Antithrombin III (ATIII) activity in plasmas from normal and diseased horses, and in normal canine, bovine and human plasmas.

The study measures the activity of Antithrombin III, a protein that helps regulate blood clotting, in horses, dogs, cows, and humans. It finds that the activity of this protein varies in different species and certain equine health conditions.

Study Purpose and Methodology

• The study aimed to quantify the activity of Antithrombin III (ATIII), a protein involved in regulating blood clotting, in the plasma of various animal species, including horses, dogs, cows, and humans. This was done to evaluate any differences between healthy and diseased animals, particularly horses.
• The ATIII activity was measured in 24 healthy Standardbred/Thoroughbred horses using a clotting time technique, which used the length of clotting time to determine the ATIII activity level.
• The same technique was then applied to horses with various health conditions such as colic, diarrhea/colitis, and liver disease.
• A rapid chromogenic substrate was also applied to fifty-seven equine plasmas as a secondary testing methodology, driven by the desire to cross-verify results and establish a correlation between clotting time and chromogenic ATIII activity determinations.

Key Findings

• The study found that healthy horses had on average 94% ATIII activity level of the reference plasma standard, with the activity ranging from 80 to 106%.
• Horses with impaction or spasmotic colic had normal ATIII activity. However, horses suffering from acute diarrhea/colitis had significantly lower ATIII activity, only 74% of the reference plasma.
• Contrastingly, horses with liver disease showed higher ATIII activity, ranging from 127% to 177% of the reference plasma standard.
• In comparison to equine plasma, the pooled canine, human, and bovine plasmas had lower ATIII activity levels, with 65%, 62%, and 79% of the equine reference plasma activity, respectively.
• A strong correlation (r =+0.83) was observed between clotting time and chromogenic ATIII activity determinations, substantiating the findings from the clotting time technique.

Implications of the Research

• The research suggests that ATIII activity can vary in different health conditions and animal species.
• These findings may have significant implications for understanding, diagnosing, and treating diseases that relate to blood coagulation in different species and particularly in horses.
• Because ATIII activity differs in diseased and healthy horses, ATIII activity might be a relevant parameter to consider in the case of equine diseases affecting the gut or the liver.
• Furthermore, the significant correlation between clotting time and chromogenic determinations of ATIII confirms the relevance of this relationship in coagulation studies.