Platelet count and plateletcrit in Cavalier King Charles Spaniels and Greyhounds using the Advia 120 and 2120.
BACKGROUND
Models for the regulation of thrombopoiesis predict that platelet mass is the biologically regulated variable, yet clinical evaluations of thrombopoiesis are often based on platelet number. When thrombocytopenia and variation in platelet size occur concurrently, platelet count may poorly estimate total platelet mass, confounding clinical decision making.


OBJECTIVE
We hypothesized that plateletcrit (PCT) provides clinically important information when platelet number is an incomplete representation of platelet mass, such as in genetic macrothrombocytopenia.


METHODS
We retrospectively compared platelet count and PCTs with general reference intervals for 4 groups of dogs: sick Cavalier King Charles Spaniels (CKCS) and Greyhounds, presented for nonhematopoietic disease to the University of Minnesota (measured using an Advia 2120) and Auburn University Teaching Hospitals (measured using an Advia 120) over a 3-year period.


RESULTS
A canine PCT reference interval of 0.129-0.403% was established. None of the 4 sample groups had significantly more individuals below the reference interval for plateletcrit. For platelet count, only the 2 CKCS groups had significantly more individuals below the reference interval than predicted.


CONCLUSIONS
Use of the PCT as determined by the Advia 120/2120 appeared to avoid overestimation of low platelet mass in sick CKCS in a clinical setting. In contrast, the PCT performed similarly to the platelet count in evaluation of platelet mass in sick Greyhounds. Evaluation of the PCT should be considered in other conditions associated with increased mean platelet volume.
Veterinary Clinical Sciences Department, University of Minnesota, St. Paul, MN, USA.
Jessica
J
Kelley
Leslie C
LC
Sharkey
Pete W
PW
Christopherson
Aaron
A
Rendahl
D000818:Animals; D004283:Dog Diseases / Q000097:blood* / Q000151:congenital; D004285:Dogs; D005260:Female; D008297:Male; D063847:Mean Platelet Volume / Q000295:instrumentation / Q000662:veterinary; D008910:Minnesota; D010976:Platelet Count / Q000295:instrumentation / Q000662:veterinary; D012016:Reference Values; D012189:Retrospective Studies; D013045:Species Specificity; D013921:Thrombocytopenia / Q000097:blood / Q000151:congenital / Q000662:veterinary*
Congenital macrothrombocytopenia; platelet mass; primary hemostasis