Chronic enteropathy / inflammatory bowel disease

WSAVA guideline

Key findings

• 5 criteria (all required): (1) chronic GI signs > 3 weeks; (2) histopathologic mucosal inflammation; (3) other causes excluded; (4) inadequate response to dietary, antibacterial, anthelmintic trials; (5) clinical response to anti-inflammatory/immunosuppressive agents (§Definition of IBD). Breeds: Siamese, GSD, Basenji, Wheaten, Shar Pei.
• CE spectrum: IBD responds to immunosuppressives but NOT to dietary or antibiotic therapy alone.
• Biopsy numbers: cat ~6 marginal-or-adequate stomach/duodenum samples diagnose villus atrophy + mild-to-moderate infiltration; dog ~6–7 adequate or 10–15 marginal gastric/duodenal; canine duodenal crypt lesions ~13 adequate or 28 marginal; skilled endoscopists need fewer (§Endoscopic Biopsy).
• Adequate sample = at least 3 villi with full mucosal depth (mucosa–muscularis mucosae border); inadequate = villus tips only (Figs 1–3).
• Duodenal lesions (Table 3): villus stunting, epithelial injury, crypt distension, lacteal dilation, mucosal fibrosis + IEL, LP lymphocytes/plasma cells, LP eosinophils, LP neutrophils — each 0–3 at 40×. Dog anchors: villus 722±170 μm, crypt 1,279±203 μm, V:C 0.7±0.3; cryptal-LP leukocytes 156.3±24.9 vs tip 100.7±43.9; cryptal eosinophils 9.8±7.5 per 10,000 μm².
• Lymphoma vs IBD: 2 feline variants — small-cell lymphocytic villus T-cell (older cats) and large-cell lymphoblastic (any age, aggressive). HE often insufficient → IHC CD3/CD79a (32-cat study: 5 "lymphomas" were IBD); TCRG clonality: polyclonal 9/9 IBD vs clonal 22/28 T-cell lymphoma cats; IHC retains precedence; both on paraffin tissue from one biopsy set.
• Histology ↔ clinic: lacteal dilation ↔ hypoalbuminemia; severity at diagnosis did not predict 3-year outcome (70 dogs); prednisone+metronidazole or cyclosporine improved signs without histologic change — biopsy documents inflammation but cannot alone diagnose or prognose.
• Helicobacter: IBD- vs Helicobacter-gastritis often indistinguishable on HE; dual inflammation + mucosal invasion (Warthin-Starry/PCR/FISH) differentiates.

Drugs named in WSAVA’s own guideline text

As printed in WSAVA’s document, not this app’s own extracted data — see “Related drugs in this reference” below for that.

• Prednisone (🐕) — [dose not printed in source]

  With metronidazole — improved signs, no significant histologic change

• Metronidazole (🐕) — [dose not printed in source]

  Partner to prednisone in same study

• Cyclosporine (🐕) — [dose not printed in source]

  Clinically successful; duodenal lymphocytes unchanged

• Anti-inflammatory / immunosuppressive agents (🐕🐈) — [dose not printed in source]

  Criterion 5 — response defines IBD within the CE spectrum

• Antibacterial / anthelmintic / probiotic trials (🐕🐈) — [dose not printed in source]

  Pre-diagnosis therapeutic trials (criterion 4)

• NSAIDs (🐕🐈) — [dose not printed in source]

  Named as gastritis cause, not IBD therapy

Recommendations

• Diagnose IBD only with all 5 criteria; run diet/antibacterial/anthelmintic trials BEFORE the label

  Consensus — Conclusion (b)

• Endoscopic biopsy preferred; EARLY with severe weight loss, poor BCS, anorexia, hypoalbuminemia, US infiltrates

  Consensus — Conclusion (a)

• Biopsy the ileum whenever gastroduodenoscopy/colonoscopy is performed

  Consensus — Conclusion (a)

• Sample counts: cat ~6; dog 6–7 adequate or 10–15 marginal; crypt lesions 13/28

  Evidence-based (Class II/III)

• Insist path reports state sample number + quality (adequate/marginal/inadequate); use WSAVA grading (40×, 0–3)

  Consensus — Conclusions (d), (e)

• If HE cannot separate small-cell lymphoma: IHC CD3/CD79a ± TCRG clonality; IHC retains precedence

  Group endorsement of cited evidence

• Do not separate IBD- vs Helicobacter-gastritis on HE alone; histology alone cannot diagnose or prognose

  Group conclusion

Related drugs in this reference (6)

The quoted line under each drug is its own already-extracted indication text that matched this condition — the reason it’s listed, not a paraphrase. Open a drug for its full species/route breakdown, calculator, and complete adverse-effect list.

Showing 6 of 6 linked drug records. Open a record for species, route and source details.

• AZATHIOPRINE

  “IMHA, pemphigus, IBD, other immune-mediated diseases (steroid-sparing)”

  Source dose preview: 2 mg/kg initial, q24h, PO (Dog)

  Adverse-effect notes: **Bone marrow suppression (leukopenia, anemia, thrombocytopenia)** — **Principal adverse effect** · GI upset, poor hair growth, pancreatitis, hepatotoxicity — Reported

• CHLORAMBUCIL

  “**Chronic low-grade intestinal lymphoma (with prednisolone); refractory/severe IBD; pemphigus foliaceus; eosinophilic granuloma complex** — preferred over cyclo…”

  Source dose preview: 0.1–0.2 mg/kg, q24–48h, PO (Dog)

  Adverse-effect notes: Myelosuppression (mild, gradual) — Lower than cyclophosphamide — the point of choosing it · GI toxicity, anorexia — Occasional

• CLONIDINE

  “Refractory IBD adjunct (4th-line per Washabau)”

  Source dose preview: 0.01–0.05 mg/kg, q12h, PO (Dog)

  Adverse-effect notes: Sedation — Common · **Hypotension, collapse, bradycardia** — Cardiovascular core effects

• CYCLOSPORINE

  “Atopic dermatitis (well-established, similar efficacy to prednisolone), perianal fistulas, IMHA (refractory), IBD”

  Source dose preview: 5 mg/kg (range 2.5–7 mg/kg), q24h x 30 days, then taper to EOD/2x-week, PO, ≥1h before or 2h after meal (Dog)

  Adverse-effect notes: Vomiting, anorexia, diarrhea — Most common, especially early in therapy · Gingival hyperplasia, hypertrichosis, papillomatosis — With chronic use

• METRONIDAZOLE

  “Giardia, other enteric protozoa, anaerobic infections, adjunct for IBD/colitis”

  Source dose preview: 15–25 mg/kg, q12–24h x 5–7 days, PO (Dog)

  Adverse-effect notes: **Neurotoxicity (ataxia, nystagmus, head tilt, seizures)** — **Dose-related, typically >60 mg/kg/day or chronic "recommended" dosing** · Hepatotoxicity, vomiting, anorexia — Reported

• TYLOSIN

  “Chronic enteropathy / antibiotic-responsive diarrhea (ARD); tylosin-responsive diarrhea; tear staining (epiphora, extra-label cosmetic)”

  Source dose preview: 20–40 mg/kg (or 25 mg/kg fixed), q12h (or q24h), PO (Dog)

  Adverse-effect notes: GI upset (anorexia, diarrhea) — Main oral effect · Pain/local reaction at IM injection sites — Injectable use (rare parenteral use in small animals)