Current recommendations in canine blood banking involve the processing of blood within 8 hours of collection. It is unknown if longer periods of time prior to processing will reduce the coagulation factor content (CFC) of canine plasma. The aim of this study was to investigate the CFC of plasma produced from canine blood stored for 24 hours compared to CFC of plasma processed within 8 and 12 hours. A secondary aim of the study was to compare the CFC of Greyhound plasma with that of other breeds.

A convenience sample of 58 units of canine blood were collected and processed in 3 different time frames - 8 hours (20), 12 hours (18) and 24 hours (20) post collection. Each group contained 10 Greyhound units and 10 units from other breeds (excepting the 12 hour other breed group that contained 8 units). The activities of factors II, V, VII, VIII, IX, X, antithrombin, von Willebrand Factor concentration (vWF:Ag) and clottable fibrinogen in each unit was measured. The CFC of each factor was compared between time points and breeds.

There was no significant difference in the CFC of factors II, VII, IX, vWF or fibrinogen across all time groups. The CFC of factor V was significantly lower in the 12 hour group compared to the 8 hour group. The CFC of factors VIII, X and antithrombin were significantly higher in the 24 hour group compared to the 8 hour group. CFC of factors VIII, and X were also significantly higher in the 24 hour group compared to the 12 hour group. The CFC of factor X, fibrinogen and vWF was significantly lower in plasma collected from Greyhounds compared to other breeds. There was no statistically significant difference between the breed groups across all other factors. The CFC of factor VIII was widely variable across all units (median 71.5%, range 31–225%).

These results suggest that storing blood at ambient temperature for 24 hours causes no clinically relevant loss of plasma CFC and is an acceptable option for processing plasma for transfusion. We also found that Greyhound plasma contains acceptable levels of all coagulation factors for the treatment of deficient dogs. The wide individual variation in factor VIII has implications for transfusion dosage recommendations and cryoprecipitate production and therefore warrants further investigation.