Haematological Conditions

Question 1

What is the aetiology of IMHA?

Answer 1

Idiopathic
Neoplasia
Some drugs/recent vaccination?
Hereditary?

Question 2

What is the pathophysiology of haemolytic anaemia?

Answer 2

Destruction of RBCs by animal’s own immune system
.. leading to reduced circulating red blood volume
the total blood volume does not change

Bone marrow then attempts to respond producing a regenerative anaemia - releases immature RBCs into circulation.
Spherocytes may be seen in circulation (‘half-eaten’ RBCs)
In some cases haemolysis can lead to jaundice (increased bilirubin in the blood)

Question 3

What are the clinical signs of IMHA?

Answer 3

Pyrexia and Jaundice
- Pale MM, but normal CRT
- weakness, exercise intolerance
In severe anaemia: dyspnoea, collapse, tachycardia
In-appetent
May have heart murmur

Question 4

How can we diagnose IMHA?

Answer 4

• PCV
• Reticulocyte count (determines if regenerative or not)
• MCV (mean corpuscular (RBC) volume) - reticulocytes are larger and will increase the MCV
• MCHC (mean corpuscular Hb count ?) - measures how much Hb in RBC - reticulocytes have less Hb therefore decreasing MCHC in regenerative anaemia
• RBC morphology - blood smear (look for reticulocytes, H-J bodies and spherocytes)
• Coomb’s Test (specific for IMHA) - tests for antibodies against own RBCs. External but confirms IMHA.
• Agglutination test - see if RBCs clump together. Can be done in- house and indicates IMHA.