Platelets/Retics Flashcards
What is a platelet?
a disc shaped blood cell that facilitates blood coagulation (clotting)
What are the 4 clotting functions that a platelet performs?
maintain vascular integrity, help arrest bleeding, contribute to fibrin formation promote vascular healing
How do you obtain a manual platelet count?
count platelets in 10 fields, then average, then multiply by 15,000
What units is a platelets count recorded in?
/uL
What is the normal platelet count for canines?
200,000-500,000/uL
What is a normal platelet count for felines?
300,000-800,00/uL
Why would an animal have thrombocytosis (high platelet count)?
primary bone marrow disorders, secondary to disease, physiological
Why would an animal have thrombocytopenia (low platelets)?
abnormal platelet production, accelerated platelet removal, abnormal distribution of platelets, combination of above
What are platelets also called?
thrombocytes
What do platelets derive from?
megakarocyte
Where are platelets produced?
bone marrow
All platelets are _______.
anucleated
Canine platelet morphology
small, round to oval shaped, light blue
Feline platelet morphology
small, round to oval shaped, light blue
When can macroplatelets be found?
when there is a demand for platelets
Cat platelets tend to _______________.
clump easily
An average of _______ platelets per field
7-21 platelets
What is used most by clinical blood machines?
impedance-based platelet counts
What two species is platelet clumping normal in?
cats and cows
What is thrombocytosis?
increase in thrombocytes
What is thrombocytopenia?
decrease in platelets
What are some clinical signs of anemia?
pale MM, increased RR, lethargic, may even collapse
What is the most common red cell disturbance in animals?
anemia
What is regenerative anemia?
indicates that the body is responding to the decreased level of red blood cells in the body
What is nonregenerative anemia?
indicated that the body is not responding to the decreased levels of red blood cells in the body
What are reticulocytes?
young, anucleated erythrocytes
What are the two methods of performing a reticulocyte count?
tube methods, slide methods
How is the tube method performed?
mix equal amounts of whole blood and new methylene blue stain in a small test tube, allow to stand for 10-15 minutes, prepare blood smear
How you manually get a reticulocyte count?
use tube method to create blood smear
count reticulocytes in 10 fields, add all and divide by 10 (record as %)
What types of reticulocytes do cats have?
aggregate and punctate
What reticulocytes do you count in cats?
aggregated
What is the difference between aggregate and punctate reticulocytes?
aggregate granules clump, punctate have less granules
How long does it take for aggregate to change to punctate?
12-24 hours
How long do punctate reticulocytes circulate in the blood?
7-10 days
What is a marked degree of anemia in cats?
severe anemia, >5.0% reticulocyte count, >200,00/uL ARC
What is anisocytosis?
varying sizes
What are some causes of nonregenerative anemia?
chronic renal disease, hypothyroidism, hypoadrenocorticism (Addison’s disease)
What is erythroblastosis?
production of immature RBCs
Why would a non-anemic animal have NRBCs?
bone marrow injury, splenic function abnormality, seen with basophilic stippling (lead poisoning)
What is reticulocytosis?
increased amount of reticulocytes
How long does it take for reticulocytes to be seen in anemic animals?
takes 2-3 days
What is a marked degree of anemia in dogs?
severe anemia, 500,00/uL ARC
What should you assume a normal HCT for dogs is?
45%
What should you assume a normal HCT for cats is?
35%
What is a normal CRP in dogs?
<1%
What is a normal CRP in cats?
<0.4%
RBC production should ____________.
production should equal destruction
What is a normal red cell production index (RPI)?
~1 day
What is the shape of a thrombocyte?
round to oval shaped
Thrombocytes are technically not cells because they lack a ________.
nucleus
What type of platelet is a normal finding in a King Charles Cavalier Spaniel?
macroplatelets
Regenerative is a good thing except in what species?
horses
What species platelets are very small?
llamas
