Clinical presentation and outcome of gastric impactions with or without concurrent intestinal lesions in horses

Abstract Background Gastric impactions (GI) have been identified as primary lesions (lone GI; LGI) or associated with other intestinal lesions (concurrent GI; CGI). Anecdotally, CGI resolve more rapidly with a better prognosis than LGI. Objectives To determine clinical, laboratory, and ultrasonographic findings, and short‐ and long‐term survival in horses with GI. We hypothesized that LGI carries a worse prognosis than CGI. Animals. Seventy‐one horses from 2 referral hospitals (2007‐2022). Methods Retrospective cohort study. Gastric impactions were defined as feed extending to the margo plicatus after ≥24 hours of fasting. Clinical, diagnostic and outcome findings were compared between LGI and CGI. Long‐term survival was determined by a questionnaire. Results Twenty‐seven horses had LGI, 44 had CGI. Large intestinal lesions (32/44) were more common than small intestinal lesions (12/44). Concurrent gastric impactions resolved more slowly than LGI (LGI median 2 days, range 0‐8; CGI median 4 days, range 1‐10; P = .003). Short‐ (LGI 63%, 17/27; CGI 59%, 26/44; P = .75) and long‐term survival (LGI 3.5 ± 1.9 years; CGI 2.3 ± 2.3 years; P = .42) were not significantly different. However, Lone gastric impactions were more likely to experience gastric rupture (LGI 29.6%, 8/27; CGI 11.4%, 5/44; P = .05). Lone gastric impactions were 8.7 times more likely to require dietary changes (LGI 72.7%, 8/11; CGI 25%, 4/16; 95% confidence interval [CI], 1.53‐49.22; P = .01). Gastric impactions recurred in 21.7% (LGI, 6/20; CGI, 4/26; P = .23) of affected horses. Conclusions and Clinical Importance Lone gastric impactions and CGI present similarly with a comparable prognosis, but LGI are more likely to rupture. Long‐term dietary changes are often necessary for horses with LGI.