparasitics, dietary changes) (merckvetmanual.com, sciencedirect.com)
- Surgical Intervention:
- Submucosal resection for partial-thickness necrosis
- Rectal amputation for full-thickness necrosis
- Colopexy or resection, rarely used in cattle (open.lib.umn.edu, vin.com)
Prognosis
- Good for early-stage (Grade I–II) with viable tissue and conservative treatment
- Guarded to poor for advanced grades, necrosis, or recurrent cases
- Grade III/IV often require surgical management and have higher complication rates
NAVLE-Style Multiple-Choice Questions
Question 1 – Diagnosis
A 3-month-old calf with coccidiosis shows a protruding cylindrical mass at the anus, mucosal only. A probe cannot be passed between the mass and rectal wall. What is the most likely diagnosis?
A. Vaginal prolapse
B. Rectal intussusception
C. Rectal prolapse (Grade II)
D. Uterine prolapse
E. Anal adenoma
Correct Answer: C
Explanation: The cylindrical protrusion and inability to pass a probe indicate full-thickness rectal prolapse (Grade II). Partial mucosa-only prolapse would allow separation (cmapspublic3.ihmc.us, merckvetmanual.com, en.wikipedia.org, edgemontvet.com, skat.ihmc.us).
Question 2 – Treatment
Initial treatment in a Grade II rectal prolapse with viable tissue should include:
A. Rectal amputation
B. Colopexy
C. Purse-string suture with lubrication and stool softeners
D. Epidural alcohol injection
E. Immediate feeding of high-estrogen clover
Correct Answer: C
Explanation: For viable rectal tissue in early stages, reduction and purse-string suture—combined with lubrication, analgesia, stool softeners—are the recommended conservative measures (merckvetmanual.com, cmapspublic3.ihmc.us).
Question 3 – Prevention/Etiology
Which is least likely to contribute to rectal prolapse in cattle?
A. Clover pasture producing phytoestrogens
B. Chronic coughing
C. Low-fiber high-starch diet
D. Short tail docking
E. Coccidiosis causing diarrhea
Correct Answer: D
Explanation: Short tail docking predisposes to rectal prolapse in sheep, not cattle. The other options—estrogenic diet, tenesmus from coughing or diarrhea, and high-grain diets—increase abdominal pressure and straining in cattle (pmc.ncbi.nlm.nih.gov, en.wikipedia.org, cmapspublic3.ihmc.us).
References
- Merck Veterinary Manual – Rectal Prolapse in Animals
- Anderson & Miesner (2008). Veterinary Clinics: Food Animal Practice – “Rectal prolapse in cattle and small ruminants”
- Alaa Samy et al. (2022). PMC Research – “Rectal prolapse risk factors in calves”
- University of Minnesota – Large Animal Surgery notes on prolapse
- Vetlexicon Bovis – “Rectal prolapse correction in cows”