Topics:
Animal Physiology, Animal Refresher
Erythrocyte Sedimentation Rate (ESR) Highest in
Erythrocyte sedimentation rate (ESR) is highest in the blood of:
- Sheep
- Horse — Correct Answer
- Goat
- Cattle
Explanation:
Correct Answer: Horse
ESR (Erythrocyte Sedimentation Rate) is highest in horse blood. Horses have a naturally very high ESR compared to other domestic animals.
What is ESR?
- ESR measures how fast red blood cells settle to the bottom of a tube over one hour.
- RBCs settle faster when they form rouleaux (stacked coin-like aggregates).
- Rouleaux formation depends on the concentration of fibrinogen, globulins, and acute-phase proteins in plasma.
Why ESR is High in Horses
- Horse RBCs have a very strong tendency to form rouleaux because of high fibrinogen levels.
- This is a normal physiological feature — even healthy horses have high ESR.
- In horses, ESR is relatively less useful as a diagnostic indicator of inflammation because it is already high at baseline.
ESR Order in Animals
Horse >> Cattle > Sheep, Goat > Dog > Cat
- In goats and sheep, rouleaux formation is minimal, hence ESR is very low.
📚 About this Topic — Animal Physiology
This multiple choice question is from Animal Physiology, Animal Refresher. It has 4 options with a detailed explanation of the correct answer. Practice more MCQs from Animal Physiology to strengthen your preparation.
