Megacolon secondary to autonomic ganglioneuritis in a dog

Myenteric ganglionitis and intestinal leiomyositis in a Jack Russell terrier

A 9-year, 6-month old spayed female Jack Russell terrier presented with a 3-week history of intermittent vomiting, diarrhoea and weight loss. Serum biochemistry demonstrated severe panhypoproteinaemia, mild hypocalcaemia and mild hypocholesterolaemia, consistent with protein-losing enteropathy. Full-thickness biopsies obtained from the stomach and different sections of small intestine demonstrated histological features of both myenteric ganglionitis and early intestinal leiomyositis. Complete resolution of clinical signs occurred within 1 week of implementing immunosuppressive therapy. At the time of writing, 9 months following diagnosis, the dog remains in remission.

Loss of alpha-smooth muscle actin expression associated with chronic intestinal pseudo-obstruction in a young Miniature Bull Terrier

Background

Chronic intestinal pseudo-obstruction (CIPO) is a rare clinical syndrome in veterinary medicine characterized by severe intestinal dysmotility without evidence of mechanical occlusion of the intestinal lumen. The exact pathogenesis of CIPO is unknown.

Case presentation

A 1-year-old male Miniature Bull Terrier dog was presented with a history of chronic weight loss, regurgitation, lethargy, vomiting and diarrhea. The dog was submitted for exploratory laparotomy. A full thickness intestinal biopsy was taken and a CIPO was suspected. The clinical condition deteriorated and the dog was euthanized. At gross examination the small intestine was severely dilated. Histologically severe fibrosis of the submucosa and severe atrophy of the tunica muscularis were present in small intestine and colon. Immunohistochemical examination with a panel of antibodies for gastro-intestinal neuromuscular disease-associated antigens revealed a severely reduced expression of alpha-smooth muscle actin in the tunica muscularis.

Conclusions

This case report describes the gross, histological and immunohistochemical findings of CIPO affecting a 1-year-old Miniature Bull Terrier; on the basis of these findings a myopathic form of CIPO is hypothesized in this case.

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.