Background

Physiologic factors in dogs that might contribute to enhanced platelet yield in platelet concentrates (PCs) are largely unknown.

Objective

To determine whether individual differences in weight, age, preprocessing blood chemistry, and CBC variables predict the final platelet concentrations in PCs. Our hypotheses were (1) increased lipemic indices would be positively associated with increased platelet concentrations in PCs and (2) increased preprocessing platelet concentrations would be associated with higher platelet concentrations in the PCs.

Animals

All blood donation records of dogs from February 2, 2009 through April 1, 2015 at the University of California-Davis Veterinary Blood Bank were examined with 104 cases included in this study.

Methods

In this retrospective study, data were collected from medical records of canine blood donors. Records were reviewed for internal consistency and accuracy and subjects were included in the study if donor screening and donation occurred on the same day and a viable PC was obtained. Univariate and multivariable regressions were used to test the impact that each variable had on the final platelet concentration in PCs.

Results

Final platelet concentration in PCs was positively associated with the predonation CBC platelet values (P < .001), lipemic index (P = .01), and phosphorous levels (P = .001). Collectively these 3 variables explained 29% of the variance in platelet concentrations in PCs.

Conclusions and clinical importance

Future prospective studies are required to determine if canine blood donations from dogs with lipemia yield PCs with higher platelet concentrations without negatively affecting other blood components.

Background

A degenerative left shift (DLS) is reported to be a poor prognostic indicator in dogs and cats. Limited data in dogs and no studies in cats have been published to investigate this claim.

Hypothesis/objectives

To characterize the feline population affected by DLS and to determine if the presence and severity of DLS are associated with increased risk of euthanasia or death.

Animals

One hundred and eight cats with DLS (cases) and 322 cats without DLS (controls) presented to the University of California, Davis Veterinary Medical Teaching Hospital between April 1, 1995 and April 1, 2010.

Methods

Retrospective case-control study. All cases had a CBC performed within 24 hours of presentation in which immature granulocytic precursors exceeded mature neutrophils. Controls were matched by year of presentation and primary diagnosis. Survival analysis was used to determine risk of death or euthanasia from DLS and other potential predictors of outcome.

Results

Cases were more likely to die or be euthanized in hospital compared to controls (60/108 [56%] versus 107/322 [33%]). DLS was a significant predictor of death or euthanasia in hospitalized cats in both univariate and multivariate analysis (hazard ratio, 1.57; 95% confidence interval, 1.13-2.18). Trend analysis showed an increasing trend in the hazard of euthanasia or death with increasing severity of DLS.

Conclusions and clinical importance

Cats with DLS are 1.57 times more likely to die or be euthanized in hospital than cats without DLS. In addition, increasing severity of DLS is associated with increased likelihood of death or euthanasia.

Background

A degenerative left shift (DLS) in dogs is reported to be a poor prognostic indicator, but no studies have been reported to verify this claim.

Hypothesis/objectives

To characterize the canine population affected by DLS and to determine if the presence and severity of the DLS are associated with increased risk of euthanasia or death.

Animals

Three-hundred and nineteen dogs with DLS (cases) and 918 dogs without DLS (controls) presented to the University of California, Davis Veterinary Medical Teaching Hospital between April 1, 1995 and April 1, 2010.

Methods

Retrospective case-control study. All cases had a CBC performed within 24 hours of presentation that showed an immature neutrophil count higher than the mature neutrophil count. Controls were matched by year of presentation and primary diagnosis. Survival analysis was used to determine the risk of death or euthanasia associated with DLS and other potential predictors.

Results

Half of cases versus 76% of controls were alive at discharge. Median in-hospital survival time was 7 days for cases and 13 days for controls. DLS was a significant predictor of death or euthanasia in both univariate and multivariate analysis (hazard ratio, HR, 1.9; 95% CI 1.54-2.34).

Conclusions and clinical importance

DLS in dogs is associated with an increased risk of death or euthanasia. This finding, however, varies with disease diagnosis and should be interpreted in light of the individual patient.

Background

Cats with hypertrophic cardiomyopathy (HCM) are at risk for development of systemic thromboembolic disease. However, the relationship between platelet activation state and cardiovascular parameters associated with HCM is not well described.

Objectives

To characterize platelet activation by flow cytometric evaluation of platelet P-selectin and semiquantitative Western blot analysis of soluble platelet-endothelial cell adhesion molecule-1 (sPECAM-1).

Animals

Eight normal healthy cats (controls) owned by staff and students of the School of Veterinary Medicine and 36 cats from the UC Davis Feline HCM Research Laboratory were studied.

Methods

Platelet-rich plasma (PRP) was used for all flow cytometry studies. Platelet surface CD41 and P-selectin expression were evaluated before and after ADP stimulation. sPECAM-1 expression was evaluated by Western blot analysis of platelet-poor plasma that had been stabilized with aprotinin. Standard echocardiographic studies were performed.

Results

Resting platelets from cats with severe HCM had increased P-selectin expression compared to controls, and expressed higher surface density of P-selectin reflected by their increased mean fluorescence intensities (MFI). Stimulation with ADP also resulted in significantly increased P-selectin MFI of platelets from cats with severe HCM. Increased P-selectin expression and MFI correlated with the presence of a heart murmur and end-systolic cavity obliteration (ESCO). sPECAM-1 expression from cats with moderate and severe HCM was significantly increased above those of control cats.

Conclusions and clinical importance

P-selectin and sPECAM expression may be useful biomarkers indicating increased platelet activation in cats with HCM.