Evaluation of a citrate-based anticoagulant with platelet inhibitory activity for feline blood cell Counts

Area of Science:

• Veterinary Hematology
• Clinical Pathology
• Animal Science

Background:

• Feline platelet aggregation in vitro complicates accurate platelet count assessment.
• Existing anticoagulants like EDTA can lead to pseudothrombocytopenia in cats.
• Theophylline, adenosine, and dipyridamole citrate (CTAD) is an anticoagulant developed for human studies.

Purpose of the Study:

• To evaluate the efficacy of CTAD in minimizing platelet aggregation in feline blood samples.
• To compare the accuracy of platelet counts obtained using CTAD versus EDTA and citrate.
• To assess the impact of CTAD on white blood cell (WBC) counts and cell morphology in feline blood.

Main Methods:

• Blood samples from 51 cats were collected and anticoagulated with EDTA, CTAD, or citrate.
• Platelet counts were determined using impedance counters, hemacytometers, and smear estimations.
• Blood smears were microscopically examined for platelet aggregates and cell morphology.
• Automated and manual WBC counts were performed.

Main Results:

• CTAD samples showed significantly higher platelet counts and fewer platelet aggregates compared to EDTA samples (P<.001).
• Platelet counts were significantly higher and aggregation was significantly less in CTAD samples versus citrate samples (P<.05).
• Automated WBC counts were significantly lower in CTAD samples than EDTA samples (P<.001), but comparable to manual counts.

Conclusions:

• The anticoagulant CTAD effectively reduces feline platelet aggregation, improving platelet count accuracy.
• CTAD offers advantages over EDTA and citrate for feline hematologic analysis by mitigating pseudothrombocytopenia and pseudoleukocytosis.
• CTAD does not adversely affect feline blood cell morphology or staining characteristics.