Rabbit and guinea pigs are prone to bladder problems such as bladder sludge and stones. Bladder sludge is urine that has thickened due to the presence of large amounts of calcium – it can be sandy and toothpaste-like in consistency. This can irritate the bladder lining, leading to cystitis, and can also be difficult to pass. Rabbits and guinea pigs are also prone to forming bladder stones, which can form a physical obstruction to urine flow and need surgical removal.
What causes bladder sludge and stones in rabbits and guinea pigs?
There are many factors that contribute to the development of bladder sludge and stones, so it is important to take these into account when trying to treat the condition.
Firstly, rabbits and guinea pigs have an unusual calcium metabolism compared to other animals. They absorb almost all of the calcium that is present in their food, whereas other animals will only absorb what they need, and the rest is excreted in the faeces. This means that the blood calcium level in rabbits and guinea pigs is higher than other animals, with excess calcium (not required for the bones and teeth) being filtered by the kidneys and excreted in the urine. The high levels of calcium in the urine can make it chalky and lead to the formation of bladder sludge and stones. So feeding a diet that is high in calcium (e.g. alfalfa hay) can predispose your rabbit or guinea pig to bladder problems.
Importantly, though, there are also other factors that contribute to the risk of bladder problems, so just reducing the amount of calcium that is fed does not always prevent the problem from recurring. These following factors are also thought to be important:
- Low water intake: this is an important factor, since low water intake leads to a more concentrated urine where the calcium is more likely to turn into salts, leading to sludge and stones.
- Obesity: rabbits and guinea pigs that are overweight find it more difficult to completely empty their bladder. This means that any calcium present in the urine can settle and accumulate.
- Lack of exercise: this can promote sludge formation as the urine in the bladder is moving around less.
- Genetics: some rabbits and guinea pigs seem prone to developing sludge and stones, and it is suspected that there may be an underlying genetic reason in these cases. These animals should therefore not be bred from.
- Dirty litter tray: this may discourage your pet from using the litter tray when they need to and may increase the risk of sludge and stones forming.
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What are the symptoms of bladder problems?
The symptoms can be subtle and difficult to spot initially, as rabbits and guinea pigs are prey species and so they tend to hide signs of illness and pain, as this would lead to them being killed by predators in the wild. It is therefore very important to keep a close eye on your pet, to identify any symptoms early. The symptoms of bladder problems typically include:
- Quiet and reduced activity
- Sitting with hunched posture
- Teeth grinding
- Reduced food/water intake
- Urinating more frequently than usual
- Straining to urinate
- Not passing any urine at all (this can occur with a blockage)
- Blood in the urine
- Wet fur around the back end
- Licking at the back end
- Skin red around the back end
- Smelly urine
If you have any concerns about your rabbit or guinea pig then please contact your vet straight away.
How are bladder problems diagnosed?
The vet will be suspicious of a bladder problem based on the clinical history and physical examination. They will suggest running further tests (e.g. urine and possibly blood tests) to diagnose the problem. They vet may also suggest taking an x-ray or ultrasound scan of the abdomen to check for the presence of bladder sludge and stones.
How are they treated?
The treatment of bladder problems will depend on the underlying cause and severity. For instance, bladder stones will need to be removed surgically under general anaesthetic, whereas bladder sludge can usually be expressed from the bladder manually, but a urinary catheter may need to be placed to allow flushing of the bladder.
Specific treatments for bladder problems typically include:
- Encouraging water intake by:
- Adding some juice to the water to entice them to drink more.
- Providing both a bottle and tip-proof water dish to encourage drinking.
- Using a water fountain – some rabbits and guinea pigs like the continuously moving water.
- Adding water to the food.
- Reducing the amount of calcium in the diet. Alfalfa hay is particularly high in calcium, so it is usually best to feed timothy and grass hay instead of alfalfa, and timothy-based pellets rather than alfalfa pellets.
- Weight loss.
- Encourage exercise.
- Ensure the litter tray is clean.
- Urinary supplements can be helpful in preventing recurrence. We sell one in our shop - Vetcare Urinary Tract Health Formula.
If the rabbit or guinea pig is unwell and not eating, then they will need symptomatic and supportive care to get them eating again, as this can cause other problems with gut stasis. Your pet may be able to be treated at home, if they are not too unwell, but hospitalisation is often needed, particularly if they are not eating at all and not passing any faeces. Treatment in these cases involves nutritional support e.g. syringe feeding with a recovery food, pain relief, medications to promote gut movement and fluids given into the vein or under the skin if the rabbit is dehydrated.