LR&H Flashcards
(133 cards)
With low PCV - what is the first question you always want to ask?
Is this anemia regenerative or non-regenerative?
If suspected IMHA, what are the best diagnostic tests to confirm?
In Saline Agglutination test - will agglutinate due to antibodies on RBC surfaces
Coomb’s test
What is the difference between pyrexia and hyperthermia?
Pyrexia - body’s increase in hypothalamic set point as a response to a pathological state carried out by pyrogens (cytokines)
Hyperthermia - sudden, uncontrolled increase in body temperature due to a failure of the body’s thermoregulation - body unable to lose enough heat in relation to the production (heat stroke, exercise)
What are the first tests to do when anemia is suspected?
PCV/TP
Blood smear
What will be seen on a blood smear with regenerative anemia?
Polychromasia - bluer RBCs = immature Aniscytosis - different RBC cell sizes Spherocytes - dents in RBCs - extravascular hemolysis Ghost cells - intravascular hemolysis Reticulocytes/polychromatophils
How to differentiate between 1º and 2º IMHA?
Trigger factors - infectious, UTI, drugs, toxins, neoplasia
Abdominal/thoracic radiographs
If negative without abnormalities - 1º
Treatment for 1º IMHA
Blood type and blood transfusion
Prednisolone to stop immune-mediated destruction
Clopidogrel - decrease risk of thromboembolic disease
Add a second immuno suppressant (chlorambucil in cats and azathioprene in dogs) to taper down corticosteroid
Consider using a gastroprotectant (omeprazole)
Reasons for pyrexia with IMHA
Immune mediated diseases cause recurrent pyrexia
What will be seen on a blood smear with iron-deficient anemia?
Microcytosis
Hypochromasia - RBCs very pale
- Usually due to chronic intestinal loss of iron
What are the canine blood types?
DEA 1, 3, 4, 5, and 7 - positive or negative
Generally, test for DEA 1 because there are anti-DEA 1 antibodies that will form if you give DEA 1 positive blood to a DEA negative dog
* Naturally occurring ABs are uncommon for all other DEAs*
What are the feline blood types?
A, B, or AB
* Cats have naturally occurring alloantibodies to A or B antigens (unless AB type) – ALWAYS BLOOD TYPE CATS!
With severe thrombocytopenia, what are the major diagnoses?
- Could be artefactual (on CBC measurement)
- Immune-mediated thrombocytopenia
1º - just occur, idiopathic
2º - underlying disease process, neoplasm, infection, drug treatment - BM disease (fibrosis, neoplasia)- kicking out platelets
- DIC - disseminated intravascular coagulation - coagulopathy forming clots in body using platelets - usually not severe thrombocytopenia ** ALWAYS SECONDARY PROCESS TO NEOPLASIA/Pancreatitis/etc.*
- Drug therapy - phenobarbitone
- Infectious disease - lepto
What is the ddx in a dog with signs of shock with harsh lung sounds, bilateral SCLERAL hemorrhage (no trauma), and thrombocytopenia?
Angiostrongylus vasorum
Dx with Angiosnap, Baermann
DDX for 2º hemostasis disorders
Hepatic failure - has to be severe - produces coagulation factors, albumin
Rodenticide intoxication
Inherited coagulopathies - hemophilia (affect one clotting factor)
Heparin administration
When looking at blood smear - what are the three components to look at?
Red Blood cells
White blood cells
Platelets
How to recognize left shift toxicity on blood smear?
You will see band neutrophils with parallel walls of the nucleus and FOAMY cytoplasm and basophilia of cytoplasm where it looks BLUE
Toxicity - accelerated production meaning that cells are produced too fast - do not look normal
What is the most common cause of thrombocytopenia?
Immune-mediated thrombocytopenia
ABs produced against platelet antigens
Summarize the 3 stages of hemostasis
1º - formation of the platelet plug - damage to endothelium –> release of vWF –> platelet adhesion to exposed collagen –> platelet shape change and aggregate –> degranulate and release pro-coagulants
2º - coagulation cascade and generation of the insoluble fibrin to stabilize the plug
3º - enzyme breakdown of fibrin by plasmin - fibrinolysis
What are some tests utilized to evaluate platelets?
Automated platelet concentration counts with machine - can be inaccurate if blood clotted/clumps
Estimated platelet count from blood smear
Buccal mucosal bleeding time
What are some causes of thrombocytosis?
- Physiological - epinephrine –> splenic contraction releasing more into circulation
- Reaction - inflammation, hemorrhage, iron deficiency
What are some laboratory evaluations of coagulation?
- Activated clotting time (ACT) - draw blood, incubate, see how long it takes a clot to form
- Partial thromboplastin time (PTT) - test for intrinsic and common pathways of coagulation
If Prolongation of PTT alone - defects of intrinsic pathway like Hemophilia A or B - Prothrombin time (PT) - test for extrinsic and common pathways of coagulation
If prolongation of PT alone - consider early vitamin K deficiency, liver disease, early DIC, F7 deficiency
IF BOTH PROLONGED - Vitamin K deficiency, DIC, liver failure
Which portion of the spleen is NOT fixed?
The tail end - it is relatively mobile
HEAD END fixed in the abdomen by the gastrosplenic ligament
What are common differential diagnoses for splenomegaly?
Localized: hematoma, abscess, hemangiosarcoma, lipoma, leiomyoma/sarcoma
Diffuse:
Splenic torsion/trauma, Splenic Hyperplasia, lymphoma, leukemia, Infection, IMTP
What virus is mostly associated with feline lymphoma?
FeLV
Once the virus integrates itself into the host genome - it can integrate into a proto-oncogene causing neoplastic transformation
Usually causes thymic/mediastinal lymphoma