Blood in the urine, haematuria, can occur with inflammation or infection of the urinary tract, urinary stones, kidney disease and changes in the bladder or reproductive organs, among other things. Sometimes the blood is clearly visible, but small amounts are only found in a urine test.
It helps to note how often your dog pees, whether it needs to strain, whether only small amounts come out and whether it seems to be in pain. Fever, tiredness, increased thirst and a changed appetite can give further information. To tell the different causes apart, the vet may need to analyse the urine, take blood tests and sometimes use X-rays or ultrasound.
Book a vet assessment if you see blood in the urine. Seek help sooner if your dog is clearly in pain, has a fever, becomes lethargic or has difficulty passing urine. Treating a suspected urinary tract infection without first trying to establish the cause can mean that other problems are missed.