RESUMO
A male cat suffered from a severe haemorrhagic disorder manifesting as deep, partly infected cutaneous haematomas, enhanced and prolonged bleeding after injuries and subsequent lameness at several occasions. Bleeding resulted in severe anaemia with haematocrit falling to as low as 0.10 L/L. Haemophilia B was diagnosed based on factor IX deficiency with a functional residual activity of 5% and factor IX antigen of 8%, respectively. Additionally, factor XII activity was reduced to 32% of normal. The mutation 31217G==>A in exon 8 of the factor IX gene, predicting the amino acid exchange G366R was identified as the cause of moderate factor IX deficiency. This is the first mutation identified in cats with haemophilia B. Treatment was limited to local therapy and palliation, insufficient to prevent lethal outcome due to severe anaemia.
Assuntos
Doenças do Gato/genética , Deficiência do Fator XII/veterinária , Hemofilia B/veterinária , Animais , Coagulação Sanguínea/genética , Doenças do Gato/sangue , Doenças do Gato/diagnóstico , Gatos , Fator IX/genética , Deficiência do Fator XII/complicações , Deficiência do Fator XII/diagnóstico , Deficiência do Fator XII/genética , Evolução Fatal , Hemofilia B/complicações , Hemofilia B/diagnóstico , Hemofilia B/genética , Masculino , MutaçãoRESUMO
Two different laboratory assays exist for the determination of clotting factor VIII activities in human plasma. One method is based on the one-stage clotting principle, the other one on the chromogenic principle. To evaluate the suitability for veterinary medicine human plasma and plasma of ten mammalian species (pig, cattle, dog, cat, zebra, llama, snow leopard, greater kudu, horse-like antelope, mink) were examined with each method. Factor VIII activities in human plasma determined using both assays were in a good agreement. Results of factor VIII activities in plasma of mammals obtained with both methods were similar, if a species-specific reference plasma was used. The practicability of the chromogenic method was reduced. However, the factor VIII activities differed nonsystematically up to 500% between both methods, if a human plasma was used as a reference plasma. Determination of factor VIII activities in plasma of mammals using the chromogenic assay cannot be recommended.