Diagnostic and prognostic value of hematology measurands and lactate dehydrogenase isoenzyme activities in canine immune thrombocytopenia at a primary care hospital.

Immune thrombocytopenia (ITP) is a common hematologic disorder in dogs for which reliable diagnostic and prognostic markers are limited. We evaluated retrospectively the diagnostic and prognostic value of hematology measurands and lactate dehydrogenase (LDH) isoenzyme activities in a primary care setting. Dogs with thrombocytopenia were classified into ITP (n = 14) and non-ITP (n = 27) groups, and platelet count, plateletcrit, mean platelet volume (MPV), and LDH isoenzyme activity profiles were compared between groups. Platelet count and plateletcrit were significantly lower in the ITP group, with sensitivities and specificities of 92.3% and 100% and 85.7% and 100% at cutoffs of 8 × 109/L and 0.0001 L/L, respectively. LDH1-3 activities were significantly higher, whereas LDH5 activities were significantly lower in the ITP group, although specificity was limited. Within the ITP group, dogs with bleeding (n = 8) had significantly lower MPVs. Dogs responding to prednisolone monotherapy (n = 7) had higher platelet counts and MPVs. The outcome predictive performance of a platelet count ≥3 × 109/L or MPV ≥15.8 fL was excellent (100% sensitivity and specificity in this cohort). Platelet count and plateletcrit were reliable diagnostic indicators for canine ITP in primary care. LDH isoenzyme activities offer limited standalone diagnostic value but may provide supplementary information. MPV may serve as an indicator of bleeding risk and a predictor of treatment response.