Haematology Flashcards
How do you work out how much blood to give dog/cat in transfusion?
weight x blood volume x (desired PVC - Current PCV)/donor pcv)
- Blood volume Cats = 60ml/kg
- Dogs 90ml/kg
1ml/kg pRBC will rise pcv 1%
2ml/kg FWB will raise PCV 1%
Give slow 1ml/kg/hr for 15mins
If no reactions
Give remanider / 4hrs
If treatint immune mediated polyarthropathies with Azathioprine
WHat is the minimum lenght of time to use?
Whats the precautions?
- Using the drug
- Minimum of 10 days to full effect (possibly up to 6 weeks) (Lag phase)
- Precautions
- Monitor haemogram, ALT
With Pallor whats the difference in PCV and CRT for the 2 causes?
- Anaemia
- PCV = Reduced
- CRT = Normal
- Shock
- PCV = Normal
- CRT =Prolonged
What is the intrinsic pathway?
aPTT
12
11
9
8
10
5
pro–> Thrombin
Fibrinogen–>Fibrin
Clot
Whats the name for low platelet count?
Thrombocytopenia
Normal = 10-30 platelets [per High power field (100X)
Mechanisms that can lead to thrombocytopenia
- Destruction (Immune mediateds
- Consumption/loss
- Sequestration - Called to the spleen (Splenomegally, or IMHA, torsion, haemangiosarcoma
- Reduced production (Bone marrow issue)
What does a Neutrophil left shift indicate?
Bands - Immature
- Infection
- Severe Bacterial infection will have morphologic changes
- Immune mediated disease
- Necrosis
What are teh diagnostic criteria for Immune mediated polyarthritis (IMPA)
- Type 1
- non erosive, no underlying cause found
- Type 2
- Non erosive, underlying infection/inflammation found
- Type 3
- Non erosive, underlying enteropathy found
- Type 4
- non erosive underlying neoplasia found
What Blood factor has the shortest half life and there for will become deficient first?
Factor 7
Vitamen K Dependant 2, 7, 9, 10
What is the extrinsic pathway
3 (Tissue factor)
7
10
5
Pro–>thrombin
Fibrinogen–>Fibrin
Clot
Pred Typical therapeutic course for a dog?
- Induction
- 2-4mg/kg/day
- Maintenance
- 0.5mg/kg/day
What tests do we do on a oder dog we think has Hyperadrenocorticism?
ACTH Stimulation Corticol >600 = disease
Low Dose Dexamethasone Suppression test
Treatment
Remove cortisol production with Trilostane
What of the polyarthropathies do we see in perth a fair bit?
- Steroid-responsive meningitis arteritis (SRMA)
- Young large breed dogs <18mths
- non erosive
- underlying/ concurrent immune mediated meningitis
- Present with fever and terrible neck pain, no to minimal neurologic signs.
Treatment of polyarthritis
- Treat underlying disease
- Analgesia as required, environmental modification
- Dogs Immunosuppression
- Pred +/- azathioprine
- Cats, immunosuppression
- Pred + Chlorambucil
- Rheumatoid arthritis
- Pred +/- azathioprine, consider gold salts, lefunomide
- Manage concurrent glomeruloephritis if present
What PVC do we do a transfusion in a
Stable dog
Unstable patient?
- Unstable PCV ~25%
- Stable <20%
DDX’s for primary haemostatic defect?
- Thrombocytopaenia
- thrombocytopathia
- Vasculitis
What tests can you do to diagnose primary bleeding disorders?
ANd Secondary disorders?
- Platelet COunt (confirm with a smear)
- Platelet function test
- Buccal mucosal bleeding time (BMBT)
- Platelet function analyser - 100
- Aggregometry
- VWF: antigen assay
- Secondary haemostasis testing
- Clotting times
- Prothrombin time PT - Extrinsic and common
- Activeted partia thromboplatin time (APTT - intrinsic and common
- Activtated clotting time - intrinsic and common
- Individual factor analysis
- Clotting times
Haemophilla A & B are congenital deficencys of which factor?
- Haemophilla A = Factor 8 Difeciency
- Haemophilla B = Factor 9 Difeciency
How do we cross match cat blood?
- Patient serum x donar RBC
- Type B has strong antibodies against A
Dogs donat >25kg - take 450 - No fluids
Cats Donat >5kg - take 54ml- Give 100ml fluids
Testing cats for hyperthryoidism?
- Total T4 if >60nmol/L confirms disease
If its high range do a Free T4 - Beware of false positives
Treatment = Carbimazole or methimazole
Surgery thyroidectomy
at what platelet cound do we know its not the cause of bleeding?
>50x1019/L
