Piroplasmosis in Italian Standardbred Horses: 15 Years of Surveillance Data.

The research conducted surveillance on Italian Standardbred horses over a period of 15 years to document the prevalence of chronic equine piroplasmosis (a parasitic disease) in those showing poor performance and to study its relation to the horse’s sex, age and certain blood parameters.

Methods

• The researchers analyzed data from blood collected between 2004 and 2018.
• Counts of blood cells were carried out using a cell counter analyzer, biochemical parameters were measured by a photometer, and serum proteins were identified using agarose gel electrophoresis.
• Blood smears were colored with a modified Giemsa stain which helped in assessing the presence of the disease-causing protozoa.
• On the basis of the presence or absence of piroplasmosis, the horses were divided into two categories: Piroplasmosis Positive (PP) and Piroplasmosis Negative (PN).

Results

• The sample comprised 520 Italian Standardbred horses, of which 142 were female. Their median age was 4 years (with an interquartile range of 3-8 years).
• The recorded prevalence of the disease was 9.3%, and there was no direct correlation noted between the disease and the horse’s sex, age or blood parameters.
• Among those affected by piroplasmosis, symptoms included mild normocytic, normochromic anemia, an excess of bilirubin (hyperbilirubinemia), low platelet count (thrombocytopenia), and high levels of gamma globulin (hypergammaglobulinemia).
• However, the study warns that blood analysis results need to be interpreted with caution as there were overlapping parameters in both PP and PN horses. There was also noticeable variation compared to what is considered the ‘normal’ range.

Conclusions and Further Steps

• For horses showing poor performance, particularly those living or recently moved to a region endemic to EP, blood cytology should be considered as a first step in differential diagnosis procedures to exclude chronic EP as a potential cause.
• The study also suggests using additional diagnostic tests, such as PCR and ELISA, as they not only help in the correct diagnosis but also ensure “lack of disease,” aligning with the welfare principle of maintaining good health in horses.