Hyperfibrinolysis in Cats: Insights from a Retrospective Case-Control Study
Hyperfibrinolysis (HFL), a condition characterized by accelerated breakdown of blood clots, has been described in dogs and humans, but data in cats remain limited. A recent retrospective case-control study published in the Journal of Veterinary Internal Medicine sought to identify risk factors associated with HFL in cats and determine whether its presence affects survival.
The study included 154 client-owned cats that underwent thromboelastography (TEG) for a variety of clinical indications. Cats were classified as cases if they exhibited HFL, defined as clot lysis at 30 minutes (LY30) ≥ 5% or at 60 minutes (LY60) ≥ 10%, and as controls if TEG showed no evidence of HFL. The investigators recorded demographic information, underlying conditions known to influence fibrinolysis, TEG parameters, indications for testing, and outcomes.
Of the cats evaluated, 52 (33.8%) were identified with HFL, while 102 (66.2%) served as controls. Demographic factors were similar between groups. Statistical analysis revealed that liver disease and the presence of cavitary effusions were significant risk factors for HFL, with odds ratios of 5.0 and 5.9, respectively. Interestingly, cats with heart disease were less likely to exhibit HFL (OR 0.2).
TEG analysis showed distinct coagulation patterns between groups. Cats with HFL were more often hypocoagulable, while cats without HFL tended to be hypercoagulable. Despite these differences in coagulation profiles, the presence of HFL did not correlate with poorer survival, suggesting that while HFL reflects underlying pathophysiologic changes, it may not directly impact prognosis in cats.
Clinically, these findings highlight the importance of considering underlying liver disease and cavitary effusions when interpreting TEG results in feline patients. Awareness of HFL can assist veterinarians in managing coagulation abnormalities, particularly in cats with hepatic compromise or effusions, while providing reassurance that HFL alone may not worsen survival outcomes.
This study represents an important step in characterizing hyperfibrinolysis in cats, providing evidence to inform both diagnostic interpretation and clinical decision-making in veterinary practice.
