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Article by Phyllis O’Beollain
Dayton Small Pets Examiner

Normal rabbit urine comes in a rainbow of colors including nearly clear yellow, very dark orange, rust and red. The colors are produced by porphyrin, a pigment which may be produced in relation to foods eaten by the rabbit (especially foods high in carotenes, such as carrots). Porphyrin can also be produced when the rabbit is stressed, but porphyrin production in itself is not abnormal. Cloudy urine can be the result of the rabbits’ normal excretion of large amounts of calcium in their urine.

Color variance in the urine is not a cause for concern unless other worrisome signs are present, which may be indicative of urinary tract disorders such as infection, stones (calculi) or bladder sludge (hypercalcinuria). Signs to watch for include:

♦ Straining to urinate
♦ Frequently urinating very small amounts
♦ Inability to urinate or urinating excessively
♦ Changes in water consumption (either very little or drinking water excessively)
♦ Decrease in appetite
♦ General lethargy
♦ Dribbling of urine
♦ Urine scald (fur loss and skin inflammation in and around their private areas or inner legs)
♦ Fever
♦ Blood-tinged urine (although usually the blood in the urine is not visible to the naked eye and is detected at the veterinarian’s office via dipstick and/or microscopic examination of the urine).

Urinary tract disease can develop at any age, although it is more common in older rabbits; arthritis (as well as obesity) can make it difficult for rabbits to properly posture and lift their tails in order to completely empty their bladders. Incompletely emptied bladders lead to “stale” urine and bacteria build-up creating just the right conditions for UTIs. Male and female rabbits are equally likely to develop urinary tract disease, although male rabbits are more prone to complete urinary obstruction by calculi or sludge, due to the male rabbit’s anatomy. Urinary obstruction is life-threatening and a true veterinary emergency.


Accurate diagnosis begins with a urinalysis; if bacteria are present, a culture and sensitivity should be performed to determine what antibiotics should be used to treat the infection. Abdominal X-rays may show sand or stones in the bladder or kidneys, and an ultrasound may be recommended, as some types of stones can only be visualized on ultrasound.

Bloodwork will reveal any problems with kidney functions as well as blood calcium levels and white blood cell count (the latter being part of the body’s responses to infection).

Antibiotics will be prescribed for a diagnosis of urinary tract or bladder infection, but as sludge crystals can scratch the urinary tract and stones can cause stasis of urine and bacteria buildup, your bunny will probably be on antibiotics regardless.

Fluids likely will be given, usually under the skin.

If calcium sand (sludge) is diagnosed, the veterinarian may perform a bladder flush, which usually (not always) requires sedation. A flush is not always necessary, sometimes a change in diet (eliminating foods high in calcium) and increased fluids does the trick in milder cases.

Bladder stones generally require surgery unless they are very small.

Regardless of the specific diagnosis, urinary tract issues require strict adherence to the veterinarian’s instructions as well as close monitoring of your bunny and regular follow-up visits. With proper care, however, your bunny can lead a long, comfortable and healthy life.