LR&H Flashcards
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
What is the most common site of lymphoma in a cat?
GASTROINTESTINAL LYMPHOMA
*low grade GI lymphoma usually T cell
What is the most common type of lymphoma in a dog?
Multicentric lymphoma
What are the common diagnostic approaches to lymphomas?
- FNA
- Biopsy and hitopathology
- US! Especially when it is suspected GI lymphoma
- Endoscopic biopsies - when difficult to tell on US
- ExLap
What is the best treatment protocol for feline lymphoma?
High grade - COP protocol - cyclophosphamide, oncovin (vincristine), prednisolone (COAP for renal/CNS lymphoma)
Low grade GI lymphoma - Chlorambucil and Prednisolone
What cells do myelomas form in?
PLASMA CELLS
What are we trying to differentiate between when looking at a lymph node cytology? And what are the differences?
Hyperplasia, inflammation, neoplasia, metastasis
NORMAL - will be dominated by small lymphocytes ~ 90%
Hyperplastic - Increased number of medium to large lymphocytes but LESS THAN 50%
Lymphadenitis - Increased inflammatory cells - neutrophils, macrophages, eosinophils
Lymphoid neoplasia - >50% immature medium to large lymphocytes/monotonous! - few small ones seen
Metastasis - foreign cells present
* when sampling submandibular LN - ensure you are not sampling the salivary glands
What is the main symptom seen with paraneoplastic syndrome and what are the clinical signs seen with this?
HYPERCALCEMIA
PD/PU, dehydration, depression, weakness, anorexia, vomiting, constipation, dysrhthymias, muscle tremor
What are the clinical stages for lymphoma? What are the substages?
Stage 1-5 1- single LN enlarged (RARE) 2- multiple LNs in one area enlarged 3- generalized lymphadenomegaly 4- stage 3 + spleen and liver involved 5 - stage 4 + BM involvement
Substage
a - WITHOUT clinical signs
b - WITH clinical signs
How would you differentiate between stage 3 and stage 4 lymphoma?
US to look at spleen and liver
FNA 2 organs to ensure involvement
What are the treatment protocols for B cell lymphoma vs. T cell lymphoma in dogs?
- B cell - COP or CHOP - Cyclophosphamide, Oncovin (Vincristine), Prednisolone
H = DOXORUBICIN (CHOP slightly better than COP) - T cell - LOPP - Lomustin, Oncovin (Vincristine), Procarbazine, Prednisolone
Are mediastinal lymphomas usually associated with T cells or B cells?
T CELLS BITCH!!!!! FOCUS!!!!
Once exposed to FeLV, what are the 3 primary outcome stages?
- Abortive - effective immune response (test negative) so have antibodies
- Regressive - ineffective immune response but will not shed virus and eventually become asymptomatic (test positive and then negative)- left with LATENT infection
- Progressive - ineffective immune response, continue to shed virus throughout life and have a decreased life expectancy (test positive)
What is the core protein as the basis for FeLV diagnostic tests?
Core protein p27!! (gag protein) antigen detection by ELISA
How is FeLV mainly transmitted?
Saliva, nasal secretions, feces, urine, milk (and blood transfusions)- usually spread via prolonged contact - shared food and water, mutual grooming
What is the main route of transmission for FIV?
Bite wounds - large amount of virus in the saliva/blood
What are the stages of FIV pathogenesis?
Acute (high amounts of replication- in T cells, B cells, macrophages) –> asymptomatic carrier –> general lymphadenopathy –> terminal (AIDS) - not many cats (~10%) get to terminal stage
What type of cells does FIP infect?
MACROPHAGES! Duh
What is the cause of feline infectious anemia?
Mycoplasma hemofelis - attach to RBCs leading to immune-mediated destruction
What is the main form of treatment for FIA?
Doxycycline
Flea control!
Blood transfusion if necessary
May need immunosuppressive therapy if know IMHA but waiting for mycoplasma results
What is the main diagnostic test for EIA?
Plasma lactate concentration and PvO2 levels
Testing PCV is useless
COGGINS TEST or ELISA
What is the best blood product to use with coagulopathies?
FRESH (frozen) PLASMA
high in all the clotting factors
What is cryoprecipitate mostly used for?
Patients with vWF disease as it is enriched with factor 8, vWF and fibrinogen
What are some common differentials for non-regenerative anemia?
Renal disease - decreased EPO
Endocrine disease - hypothyroid, hypoadrenocorticism
FeLV - depressed erythropoiesis, dysplastic production of RBCs
Non-regenerative BM
- Neoplasia crowding out
- Fibrosis
Iron deficiency anemia can become non-regenerative in long term
Bleeding patients: what is the clinical approach?
1) Trauma (hemorrhage) or impaired homeostasis?
- If platelets around 100 x 10^9/L then hemorrhage is more likely.
- If platelets < 25 x 10^9 then consider immune mediated thrombocytopenia
- If platelets within range but dog is bleeding -> consider vWD or platelet function defect
2) Impaired homeostasis due to platelet defect (thrombocytopenia or functional issue) or coagulation?
- Buccal mucosal bleeding time-> if increased then the dog has platelet deficiency. If normal -> coagulation defect
- Presence of petechiae/ecchymoses -> the dog has platelet defect
- Presence of internal bleeding/large hematoma -> coagulation defect more likely
Platelet numbers <10 x 10^9/ L, what are the differentials?
1) IMMUNE MEDIATED
- Primary
- Secondary to SLE, drugs, vaccines, neoplasia
2) DIC
- If PT and PTT are also prolonged
An otherwise well CKCS presents with thrombocytopenia on an automated CBC count, is that an issue?
Not really, they have giant platelets that get counted as erythrocytes. Look at smear to be sure
Also ALWAYS look at smear platelets in cats, sheep, goat
At what level of vWF antibodies (ELISA) is the dog likely to suffer clinical signs?
At what level is the dog likely to transmit the disease to offspring?
- Clinical signs if <35% (0% in Type III)
- Transmission if <50%
What is Evans Syndrome
immune mediated anemia + thrombocytopenia
Infectious causes of thrombocytopenia
FeLV, Ehrlichia, Leishmania