Urinary Disorders in Rabbits

Normal rabbit urine can vary in color from almost clear yellow to very dark orange or rust color. The color is produced by a pigment called porphyrin, which may be caused by eating plant pigments, especially those foods high in carotenes, like carrots. It may also be produced in times of stress or illness, but should not be considered abnormal. The exact reason this pigment is produced is not known. The urine can also range from clear to cloudy or milky, because rabbits normally excrete large amounts of calcium in their urine.

Types of Urinary Disorders

• Urinary tract infection
• Bladder stones or kidney stones
• Calciuria, the accumulation of excess calcium sand in the bladder. The main dietary factor related to this disease is excess calcium consumption. High levels of calcium are present in alfalfa pellets and alfalfa hay.
• Although males and females can develop urinary disease with equal frequency, males may be more likely to suffer from complete urinary obstruction, as the opening of the penis is narrower than the opening of the vulva, increasing the likelihood that stones or sand will “plug” the opening. This condition can be life threatening within 24 hours.
• The sand (crystals) or stones can irritate the bladder wall, scraping along much like sandpaper, which can then provide a route for bacterial infection. The presence of bacteria, crystals or stones in the bladder can be very uncomfortable to your pet.
• Bacteria in the bladder can travel upwards into the kidneys, and if untreated, can lead to kidney damage and even kidney failure.
• Urinary tract disease can develop in any rabbit at any age, although it is more common in older rabbits. Symptoms of urinary tract disease may be very subtle or very severe.

What to Watch For

• Decrease in appetite
• General lethargy
• Straining to urinate
• Urinating outside of the box
• Passing only small amounts of urine frequently
• Drinking excess water and urinating excessively
• Inablity to urinate
• Blood-tinged urine
• Dribbling of urine
• Urine scald (redness and hair loss) around the genitalia or the insides of the legs

Diagnosis

• Urinalysis should be performed to look for bacteria, white blood cells or crystals.
• Radiographs (X-rays) of the abdomen can help show sand or stones, either in the bladder or kidneys.
• Ultrasound might be recommended to look at the bladder and kidneys, as well as the other organs in the abdomen (body cavity). Some types of stones will not show up on radiographs, and can only be seen on ultrasound.
• A culture and sensitivity should be performed on the urine sample if there is evidence of bacteria and/or white blood cells in the urine.
• A blood profile is recommended to look at kidney function, blood calcium levels, and the white blood cell count to evaluate for the body’s response to infection.\

Treatment

• If a urinary tract or bladder infection is diagnosed, your veterinarian will prescribe antibiotics.
• Fluids may be given to your rabbit, either subcutaneously (under the skin) or intravenously (into the vein).
• If calcium sand is diagnosed, your rabbit may need to have his bladder flushed. Some rabbits require sedation for this procedure. This step is not always necessary.
• If bladder stones are present, your veterinarian may recommend surgery. Some very small stones may pass, but the larger stones create a risk of obstruction, in addition to pain and discomfort.
• If your rabbit has calcium sand or stones, your veterinarian will recommend diet change to eliminate most foods high in calcium.
• Close monitoring and follow up visits will be required in all cases.

Home Care and Prevention

• Follow-up appointments are essential to be sure the infection is gone or the calcium is resolved. If infection is present, give all antibiotics.
• Follow your veterinarian’s instructions for feeding. Diet changes are likely to be necessary if calcium is the problem. Pellets should be restricted to 1/8 cup per 5 lb. body weight. Alfalfa hay should be eliminated. Instead, offer timothy or grass hays that are lower in calcium. Fresh leafy vegetables can also be offered.
• Observe urination habits closely, and report any changes to your veterinarian. Keep fresh water available at all times. Ask your veterinarian to check a urine sample as well as full blood profile on a yearly basis after age three.
• Bladder stones (cystic calculi) are easily recognized in rabbits. Calciuria, the accumulation of calcium “sand” in the urinary tract of rabbits, is recognized with increasing frequency. This syndrome is related to the consumption of excessive dietary calcium.
• Absorption of calcium in rabbits is unique because there is almost complete intestinal absorption of all dietary calcium. Humans and most mammals can only absorb a portion of all the calcium consumed; the rest passes undigested through the intestines. Excess absorbed calcium is then excreted in the urine in rabbits. The percent of calcium excreted through the urine in rabbits 20 to 30 times greater than other mammals. Because of this unique feature, blood calcium levels in rabbits may be much higher than other mammals without any associated symptoms. This elevation in blood calcium may be the earliest indicator of excessive dietary calcium and impending urinary calcium deposits.
• Because so much calcium is excreted through the kidneys and urine, this becomes a site for the precipitation of excess calcium. The urine may appear thick and cloudy. In some rabbits, the calcium sand forms a precipitate; the rabbit eliminates the clear “supernatant,” the clear part on top once the calcium sand settles to the bottom of the bladder, allowing the crystals to remain in the bladder. This can lead to chronic irritation of the bladder, urine retention, bladder infection, and in severe cases, distention of the bladder leading to complete loss of muscle tone and overflow incontinence, which is uncontrolled dribbling occurring only because the bladder is too full to hold anymore urine. The calcium forms stones anywhere along the urinary tract, but it occurs most commonly in the bladder. Calcium in the kidneys can be much more serious. Stones or crystals can plug the urethra and prevent your rabbit from urinating.
• Urinary tract infection occurs when there are bacteria in the urine. In rabbits, the opening of the rectum is just above the opening of the penis or vulva under the tail. Feces can come in contact with this opening, and may contribute to infections. Another possible cause for infection is calciuria, as the ‘sand’ can abrade or scrape the bladder like sandpaper, leaving it raw and more susceptible to infection by bacteria.
• Stones or infection in the kidneys themselves can cause temporary or permanent damage to the kidneys. In the bladder, the greatest risk is that of obstruction, a stone or ‘plug’ of sand becoming lodged in the urethra, which is the passageway from the bladder out the body. This would prevent passing of any urine, and can be fatal in as little as 24 hours.
• Excessive thirst and urination are common signs of urinary disorders. Unfortunately, there are a variety of other illnesses that can mimic these signs, making diagnosis difficult. Some of these include:
• Similar signs that occur from diabetes, which is uncommon in rabbits but can cause excessive thirst and urination
• Hotter weather causes rabbits to drink more.
• In females, infection or cancer of the uterus can also cause similar signs. Blood in the urine and straining may occur.
• Kidney disease can also cause increased thirst and increased urination.
• Behavior problems can also lead to inappropriate urination.
• Any illness that causes discomfort can have a similar appearance, as many of these symptoms are general signs of any disease causing your rabbit to not eat or act lethargic.
• Diagnosis in-depth
• Urinalysis should be performed to look for bacteria, white blood cells, or crystals. Your veterinarian may ask you to bring this sample or may collect it during the examination. Sometimes your veterinarian will want a sterile urine sample, which is collected from the bladder either by a catheter or directly from the bladder with a needle. Most rabbits tolerate this well without anesthesia.
• Radiographs (X-rays) of your rabbit’s abdomen can help show sand or stones, either in the bladder or kidneys. These can also be used to monitor progress, particularly with calciuria.
• Ultrasound might be recommended to look at the bladder and kidneys, as well as the other organs in the abdomen (body cavity). Some types of stones will not show up on radiographs, and can only be seen on ultrasound. Dilation of the ureters and some types of damage to the kidneys can also be seen. Your veterinarian might refer your rabbit to a specialist if there is not an ultrasound in their practice.
• A culture and sensitivity should be performed on the urine sample if there is evidence of bacteria and/or white blood cells in the urinalysis. The white blood cells are the cells that respond to infection. This will also help your veterinarian to choose the best antibiotic to specifically treat the bacteria infecting your rabbit.
• A blood profile may be helpful to look at kidney function, blood calcium levels, and the white blood cell count to evaluate for the body’s response to infection. Therapy in-depth
• While most stones require surgical removal, calciuria and urinary tract infections can often be treated with prompt, aggressive medical management. Treatment in your rabbit will initially be directed at resolving the problem, and at the same time will focus toward preventing future problems if possible. Initial treatment will likely include fluid therapy to help flush the kidneys and bladder. Antibiotics may be given if infection is suspected.
• In some cases, the bladder will require more direct flushing with a catheter. However, these conditions will reoccur in nearly 100 percent of cases unless predisposing factors in the diet and environment are corrected. Predisposing factors include obesity, lack of exercise, and excessive dietary calcium in the form of feeding solely pellets or feeding pellets with alfalfa hay.
• If a urinary tract or bladder infection is diagnosed, your veterinarian will prescribe antibiotics to kill the causative bacteria. These antibiotics may be changed once the results of the urine culture are available.
• Fluids may be given to your rabbit, either subcutaneously (under the skin) or intravenously (into the vein). This will help flush the kidneys and bladder.
• If calcium sand is diagnosed, your rabbit may need to have his bladder flushed. This involves placing a small catheter (flexible soft tube) into the urinary bladder through the penis or vulva, and flushing to remove some of the crystals. Some rabbits require sedation for this procedure, although this step is not always necessary.
• If bladder stones are present, your veterinarian will recommend surgery. Some very small stones may pass, but the larger stones create a risk of obstruction, in addition to pain and discomfort. These stones should be removed surgically.
• Rabbits with calciuria or calculi (stones) must be placed on very restricted pellets (maximum 1/4 cup per 5 to 8 pounds of body weight). Complete elimination of pellets may be necessary in severe cases. This will help lower blood calcium and will decrease the amount of calcium that passes through the kidneys and bladder.
• Alfalfa hay should be replaced with lower calcium hays such as timothy or other grass hays.
• Leafy vegetables should be offered in abundance to increase dietary fiber content. It is usually not necessary to restrict consumption of calcium-rich vegetables once the rest of the diet is corrected, but may be important in severe cases.
• Follow up radiographs and bloodwork are recommended to monitor progress and prevent further problems. Close monitoring and follow up visits will be required in all cases.

Follow Up

• Optimal treatment for your pet requires a combination of home and professional veterinary care. Follow-up can be critical, especially if your pet does not rapidly improve. Administer all prescribed medication as directed. Alert your veterinarian if you are experiencing problems treating your pet.
• Repeat radiographs are recommended; your veterinarian will probably suggest initial repeat radiographs in four to six weeks, and once the condition is resolved, once to twice a year to check for calcium accumulation or stones.
• If the diagnosis was a urinary tract infection, repeat urinalysis will be recommended prior to stopping the antibiotics; to be sure the infection is gone.
• If calcium sand or stones are part of the problem, follow-up monitoring of blood calcium levels will also be helpful. This may initially be done in four to six weeks, then once or twice a year once levels are controlled.
• Be sure to follow diet instructions very strictly. Limit or eliminate pellets as directed by your veterinarian, and provide plenty of timothy or other low-calcium hay at all times. Fresh leafy vegetables should also be provided in abundance.
• Continue to pay close attention to your rabbit’s urination habits.