Gastrointestinal conditions

Alpha-1-antitrypsin related hepatitis

A form of chronic progressive hepatitis associated with the accumulation of the acute-phase protein alpha-1-antitrypsin.


Amyloidosis results from the deposition of an insoluble fibrillar protein (amyloid) in a variety of organs, resulting in organ dysfunction. It may occur as an abnormal response to inflammatory or lymphoproliferative disease.

Antral pyloric hypertrophy syndrome (pyloric stenosis)

In this syndrome, gastric-outlet obstruction is caused by hypertrophy of the pyloric muscle, hyperplasia of the antral mucosa or both, and results in persistent vomiting. Congenital hypertrophy of the pyloric muscle is seen in young Boxers and Boston Terriers and may be referred to as congenital pyloric stenosis.

Adult-onset antral pyloric hypertrophy syndrome is seen in older (>6 years) small Oriental canine breeds. In these cases there may be antropyloric mucosal hyperplasia only or a combination of mucosal and muscular hypertrophy.


The development of gallstones. Gallstones are uncommon in the dog and where found are usually asymptomatic.

Chronic hepatitis

Inflammatory liver disease which usually progresses to cirrhosis. There are many types of hepatitis, and classification remains controversial, however certain breeds of dog may be predisposed, and individual breeds may demonstrate particular patterns of inflammation.

Chronic idiopathic (lymphocytic-plasmacytic) colitis

Colonic inflammation characterised by the presence of large numbers of lymphocytes and plasma cells in the mucosa. Patients have chronic, intermittent large-bowel-type diarrhoea.

Cleft palate

A congenital defect in the hard or soft palate allowing abnormal communication between the oral cavity and the nasal cavity/nasopharynx.

Congenital bronchoesophageal fistula

This is an abnormal communication between the oesophagus and a bronchus resulting from incomplete separation of these structures in the developing embryo. Symptoms of regurgitation and coughing (especially after eating and drinking) are seen.

Congenital polycystic liver disease

Multiple hepatic cysts usually derived from the bile duct epithelium. They may be associated with cysts in other organs (especially the kidneys). Cysts may also be seen as an acquired lesion.

Congenital portosystemic shunts

Failure of foetal venous shunts to close after birth leads to persistent shunting of blood from the gastrointestinal tract to the systemic circulation without hepatic metabolism. Shunts may be single or multiple, intrahepatic or extrahepatic. Large breeds of dog are more likely to have intrahepatic shunts than small breeds.

Copper storage hepatopathy

Copper accumulation in the liver may be the result of a primary defect in copper excretion resulting in hepatic necrosis, as seen in the Bedlington. Alternatively, copper may accumulate as a result of chronic hepatitis and reduced biliary excretion.

Cricopharyngeal achalasia

Difficulty in swallowing due to failure of the cricopharyngeal sphincter (the upper oesopha-geal sphincter) to relax.

Diarroheal syndrome of Lundehunds

A chronic progressive form of lymphocytic-plasmacytic enteritis specific to this breed.


Difficulty swallowing.

Eosinophilic gastroenteritis, enteritis and enterocolitis

Chronic inflammatory disease of the stomach and small intestine, small intestine only, or small intestine and colon. Eosinophilic infiltration is a predominant feature of the inflammation and peripheral eosinophilia may also be present.

Exocrine pancreatic insufficiency

Inadequate production of digestive enzymes leading to malabsorption and chronic diarrhoea. This is most commonly due to Pancreatic acinar atrophy, or occasionally due to chronic pancreatitis or pancreatic neoplasia.

Gastric carcinoma

A primary, malignant stomach tumour derived from epithelial cells.

Gastric dilatation/volvulus

Gastric distension due to the rapid accumulation of food, fluid or gas resulting in torsion of the stomach. Usually an acute and severe condition which is rapidly fatal without treatment. Large deep-chested dogs are predisposed.

Gastric neoplasia

Primary stomach tumours include gastric carcinomas, lymphosarcoma, leiomyoma/sarcoma, adenomatous polyps, fibroma/fibrosarcoma, plasmacytoma and squamous cell carcinoma.

Gastro-oesophageal intussusception

Invagination of the stomach into the thoracic oesophagus. A rare condition with high mortality.

Gastrointestinal eosinophilic granuloma

Chronic inflammatory masses which may be found anywhere in the gastrointestinal tract. Histologically, the predominant cell type is the eosinophil.

Gluten-sensitive enteropathy

An intolerance to gluten-containing foods, most commonly seen in Irish Setters. Weight loss and chronic diarrhoea due to malabsorption are seen.


See under Neoplastic conditions.

Haemorrhagic gastroenteritis

A haemorrhagic diarrhoea syndrome of unknown cause.

Hepatic lipidosis

A potentially severe liver disease wherein hep-atocyte function is compromised by extensive lipid accumulation. Seen most commonly in anorexic, obese female cats, but occasionally seen in puppies of toy breeds.

Hiatal hernia

Displacement of part of the stomach or other abdominal organs cranially through the oseo-phageal hiatus in the diaphragm. The condition may be congenital or acquired.

Histiocytic colitis

Chronic inflammatory disease of the colon characterised histologically by an inflammatory infiltrate with large numbers of histiocytes. Ulceration of the mucosa may be a prominent feature and the disease tends to be refractory to treatment.

Hypertrophic gastritis

A chronic condition of the stomach characterised by hypertrophy of the mucosa. A diffuse form is seen in the Basenji, whereas a focal form affecting primarily the antrum (part of the Antral pyloric hypertrophy syndrome) is seen in small breeds of dog.

Idiopathic hepatic fibrosis

Fibrosis of the liver of unknown cause which is seen without preceeding active inflammation. Various patterns of fibrosis are described. The condition is mostly seen in young dogs. Fibrosis results in portal hypertension, vascular shunting, ascites and hepatic encephalopathy.

Immunoproliferative enteropathy of Basenjis

A specific disease of Basenjis, of unknown cause. Several forms of pathology may be identified in the gastrointestinal tract including hypertrophic gastritis and lymphocytic-plasmacytic enteritis resulting in chronic diarrhoea and protein-losing enteropathy.

Intestinal adenocarcinoma

A malignant tumour found most frequently in the colon of dogs and the jejunum and ileum of cats. Most are locally invasive and metastasise early to the lymph nodes and liver.

Lobular dissecting hepatitis

A form of progressive hepatitis where there is a random pattern of inflammation and fibrosis leading to weight loss and ascites. Seen mostly in young dogs.


Distension of the lymphatic vessels in the intestinal mucosa. It may be a primary congenital disease, or it may be secondary to other disorders including right-sided heart failure or lipogranulomatous inflammation.

Lymphocytic-plasmacytic enteritis

A form of inflammatory bowel disease in which the cellular infiltrate of the intestinal mucosa is mainly composed of lymphocytes and plasma cells.


Dilation of the colon which results in constipation.


Oesophageal dilation and reduced motility resulting in regurgitation. Megaoesophagus can be classified as congenital idiopathic megaoesophagus, which presents shortly after weaning, adult-onset idiopathic megaoesophagus which occurs later in life or secondary megaoesophagus where an underlying primary cause can be found.

Microvascular portal dysplasia

Congenital malformation of the intrahepatic portal circulation resulting in vascular shunting and hepatic dysfunction.

Oral eosinophilic granuloma of the Siberian Husky

Raised, ulcerative lesions usually seen on the lateral and ventral areas of the tongue.

Oropharyngeal neoplasia

The most common canine oropharyngeal tumours are squamous cell carcinomas, malignant melanomas, epulides and fibrosarcomas. The most common feline oropharyngeal tumours are squamous cell carcinomas and fibrosarcomas.

Pancreatic acinar atrophy

A condition where there is spontaneous and progressive loss of pancreatic acinar cells, responsible for the production of digestive enzymes, leading to Exocrine pancreatic insufficiency.

Pancreatic carcinoma

A tumour of the duct cells of the pancreas. Uncommon, but usually highly malignant.


Inflammation of the pancreas.

Parvovirus enteritis

An infectious viral disease which most commonly causes a severe gastroenteritis, however may also manifest as acute myocarditis or neonatal mortality.

Perianal fistula (anal furunculosis)

Chronically infected and often deep tracts in the soft tissues around the anus.

Portosystemic shunts

See Congenital portosystemic shunts.

Protein-losing enteropathy

Excessive loss of plasma proteins via the gastrointestinal tract. It is seen with a number of gastrointestinal and systemic disorders, but particularly with inflammatory enteropathies and lymphangiectasia.

Pyloric dysfunction

Delayed gastric emptying with no evidence of pyloric stenosis. Seen in Siamese cats.

Pyloric stenosis

See Antral pyloric hypertrophy syndrome.

Rectal Prolapse

Eversion of the rectum through the anus. Generally seen in young animals.

Salivary mucocoele

An accumulation of saliva in the subcutaneous tissues.

Selective malabsorption of cobalamin (vitamin B12)

Malabsorption of vitamin B12 (cobalamin) may occur as a result of an absence of the appropriate receptors in the ileum. The condition is inherited in the Giant Schnauzer and symptoms include inappetance, failure to grow and anaemia.

Small intestinal bacterial overgrowth (SIBO)

Increased numbers of bacteria in the upper small intestine associated with chronic diarrhoea. SIBO is often a secondary condition, however in some cases it may be primary with no evidence of other underlying gastrointestinal disease.

Small-intestinal volvulus

A rare condition where the small intestine rotates about its mesenteric axis resulting in intestinal obstruction and ischaemia. The condition is rapidly fatal.

Tuberculosis (See also Mycobacterial infections under Infectious conditions)

Infection with a species of Mycobacterium. Infection may be gained by the oral, respiratory or percutaneous routes and usually gives rise to granulomas in the affected organs. Infected animals are a public health risk.

Vacuolar hepatopathy

A type of liver disease (seen primarily in Miniature Schnauzers with hyperlipidaemia) wherein the hepatocytes appear severely vacuo-lated on biopsy.

Vascular ring anomaly

Congenital abnormalities of the major thoracic arteries leading to entrapment of the oesophagus and clinical signs of regurgitation at or after weaning. Persistent right aortic arch is the most common vascular ring anomaly.