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| − | * There is a wide range of diseases and syndromes that are characterised by haemorrhagic disease.
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| − | * Show either:
| + | |pagetitle =Haemorrhagic Diseases |
| − | ** An increased tendency to bleeding - haemorrhagic diathesis.
| + | |pagebody =There are a wide range of diseases and syndromes that are characterised by haemorrhagic disease. They show either frank haemorrhage such as purpura or an increased tendency to bleeding - haemorrhagic diathesis as a clinical feature. Although haemorhagic disease is sometimes obvious, it may also be discovered incidentally, for example following surgery or trauma. |
| − | ** Frank haemorrhages as a clinical feature - [[Haemorrhage - Pathology#Purpura|purpura]].
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| − | * Altought this disease is sometimes obvious, it may also be discovered incidentally, for examply following surgery or trauma.
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| − | ===Classification of Haemorrhagic Diseases=== | + | |contenttitle =Content |
| | + | |contentbody =<big><b> |
| | + | <categorytree mode=pages>Haemorrhagic Diseases</categorytree> |
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| − | * Haemorrhagic diseases may be due to
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| − | *# '''Increased vessel fragility'''.
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| − | *#* Causes non-thrombocytopenic purpura.
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| − | *# '''Inadequate haemostatic response'''.
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| − | *#* This may be caused by:
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| − | *#** Platelet dysfunction or deficiency.
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| − | *#*** Causes primary or secondary thrombocytopenic purpura.
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| − | *#** Deficiencies or derangements of clotting factors.
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| − | * Syndromes caused by vascular fragility and platelet dysfunction tend to be purpuric and aquired.
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| − | * Sydromes caused by clotting factor defects tend to cause more severe bleeding and are usually congenital.
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| − | === Haemorrhagic Disease Due To Vascular Fragility===
| + | [[Category:Haemostasis and Bleeding Disorders]] |
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| − | * There are several ways that vascular fragility may arise.
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| − | # Capillary damage by toxins.
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| − | #* This occurs in severe bacterial infections in all species.
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| − | #* [[:Category:Streptococcus species|''Streptococcus'']] and [[:Category:Pasteurella and Mannheimia species|''Pasteurella'']] infections and [[Bacillus species|anthrax]] can all cause this.
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| − | # Drug-induced damage.
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| − | #* The mechanisms of damage induced by drugs are not clearly understood.
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| − | #* Examples include:
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| − | #** Heavy metals, e.g. lead, bismuth, mercury.
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| − | #** Iodides.
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| − | #** Fluorides.
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| − | #** Chlorinated hydrocarbon pesticides.
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| − | #** Salicylates.
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| − | # Other miscellaneous causes:
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| − | #* Allergy or anaphylactic responses.
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| − | #* Connective tissue disease.
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| − | #** E.g. Ehlers-Danlos syndrome in dogs.
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| − | #* [[DM|Diabetes mellitus]].
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| − | #* Antibody-antigen complex reaction.
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| − | ===Disease associated with platelet abnormalities===
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| − | ====Primary Thrombocytopenic Disease====
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| − | * The aetiology of primary thrombocytopenic disease is often uncertain.
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| − | ** It is therefore also known as idiopathic thrombocytopenia.
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| − | ** The cause may be automimmune.
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| − | * Although the [[Bone Marrow - Anatomy & Physiology|bone marrow]] contains adequate normal megakaryocytes, there is a reduced peripheral blood thrombocyte count.
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| − | * Usually seen in young animals.
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| − | ====Secondary Thrombocytopenic Disease====
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| − | * Secondary thrombocyopaenic disease is fairly common in adult and older domestic animals.
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| − | * Associated with diseases which cause [[Bone Marrow - Anatomy & Physiology|bone marrow]] depression.
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| − | * The [[Bone Marrow - Anatomy & Physiology|bone marrow]] is depleted or devoid of megakaryocytes, and there is a nil or markedly reduced peripheral blood thrombocyte count.
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| − | * Secondary thrombocyopenic disease is seen in the following conditions:
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| − | *# Severe viral infections.
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| − | *#* For examople, ICH, feline panleucopenia, [[Bovine Viral Diarrhoea Virus|mucosal disease]], [[Classical Swine Fever|swine fever]].
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| − | *# Severe protozoal infections.
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| − | *#* For example, in the UK, Haemobartonella may be a cause.
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| − | *# Plant intoxications.
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| − | *#* For example, bracken, kale, or ragwort poisoning.
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| − | *# Drug-induced conditions.
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| − | *#* High doses of oestrogens and salicylate.
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| − | *#* Prolonged use of phenyl butazone.
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| − | *# [[Bone Marrow - Anatomy & Physiology|bone marrow]] neoplasia.
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| − | *#* For example, lymphosarcoma or myeloid leukaemia.
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| − | *# Radiation.
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| − | *#* May cause damage to the [[Bone Marrow - Anatomy & Physiology|bone marrow]] if it is severe and generalised.
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| − | *# Other miscellaneous causes.
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| − | *#* Severe bacterial infections.
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| − | *#** For example, [[:Category:Staphylococcus species|''Staphylococci'']], and those Gram -ve bacteria producing endotoxins (e.g. [[:Category:Pseudomonas and Burkholderia species|''Pseudomonas'']] or [[Salmonella|''Salmonella'']] spp.).
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| − | *#* [[Liver - Anatomy & Physiology|Liver]] disease.
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| − | ====Thrombocytopathia====
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| − | * A rare inherited condition.
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| − | * Recorded in the dog.
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| − | * Characterised by defective thrombocyte formation.
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| − | ** Poor adhesiveness.
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| − | ** Poor aggregations.
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| − | ** Poor platelet factor release.
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| − | ===Diseases associated with coagulation factor defects===
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| − | * Most cases of "factor disease" in animals are similar to those studied in man.
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| − | ** Congenital.
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| − | ** Based on familial occurence.
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| − | ** Clotting biochemistry is similar in man and animals.
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| − | * Most investigations have been carried out in the dog.
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| − | * [[Haemostasis - Pathology#Factor VIII|Haemophilia]] (factor VIII deficiency) is probably the best understood condition.
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| − | ====Von Willebrand's Disease====
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| − | * Seen in the dog.
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| − | ** Most common in Scottish Terriers and Chesapeake Bay Retrievers.
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| − | ** Has been seen more recently in Dobermanns, Setters and German Shepherd dogs.
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| − | ** A similar disease has been recorded in the pig.
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| − | * Von Willebrand's Disease is an inherited autosomal recessive trait.
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| − | ** It is incompletely dominant, so there is variable expression.
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| − | * '''Presentation'''
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| − | ** Purpura.
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| − | ** Prolonged bleeding time.
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| − | ** Reduced platelet adhesiveness.
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| − | ** Low Factor XIII levels.
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| − | * The disease can be assessed by the measurement of Von Willebrand Factor protein levels.
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| − | ** A Factor VIII-related protein.
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| − | ** Synthesised in endothelial cells and megakaryocytes.
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| − | ** Stored in platelets.
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| − | ** Levels are low in affected animals.
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| − | '''Deficiency states of other factors have been recorded sporadically as follows:'''
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| − | ====Factor I ====
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| − | * Factor 1 is fibrinogen.
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| − | * '''Hyperfibrinogenaemia''' occurs in
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| − | ** Pregnancy
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| − | ** Acute infections
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| − | ** Post-operative states
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| − | ** Pyometra
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| − | * '''Hypofibrinogenaemia''' is seen in
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| − | ** Liver disease.
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| − | ** Depletion by intravascular coagulation.
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| − | ====Factor II ====
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| − | * Factor II is part of the prothrombin complex.
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| − | * '''Hypoprothrombinaemia'''
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| − | ** A depression of the components of the prothrombin complex.
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| − | *** I.e. Factors II, VII, IX, X
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| − | ** May be caused by dicoumarol and its derivatives, for example sweet clover and warfarin.
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| − | *** Competitively inhibits Vitamin K in the liver, where the above Factors are synthesised.
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| − | ====Factor IV ====
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| − | * Factor IV is calcium.
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| − | ** Necessary at several stages of coagulation.
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| − | * '''Hypocalcaemia''' at a level sufficient to impair haemostasis is incompatible with life.
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| − | ** There is therefore no bleeding defect associated with hypocalcaemia.
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| − | ====Factor VII====
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| − | * Factor VII is Proconvertin.
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| − | * Deficiencies do not appear to impair the formation of haemostatic plug.
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| − | ** The bleeding defect is normally mild.
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| − | * Newborn pups have a very low plasma level of Factor VII.
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| − | ** Spontaneous and inherited deficiencies have been reported in Beagle colonies.
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| − | * Deficiencies may also occur associated with [[Liver - Anatomy & Physiology|liver]] disease and in dicoumarol poisoning.
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| − | ====Factor VIII ====
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| − | * Factor VIII is known as antihaemophilic factor (AHF).
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| − | * Deficiency of this factor causes '''haemophilia A'''.
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| − | ** The primary thrombocyte plug is abnormal.
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| − | *** More vascular channels than usual.
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| − | *** Less fibrin-collagen contact around the edges.
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| − | ** Plugs are therefore easily dislodged.
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| − | *** Results in rebleeding.
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| − | *** Secondary plugs only form with difficulty.
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| − | * Haemophilia is reported in horses and in around 20 breeds of dogs.
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| − | * Haemophilia is as a sex-linked recessive condition.
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| − | ** Associated with the X chromosome.
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| − | ** Affects males only.
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| − | * The severity of the disease correlates with the Factor VIII levels.
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| − | * Haematomas and haemarthrosis are common lesions.
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| − | ====Factor IX ====
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| − | * Factor IX is Christmas Factor.
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| − | * Deficiency causes '''haemophilia B'''.
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| − | ** Seen in Cairn Terriers and Black and Tan Hounds.
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| − | ** A sex-linked (X chromosome) recessive.
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| − | ** Results in a deficient haemostatic plug.
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| − | *** Similar to Factor VIII deficiency.
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| − | ====Factor XI====
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| − | * Factore XI is Plasma Thromboplastin Antecedent.
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| − | * Deficiency has been reported in a cow, and reduced levels in the horse.
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| − | ====Factor XII====
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| − | * Factor XII is Hageman Factor.
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| − | * Low plasma levels had been reported in cats and horses.
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| − | [[Category:Haemostasis - Pathology]]
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