It can be alarming to see rabbit urine. It varies in colour from fairly pale to orange or sometimes red and it may be quite cloudy and thick. As long as there are no blood flecks or any sludge, there is generally no need for concern.
Rabbits’ urine can change dramatically depending on what they have eaten. If they have eaten red cabbage, beetroot leaves or other foods with strong colouring, their wee may be stained red. This is called beeturea, and it’s normal.
Most animals take as much calcium from food as they need. Rabbits are different. They extract all the calcium from their diet and any they don’t need is processed by their kidneys and expelled in their wee. This is fine as long as
they are drinking enough and urinate frequently
they don’t have mobility problems and are able to empty their bladder fully every time and
the amount of calcium they eat is appropriate
Drinking and urination
Drinking enough is probably the single most important factor. All animals need to drink enough water to keep their body tissues healthy. They take in some liquid from vegetables, but they need a lot more than that and must be given plenty of fresh water every day.
Offer a bowl as well as a bottle. It’s far more natural for rabbits to drink from a bowl – in the wild they would drink from puddles. In hutches bowls can get filled with bedding and hay, and they can be tipped over, but it’s still the most natural way for them, and bowls are easy to clean. Bottles can get clogged and in winter the spout is likely to freeze. While hay and bedding won’t make the water dirty, algae will build up and they are harder to clean than bowls. So it’s best to exercise caution and give both and wash them out regularly so your rabbits always have a constant supply of clean water.
Mobility preventing a completely empty bladder
Rabbits with arthritis or back problems find it hard to perch properly when they wee. They need to tilt their pelvis to a certain angle so that they can empty their bladder completely. If some urine is left in the bladder, that will have some calcium in it. If this happens every time they wee, calcium sludge will soon build up until your rabbit has a serious sludge problem (pictured).
Sludge gets into the urethra, (the tube that the urine passes through on its way out) and will sometimes block it. Sometimes the sludge will form into bladder stones and these can block the urethra too.
Rabbits with sludge may need a bladder flush to get things moving again. In more serious cases, surgery may be needed. Stones can usually only be removed by surgery. If you think your rabbit may have arthritis ask your vet about pain control. This is important for your rabbit’s comfort and also so that it’s possible to wee properly.
Calcium in food
Most foods that rabbits eat contain calcium. Certainly green vegetables can be high in calcium and they also have very high water content. It’s impossible to avoid calcium in the diet, in fact, and your rabbits need it to keep teeth and bones strong. It’s possible to find figures telling you the mineral content of veg. What is not often explained is that these refer to a very small percentage of the overall content of the veg. Approximately 90% is water, so the figures you see are percentages of the remaining 10% only. While you need to keep in mind that some rabbits are prone to sludge, the water content of veg is probably going to do them more good than the minerals will do them harm.
Rabbits can suffer from bladder conditions such as cystitis. Cystitis is inflammation of the lining of the bladder. This can be caused by bacteria, but it can also be triggered by the presence of sludge in their bladder. Rabbits with cystitis will usually strain to wee but not produce much, or any at all in extreme cases. What they do manage may be blood flecked. They will sometimes grunt or quietly whimper because of pain and it’s very likely they won’t want to eat. They may sit hunched up or pant.
This is very painful and they need urgent veterinary treatment. Your vet will examine your rabbit, pressing on its tummy, looking for signs of flinching and feeling for a full bladder. If they are able to help your rabbit wee, that may relieve some pressure. They will probably prescribe painkillers and antibiotics.