Haematopoietic diseases Flashcards
Why is anaemia common in cats?
RBC shorter life span Sensitive to oxidative stress Cats adjust life style to composate not found until late Lower RBC mass Feline Hb low affinity for oxygen
What are the clinical signs associated with anaemia?
Jaundice (haemolytic anemia) Pallor MM nose and pads Increased HR Hyper dynamic pulses Increased RR Increased size lymph nodes and spleen Pica Underlying disease Excercise intolerance Felv FIV FIP clinical signs
At what pcv should anaemia be investigated?
Below 24% in cats below 37% in dogs
What is regenerative anaemia?
Bone marrow compensates for loss of blood by producing immature RBCs increased MCV presence of anisocytosis polychromasia (high number of immature RBC) nucleated RBC look for aggregate reticulocytes in cats (not present normally)
What is non-regenerative anaemia?
Bone marrow does not respond to anaemia
How should a reticulocyte count be performed?
Blood smear, new methylene blue stained blood smear by counting the % of RBCs that are aggregate reticulocytes
Decide if the proportion of aggregates present is proportionate to the anemia present
What is the reticulocyte equation?
%reticulocyte on smear X RBC count X 10
At what number of absolute reticulocytes suggest regenerative anaemia?
50-100
What other conditions can cause you to believe that anaemia is non regenerative when in fact it is regenerative?
Duration of anaemia it takes 3-5 days for new RBCs to be released
Chronic blood loss will lead to an iron deficiency which imparts RBC formation
Concurrent disease
FELV, infectious and inflammatory diseases (cat flu) can reduce the bone marrow response
What are the two causes of regenerative anaemia?
Blood loss and haemolysis
What can cause blood loss anaemia?
Coagulopathies
Amylodiosis (haemorrhage from the liver)
Congenital and inherited clotting defects
Thrombocytopenia
Ulcerated tumour
Flea infestation
What can cause haemolytic anaemia
FeLV infection Feline infectious anaemia Immune mediated haemolytic anaemia Heinz body anaemia Severe hypophosphateamia Neonatal isoerthrolysis Inherited defects
What is feline infectious anaemia caused by?
Caused by mycoplasma haemofelis
Mycoplasma haemominutum
Mycoplasma turicensis
Blood sucking parasites
What are the clinical signs associated with feline infectious anaemia?
Pallor Lethargy Jaundice Anorexia Weight loss Pyrex is Dehydration
How is feline infectious anaemia diagnosed?
Presence of mycoplasma on RBC dried smear
PCR test of choice
How is Feline infectious anaemia treated?
Doxycycline antibiotic follow immediately with water or food
What is Heinz body anaemia?
Paracetamol/onion poisoning
irreversibly denatured Oxidised haemoglobin
Are present in small number in the cat normally
Lymphoma
Diabetic ketoacidosis
Destroyed via haemolysis
What is Neonatal isoerythrolysis anemia
Cats breed with varying blood types two types type A and type B (pedigree) type B have strong antibodies to type A blood if queen (type B) gives birth to type A kittens antibodies against type A blood will pass through to the kitten via the colostrum in first 24 hours Haemolysis of the RBC
What tyoes of disorders cause non-regenerative anaemia?
Disorders of the bone marrow
Myeloprofilerative (leukemia) and myelodysplastic (abnormal cells)
Marrow failure (stream cell formation)
Toxins (heavy metals)
Suppression of the bone marrow
FeLV FIP, FIV, chronic kidney disease, chronic inflammation
Why does chronic kidney disease cause non regenerative anaemia?
Shorter RBC lifespan
Erythropoietin deficiency (produced in response to hypoxia in the kidney)
Blood loss
Impaired iron utilisation
What is AID and what does it stand for?
Anaemia of inflammatory disease
Very common
As a result of chronic inflammation and circulating toxins
PCV rarely falls below 18% does not need specific investigations
How is anaemia treated?
Blood transfusion PCV above 10% unnecessary
Oxyglobin
Frozen plasma
Erythropoietin therapy
Bone marrow stimulation (anabolic steriods, prednisalone)
What is a bleeding disorder?
An abnormal condition which allows blood to escape injured vessels
What is primary haemostasis?
Vasoconstriction of local blood vessels and formation of the platelet plug
What is secondary haemostasis?
Stabilisation of the platelet plug with fibrin
What three pathways are involved in secondary haemostasis
Intrinsic extrinsic common
What is involved in the extrinsic pathway?
Tissue factor VII calcium
What test is used to assess the intrinsic pathway?
APTT ACT
What is involved in the intrinsic pathway?
Calcium factors , XI, XII, IX VIII
What is involved in the common pathway
Factor V and X and calcium
Convert prothrombin to thrombin
Thrombin then converts
Fibrinogen to fibrin
What test is used to assess the extrinsic pathways
Prothrombin time
Where are coagulation factors synthesised? And what vitamin di they require?
In the liver vitamin k
What clinical condition can lead to vitamin K deficiency?
Cholestasis -blockage of the bile duct fat malabsorption
Rodenticide toxicity
What history apshould be obtaine when a clotting disorder is suspected?
Previous reports of prolonged bleeding at surgery Easily bruised Prolonged bleeding after blood samples Less than 6 months of age Haemophilia effects makes Recent exposure to toxins
Clinical signs associated with a primary haemostasis disorder?
Petechaie Multiple bleeding sites Prolonged bleeding. Surface bleeding(mucous membranes) Multiple bleeds and prolonged
Clinical signs associated with a secondary haemostasis disorder?
Haematomas Localised site of bleeding Delayed bleeding rebelling from cuts Deep cavity bleeds joints abdomen thoracic cavity Single large bleeds and rebleeding
What laboratory tests can be used to test for primary haemostasis disorders?
Buccal mucosal bleeding times
Platelet counts
What labrotary tests can be used to test secondary haemostasis disorders?
Activated clotting time
Prothrombin time
What re platelet counts used for and how should they be completed?
Quantity of platelets
Collect in edta tube send to lab anticoagulant tests
Use of dif quick staining
Look for platelet clumps this will affect the numbers
Number of platelets per high field are counted repeated for 10 fields average obtained
Approximately 11-25 per field is normal
What is bucxal mucosal bleeding time used for and how it is preformed?
Primary haemostasis disorders of the vessels and platelet function
Upper lip folded up and held in place with a gauze
A pair of small standardised incisions are made with a spring loaded bleeding time device
Time taken for the cessation of bleeding is recorder
Less than 3mintues cats less than 3.5 dogs
What are activated clotting times used for and how are they preformed?
Secondary haemostasis evaluates intrinsic and common pathways
The collection tube activates the intrinsic pathway.
2mls of blood is collected
Tube is inverted then left for 40 seconds after this point tube is inverted every 10 seconds and the time for a clot to form, is recorded
What is APTT and how is it preformed?
Evaluates the intrinsic and common pathways activated partial thromboplastin time
Sample collected into sodium citrate tube assesse by external lab factor xII
What is PT and how is it preformed
Prothrombin time assessed the extrinsic and common pathways sodium citrate tube is filled and sent off to the lab.
Very sensitive to rodenticide posing and vitamin k deficiency
What is a point of care analyser?
Coagulation instrument
Determine APTT and PT
Small amounts of citrate blood
