[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"notifications-list":3,"$fz0tvubmlqydr":5},{"data":4},[],{"data":6,"error":18},{"id":7,"documentId":8,"slug":9,"title":10,"associated_anatomy":11,"differential_diagnosis":12,"epidemiology":13,"expected_prognosis":14,"pathophysiology":15,"primary_prevention":16,"sign_or_symptom":17,"medical_code":18,"species":19,"citations":22,"is_zoonotic":18,"reservoir":18,"drugs":58,"medical_tests":59,"clinical_signs":60,"animal_species":61},223,"j53rvl3a27hkh3nr08rnu9lt","hemophilia-a","Hemophilia A","Blood coagulation system (intrinsic pathway, factor VIII), joints, subcutaneous and muscle tissue, oral cavity and gums, nasal cavity, thoracic cavity, gastrointestinal tract","Haemophilia B (factor IX deficiency) is clinically indistinguishable and is separated by factor VIII and IX activity assays. Von Willebrand disease is a primary haemostatic defect with mucosal bleeding and low von Willebrand factor; in haemophilia A von Willebrand factor is normal or high. Anticoagulant rodenticide poisoning should be considered, but haemophilic bleeding does not respond to vitamin K and the prothrombin time is normal. Acquired disorders such as immune-mediated thrombocytopenia, liver disease and disseminated intravascular coagulation are more common in practice, especially in older animals.","The factor VIII gene is on the X chromosome, so males are affected and females are usually carriers; an affected male dog sired a litter with five carrier daughters. Haemophilia A and von Willebrand disease are the most common inherited bleeding disorders in dogs. Reported breeds include Irish Setters (founders of a colony kept since 1947), a German Shepherd cross, a Staffordshire Bull Terrier and an Old English Sheepdog; cases can appear without any family history of bleeding. Inherited haemostatic disorders are recognised most often in dogs, are rare in horses and cattle, and occur in cats, which often show no bleeding until surgery such as neutering.","Untreated, bleeding in severe cases is debilitating and can be fatal. Plasma, cryoprecipitate or canine factor VIII controls episodes, but treatment is lifelong and costly; prophylaxis or gene transfer reduces bleeding frequency without full correction.","Haemophilia A is an inherited deficiency of coagulation factor VIII, a disorder of secondary haemostasis. Activated factor VIII is the cofactor that greatly accelerates the activation of factor X by activated factor IX in the intrinsic pathway. Without it, too little factor Xa, and therefore thrombin, is generated, so fibrinogen is not converted into a stable fibrin clot. In dogs, as in people, severe disease corresponds to factor VIII activity below 1% of normal, and clinical severity is inversely related to the circulating factor VIII level. Causal mutations in dogs include a factor VIII gene inversion (intron 22) in the Chapel Hill research colony and a nonsense point mutation creating a premature stop codon in an Old English Sheepdog.","Inherited and X-linked: affected males sire carrier daughters. Where a family's factor VIII mutation is known, PCR genotyping can identify affected and carrier offspring.","Severely affected puppies bleed from a few weeks of age; littermates have died or been euthanised by seven weeks. Typical signs of a secondary haemostatic defect are large haematomas and bleeding into joints and body cavities rather than petechiae. Reported episodes include spontaneous haematomas of the limbs, head, neck and shoulder, lameness from haemarthrosis, suspected haemothorax with cough and laboured breathing, oral bleeding when teeth are shed, nosebleeds, gum bleeding, melaena and prolonged bleeding after castration, suturing or microchipping, often with blood loss anaemia. Research-colony dogs average about four to six spontaneous bleeds a year. Laboratory findings are a prolonged aPTT with a normal prothrombin time.",null,[20,21],"Dogs","Cats",[23,30,35,40,44,49,53],{"claims":24,"source":25,"licence":26,"source_url":27,"harvested_by":28,"retrieved_at":29},"factor VIII cofactor role and defective thrombin formation, X-linked inheritance, most common inherited bleeding disorders in dogs, Chapel Hill Irish Setter colony since 1947, severity below 1% and inverse relation to factor VIII level, replacement with plasma-derived and recombinant products","ILAR Journal (2009) - Protein Replacement Therapy and Gene Transfer in Canine Models of Hemophilia A, Hemophilia B, von Willebrand Disease, and Factor VII Deficiency (PMC3101868, author manuscript)","not stated on source page (author manuscript in PMC)","https:\u002F\u002Fpmc.ncbi.nlm.nih.gov\u002Farticles\u002FPMC3101868\u002F","load-reference-corpus.cjs","2026-09-17",{"claims":31,"source":32,"licence":33,"source_url":34,"harvested_by":28,"retrieved_at":29},"intron 22 inversion and nonsense mutation, joint and soft-tissue bleeding unresponsive to vitamin K, prolonged aPTT with normal PT and normal von Willebrand factor, carrier daughters, PCR genotyping of offspring, cost of treatment","Comparative Medicine (2016) - Severe Hemophilia A in a Male Old English Sheep Dog with a C to T Transition that Created a Premature Stop Codon in Factor VIII (PMC5073066)","(c) American Association for Laboratory Animal Science; no open licence stated","https:\u002F\u002Fpmc.ncbi.nlm.nih.gov\u002Farticles\u002FPMC5073066\u002F",{"claims":36,"source":37,"licence":38,"source_url":39,"harvested_by":28,"retrieved_at":29},"clinical indistinguishability from haemophilia B, bleeding episodes in two owned dogs (haematomas, haemarthrosis, suspected haemothorax, oral bleeding, epistaxis, melaena, post-surgical bleeding, anaemia), littermates euthanised at 7 weeks, no family history, cryoprecipitate and plasma support, normal FIX and raised vWF","PLoS One (2016) - Successful Phenotype Improvement following Gene Therapy for Severe Hemophilia A in Privately Owned Dogs (PMC4807047)","Creative Commons Attribution License","https:\u002F\u002Fpmc.ncbi.nlm.nih.gov\u002Farticles\u002FPMC4807047\u002F",{"claims":41,"source":42,"licence":26,"source_url":43,"harvested_by":28,"retrieved_at":29},"untreated bleeding severe, debilitating and can be fatal; 4-6 spontaneous bleeds per year; prophylaxis and gene transfer reduce bleeding frequency without complete correction","Haemophilia (2010) - Prevention of spontaneous bleeding in dogs with haemophilia A and haemophilia B (PMC3101869, author manuscript)","https:\u002F\u002Fpmc.ncbi.nlm.nih.gov\u002Farticles\u002FPMC3101869\u002F",{"claims":45,"source":46,"licence":47,"source_url":48,"harvested_by":28,"retrieved_at":29},"inherited disorders most common in dogs, rare in horses and cattle, cats show signs mainly after surgery; vWD and haemophilia A most common inherited; acquired disorders (IMTP, rodenticide, liver disease, DIC) most common in practice and in older animals","eClinpath (Cornell University College of Veterinary Medicine) - Hemostasis: Disorders","(c) eClinpath; no open licence stated","https:\u002F\u002Feclinpath.com\u002Fhemostasis\u002Fdisorders\u002F",{"claims":50,"source":51,"licence":47,"source_url":52,"harvested_by":28,"retrieved_at":29},"secondary haemostatic defects cause ecchymoses, haematomas and bleeding into body cavities and joints; primary defects cause mucosal bleeding and petechiae","eClinpath (Cornell University College of Veterinary Medicine) - Hemostasis: Clinical signs","https:\u002F\u002Feclinpath.com\u002Fhemostasis\u002Fclinical-signs\u002F",{"claims":54,"source":55,"licence":56,"source_url":57,"harvested_by":28,"retrieved_at":29},"species: factor VIII deficiency reported in a cat (title), with cited reports of haemophilia A in cats","Canadian Veterinary Journal (1987) - Factor VIII Deficiency in a Cat (PMC1680506; bibliographic record and reference list only, full text is a scanned PDF)","not stated on source page","https:\u002F\u002Fpmc.ncbi.nlm.nih.gov\u002Farticles\u002FPMC1680506\u002F",[],[],[],[62,67],{"id":63,"documentId":64,"slug":65,"name_en":66,"name_ar":18},1414,"rvkmhyozs6s1tlfu4ehuopce","dog","Dog",{"id":68,"documentId":69,"slug":70,"name_en":71,"name_ar":18},1426,"j7o7tp1w2784juwb4te34z5r","domestic-cat","Domestic cat"]