Lymphocytic / plasmacytic enteritis in Cats (Felis) | Vetlexicon
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Lymphocytic / plasmacytic enteritis

ISSN 2398-2950


  • An idiopathic chronic inflammatory disease of small and/or large intestine Inflammatory bowel disease: overview.
  • Cause: unknown; immune-mediated sensitivity to range of possible antigens, eg diet, parasite, bacteria etc.
  • Signs: vomiting, diarrhea and weight loss.
  • Diagnosis: intestinal biopsy and histopathology, (infiltration of lamina propria by lymphocytes and plasmacytes).
  • Treatment: diet and immunosuppression.

Presenting signs

  • Chronic vomiting.
  • Diarrhea.
  • Weight loss.




  • Hypothesized hypersensitivity to antigen(s)   →   chronic inflammation   →   loss of mucosal integrity and increased permeability   →   antigens can access lamina propria   →   further immune reaction and inflammation   →   malabsorption   →   protein-losing enteropathy.
  • May be a non-specific reaction to a variety of agents.


  • Chronic.


Presenting problems

  • Diarrhea.
  • Vomiting.
  • Weight loss.
  • Anorexia.

Client history

  • Chronic intermittent gastrointestinal problems ranging from a few weeks to several years.
  • Clear or bilious foamy vomit, (usually related to duodenal inflammation).
  • Usually unrelated temporally to eating.
  • Anorexia.
  • Chronic diarrhea.
  • Diarrhea of small intestinal origin (enteritis) - ranges from soft/semi formed to profuse watery; may be steatorrhea.
  • Diarrhea of large intestinal origin (colitis) - increased frequency of defecation, urgency, tenesmus, mucus, hematochezia.
  • Weight loss.

Clinical signs

  • Thickened intestinal loops.
  • Enlarged mesenteric lymph nodes.
  • Symmetric alopecia.
  • Poor body condition + haircoat.

Diagnostic investigation

  • Baseline information is necessary to exclude differential diagnoses.




  • Thickened intestinal loops.
  • Mesenteric lymphadenopathy.
  • Peritoneal effusion.


  • To examine intestinal mucosa.
  • Often grossly normal - lesions often microscopic.
  • Pathology may be diffuse.
  • Signs may not correlate with area of greatest infiltration.
  • Erythema, increased friability, increased surface granularity.
  • Erosions, ulcers.
  • In colon - petechiae, dry granular surface with strands of mucus and occasional ulceration.


  • Endoscopic or surgical biopsies from stomach, duodeum, jejunum, colon, ileum (if possible).
  • Inflammatory infiltrates in lamina propria of lymphocytes, plasmacytes, eosinophils and neutrophils.


(Generally less useful than ultrasound in investigation of diarrhea or IBD)

  • Plain and contrast films.
  • Usually unremarkable or non-specific findings.
  • May reveal unexpected alternative diagnosis.
  • Fluid and gas-distended bowel loops.
  • Diffuse mucosal irregularities.

Hormone assay


  • FeLV antigen FeLV test.
  • FIV antibody FIV test.
  • Depressed cobalamin levels are relatively common Low serum folate and cobalamin suggests severe IBD or intestinal lymphoma.


Fecal analysis

Therapeutic trials

  • For diet-responsive conditions, eg food hypersensitivity/intolerance.
  • For antibiotic responsive conditions, eg occult giardiasis, bacterial enteritis.

Confirmation of diagnosis

Discriminatory diagnostic features

  • Hematology.
  • Biochemistry.
  • Serology.
  • Ultrasonography.
  • Radiology.
  • Endoscopy.

Definitive diagnostic features

  • Histopathology.

Gross autopsy findings

  • Rapid intestinal autolysis, so examine and fix tissues promptly. Villus architecture critical thus handle with great care.
  • Examine other organ systems to rule out other causes of weight loss: kidney, liver, pancreas, neoplasia, chronic inflammation etc.
  • Often intercurrent IBD, pancreatitis and liver disease (cholangiohepatitis) in cats.

Histopathology findings

  • Fix stomach, duodenum, jejunum (multiple sites), ileum, colon, liver, kidney, pancreas, mesenteric node. Fix serosal side on card to avoid curling.
  • Moderate to severe diffuse infiltration of lamina propria with mature lymphocytes and plasmacytes, occasionally extending to submucosa.
  • Mucosal damage, eg atrophic or fused villi, fibrosis, epithelial hyperplasia, degeneration, ulceration.
  • Maybe other inflammatory cells.
    Criteria for an unequivocal diagnosis of lymphocytic-plasmacytic enteritis/colitis must include increased lymphocytes in the lamina propria and altered mucosal structure.
  • Severe infiltration of lymphocytes beyond mucosa suggests lymphoma. Take full-thickness biopsy.

Differential diagnosis

  • Hepatic disease Liver: chronic disease.
  • Eosinophilic enteritis.
  • Lymphangiectasia.
  • Dysphagia/swallowing disorders.
  • Chronic vomiting/regurgitation.
  • Small intestinal bacterial overgrowth.
  • Drug therapy.
  • Gluten sensitive enteropathy.
    Often intercurrent IBD, pancreatitis and liver disease (cholangiohepatitis in cats).


Standard treatment

  • Combination of dietary modification and immunosuppressive/anti-inflammatory.

Dietary therapy

  • Highly digestible, high-quality diet.
  • Single protein antigen-restricted diets (containing a protein to which the cat has not been sensitized).
  • Protein hydrolysate-based diet.
  • Can be home-prepared or commercial Dietetic diet: for nutrient intolerance.
  • Some relapse on conversion from home-prepared to commercial diets.
  • Use easy to assimilate carbohydrate, eg rice in 2:1 ratio to protein source.
  • Balance home-made diets with taurine, vitamins and minerals.
  • Fiber enriched diets may be useful to ameliorate diarrhea in colitis.


  • Oral prednisolone Prednisolone, 2-4 mg/kg divided BID.
  • Expect improvement within 1-2 weeks.
  • After 2 weeks of remission, taper in 2-4 week increments to effective alternate day dosage (around 0.5-1.0 mg/kg).
  • Dexamethasone Dexamethasone 0.2 mg/kg PO BID-SID is sometimes more effective in refractory cases.

Subsequent management


  • After 8-12 weeks, discontinue anti-inflammatories for trial period (many cases relapse).
  • If diet and prednisolone Prednisolone  unsuccessful, try tylosin or metronidazole   Metronidazole10-15 mg/kg BID for immunomodulatory effect and may be useful in reducing bacterial antigens. Long-term metronidazole therapy (>2 weeks) is contraindicated as it is mutagenic.
    Metronidazole tablets have an unpleasant taste, so a liquid suspension may ease administration.
  • Tylosin Tylosin  or doxycycline Doxycycline , 5 mg/kg BID may be useful if bacterial etiology is suspected.
  • Immuno-suppressive agent for most refractory cases, eg Chlorambucil Chlorambucil.
    Reduce steroid dose by 50%.




  • Fair.
  • May need life-long treatment.

Expected response to treatment

  • Resolution of clinical signs within 1-2 weeks of treatment starting.
  • Weight gain over 4-8 weeks.

Reasons for treatment failure

  • Dietary indiscretion in some cases.

Further Reading


Refereed papers

  • Recent references from PubMed and VetMedResource.
  • Guilford W G, Jones B R, Markwell P J et al (2001) Food sensitivity in cats with chronic idiopathic gastrointestinal problems. JVIM 15 (1), 7-13 PubMed.
  • Simpson K W, Fyfe J, Cornetta A et al (2001) Subnormal concentrations of serum cobalamin (vitamin B12) in cats with gastrointestinal disease. JVIM 15 (1), 26-32 PubMed.
  • Weiss D J, Gagne J M & Armstrong P J (1996) Relationship between inflammatory hepatic disease and inflammatory bowel disease, pancreatitis, and nephritis in cats. JAVMA 209 (6), 1114-1116 PubMed.
  • Yamasaki K, Suematsu H, Takahashi T (1996) Comparison of gastric and duodenal lesions in dogs and cats with and without lymphocytic-plasmacytic enteritis. JAVMA 209 (1), 95-97 PubMed.
  • Edwards D F, Russell R G (1987) Probable vitamin K-deficient bleeding in two cats with malabsorption syndrome secondary to lymphocytic-plasmacytic enteritis. J Vet Intern Med (3), 97-101 PubMed.
  • Willard M D, Dalley J B, Trapp A L (1985) Lymphocytic-plasmacytic enteritis in a cat. JAVMA 186 (2), 181-182 PubMed.