Contributors: Julien Bazelle, Ed Hall, Kenneth Simpson
Species: Feline | Classification: Miscellaneous
- Most common cause of chronic vomiting Vomiting and diarrhea Diarrhea: overview.
- Cause: any idiopathic inflammatory condition of the small or large intestine:
- Signs: chronic gastroenteritis (diarrhea and vomiting), weight loss.
- Characterized by infiltration of gastrointestinal tract with inflammatory cells including:
- Plasma cells.
- Diagnosis: idiopathic nature makes it a diagnosis of exclusion.
- Treatment: dietary change, immunosuppressive therapy (prednisolone/azathioprine/chlorambucil).
- Prognosis: good with appropriate treatment.
Print off the owner factsheet on Inflammatory bowel disease Inflammatory bowel disease to give to your client.
- Underlying cause unknown but immune mechanisms involving the response of the gut-associated lymphoid tissue (GALT) implicated:
- Genetic factors, eg major histocompatibility type.
- Specific defects in the immune system.
- Mucosal and/or systemic infection (viral, bacterial or parasitic).
- Abnormal or inappropriate antigen presentation.
- Complement activation, mast cell degranulation and T-cell and macrophage activation → active inflammation.
- Location and relative amount of inflammatory mediators depend on inciting factors and immune response → variable clinical and pathological presentations.
- Possible progression from IBD to lymphoma Lymphoma in some cases.
- Hypersensitivity to luminal dietary or microbial antigens implicated.
- IBD is often found concurrently with other diseases, such as cholangiohepatitis Liver: cholangitis, and Pancreatitis Pancreatitis. The concurrent occurrence of these three disorders in cats is termed "triaditis".
- Baseline information is necessary to exclude other causes.
- A clinical scoring system has been developed by Texas A&M to measure severity of disease and response to treatment Feline Chronic Enteropathy Activity Index Score (FCEAI).
- Routine parameters Hematology: complete blood count (CBC) may be normal, but occasionally see mild anemia (anemia of chronic disease, GI blood loss, cobalamin deficiency Blood biochemistry: vitamin B12).
- Leukocytosis (mature neutrophilia) may also be seen.
- Routine parameters Blood biochemistry: overview maybe normal.
- Hypoproteinemia Blood biochemistry: total protein may occur in severe cases.
- +/- liver enzymes increased.
- Ionized hypocalcemia Blood biochemistry: ionized calcium, hypovitaminosis D (Lalor et al, 2014).
- Cobalamin/folate Blood biochemistry: folate concentrations may be low.
- Hypophosphatemia Blood biochemistry: phosphate in approximately 50% cases.
- TLI Blood biochemistry: trypsin-like immunoreactivity may be high without obvious pancreatic disease.
- fPLI Feline pancreatic lipase immunoreactivity (fPLI) test may be increased.
- FeLV antigen FeLV test and FIV antibody testing FIV test (may be part of panel when investigating weight loss).
- Urinalysis Urinalysis: dipstick to rule out protein losing nephropathy Glomerulonephritis, diabetes mellitus Diabetes mellitus as causes of weight loss.
- Fecal analysis Fecal analysis: overview for parasitic and bacterial infections, eg Tritrichomonas Tritrichomonas foetus infection , salmonellosis Salmonellosis).
- Increased fecal alpha1-proteinase inhibitor concentration: severity marker (Burke et al, 2013).
- For diet-responsive conditions (rarer in cats than in dogs).
- For antibiotic responsive conditions (rarer in cats than in dogs).
- Plain and contrast films Radiography: gastrography Radiography: large intestine contrast.
- Usually unremarkable or non-specific findings (mucosal irregularities or thickened bowel segments).
- +/- thickened GIT Ultrasonography: GI system. Older cats with thickened muscularis layer more likely to have lymphoma than IBD (Zwingenberger et al, 2010).
- Raised lymph nodes.
- +/- hepatic/pancreatic abnormalities.
- To examine intestinal mucosa - often granular, friable lesions or erosions Flexible endoscopy Gastroscopy.
- May be normal - lesions can be microscopic.
- Intestinal biopsy is the only method of definitive diagnosis. Endoscopic biopsy safest; surgical biopsy to assess muscularis and to sample pancreas/liver.
- Biopsy several sites (6-15 depending on quality of biopsies) because signs do not always correlate with site of pathology. Biopsy of both duodenum and ileum increases likelihood to reach diagnosis.
- Lymph node biopsy/aspirate Cytology: lymph node aspirate should be taken if lymphadenopathy Lymphadenopathy is detected.
- Usually lymphocytic-plasmacytic or eosinophilic infiltrate predominates.
- In chronic cases mucosal villus atrophy and fibrosis may be severe.
- Sometimes difficult to differentiate lymphocytic inflammation with low grade small cell lymphoma Lymphoma. Assess immunohistopathology for immunophenotyping or polymerase chain reaction (PCR PCR (Polymerase chain reaction) ) results for B and/or T cell clonality (Kiupel et al, 2011).
- Liver and pancreas histopathology: lymphocytic-plasmacytic inflammation.
- Triaditis (cholangiohepatitis Liver: cholangitis and pancreatitis Pancreatitis with IBD).
- Hyperthyroidism Hyperthyroidism.
- Trichonomonas Tritrichomonas foetus infection, giardiasis Giardiasis and other infectious gastrointestinal diseases.
- Lymphoma Lymphoma.
- Feline infectious peritonitis (FIP) Feline infectious peritonitis.
- Colitis Colitis.
- Exocrine pancreatic insufficiency Exocrine pancreatic insufficiency.