Urine blood / hemoglobin
Urine ·Also called: BLD, haematuria, hematuria, occult blood urine, haemoglobinuria
What it is
The pad reacts to haem, the iron-containing part of both haemoglobin and the muscle pigment myoglobin. A positive therefore means blood, broken-down blood, or damaged muscle — and the distinction matters, because they come from entirely different places.
Why your vet measures it
Visible or hidden blood in urine is one of the commonest reasons pets are presented with urinary signs. In cats, it is central to feline lower urinary tract disease, which can progress to a life-threatening blockage in males. In dogs, it points towards infection, stones or, in older animals, a bladder tumour.
What a positive result can mean
- Cystitis or a urinary tract infection
- Bladder or kidney stones
- Feline idiopathic cystitis, the most common cause of blood in a young cat's urine
- A bladder tumour, more likely in older dogs
- Contamination from the collection itself, particularly after a needle sample or catheterisation
- A season in an unspayed female dog
- Free haemoglobin from red cell destruction, or muscle pigment after severe muscle damage
What a negative result means
- A negative result is the expected finding in a healthy dog or cat
Dogs and cats differ
In cats under ten, blood in the urine with straining is most often idiopathic cystitis — a stress-related condition with no infection to treat. Bacterial urinary infection is genuinely uncommon in young cats but routine in dogs, so the same finding leads to different first steps in each species.
Questions worth asking your vet
- Did the sediment show red cells, or was this free pigment?
- How was the sample collected — could that explain it?
- Is a urine culture or imaging the right next step?
Related terms
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