Outbreak of salt poisoning in a dairy cattle farm

Background: Salt toxicosis represents a significant neurological condition in ruminants, often resulting in high mortality rates. This study reports an outbreak of neurological disease and mortality in a dairy cattle farm. The outbreak occurred in December ۲۰۲۴ when the cows showed clinical signs such as hindlimb paralysis, nystagmus, opisthotonus, exophthalmia and diarrhea. Methods: A complete necropsy was performed on affected cows and comprehensive diagnosis protocols including gross pathology, histopathology and ancillary tests including Blood biochemistry, Hematology and inductively coupled plasma (ICP) analysis were used to measure the mineral concentrations in cerebrospinal fluid (CSF), blood, the farm’s water and feed. Results: Gross pathology revealed meningeal edema and flattening of the cerebral gyri, multifocal discoloration of cerebrocortical gray matter, abomasal and intestinal mucosal hyperemia with edema, enteritis, and renal corticomedullary hyperemia. Histopathology findings demonstrated severe meningeal edema and hyperemia, severe cerebrocortical lamellar neuronal necrosis (polioencephalomalacia), perineural satellitosis and perivascular edema, and myocardial edema with hemorrhage. Blood biochemistry and hematology results revealed neutrophilia, leukocytosis, hypernatremia and hyperchloremia. ICP analysis confirmed markedly elevated sodium concentration in cerebrospinal fluid (CSF) (۵۳۷۴.۵ ppm; ۲۳۳.۶۷mEq/L) and blood (۵۷۴۸ ppm). The farm’s water also contained high levels of sodium (۹۸۶ ppm, the standard concentration of Na in water is ۲۰۰ ppm). Conclusions: This finding confirms salt intoxication as the etiological agent of the neurological issues and identified water source as the primary source agent of the exposure. The findings emphasizes the importance of water quality monitoring in dairy cattle farms.

کلیدواژه ها:

Salt intoxication ، Neurological disease ، Dairy cattle ، Water quality