AG MED - Hematopoietic Disorders 1 Flashcards
Regenerative anemia is characterized by ____ in ruminants and camelids.
Reticulocytes and uncleared RBCs
Increased MCV indicates ____.
Decreased MCV indicates ____.
MCV = Mean corpuscular volume / average RBC volume
Increase —> regenerative anemia
Decrease —> iron and copper deficiency OR healthy calves
What do increased/decreased MCHC indicate?
MCHC = mean corpuscule [Hgb] / Hgb per RBC
Increase —> typically false due to hemolyzed, icteric, or lipemic samples)
Decrease —> iron deficiency anemia
Definition of anemia and two sequelae.
Absolute decrease in circulating RBCs
- Inadequate oxygen transport
- Interference with organ function
Differentiate hemoglobinuria and Hematuria.
Hemoglobinuria
- Plasma reflects hemolytic state with possible development of icterus
- deep red to black urine
- throughout urination
Hematuria
- Blood in urine
- Red/pink/brown
- RBCs seen on microscopic exam
- Beginning (urethra, Repro tract); End (bladder); throughout urination (kidney, ureters)
What is anaplasmosis?
Vector-borne
Infectious
Hemolytic
Rickettsial disease
Anaplasmosis
Vectors:
Geographic location:
Reservoir:
Season:
Incubation:
Primary exposure:
Other species:
Vectors: tick borne - dermacentor, biting flies, mechanical vectors
Geographic location: 40 + states
Reservoir: Asymptomatic cattle
Season: Late spring through summer
Incubation: 15-30 days
Primary exposure: calfhood; less severe in calves up to 9 mo.
Other species: sheep (typically subclinical); goats (rare, severe anemia); camelids (rare anemia)
When are clinical signs seen with anaplasmosis?
CS highly variable
Seen with 35-50% decrease in RBC
Describe acute cases of anaplasmosis.
Develop over 4-9 days
Pyrexia (103-106 F); wanes over 12-24 hours; subnormal temp at death
Anorexia, lethargy, decreased milk production
Anemia
Pale, then icteric (if survives) mm
+/- dark brown feces, pollakiuria
Abortion
- DO NOT SEE HEMOGLOBINURIA
Best way to definitively diagnose anaplasmosis.
Serology - ELISA; high sensitivity and specificity
Microscopic Eval difficult
PCR - typically seroconversion in acute dz
Clin path for anaplasmosis
ID on blood smear
Rapid PCV drop (24-48 hrs) - death @ < 20%
Gradual PCV drop - death @ <10%
May see RBC regeneration in chronic cases
Treatment for acute cases of anaplasmosis
Oxytetracycline - does not eliminate persistent infection
Supportive care - whole blood transfusion
PCV < 8% = poor prognosis
Prevention of anaplasmosis
Vaccinate endemic areas with low transmission rates (killed experimental vaccine)
A. marginale-free herd in non-endemic areas —> quarantine and serological screening
With chronic blood loss, physiologic adaptation masks signs until when?
PCV < 15%
6 common causes of chronic blood loss
Bleeding GI lesions
Haemonchus
Anaplasmosis
Ticks
Hemostatic dysfunction
Renal disease
Clinical signs of chronic blood loss
Ill thrift
Poor body condition
MM pallor
Edema (protein/albumin loss)
Weakness, lethargy
8 common causes of acute blood loss
Epistaxis
Surgery
Ruptured liver/spleen/lung
Large vessel bleed
Clotting defect
Gastric ulcer
Hemoperitoneum
Hemothorax
Clinical signs of acute blood loss
May or may not have obvious source
Hypovolemic shock
- tachycardia
- tachypnea
- cold extremities
- pale MM
- muscle weakness
- eventual death
Clin path / DX for acute blood loss
Change in PCV/TP (several hours)
Ultrasound
Abdominocentesis / thoracocentesis
Treatment for acute blood loss
Stop hemorrhage
Treat hypovolemic shock
- shock rate, isotonic crystalloids (40-80 mL/kg)
- hypertonic saline (2-4 mL/kg); 1-2 L for an average cow
- whole blood transfusion
When does hemorrhagic shock occur?
At 30% of total blood volume lost
How do you calculate total blood volume?
8% of total body weight (kg)
A single unmatched transfusion is generally safe in ruminants. What are signs of transfusion reactions?
Tachypnea
Tachycardia
Dyspnea
Restlessness
Defecation
Piloerection
Muscle fasciculations
Treatment for whole blood transfusion reactions
Epinephrine .01-.02 mL/kg 1:1000 IM
Flunixin meglumine 1.1 mg/kg IV
