L11: Ruminant Hemolymphatic Diseases (Maunsell) Flashcards
Anemia etiology
A decrease in RBC mass as measured by reduced RBC numbers, PCV, and hemoglobin levels
- reduced ability of blood to supply oxygen to the tissues
- results from blood loss, hemolysis, and/or decreased production
Normal PCV fro ruminants
27-48%
PE of the hemic system
- mm (color, CRT, hemorrhages)
- color and consistency of urine and feces
- eval the heart
CS of anemia
- tachycardia
- tachypnea, dyspnea
- mm pallor icterus
- heart murmur
- weakness
- exercise tolerance
- collapse, death
- signs specific to cause of anemia (ie. Melena)
- acute vs. chronic manifestation of signs
Chronic anemia: usually won’t see CS until PCV is?
Acute anemia: usually won’t see CS until PCV is?
Approach to anemic ruminants (10 steps)
1) complete hx and PE
2) check urine for hemaglobinuria since most hemolytic anemias in ruminants will cause this (except anaplasmosis)
3) PCV/TP, look at plasma color
4) fecal float
5) CBC: regenerative or non-regenerative?
6) Chem +/- blood gas
7) fecal occult blood
8) thoracic/abd U/S and/or rads, ab tap
9) bone marrow aspirate sometimes indicated
10) copper/toxin testing
If during anemia work-up the plasma is discolored, what should you do?
Work-up for destruction
If during anemia work-up the plasma is not discolored and protein is low, what should you do?
Work-up for external loss
If during anemia work-up the plasma is not discolored and protein is normal, what should you do?
Work-up for chronic disease, iron/copper/cobalt deficiency, bone marrow toxins
Approach to anemic camelids
- bone marrow evaluation remains the best way to evaluate red blood cell regeneration
- camelids produce retics as a regenerative response, but rarely >1.5%. Therefore retics, anisocytosis, polychromasia, and nucleated RBCs are not predictable in magnitude
Site of bone marrow aspirate in ruminants
3rd or 4th sternal vertebrae
Site of bone marrow aspirate in camelids
3-4cm dorsal to the callous on ventral sternum
Indications for ruminant blood transfusions
- based on CS***
- low but STABLE PCV of 12-20% does NOT necessitate
- PCV 25% above normal
How long do cross-matched cells survive after transfusion?
2-4 days
25% RBCs survive 4 days
2nd transfusion may only last a few hours
must treat primary cause!
When NOT to transfuse
- maniacal behavior
- poor temperament (stress from handling can –> death)
- animal over the crisis and stable
- anaphylaxis
How to determine how much blood to transfuse for a ruminant >50kg
- 10ml/kg or calculate
- usually don’t give >6L total
Def = [(desired PCV - recipient PCV)/donor PCV] x recipient BW x Bl volume (ml/kg)
How to determine how much blood to transfuse for a ruminant
Calculate deficit using BV = 100 ml/kg neonates, 70-80 for adults. Replace 20-50%
Def = [(desired PCV - recipient PCV)/donor PCV] x recipient BW x Bl volume (ml/kg)
How much blood can a (nonpregnant) donor donate?
20% of its blood volume (10-15 ml/kg) at 2-4 week intervals
4-6L for adult cattle
0.5-1 L for adult sheep goats
1-2 L for adult camelids
Causes of anemia
- blood loss
- hemolytic anemias (infectious and non-infectious)
- inadequate production
Cattle with what antigen more commonly get transfusion reactions?
J positive
Cattle donors should test negative for what diseases to be blood donors?
BLV
BVDV
(CAE for goats)
Steps of blood transfusion
Collect from donor using aseptic technique:
2) clip and prep donor
3) place catheter
4) collect into sterile commercial kit bags or into bottles containing ACD
5) administer to patients through an in line filter to remove small clots, fibrin strands, and debris
6) initially administer slowly (0.1 mg/kg) for the first 10-15 minutes then up to 20 ml/kg/hr
Signs of transfusion rxn
- anaphylaxis or CV overload
- urticaria, shivering, sweating early
- tachycardia
- tachypnea
- fever
- colic
- pulmonary edema
- hemaglobinuria
Tx for severe transfusion reaction
-epinephrine
Tx for mild transfusion rxn
- slow transfusion
- flunixin meglumine
- corticosteroids
Causes of inadequate production or bone marrow suppression leading to anemia
- nutritional (Fe, Cu, Co deficiencies)
- chronic dz
- renal dz
- BM toxins (bracken fern, citrus)
Causes of hemolysis
- infectious
- Heinz body hemolytic anemia (due to toxicity)
- post-parturient hemaglobinuria
- water intoxication
- other (congenital porphyria, IMHA)
Causes of acute blood loss
- injuries during birth
- trauma
- castration, dehorning
- secondary to other disease (abomasal ulcer, caudal vena cava syndrome)
- bleeding from umbilicus at birth
Common causes of CHRONIC blood loss
- internal parasites
- external blood-sucking parasites
- abomasal ulcers
Causes of anemia due to hemostatic dysfx
- moldy sweet clover (dicoumarol) toxicity
- DIC (rare)
Etiology of moldy sweet clover (dicoumarol) toxicity
- most common in north-central states
- natural coumarols in the plant are converted to dicoumarol by molds during poor storage conditions
- causes increased PT, aPTT, normal platelet count
CS of dicoumarol toxicity
- lameness
- epistaxis
- melena
- SC hematomas
- bleeding from injection sites
- hematuria
- bloody milk
Tx of dicoumarol toxicity
- remove access to moldy feed
- Vit. K1
- transfuse if anemia is life-threatening