Haematology Flashcards
(125 cards)
absolute decrease in platelet count
Absolute decrease in platelet count, it’s a clinical sign and NOT a diagnosis
predisposition of thrombocytopenia
cocker spaniels, poodles, greyhounds (physiologic decreased platelet number), CKC spaniels (hereditary macrothrombocytopaenia)
cause of thrombocytopenia
primary (idiopathic/IM), secondary (infectious, neoplasia, drugs)
- Increased platelet destruction: immune mediated thrombocytopenia, infection, drug induced, disseminated intravascular coagulation
- Decreased platelet production: drug-induced megakaryocytic hypoplasia, Myelophthisis
signs of thrombocytopenia
may be no clinical signs or signs of bleeding, haematuria, melena, petechial haemorrhages, epistaxis
diagnosis of thrombocytopenia
always do a blood smear
- clinical exam, lab diagnostics
- Haematocrit, platelets, total protein, urine colour
o low platelet count, normal coagulation panel, pancytopenia + megakaryocytic hypoplasia (bone marrow suppression), platelet bound antibody (IM)
- Differential WBC count, biochemistry profile, radiography, PT and aPTT
treatment of thrombocytopenia
depends on cause, cage rest, IM give prednisolone, doxycycline (E.canis + haemobarotonella), desmopressin and transfusion is not recommended
BMBT procedure
- Position the animal in lateral recumbency with manual restraint
- Place a 5-cm wide strip of gauze around the maxilla to fold up the upper lip, causing moderate engorgement of the mucosal surface
- Position the Sim plate against the upper lip mucosa and push the trigger
- Start a stopwatch when the incisions are made
- Blot the blood with a gauze or blotting paper placed 1-3mm ventral to the incision without dislodging the clot
- Stop the stopwatch when the incision ceases to bleed
- Normal times are 2-3 minutes
platelet dsyfunction
- Congenital: vWD
- Acquired: drugs (prostaglandin inhibitors, atb, vaccines), secondary to diseases (monoclonal gammopathies, ehrlichiosis, uraemia, retroviral infections, drug therapy, liver disease)
immune mediate thrombocytopenia predisposition
Most common acquired primary haemostatic defect in dogs
middle-aged female dogs, cocker spaniels, old English sheep-dog
cause of I.M thrombocytopenia
characterised by IM destruction of antibody coated platelets
signs of I.M thrombocytopenia
petechiae, epistaxis, haematemesis, melena, haemturia
diagnosis of I.M thrombocytopenia
made by excluding other diseases and initiating immunosuppressive drug therapy, exclude vector-borne diseases (ehrlichia, anaplasma, borrelia, leishmania, babesia, bartonella, drugs)
- haematology: thrombocytopenia with/without anaemia (degree of bleeding/presence of IHA)
- Bone marrow punction: megakaryocytic hyperplasia (occasionally: megakaryocytic hypoplasia with free megakaryocyte nuclei)
treatment of I.M thrombocytopenia
immunosuppressive drugs, glucocorticoids
prognosis of I.M thrombocytopenia
good, rarely fatal
predisposition of Von Willebrand
severe form may become obvious in neonate
- Type 1: Airedale, akita, dachshund, Doberman, golden, poodles, etc
- Type 2: German short/wirehaired pointed
- Type 3: Scottish terrier, Shetland sheepdog, cocker spaniel, labs, Maltese
cause of VW
typically an inherited disorder
Types of VW
Type 1:
- most common type, decreased concentration or activity of vWF
- partial lack of VWF
- typically mildest manifestation
- autosomal dominant inheritance with incomplete penetrance
Type 2:
- low to normal concentration of an abnormal vWF
- associated with a partial lack of VWF
- more severe clinical manifestation possible
- autosomal recessive inheritance
Type 3:
- absence of circulating vWF
- typically severe clinical manifestation
- autosomal recessive inheritance
signs ofVW
excessive bleeding during/after surgery, petechiae and ecchymoses, perinatal death, abortion, stillbirth, epistaxis, urinary tract haemorrhage, gastrointestinal haemorrhage
diagnosis of V.W
PFA-100 test (closure time) and BMBT is prolonged
- BMBT, activated clotting time, activated partial thromboplastin time (APTT), prothrombin time (PT)
treatment of VW
transfusion with plasma/fresh blood. Desmopressin (DDAVP) may have some beneficial effect
prognosis of VW
incurable, problems are usually mild and inconsequential, risk of life-threating haemorrhagic
differential of VW
haemophilia, anticoagulant rodenticide poisoning, thrombocytopenia, hereditary platelet defects, acquired platelet dysfunction
secondary haemostat defects predisposition
more common in dogs than cats
cause of 2nd hemeostatic defect
severe liver disease, rodenticide poisoning (vit K deficiency), congenital deficiency (haemophilia), systemic diseases (neoplasia, DIC, toxins, severe bleeding)