Autoimmune haemolytic anaemia in eight horses.

The research examines eight cases of horses diagnosed with autoimmune haemolytic anaemia, a condition wherein the immune system attacks the red blood cells, causing anemia and other related symptoms. The study reveals that the condition was idiopathic in three horses and secondary in the remaining five. The study also looks at the efficacy of dexamethasone as a treatment.

Methodology and Findings

• The diagnosis for autoimmune haemolytic anaemia was confirmed in all eight horses using a Coomb’s test. This test is a direct antiglobulin test that detects antibodies attached to the surface of red blood cells, helping determine if the horses’ immune systems are attacking their own red blood cells.
• For three of the horses, the onset of the disease was classified as idiopathic, meaning it began spontaneously with no identifiable cause. The other five horses were found to have developed the disease as a secondary condition to another existing health issue.

Observed Clinical Signs

• Common clinical signs observed in the horses included dullness and depression, pyrexia (fever), jaundice (yellowing of the skin and eyes due to liver dysfunction), and haemoglobinuria (the presence of haemoglobin in the urine).
• Additional symptoms found in a haematological evaluation of these horses included auto-agglutination of red blood cells and anisocytosis. Auto-agglutination is the clumping together of the red cells, while anisocytosis is a medical condition characterized by a significant variation in the size of the RBCs.
• A lesser number of horses showed evidence of reticulocytosis, an increase in the number of immature red blood cells, and an increased mean corpuscular volume, meaning their red blood cells were larger than normal.

Treatment and Outcomes

• Dexamethasone, a type of corticosteroid medication, was used as a treatment in these cases. Four horses responded positively to the treatment, showing improved health conditions.
• Unfortunately, the remaining four horses either had to be euthanized or they succumbed to the underlying disease that led to the onset of autoimmune haemolytic anaemia.