Crystalline inclusions in erythrocytes parasitized with Babesia equi following treatment of ponies with imidocarb.

This study investigates the effects of a drug called imidocarb dipropionate on ponies infected with a parasite known as Babesia equi. The research reveals an emergence of crystalline structures in the red blood cells of treated ponies, an interesting phenomenon not present in non-treated infected ponies or in non-infected treated ponies.

Research Background

• The parasite Babesia equi is known to cause significant diseases in horses. Four splenectomized Welsh ponies were infected with this parasite for the study.
• Imidocarb dipropionate is a drug often used to treat conditions caused by parasites like Babesia equi. The researchers treated two of the infected ponies with this drug while leaving the remaining two ponies untreated.

Observations and Findings

• Under light microscopic examination, the researchers found that 1% to 2% of the red blood cells parasitized by Babesia equi in the treated ponies contained crystalline inclusions. These inclusions were not found in the infected but untreated ponies or non-infected treated ponies.
• The crystals found were of different shapes, including rectangular, diamond, or burr-shaped, and they occupied most of the erythrocytic cytoplasm. This made the rest of the cytoplasm, which was pale-staining, less noticeable in blood smears stained with Wright-Giemsa.

Further Analysis

• By using electron microscopy, further differences were observed in the size and shape of the crystals found within the red blood cells. In most cases, these crystals were found either adhered to the parasite or located close to it. This suggests some relation between the parasite and the crystal formations.
• The sides of these crystals were either smooth or serrated, and their corners were either sharp or notched. Fractures or faults were found to be common in large crystals.
• The researchers also identified four different types of hemoglobin in five non-infected, non-treated Welsh ponies from the same herd. This part of the study was essential as a control, showing that the observed crystalline formations were not simply a function of the species or environmental factors.

Conclusion

• The study suggests that the treatment of Babesia equi infection with imidocarb dipropionate in ponies leads to the formation of crystalline inclusions in the parasitized red blood cells. Further investigation is needed to fully understand the nature, function, and implications of these crystals in response to the treatment.