What is the difference between hemoglobinuria and myoglobinuria?

Both can cause changes in urine colour, but they come from different sources: haemoglobin comes from red blood cell breakdown, while myoglobin comes from muscle damage. The exact cause must be assessed with blood and urine tests, so ask your vet for guidance.

What samples or information should I bring to the vet visit?

Bring recent urine photos or a fresh urine sample, records of appetite and toileting, and a list of recent medications. This can help your vet assess the case and arrange tests more quickly.

How quickly should I see a vet if my pet's urine becomes darker?

If it happens only once, you can record it first, but if the urine colour stays abnormal for more than a day, energy drops or vomiting occurs, see a vet within 24-72 hours. If your pet collapses or has obvious breathing or heart rate abnormalities, seek veterinary care immediately.

What tests are usually included, and how long do results take?

Common tests include blood and urine tests, X-rays or ultrasound. Some blood and urine results may be available the same day, while advanced imaging or specialist tests depend on the clinic's equipment and scheduling. Follow your clinic's advice.

How much do the tests and treatment usually cost?

Costs vary by clinic and region — ask your vet for an estimate before proceeding.

Disease Guide

Hemoglobinuria and Myoglobinuria in Dogs and Cats: Urine Colour Changes, Tests & Care [2025]

Hemoglobinuria and myoglobinuria indicate breakdown of red blood cells and muscle tissue respectively, and the underlying cause needs to be identified. Hemoglobinuria is commonly associated with haemolytic disease, while myoglobinuria is seen with severe muscle injury.

Take 1 minute to check the symptoms first

Last updated: 2026/01/05

Pethealthmap editorial team

Sources: AVMA, ACVIM, National Taiwan University Veterinary Hospital

When to See a Vet

Immediate veterinary care needed (emergency)

•Sudden collapse, unresponsive, or unable to be awakened
•Gums or lips are clearly blue-purple or pale white
•Persistent severe vomiting or heavy abdominal bleeding

Schedule a veterinary visit as soon as possible (within 24-72 hours)

•Urine remains dark red or reddish-brown for more than one day
•Marked decrease in energy or activity and not eating
•Rapid heartbeat, abnormal breathing, or noticeably increased panting

01What symptoms suggest something is wrong?

The main sign is a change in urine colour, often together with changes in energy, activity level or heart and lung function. Your vet will need to assess whether other whole-body signs are present.

Urine is noticeably darker or reddish-brown
Faster heartbeat or more noticeable breathing
Marked drop in energy or activity level
Jaundice appears, with yellowing of the skin or whites of the eyes
Abnormal changes in urination frequency or urine volume
Arrange a veterinary consultation and assessment as soon as possible

Seek emergency care immediately if you notice the following symptoms:

⚠️ Sudden collapse, unresponsiveness or inability to wake
⚠️ Repeated vomiting or signs of significant abdominal bleeding
⚠️ Gums or lips that are clearly blue-purple or pale

02How can you judge the problem at home? Key observation points and emergency warning signs

Observing and recording visible changes and their timing at home can help your vet quickly understand the course of illness and possible triggers.

Record when changes in alertness and activity level started
Write down appetite changes and daily food intake
Estimate or measure daily water intake
Take photos of the urine and note the time they were taken
Record changes in urine colour, frequency and volume
Bring all records and photos, or a urine sample, to the clinic

03How will the vet make a diagnosis? Common tests

Your vet will mainly use blood, urine and imaging tests to look for possible causes such as bleeding, haemolysis or muscle injury.

Blood tests, including complete blood count and biochemistry, to assess anaemia or organ function

Urine tests, including sediment, specific gravity and urine chemistry, to check for blood or myoglobin

Haemoglobin/myoglobin-related blood tests or specific assays if indicated

Abdominal or cardiac ultrasound to rule out internal organ abnormalities

Chest and abdominal X-rays, or CT if needed, to assess for tumours or sources of bleeding

Referral tests or tissue sampling may be arranged if further diagnosis is needed

04How is it treated and managed after diagnosis? Medication, diet adjustments and care guidance

Treatment focuses on stabilising the condition, addressing the underlying cause and regularly monitoring blood and urine results.

Provide supportive or symptom-based care according to the test results and arrange follow-up
Hospital observation and supportive care may be needed, with rechecks to monitor progress
Adjust the diet and maintain appropriate water intake as advised
Monitor urine colour, energy and appetite regularly at home
Return for repeat blood and urine tests as instructed by your vet
If test results do not improve or the condition recurs, referral to a specialist hospital is recommended

05What should you prepare before seeing the vet? Key details that help identify the cause quickly

Write down when signs first appeared and the order in which they changed

Bring records of diet, toileting and activity

List all recent medications, supplements and possible exposures

If possible, bring urine photos or a fresh urine sample to the appointment

Prepare a roomy, stable carrier and book the consultation in advance

This content is for reference only and cannot replace a professional veterinary diagnosis. If your pet shows signs of illness, please seek veterinary care promptly.

Related Symptoms (You May Also Be Looking For)

Anemia

Low red blood cells

Jaundice

Yellow skin/eyes

Pale Mucous Membranes

White gums

Edema

Tissue swelling

Tachycardia

Abnormally rapid heart rate