Copper Toxicity in Horses: Does it Exist?

Copper toxicity is thought to be a rare condition in horses. However, the number of cases diagnosed in Brazil is growing. This article aims to describe cases of copper toxicity involving horses from different geographic locations and discuss findings of physical examinations, differential diagnoses and potential causes. Five cases referred from 4 different properties where at least 15 other horses were affected were described. Hemolytic anemia and hemoglobinuria, presence of Heinz bodies and elevated aspartate aminotransferase and gamaglutamil transferase levels were detected in all cases. The diagnosis was based on clinical history and signs, laboratory tests results, copper level determination in feed and/or soil and histopathological findings. Two horses progressed to acute death; remaining horses responded to clinical management with or without blood transfusion, depending on disease severity. However, one of these horses, after several returns to the veterinary hospital, was euthanized due to complications. One horse was treated with ammonium tetrathiomolybdate. Two horses had several recurring episodes over the course of several months, an uncommon presentation in ruminants suffering from copper toxicity. Excess copper was associated with soil fertilization with poultry litter or treatment of previous or neighbor crops with copper-containing products. It can be concluded that copper toxicity does occur in horses and may arise from several sources and/or be associated with predisposing dietary factors. Given the growing number of cases, the condition should be included in the differential diagnosis list and proper preventive dietary and pasture fertilization measures adopted.

Equine simplified acute physiology score: Personalised medicine for the equine emergency patient.

BACKGROUND: Scoring models are useful tools that guide the attending clinician in gauging the severity of disease evolution and in evaluating the efficacy of treatment. There are few tools available with this purpose for the non-human patient, including horses. We aimed (i) to adapt the simplified acute physiology score 3 (SAPS-3) model for the equine species, reaching a margin of accuracy greater than 75% in the calculation of the probability of survival/death and (ii) to build a decision tree that helps the attending veterinarian in assessment of the clinical evolution of the equine patient. METHODS: From an initial pool of 5568 medical records from University-based Veterinary Hospitals, a final cohort of 1000 was further mined manually for data extraction. A set of 19 variables were evaluated and tested by five machine learning data mining algorithms. RESULTS: The final scoring model, named EqSAPS for equine simplified acute physiology score, reached 91.83% of correct estimates (post hoc) for probability of death within 24 hours upon hospitalization. The area under receiver operating characteristic curve for outcome 'death' was 0.742, while for 'survival' was 0.652. The final decision tree was able to refine prognosis of patients whose EqSAPS score suggested 'death'. CONCLUSION: EqSAPS is a useful tool to gauge the severity of the clinical presentation of the equine patient.