Serum hepatitis in two brood mares.

This study presents the case of two adult Quarter Horse mares from the same farm that developed indications of liver disease, roughly two months after giving birth. The symptoms were seemingly connected to tetanus antitoxin they’d been given at foaling. One horse exhibited signs of a less severe type of serum hepatitis or Theiler’s disease, while the second showed symptoms of acute liver failure and unfortunately died. No hepatotoxic substances were found on their farm.

Study Context and Objectives

• The research presents the case study of two adult Quarter Horse mares developing symptoms of liver disease after giving birth.
• The study aimed to investigate the potential causes and investigate the probable association between their condition and the administration of tetanus antitoxin at the time of foaling.

Net Findings

• One of the mares showed signs such as subcutaneous edema of the distal aspect of all four limbs, photodermatitis involving unpigmented parts of the skin, and high serum activities of liver-specific enzymes. These symptoms suggested an atypical, less severe form of serum hepatitis, also known as Theiler’s disease.
• The second mare exhibited symptoms of acute liver failure, evidenced by jaundice, hepatic encephalopathy (a decline in brain function that happens when the liver cannot sufficiently remove toxins from the blood), and high serum activities of liver-specific enzymes. This mare unfortunately died, displaying the typical signs of serum hepatitis.

Conclusion and Implication

• The study concluded that both mares suffered from serum hepatitis, with one developing a full-blown acute hepatic failure and the other manifesting milder symptoms. The onset of the disease seems to be linked with the administration of the tetanus antitoxin around the time of parturition.
• However, it is noteworthy that the study did not find any hepatotoxic agents like poisonous plants, aflatoxins, or toxic chemicals on the farm. This suggests that the cause of the liver disease was not environmental but likely stemmed from the administered treatments.