Red Urine: Blood or Plant Pigment?

by Sandi Ackerman in consultation with Barbara Deeb, DVM, MS
 
It can happen any time of the year, but it’s particularly during the winter holiday season that the House Rabbit Society receives a flood of phone calls from distraught rabbit people saying that their bunny is producing “bloody urine.” Most of the time it’s not what they think it is, but understandably these people are concerned, since the facts are not widely known.

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The Biology and Medicine of Rabbits and Rodents by Harkness and Wagner contains one paragraph on this topic:
“Bloody urine is rare in rabbits and rodents. Many cases of ‘bloody’ urine turn out to be porphyrin-pigmented basic urine or a sanguineous vaginal discharge associated with uterine adenocarcinoma, polyps, or abortion. Thick white urine containing reddish-orange pigment is indicative of an excess of dietary calcium.”

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Bloody urine in rabbits may be rare but red urine is not. People who live with house rabbits will find this out. Diseases of Domestic Rabbits (1988) by Lieve Okerman says “red color of the urine is sometimes observed in rabbits. It is probably caused by a plant pigment and does not affect the health of the animal.”

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Red urine is a descriptive term for the condition where a rabbit’s urine varies in color from the normal pale yellow to dark yellow, carrot orange, brown, or bright red. Red urine is not a medical problem. The color usually returns to normal within one to three days, although I have had a couple of rabbits take three to four weeks before their urine returned to the pale yellow color. White urine may be due to excess calcium in the diet; if it stays white for many days you may want to discuss your rabbit’s diet with your veterinarian. Dark urine resulting from heat stress or dehydration may require fluid therapy.

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For obscure reasons (my rabbits all eat the same food, drink the same water and get the same treats) some get red urine, some don’t. Red urine (due to excessive urinary pigments) may occur due to any of the following:

• While on antibiotics

• At the first cold snap in the fall

• After eating fir leaves

• After eating carrots, spinach or other veggies containing beta carotene

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It is not necessary to panic when you observe a change in color of your rabbit’s urine. However, hematuria can occur due to disease anywhere in the urogenital system. An unspayed female rabbit might show a bloody discharge from her vulva, or drops of blood after urination, which could be confused with urine. Either of these occurrences could be a sign of uterine cancer. An unneutered male rabbit could have genital cancer or trauma which could cause blood to appear in his urine.

 

BLOOD IN THE URINE (HEMATURIA)

When we see red urine, most of us worry about a bladder or urinary tract infection. However, actual blood in the urine is usually difficult to see with the naked eye. When due to kidney disease, straining to urinate may not occur, but straining is the most common sign of urinary bladder disease. A rabbit straining to urinate assumes an unusual stance, that is he sits for an unusually long period of time on the tip toes of the back feet, with the tail very high in the air. Immediately change the litter box so you will be able to determine if he is producing urine. He may only produce a drop or two of urine at a time because of the frequency with which he is attempting to urinate, but if you see urine, you might wait until your regular veterinarian is available in the morning. If you do not see urine, there may be a blockage and it’s time to see your emergency veterinarian.

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In the case of difficult urination, a urinalysis is in order. If hematuria occurs along with straining, disease of the urinary bladder is likely and additional tests may be necessary; for instance, X rays, urine culture or blood tests. Interpretation of findings must be based on knowledge of anatomical and biochemical variations of rabbits from other small animal patients.

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It is not necessary to take your rabbit to the veterinarian for the condition of red (pigmented) urine. But when should you go to your veterinarian? If you see a red or pink color in the urine (orange is OK) and there are no other symptoms, you could wait until normal office hours and ask your veterinarian to test the urine for blood. If you see your rabbit straining to urinate, but there is no urine, go to a veterinarian as soon as possible. An emergency veterinarian should be able to determine if your rabbit is blocked and unable to urinate. If he is not blocked you could wait until the following day so that your regular veterinarian can decide if further tests or an invasive procedure is necessary.

References

Harkness, J.E., Wagner, J.E.: The Biology and Medicine of Rabbits and Rodents. 3rd Edition. Philadelphia: Lea & Febiger, 1989.
Okerman, L.: Diseases of Domestic Rabbits. Cambridge: Blackwell Scientific Publications, 1988.

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