Info Sheets

Obstructions within the urinary tract prevent the rabbit from being able to pass urine. These are serious and can prove to be fatal if not treated urgently.

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The most common type of obstruction is from a solid calcium stone (urolith) that develops in the bladder and then passes out into the urethra (tube that carries urine from the bladder to pass out of the body) where it is too large to fit into and blocks this. The stone prevents the rabbit from being able to pass urine. Obstructions can also develop in the ureters (the tubes that carry urine from the kidneys to the bladder). Other types of obstructions that can occur, but are less frequently seen, include obstructions from adhesions (where tissue sticks together), tumors, abscesses or sludgy urine.

Overweight rabbits are more at risk of developing bladder stones due to their sedentary lifestyle and not voiding the bladder of urine as frequently or being able to adopt the correct position to totally empty the bladder when urinating. Other reasons that make their development and potential obstructions more likely include being male, as the urethra is longer, neutered rabbits as they do not perform territorial marking with urine, so urine stays within the bladder longer. Male rabbits can also get urethral stricture due to trauma which then prevents the urine from leaving the body. A low water intake has also been cited as a predisposing factor. The correlation of high calcium diets and development of urinary calculi is not proven, and the other factors mentioned above are much more likely to be causes. Rabbits with arthritis, E. cuniculi or spinal injuries may physically struggle to urinate causing increased urine retention and urinary tract obstruction.

If the rabbit has a full blockage and is unable to pass any urine, you will observe one or more of the following signs:

• Hopping in and out of the litter tray with no urine being passed or very small amounts which may be bloody.
• Vocalizing/squeaking when trying to pass urine.
• Painful tooth grinding (bruxism).
• Painful abdomen.
• Not eating or drinking.
• Unable to get comfortable when sitting or lying down.

If your rabbit has an obstruction that is stopping them from urinating, this is an emergency. Your rabbit will be stabilized and given pain relief and some intravenous fluids (as long as the bladder is not over distended) and medications to support their gastrointestinal system. Bloods are likely to be taken to assess the renal function and electrolyte balance which can be impaired and dangerously high, possibly causing cardiac (heart) problems during the surgery. These may be repeated a couple of days after the surgery also. Once stable the rabbit then will be given a general anesthetic, and an x-ray will be taken. Stones show up on x-ray so your vet will be able to see where they are, or if it is something else causing the obstruction, such as a tumor. An ultrasound may also be performed, which can also show stones and tumors. Your veterinarian will pass a urinary catheter into the rabbit’s urethra and aim to flush the stones that are causing the blockage back into the bladder where they can then be surgically removed. If the rabbit has a bladder tumor this will need to be removed surgically if possible. Stones that are blocking the ureter can be surgically removed. All surgical procedures are not minor and there are potential complications and risks associated with the surgery and anesthetic.

Once your rabbit is eating, is comfortable and is passing urine freely, your veterinarian will likely be happy for them to be discharged. You will probably have pain relief medication, and potentially other medications, to continue giving your rabbit at home. You will also need to make sure your rabbit does not lick or scratch the wound. Your veterinarian will let you know when your rabbit needs to go back for a check-up.

There are some things you can do to lessen the chances of your rabbit developing urinary caliculi which may go on to cause a urinary tract obstruction:

• Keep your rabbit at the right weight and do not allow them to become overweight.
• Make sure they have lots of litter trays and can always access one. Have one per rabbit plus a spare one.
• Offer your rabbit water in a heavy water bowl. If they have never used one, also offer a water bottle until you are confident they are using the bowl. Rabbits drink more when they have access to drink from a bowl.
• Make sure water does not freeze in the winter – common places for water bottles to freeze are the spout, so you may check the bottle and the water is not frozen, but the rabbit is unable to get water as the spout is frozen.
• Feed a suitable diet: hay and grass must form at least 85% of their diet, with 5% good quality rabbit nuggets and the other 10% suitable herbs and greens.
• Encourage your rabbit to exercise which encourages them to urinate more. Make sure their environment is at least 2m x 3m x 1m high and they have opportunities to forage, dig, run, hide, binky and sleep.
• Keep stress to a minimum: rabbits who are stressed, especially if their environment does not allow them to urinate somewhere they feel safe, will urinate less frequently.

If your rabbit has a urinary tract obstruction caused by a stone, and surgery to remove the obstruction, it is possible for another one to occur. Listen to your veterinarian and their advice. They may advise a weight loss program, change of diet, altering your rabbit’s environment or aiming to reduce stress in the environment. These are all ways to help prevent the condition from re-occurring.