Chronic Intestinal Pseudo-Obstruction in a Cat Caused by Visceral Myopathy

Chronic intestinal pseudo-obstruction associated with enteric ganglionitis in a Persian cat

Case summary A 7-year-old neutered male Persian cat was presented for acute vomiting and inappetence. Physical examination revealed severe abdominal distension. Radiographs demonstrated pneumoperitoneum, megaoesophagus and generalised gaseous distension of the digestive tract. Exploratory coeliotomy was performed, revealing markedly distended and thickened small and large intestines with no observable peristalsis. No intestinal perforation was present. Bacteriological and cytological analysis of abdominal fluid revealed a septic peritonitis involving Pasteurella multocida. Full-thickness intestinal biopsies demonstrated lymphocytic ganglioneuritis localised to the enteric nervous system, in association with glandular atrophy and muscular layer hypertrophy. Amoxicillin-clavulanate and analgesics were given. The cat’s general condition gradually improved after the addition of pyridostigmine bromide (0.5 mg/kg q12h PO), initiated 3 days postsurgery. Vomiting resolved and did not recur. Follow-up radiographs at 15 days, and 1 and 6 months showed persistent intestinal ileus, milder than on the pretreatment radiographs. Thirty months after presentation the cat is still alive, without clinical signs, and receives 1 mg/kg q12h pyridostigmine.

Relevance and novel information To our knowledge, this is the first case of ganglioneuritis of the myenteric plexus described in cats, as well as the first one successfully treated with pyridostigmine. Chronic intestinal pseudo-obstruction is a very rare condition in cats but should be included in the differential diagnosis of generalised gastrointestinal ileus.

Idiopathic Fibrosis of the Tunica Muscularis of the Large Intestine in Five Horses with Colic

Histological evidence of fibrosis affecting the outer layer of the large intestinal tunica muscularis was identified in five of 32 horses affected by colic. In three cases, foci of pale eosinophilia and vacuolation of myocytes were observed. These findings are suggestive of a degenerative and fibrotic abnormality in the outer layer of the tunica muscularis of the large intestinal smooth muscle of some horses with colic.

Intestinal Leiomyositis: A Cause of Chronic Intestinal Pseudo-Obstruction in 6 Dogs

BACKGROUND

Intestinal leiomyositis is a suspected autoimmune disorder affecting the muscularis propria layer of the gastrointestinal tract and is a cause of chronic intestinal pseudo-obstruction in humans and animals.

OBJECTIVE

To characterize the clinical presentation, histopathologic features, and outcome of dogs with intestinal leiomyositis in an effort to optimize treatment and prognosis.

ANIMALS

Six client-owned dogs.

METHODS

Retrospective case series. Medical records were reviewed to describe signalment, clinicopathologic and imaging findings, histopathologic diagnoses, treatment, and outcome. All biopsy specimens were reviewed by a board-certified pathologist.

RESULTS

Median age of dogs was 5.4 years (range, 15 months-9 years). Consistent clinical signs included vomiting (6/6), regurgitation (2/6), and small bowel diarrhea (3/6). Median duration of clinical signs before presentation was 13 days (range, 5-150 days). Diagnostic imaging showed marked gastric distension with dilated small intestines in 4/6 dogs. Full-thickness intestinal biopsies were obtained in all dogs by laparotomy. Histopathology of the stomach and intestines disclosed mononuclear inflammation, myofiber degeneration and necrosis, and fibrosis centered within the region of myofiber loss in the intestinal muscularis propria. All dogs received various combinations of immunomodulatory and prokinetic treatment, antimicrobial agents, antiemetics, and IV fluids, but none of the dogs showed a clinically relevant improvement with treatment. Median survival was 19 days after diagnosis (range, 3-270 days).

CONCLUSIONS AND CLINICAL IMPORTANCE

Intestinal leiomyositis is a cause of intestinal pseudo-obstruction and must be diagnosed by full-thickness intestinal biopsy. This disease should be considered in dogs with acute and chronic vomiting, regurgitation, and small bowel diarrhea.

R, Santos R. Chronic intestinal pseudo-obstruction in a dog: case report

Intestinal pseudo-obstruction is a rare disorder that affects gastrointestinal propulsion. It may be secondary to several pathological conditions or it may develop without a known cause. A 1.2 year-old intact Pug bitch had a history of vomiting and constipation, which were followed by diarrhea and distended abdomen. Hypomotility and dilation of the small intestine, which was filled with gas, were observed during laparotomy. Histologically, full thickness biopsy specimens demonstrated a severe loss and degeneration of leiomyocytes in the inner and outer muscular layers of the intestinal wall, whereas there was a marked hypertrophy and hyperplasia of smooth muscle cells in the lamina propria, and extremely thickened muscularis mucosae arranged in bundles oriented in different directions with marked hypertrophy and hyperplasia of leiomyocytes. Distribution of leiomyocytes was further characterized by immunohistochemistry. These findings support the diagnosis of intestinal pseudo-obstruction in a Pug, associated with degeneration and loss of leiomyocytes in the muscular layer.