Mercury toxicosis caused by ingestion of a blistering compound in a horse.

This research explains a case where a horse suffered from mercury poisoning after an external treatment with a mercury-containing compound was ingested. Despite treatment, the animal did not survive due to complications from the mercury.

Background and Initial Symptoms

• The subject of this case study is a three-year-old Quarter Horse mare, who was initially brought in due to a lack of appetite and signs of abdominal discomfort.
• The horse had been treated with an inorganic mercuric blistering agent to address dorsal metacarpal disease. This had been done twice in the week and a half before the horse was admitted to the clinic.

Diagnosis and Clinical Signs

• Upon referral, the horse displayed several adverse symptoms such as depression, edema (fluid build-up), pollakiuria (increased urine frequency), a nonproductive cough, and oral ulcers.
• Lab results showed the horse was suffering from renal dysfunction, implied because of impaired kidney functions.
• High levels of mercury in the horse’s blood and urine confirmed a diagnosis of mercury toxicosis. This indicated that the horse had ingested a harmful amount of mercury.

Treatment and Outcome

• The treatment process involved intensive care measures, primarily focused on intravenous fluid treatment and the use of mercury-chelating agents to try to remove the mercury from the horse’s system.
• However, the horse developed acute laminitis, a painful condition that affects the horse’s feet. This led its owners to make the difficult decision to euthanatize the horse 18 days after the mercury exposure to prevent further suffering.

Autopsy Findings and Conclusion

• The necropsy showed that the horse had renal tubulonephrosis, a severe kidney damage, and ulcerative colitis and enteritis, both inflammatory conditions affecting several parts of the digestive system.
• The study also revealed that the highest mercury concentrations were in the kidney and liver tissues.
• The research concluded that the prognosis for horses with mercury toxicosis is often poor, but some horses may recover with appropriate treatment and thorough long-term supportive care.