Hemolysis
Key concepts ·Also called: haemolysis, hemolysed sample, haemolysed, red cell breakdown
What it is
When red cells rupture, haemoglobin escapes and tints the plasma pink or red. A laboratory grades the degree of haemolysis on every sample, because it distorts several results whether or not the animal is actually unwell.
Why it matters
Haemolysis in the tube falsely raises potassium, phosphorus, AST, bilirubin and MCHC, and can send a healthy pet down an investigation for a problem that does not exist. Haemolysis inside the body, by contrast, is a serious illness — immune-mediated haemolytic anaemia is one of the more common emergencies in dogs.
What it can point to
- A difficult or slow blood draw, a narrow needle, or a sample shaken in transit — the commonest cause and not a health problem
- A sample left too long before the cells were separated from the plasma
- Immune-mediated haemolytic anaemia, where the body destroys its own red cells
- Toxins — onion, garlic, zinc from a swallowed coin, or paracetamol in cats
- Some infections, including certain tick-borne diseases and feline haemoplasmas
Dogs and cats differ
Cats are more prone to Heinz body formation, so onion, garlic, paracetamol and propylene glycol destroy feline red cells more readily than canine ones. In dogs, immune-mediated destruction is the more common cause of haemolysis that is genuinely happening in the body.
Questions worth asking your vet
- Was this haemolysis in the tube, or is my pet actually destroying red cells?
- Should the affected values be rechecked on a fresh sample?
- Are the gums pale, or is there any yellow tinge?
Related terms
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