11: Coagulopathies Flashcards
Which kind of conditions cause increased platelet consumption?
Inflammatory
Which condition is consumptive thrombocytopenia associated with?
DIC
Which conditions are mild thrombocytopenia associated with?
Vasculitis, endocarditis, intravascular coagulation
What causes primary IMTP?
Idiopathic
What are some causes of secondary IMTP?
Drugs, neoplasia, infection e.g. anaplasma
What is signalment for IMTP?
Cockers, Mini Poodles, OES esp young and middle aged
What are clinical signs of IMTP?
Primary coagulopathy signs + lethargy, weakness, fever, hepato/splenomegaly, lymphadenopathy
What is also seen on bloods in IMTP?
Left-shifted neutrophilia
What is IMTP + IMHA called?
Evans’ syndrome
How do you diagnose IMTP?
Rule out others, search other causes
How do you treat IMTP?
Preds then wean off. Sometimes transfusions or platelet-rich plasma.
Which drug can increase platelet production?
Vincristine
Why do you do splenectomy in IMTP?
Spleen is destroying platelets
What is mortality of IMTP?
30%
What do plasma blood products contain?
vWF and clotting factors
What is lifespan of plasma?
Short
What is a problem with platelet-rich plasma?
Hard to prepare
What drug can cause reduced bone marrow platelet production in cats?
Azathioprine
What are some infections that can cause reduced bone marrow platelet production?
FIV, FeLV, FIP, distemper, parvo, lepto, anaplasma
How common is immune-mediated megakaryocyte production?
Rare
What are two types of inherited thrombocytopathia?
vWD, Chediak-Higashi syndrome
How common is acquired thrombocytopathia?
Not common
What are three causes of acquired thrombocytopathia?
Hyperglobulinaemia, neoplasia, NSAIDs
What species is vWD the most common in?
Rare in cats, the most common coagulopathy in dogs
What is platelet count like in vWD?
Normal
How do you test for vWD?
Assay and genetic testing
How do you treat vWD?
Palliative e.g. desmopressin, minimise trauma
How does desmopressin work to treat vWD?
Causes vWF release
How does desmopressin affect BMBT?
Short term (4h) reduction
How reliable is desmopressin to treat vWD?
Not very
What is haemophilia A a deficiency of?
Factor VIII
Which sex gets haemophilia A?
Sex linked, males > females
What is severity of signs like in haemophilia A?
Severity of signs variable
How are APTT and OSPT affected in haemophilia A?
APTT increased, OSPT normal
How do you test for haemophilia A?
Factor VIII
What is treatment for haemophilia A?
None
What are some complications of haemophilia A?
Intra-articular or body cavity bleeds
What is the most common inherited secondary coagulopathy?
Haemophilia A
What is the most common cause of secondary coagulopathy?
Hepatic disease
What are two causes of vitamin K rodenticide?
Diet deficiency or rodenticide
Which tumours produce heparin?
Mast cell
Which antibodies can cause secondary coagulopathy?
To clotting factors
How do rodenticides work?
Inhibit epoxide reductases so inactive vit K can’t be converted to activated so clotting factors can’t be activated
What is platelet count like in rodenticides?
Normal or mildly reduced
How do you diagnose rodenticide poisoning?
Coagulation testing
Which test becomes abnormal first following rodenticide poisoning?
OSPT (II, VII, X)
Which tests become prolonged in rodenticide poisoning?
APTT, WBCT, ACT
How do you treat rodenticide poisoning?
More active vitamin K sub cut then orally for 1-6 weeks, but check 2d after stopping treatment
How do you treat severe cases of rodenticide poisoning?
Fresh blood or plasma
Which types of haemostasis do angiostrongylus and DIC both affect?
Primary and secondary
What causes DIC?
Marked inflammatory response leading to small vessel clots
What blood components are consumed in DIC?
All platelets and clotting factors
What are clinical signs like in DIC?
Subtle initially, then associated with end organ damage e.g. kidney, CNS
How do you diagnose DIC?
Low platelets and fibrinogen, high D dimers, prolonged OSPT and APTT
How do you treat DIC?
Underlying cause, with oxygen, fluids, heparin, transfusions
What is prognosis for DIC?
Poor
How do you diagnose A vasorum?
Larvae or a snap test - prolonged OSPT, APTT, thrombocytopenia, elevated D dimers
How do you treat A vasorum?
Fenbendazole, imidocloprid, moxidectin, +/- pred
What condition can cause blood stasis in cats?
Hypertrophic cardiomyopathy
What are two conditions that can cause decreased anticoagulant factors?
Cushing’s or protein-losing nephropathy
Which condition causes increased endogenous procoagulants?
IMHA
Where is vWF found?
Subendothelial matrix
What two things does vWF anchor platelets to?
Injury and each other
Which factor does vWF bind to to initiate secondary clot formation?
Factor VIII
What is type 1 vWD?
All multimers present but low conc
Which kind of vW glycoproteins are more functional?
Larger
Which breed gets type 1 vWD?
Doberman
What is type 2 vWD?
Large monomers lost
Which breed gets type 2 vWD?
German short haired pointer
What is type 3 vWD?
Lack all multimers
Which breed gets type 3 vWD?
Scottish terriers, shetland sheepdogs, chesapeake bay retrievers
