Severe acute gastroenteritis has been associated with an increased risk of developing chronic enteropathies. A compromised gut barrier function and increased food allergen exposure to a reactive immune system might delay recovery and predispose to chronic enteropathy. This prospective, block‐randomized, open‐label, single‐center study aimed at investigating whether feeding a hydrolyzed protein diet to dogs hospitalized with acute diarrhea lead to a faster recovery compared with a commercial gastrointestinal diet (GI‐diet)
Dogs ≥12 months old, hospitalized with acute diarrhea and without specific dietary requirements were allocated to either a hydrolyzed test diet (95% proteins<1kDa; Royal Canin Anallergenic (RCA)) or a GI‐diet. Dogs undergoing surgery or receiving pre‐ or probiotics during hospitalization were excluded.

Daily recordings on clinical and laboratory findings, AHDS index and treatment were collected. Following initial antiemetic treatment and stabilization, food was offered and syringe‐feeding initiated if they did not eat voluntarily. RCA was dissolved in water to make a gruel appropriate for syringe feeding and for dogs preferring wet diet. Dogs not accepting the assigned diet where offered an alternative diet and excluded if they accepted the alternative. All owners were recommended to continue the allocated diet following discharge. Data are presented as (median, IQR).

Twenty‐six dogs were enrolled (RCA N=12; GI‐diet N=14). One dog in each group was excluded due to pancreatitis. The AHDS index was similar between groups at admission. After enrollment 45% of RCA dogs refused to eat the allocated diet but accepted the offered alternative (5/11 dogs: GI canned N=4; cooked chicken N=1) and were excluded. These dogs had a higher AHDS index (14, 13‐15) on admission compared to dogs remaining in the RCA group (11.5, 11‐12).

One dog in the RCA group was euthanized on day 3 due to development of acute kidney injury and intravascular hemolysis. The median duration of hospitalization was one day for the remaining five dogs, with no significant difference compared to excluded RCA dogs. One GI‐diet dog was excluded on day two because the owner elected probiotic treatment. Median hospitalization duration was two days for remaining GI‐diet dogs.

The high number of exclusions in the RCA group due to preference for alternative diets precluded further analyses. A highly hydrolyzed diet, usually well accepted by dogs with chronic enteropathies was elected. However, the gruel preparation may have adversely impacted palatability and therefore diets offering both canned and dry versions should be preferred for dogs with severe acute gastrointestinal disease.