Phylogenetic typing of Escherichia coli isolated from goat kids with Hemorrhagic Abomasitis and associated clinical findings

Hemorrhagic Abomasitis, previously described as Salivary Abomasum Disease, is a rapidly progressive and poorly characterized condition of neonatal small ruminants. This study investigated the clinical, bacteriological, and phylogenetic features of Escherichia coli isolated from affected goat kids. Forty kids with characteristic clinical and postmortem findings were examined. Clinical signs, age and breed distribution, and severity of abomasal hemorrhage were recorded. Samples from the abomasum, heart, liver, and lung were subjected to bacteriological culture, biochemical identification, molecular confirmation, and Clermont phylogrouping. Most affected kids were within the first two weeks of life (29/40; 72.5%), with the highest occurrence at 8–14 days (20/40; 50.0%). The estimated median age at disease onset was 11.35 days (IQR: 7.85–15.38 days). Breed-specific occurrence was similar among Saanen, Mahabadi-Alpine, and Alpine kids (22.2%, 22.0%, and 22.0%, respectively), with no evidence of an association between breed and disease occurrence ( P = 0.999). Abomasal hemorrhage was observed in all cases and was classified as mild (42.5%), moderate (30.0%), or severe (27.5%). E. coli was recovered from 30/40 affected kids (75.0%; 95% CI: 59.8–85.8%), yielding 30 isolates from 160 tissue specimens. Recovery was highest from the abomasum (37.5%), followed by the heart (25.0%), liver (10.0%), and lung (2.5%). GEE analysis accounting for within-animal clustering showed a significant overall effect of tissue source ( P = 0.008); recovery from the liver and lung was significantly lower than from the abomasum, whereas the heart–abomasum difference was not significant. No significant linear trend in E. coli positivity was detected across hemorrhage severity categories ( P = 0.824). Phylogroup G predominated (21/30; 70.0%), followed by B2 (20.0%) and B1 (10.0%); 85.7% of group G isolates originated from kids within the first two weeks of life. The predominance of phylogroup G represents an important phylogenetic finding among E. coli isolates associated with Hemorrhagic Abomasitis and highlights the need for further genomic and phenotypic characterization. By integrating clinical observations with bacteriological and phylogenetic data, this study provides a broader framework for recognizing and characterizing Hemorrhagic Abomasitis and offers useful insights into its clinical presentation, epidemiology, and possible pathogenesis in neonatal goat populations.