Suspected acorn toxicity in nine horses.

This research study looks into the effects of acorn toxicity in horses, using a sample of 9 cases admitted to two referral hospitals. It investigates the diagnosis, treatment, and prognosis of acorn toxicity. The team noted some cases where horses with severe acorn toxicity, indicated by symptoms such as painful, bloody diarrhea, declined quickly and died or were euthanized. Others displayed signs of colic, experiencing discomfort and gas. A few of these survived with medical management. Autopsies showed a range of issues, including physical changes in the intestines. The study concludes that while acorn ingestion can lead to serious health problems in horses, only a small proportion seem to be affected.

Research Methodology

• The study performs a retrospective review of case records from 2004 to 2013.
• Four main criteria were established for horsed to be included in the study: exposure to acorns; signs of alimentary or renal dysfunction; detection of acorn husks in the faeces or gastrointestinal tract, and autopsy and histopathological findings consistent with acorn toxicity. Horses had to meet at least three of these for inclusion.
• Data collection from each case included: historical information; the details of clinical presentation; clinical pathology data; ultrasound findings; case progression details; as well as autopsy and histopathological evidence.

Research Findings

• Out of the nine horses that met the required criteria, five cases involving haemorrhagic diarrhoea rapidly deteriorated and either died or were euthanized.
• Four cases exhibited signs of colic with gas distension, displacement of the large colon, and diarrhoea. Of these, only one horse was euthanized, while the other three (33%) survived with medical management.
• Post mortem examinations of 6 cases revealed a number of issues, including submucosal oedema of the large intestine and caecum, acute tubular nephrosis, necrohaemorrhagic and ulcerative typhlocolitis and enteritis, and small intestinal oedema.

Conclusions

• The researchers concluded that while acorn ingestion may be associated with severe health conditions in horses leading to diarrhoea, colic, and acute renal tubular nephrosis, not all exposed horses become ill.
• Positive outcomes were possible in milder cases. However, in severe cases, clinical signs such as hypovolaemia, intractable pain, kidney dysfunction, and cardiovascular failure often led to death or euthanasia.
• Given these findings, the team recognized the need for further investigation into factors that predispose horses to acorn toxicity and suggested minimising their exposure to acorns, particularly in the autumn season when acorns are abundant.