Rodenticide toxicosis in a horse.

The study investigates a case of rodenticide poisoning in a three-year-old horse, detailing the symptoms observed, diagnostic indicators, and treatment methods employed. It offers insights into the effectiveness of the antidote, nicotinic acid, in counteracting the effects of the rodenticide N-3-pyridyl methyl N’-p-nitrophenyl urea.

Initial Observation and Clinical Features

• The horse exhibited severe muscular spasms, dilated pupils, and body-wide heavy sweating, indicative of probable toxicosis.
• Although heart rate was elevated, body temperature and respiratory rates fell within the normal parameters, complicating the diagnostic process.
• A distinct “fishy” odor could be detected during urination, which is abnormal behaviour for horses.

Owner’s Report and Diagnosis

• According to the owner, within the past 24 hours, the horse had consumed approximately 0.25 to 0.50 kg of a new rodenticide named N-3-pyridyl methyl N’-p-nitrophenyl urea.
• An analysis of blood and serum revealed abnormal chemical values including high PCV levels, abnormally high total plasma protein, an escalated serum glucose level, increased creatinine phosphokinase and serum glutamic-oxalacetic transaminase, and elevated serum alkaline phosphatase. These abnormalities contributed to the confirmation of toxicosis due to rodenticide ingestion.

Treatment Response and Effectiveness

• The horse was given nicotinic acid intravenously, an antidote often used for rodenticide poisoning, along with supplementary injections in the next 12 hours. A vitamin B-complex preparation was given to provide additional support.
• To alleviate the symptoms, supportive therapy was provided in the form of mineral oil and activated charcoal powder orally, and lactated Ringer’s solution intravenously.
• Over the subsequent two days, additional nicotinic acid injections were administered by the horse’s owner, following the recommendations of the rodenticide’s manufacturing company.

Based on these observations, it seems that the horse responded well to the treatment regime involving repeated injections of nicotinic acid as an effective antidote for N-3-pyridyl methyl N’-p-nitrophenyl urea poisoning.