Evaluation of thromboelastography in two factor XII-deficient cats

Area of Science:

• Veterinary Medicine
• Hematology
• Diagnostic Testing

Background:

• Factor XII (FXII) deficiency is the most common inherited hemostatic defect in cats.
• Thromboelastography (TEG) is increasingly utilized for hemostasis evaluation in veterinary patients.
• Previous reports on TEG findings in feline FXII deficiency were lacking.

Observation:

• Two cats, one with perinephric pseudocysts and one healthy, were tested.
• Both cats exhibited prolonged partial thromboplastin times.
• Kaolin-activated TEG tracings were hypocoagulable, while tissue factor-activated TEG tracings were normal to hypercoagulable.
• Subnormal FXII levels were confirmed in both cats.

Findings:

• TEG results in cats with FXII deficiency demonstrate distinct patterns based on the activator used.
• Kaolin activation reflects the intrinsic pathway, which is affected by FXII deficiency.
• Tissue factor activation reflects the extrinsic pathway, which is not directly impacted by FXII deficiency.

Implications:

• Recognizing these TEG patterns is crucial for accurate diagnosis in veterinary patients.
• A hypocoagulable kaolin-activated TEG with a normal tissue factor-activated TEG should prompt consideration of FXII deficiency.
• This can help differentiate FXII deficiency from true hemorrhagic diatheses, avoiding unnecessary treatments.