Acute experimentally induced aflatoxicosis in the weanling pony.

This research exposes ponies to various dosages of the toxin aflatoxin B1 (AFB1) and monitors the resulting physical responses, pathological modifications, and death rates to understand the effects of acute aflatoxicosis in these animals.

Research Design and Procedure

• The study was conducted on 19 weanling ponies and one adult pony wherein each was given different dosages of aflatoxin B1 (AFB1) to identify its effects. The concentration of AFB1 ranged from 0 to 7.4 mg/kg body weight.
• Vital signs of these animals were closely monitored and their blood and serum were subjected to various analyses such as measurement of serum enzymes, blood cell counts, prothrombin time, and serum urea nitrogen.
• For ponies that died during the study, post-mortem investigations were conducted for physical abnormalities. Tissue samples were also collected for detailed histopathologic exams and to check for residues of AFB1 and its metabolite AFM1.

Key Findings

• Of the 4 ponies subjected to the 2 mg/kg dosage, two and all others administered higher dosages succumbed within 76 hours. Symptoms included elevated body temperature, faster heart and respiratory rates, abdominal straining, bloody feces, and tetanic convulsions.
• Upon post-mortem examination, the ponies showed visceral petechiae (small spots on the skin or mucous membranes caused by minute hemorrhages) and lesions in the liver. Histopathological observation revealed severe liver necrosis, cellular vacuolation, and bile duct hyperplasia, showing a considerable adverse effect of aflatoxin intake.
• In terms of biochemical alterations, all ponies with dosages of 4 mg/kg or more showed continuous elevations in prothrombin time and serum levels of enzymes such as aspartate aminotransferase, alanine aminotransferase, and gamma-glutamyl transpeptidase. Ponies with the 2 mg/kg dose showed significant peaks in these values 2 to 3 days post-dosing, and exhibited increased PCV and hemoglobin concentration five days post-dosing.
• The residues of both AFB1 and its metabolite AFM1 were found in various tissues, including the liver, kidney, skeletal muscle, and gastrointestinal contents, showing the systemic distribution and retention of the toxin.