Chronic enteropathy in dogs: hydrolysed-protein diet vs intact-protein diets — POSSIBLE

In dogs with chronic enteropathy, how does a hydrolysed-protein diet compare with intact-protein diets (highly digestible or limited-ingredient) for achieving and maintaining remission of clinical signs?

Shelf #156 · gate-verified and approved by the developer

POSSIBLE: The two randomised diet trials point in different directions, and neither tested a novel intact-protein diet as such. In Mandigers 2010, dogs on a hydrolysed diet were no more likely to have responded at the first re-evaluation (about 3 months; P = .87) but significantly more remained asymptomatic at 6-12 months (P = .0012) and at 3 years (P < .001), with a greater fall in CIBDAI (P = .010) — yet that trial was open-label, small (18 test vs 8 control dogs), and the hydrolysed group started with significantly higher CIBDAI despite randomisation (P = .013). In the blinded Simpson 2023 trial, 19 of 23 (83%) dogs with non-protein-losing chronic enteropathy responded to their first diet with no difference between hydrolysed-fish diets and a limited-ingredient intact-protein control diet (P > .05), and all four nonresponders responded to a second diet. So diet change itself clearly induces remission in most non-PLE dogs; whether the protein must be hydrolysed is not established — hydrolysed may hold remission longer (one open-label trial) or may add nothing over a limited-ingredient intact diet (one blinded trial). No carded trial isolates a novel intact-protein elimination diet head-to-head against a hydrolysed diet, and matched-diet blinding was reported only in Simpson. Drafted Nov 10, 2026 (VetMed build, topic #156); all figures from abstracts fetched and verified at drafting.

Mandigers 2010: no difference at 3 months, but more hydrolysed-diet dogs stayed asymptomatic at 6-12 months and 3 years

Randomized, open-label, positively controlled trial (record's own wording; publication type Randomized Controlled Trial)

Who: Dogs: 26 dogs (18 test diet, 8 control diet) referred for investigation and management of naturally occurring chronic small intestinal disease, in a clinical field-trial setting; after full diagnostic investigation including endoscopy, dogs were assigned to a hydrolysed-protein test diet or a highly digestible (control) intact-protein diet on a 2:1 basis (test:control), and re-evaluated at approximately 3, 6-12 months and 3 years.

Result: There were no significant differences in baseline characteristics or histopathologic severity, but despite randomization CIBDAI was significantly higher in the test diet group (P = .013). Most dogs had responded by first evaluation, with no difference between groups (P = .87). However, significantly more dogs on the test diet remained asymptomatic at both the second (P = .0012) and third (P < .001) re-evaluation, and the decrease in CIBDAI was significantly greater (P = .010). The authors concluded a hydrolyzed protein diet can be highly effective for long-term management of canine chronic small bowel enteropathy.

Watch out: Open-label by the record's own wording — owners and assessors were not blinded, and diets were not described as matched. The control was a highly digestible intact-protein diet, not a novel-protein elimination diet, so this trial does not answer hydrolysed vs novel-protein directly. Only 8 control dogs, and the baseline CIBDAI imbalance (higher in the hydrolysed group) leaves more room for that group to improve.

Mandigers PJJ, Biourge V, van den Ingh TSGAM, Ankringa N, German AJ. A randomized, open-label, positively-controlled field trial of a hydrolyzed protein diet in dogs with chronic small bowel enteropathy. Journal of Veterinary Internal Medicine. 2010;24(6):1350-7. PMID: 21054541. Registry ID: none in the record. MeSH: Animal Feed/analysis · Animals · Body Weight · Diet/veterinary · Dietary Proteins/analysis · Dietary Proteins/pharmacology · Dog Diseases/diet therapy · Dogs · Female · Male

Simpson 2023: 83% of non-PLE dogs responded to their first diet, with no difference between hydrolysed-fish and intact-protein control diets

Randomized, blinded, controlled trial (record's own wording; publication type Randomized Controlled Trial, Veterinary)

Who: Dogs: 31 client-owned dogs with chronic enteropathy (23 non-protein-losing [non-PLE], 8 protein-losing [PLE]) in a clinical setting, randomised to hydrolyzed fish, rice starch and fish oil diets without (HF) or with prebiotics, turmeric and high cobalamin (HF+), or a limited-ingredient control diet containing mixed nonhydrolyzed (intact) antigens and oils; diets fed 2 weeks, responders continued 12 weeks, nonresponders crossed over to another diet for 12 weeks, with follow-up at 26 weeks; concurrent medications were allowed in PLE dogs, which received hydrolyzed diets only.

Result: Nineteen of 23 (83%; 95% confidence interval [CI], 60%-94%) non-PLE dogs responded clinically to their initial diet, with no difference between diets (P > .05). Four nonresponders responded to another diet, with sustained remission of 18/18 (100%; 95% CI, 78%-100%) at 26 weeks. Serum cobalamin concentration increased (P < .05) and was maintained by diet; serum folate decreased posttreatment (P < .05) but was restored by dietary supplementation. Hydrolyzed fish diets supported weight gain, serum albumin concentration and recovery (P < .05) in dogs with PLE. The authors concluded that changing diet, independent of antigen restriction or supplemental ingredients, induced long-term remission in non-PLE chronic enteropathy.

Watch out: This is the claim-carrying blinded trial and its between-diet primary comparison is null — hydrolysis itself was not shown to matter. The control was a limited-ingredient diet with mixed intact chicken and fish antigens, not a single novel protein, so it is an intact-protein comparator rather than a novel-protein elimination diet. The PLE arm had no intact-protein comparator and concurrent medications were allowed there, so PLE results cannot be attributed to hydrolysis alone.

Simpson KW, Miller ML, Loftus JP, Rishniw M, Frederick CE, Wakshlag JJ. Randomized controlled trial of hydrolyzed fish diets in dogs with chronic enteropathy. Journal of Veterinary Internal Medicine. 2023;37(6):2334-2343. PMID: 37680008. Registry ID: none in the record. MeSH: Animals · Diet/veterinary · Dog Diseases/diagnosis · Dog Diseases/diet therapy · Dogs · Fish Products · Folic Acid · Inflammatory Bowel Diseases/diagnosis · Inflammatory Bowel Diseases/diet therapy · Inflammatory Bowel Diseases/veterinary · Protein-Losing Enteropathies/pathology · Protein-Losing Enteropathies/veterinary · Retrospective Studies · Vitamin B 12

Synthesis: diet change induces remission in most non-PLE dogs; hydrolysed protein has not been shown to beat an intact-protein diet in a blinded trial

Synthesis

Who: Synthesis of the cards above: Mandigers 2010 (26 dogs, randomised open-label, hydrolysed vs highly digestible intact-protein control, follow-up to 3 years) and Simpson 2023 (31 client-owned dogs, randomised blinded, hydrolysed fish diets vs limited-ingredient intact-protein control in 23 non-PLE dogs, plus 8 PLE dogs on hydrolysed diets only).

Result: (1) Short-term response was high on any new diet: no between-group difference at first re-evaluation in Mandigers (P = .87) and 83% first-diet response with no difference between diets in Simpson (P > .05). (2) The only long-term advantage for hydrolysis comes from the open-label Mandigers trial (more dogs asymptomatic at 6-12 months and 3 years; greater CIBDAI fall), which the blinded Simpson trial did not reproduce at 26 weeks, where sustained remission was 18/18 across diets. (3) Crossover/second-diet response in Simpson shows a dog failing one diet may still remit on another, regardless of hydrolysis.

Watch out: No carded trial compares a hydrolysed diet directly with a novel intact-protein elimination diet — both controls were other intact-protein diets (highly digestible; limited-ingredient mixed antigens). Transporting these results to a specific novel protein (e.g. venison or rabbit) is an extrapolation the records do not make.

Synthesis of Mandigers PJJ et al. PMID: 21054541; Simpson KW et al. PMID: 37680008. Registry IDs as on the individual cards.

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