Category: urogenital problems

Uterine problems

The female rabbit’s reproductive tract varies greatly compared to dogs and cats. Although there is a difference in the anatomical make-up of rabbits, they can still experience some of the diseases that affect dogs and cats.

Rabbits have two uterine horns which open into the vagina independently, each of them through a separate cervix, therefore there is no uterine body. The urethra (the opening through which the bladder empties the urine out of the body) also opens into the vagina, rather than separately from it.

This anatomical peculiarity is of great importance because it makes some of the clinical symptoms that may be an indication of a disease of the reproductive tract, very difficult for your vet to interpret.

Pseudopregnancy is also called false pregnancy. It is often seen after a non-fertile mating, or may be seen during the spring months in entire female rabbits that are kept on their own. The hormonal changes that occur are responsible for some physical and behavioural changes that are very similar to those occurring in a pregnant doe. The rabbit acts as if she is pregnant but there is no foetus.

Female rabbits can become very aggressive and territorial during pseudopregnancy, exhibiting behavioural tendencies such as growling, lunging and biting, therefore care should be taken when handling her. She may also start plucking fur from her tummy, flanks and dewlap in an attempt to build a nest. Clinical examination may also reveal mammary development and milk production.

This condition normally disappears after a couple of weeks (17 days) without any need for more specific treatment. The condition can be stressful for the doe and it can recur several times.

If your rabbit suffers from pseudopregnancy, once she has made a full recovery, it is strongly recommended to have her spayed to avoid any future episodes.

Endometrial cystic hyperplasia is an abnormal thickening of the lining of the uterus. An overgrowth of cells predisposes the rabbit to abnormal tissue changes in the uterus. This is commonly seen in unspayed female rabbits over the age of 4 or 5 years. At present, it is still not clear if this condition can predispose to the development of uterine cancer.

Clinical signs may mimic those of uterine adenocarcinomas, with the rabbit showing signs of anorexia, haematuria, weight loss and lethargy. Palpation of a firm, irregular mass in the abdomen should prompt immediate investigation to rule out the possibility of a disease affecting the reproductive tract. Cystic mammary glands are also commonly seen in association with this condition.

Diagnosis of uterine disease can be made using x-ray and/or ultrasound, then surgery is usually the only available treatment option. It is normally curative and allows your vet to provide a definitive diagnosis through an histopathological examination of the organ removed.

Hydrometra is considered the third most common problem associated with the uterus in female rabbits, after endometrial hyperplasia and uterine adenocarcinomas. It occurs in older female rabbits (>4 or 5 years of age) and is characterised by the accumulation of watery fluid within the uterus.

The rabbit may have an enlarged abdomen, which, when tapped by your vet, may exhibit a fluid thrill noise. Anorexia, weight loss and a high respiratory rate, due to the pressure that the fluid filled uterus puts onto the abdominal organs, are all possible clinical signs. Diagnosis is usually made by ultrasound.

Spaying will cure hydrometra, but stabilization of the patient, if it is in poor condition prior to surgery, will be necessary; therefore the sooner the problem is diagnosed the higher the chance of a successful outcome.

Pyometra is an accumulation of pus in the uterus. It is a common finding in unspayed dogs but less common in unspayed rabbits.

The rabbit will show signs of anorexia, depression, excessive drinking and urination. Pyometra can be open or closed, meaning that there may be evidence of pus from the vulva, but this is not always the case.

Cases of pyometra are surgical emergencies and the rabbit should be spayed as soon as possible in order to remove the infected uterus. The rabbit will also require medical support and antibiotics. The condition carries a high death rate, as the rabbit is often extremely sick before it gets to surgery.

This is a metabolic disorder, whereby fat builds up in the blood following birth which can poison the rabbit’s system. Obesity is thought to be a common factor in this condition, but stress and too few calories during the final week of pregnancy may also play a part.

The rabbit will show signs of depression and weakness, quickly followed by collapse and sudden death.

If caught early enough, it may be possible to nurse the rabbit with aggressive supportive therapy in the form of nutritional support and intravenous or intraosseous fluids, but often there is little that can be done.

This is the most common type of tumour in rabbits. Uterine adenocarcinomas are estimated to affect between 50-80% of unspayed rabbits by the time they reach 5 years of age. Most breeds of rabbit have had cases reported, and there seems to be no difference in incidences if the rabbit has had previous litters.

Clinical signs of lethargy, decreased appetite, weight loss, blood in the urine and depression are often seen, but sometimes signs may be more subtle, making it very difficult for owners to realise there is a problem.

If caught early enough, it is possible that spaying the rabbit will be curative, but if the disease has progressed before a diagnosis has been made, then spaying is rarely curative as secondary tumours (metastasis) are likely to have developed in the lungs and/or other organs. It is, therefore, very important that your vet takes an x-ray of your rabbit’s chest before deciding to perform surgery, to try to identify if lung changes have already occurred. If this is the case, then it carries a grave prognosis.

If, however, the x-rays are clear, surgery can be performed, and if successful, then screening for metastasis should be performed on a regular basis, as they can develop up to 2 years following surgery.

It is clear that spaying female rabbits when they are young and healthy is the best preventative measure for all of these conditions, ensuring that your rabbit does not contract any of these conditions.

Therefore, early spaying of all female rabbits at around 4-5 months of age is recommended for preventative healthcare reasons.


Urolithiasis is the formation of calculi in the urinary tract, also called kidney and bladder calculi or stones, or urinary tract stones. The stones are rock hard crystal aggregations of all shapes and sizes. Sludge is the name given to the thick, almost toothpaste consistency deposit that can build up in the rabbits bladder or kidneys.

Calcium is very important for rabbits; they need it to form strong and healthy bones and teeth (and so to prevent dental problems and osteoporosis). Just as too little can cause problems, so can excess quantities, and although calcium consumption isn’t believed to be the sole factor responsible for the development of calculi (stones), it is thought to play a part, so getting your rabbit’s calcium intake correct may help to prevent future problems.

A rabbit fed a good balanced diet shouldn’t be calcium deficient and wont need a calcium or mineral supplement. It has been suggested that the average sized, adult, non-breeding, pet rabbit needs around 510 mg of calcium daily.

Rabbits have an unusual calcium metabolism; In most mammals, the amount of calcium absorbed from the diet is regulated at gut level by Parathyroid hormone (PTH), but rabbits predominantly absorb calcium in proportion to what is present in their diet, whether or not they require it. Meaning that whatever amount of calcium a rabbit has in their diet, they will absorb it all. Any excess calcium that is absorbed into the bloodstream from the gut is excreted through the urinary tract, where it may be deposited and form calculi/sludge. Rabbits can form solid calcifications in their kidneys, ureters, bladder or urethra, as well as depositing thick calcium sludge in their kidneys or bladder.


One or more stones may develop, with or without sludge being present. Symptoms of calculi include: loss of appetite, loud painful teeth grinding, hunched posture, lethargy, unwillingness to move, pressing abdomen on the ground, loss of litter training, blood in the urine, perineal scalding and straining to urinate. One or more symptoms may appear gradually, or have a sudden onset and be intermittent.

A blood test is useful for determining kidney function and calcium levels in the blood. A urine test should also be taken to see if calcium crystals and/or a urinary infection (cystitis) are present.


Rabbits suffering from sludge may display any of the symptoms described above for calculi, as well as passing thick, white, gritty urine that in severe cases will become semi-solid when passed. White or sludgy urine on their own are common in rabbits and often occur after the rabbit has eaten high calcium foods. They aren’t necessarily indicative of sludge within the urinary tract; this must be confirmed. Diagnosis is the same as that of calculi; as the sludge is made of calcium, it too will show up on an x-ray or ultrasound as a mass.

As some rabbits exhibiting no clinical symptoms, can upon investigation, be found to have some degree of sludge in their bladder or kidneys, treatment to flush the sludge from the bladder, is only necessary if the sludge seems to be causing the rabbit problems. Sludge in the kidneys is more difficult to eliminate, although kidneys can be flushed, and flushings may be sufficient to return the kidneys to an acceptable working capacity, it is unlikely to clear all the sludge.

Treatment depends upon the location of the calcification/s. The deposit of calcium salts (calcifications) show up on x-rays and ultrasound scans, as the calcium content makes them radiopaque (light in colour). Calcifications detected in the bladder, ureters or urethra should be surgically removed once the rabbit’s condition has been stabilised.

Rabbits suffering from calculi are often in a lot of pain and as a result will not eat or drink, subsequently being dehydrated and necessitating fluid therapy, gastrointestinal support and pain relief prior to surgery. Currently there is no known method of breaking up rabbit calculi and it is rare for the rabbit to pass them naturally, due to their often-jagged texture and size to which they can grow. Ureteral calculi may cause enlargement of the kidney (hydronephrosis) due to obstructed urine flow from the kidney to the bladder. With such a situation, once the rabbit is stabilised, prompt surgical intervention to remove the calculi is vital to avoid irreparable damage.

Rabbits presenting with calculi in both kidneys, displaying clinical symptoms have a guarded to poor prognosis. Surgically removing calculi from the kidney is extremely hazardous, and for these cases management may be the only treatment option, with their quality of life paramount. If calculi are only located in one kidney, it may be possible to remove the affected kidney, as the remaining kidney should have adequate function to keep the rabbit alive. However, if the remaining kidney becomes unable to work to near full capacity, the rabbit’s prognosis is extremely grave.

Calcium consumption isn’t believed to be the sole factor responsible for calculi/sludge development, which is why solely reducing the calcium intake often doesnt prevent the problem from reoccurring. Other possible reasons, include:

A low water intake

This is suspected to be one of the most important factors leading to the formation of urinary calculi. Less urine is produced with a low water intake and calcium precipitates out when urine is saturated with calcium. To rectify this problem you must increase the rabbits fluid intake, which can be achieved by:

  • Adding apple juice or other sweet flavouring to their water.
  • Giving the rabbit a plain salt lick or sprinkling a small amount of table salt onto their veg.
  • If neither of the above works, syringe-feeding fluids or fluid administration by your vet may be the only way of increasing the fluid intake.

Overweight rabbits

Overweight rabbits may be physically unable to completely empty their bladder, due to weak muscle tone, or adopt the correct position for urination, which will give any calcium in the urine a chance to settle in the bladder.

Kidney damage

The rabbit’s kidneys may be unable to manage the amount of calcium, which they are required to process. Kidney damage only shows up on blood tests when at least 50% of kidney function is lost.

Litter training

Most rabbits will only urinate in a select amount of places. If the rabbit is unable to reach these places, i.e. no litter tray in pen, it may wait until it can urinate in its desired area, so always ensure your rabbit is able to reach its toilet areas.

Oxalate (a poisonous salt of oxalic acid)

Some green foods are high in oxalate (spinach, parsley, spring greens, etc). Oxalates should be metabolised by bacteria in the gut, but if there aren’t enough oxalate-eating bacteria, the oxalate will be absorbed rather than broken down and excreted via the kidneys, with calcium hitching a ride.

Other illnesses

Illness which causes the rabbit to sit around and not urinate regularly, e.g. osteoarthritis, spinal problems or anything causing discomfort/malaise, etc, can cause problems. The underlying factor needs to be corrected, on top of addressing the sludge/calculi problem.


Even after a low calcium diet has been implemented and all the above explored, if the rabbit still continues to produce calculi/sludge, then a genetic reason should be considered. Some rabbits may fundamentally be “stone/sludge formers” and whilst a genetic reason cant be ruled out, rabbits affected with urolithiasis problems should never be bred from.

Fruit and vegetable can be grouped into good, moderate and poor calcium providers. The approximate calcium mg content per 100 g is shown alongside:

Good calcium providers

  • Kale (130)
  • Spinach (170)
  • Parsley (200)
  • Watercress (170)
  • Mint (210)
  • Spring Greens (210)

Moderate calcium providers

  • Cabbage (49)
  • Broccoli (56)
  • Celery (41)
  • Parsnip (41)
  • Swede (53)
  • Turnip (48)
  • Oranges (47)

Poor calcium providers

  • Brussel Sprouts (26)
  • Carrots (25)
  • Cauliflower (21)
  • Cucumber (18)
  • Peppers: Red/Green (8)
  • Tomatoes (7)
  • Apple (4)
  • Apricot (15)
  • Banana (6)
  • Grapes (13)
  • Kiwi Fruit (25)
  • Nectarines/Peaches (7)
  • Pears (11)
  • Pineapple (18)
  • Strawberries (16)
  • Baby sweetcorns (2)

Alfalfa hay contains approximately 1.5% calcium, compared with 0.4-0.8% calcium in grass hays. Nutritional values for hay and fresh foods vary depending upon the soil the product was grown in, the time of year it was harvested and other conditions that affect nutritional values.

Once the initial condition has been treated, attention must focus on trying to prevent reoccurrence of the condition, but even then there is a possibility of further calculi or sludge forming, particularly if the rabbit still has sludge within their kidneys or bladder.

The most successful approach to preventing reoccurrence of calculi or sludge seems to be by adopting a multi-tiered approach and tackling several possible factors concurrently:

  • Dried rabbit mixes should be excluded from the diet or fed in tiny proportions as an occasional treat. Any alfalfa-based foods and calcium/mineral supplements should be permanently removed from the diet.
  • Feed limited amounts of foods classed as moderate calcium providers, with their main intake from the poor group, avoiding those in the good group. This not only lowers the calcium intake but also increases water consumption, which seems to be critical for rabbits with urolithiasis.
  • Offer grass hays (timothy, fescues, ryegrass, bromegrass or orchard grass) ad lib.
  • Ensure the rabbit isnt overweight and gets plenty of exercise.
  • Always ensure the rabbit can reach its toilet areas.
  • Implement careful monitoring, usually consisting of blood and urine tests, as well as periodic x-rays/ultrasounds to monitor the condition and detect any reformation of calculi/sludge early on.

Changes in diet should be done over at least a couple of weeks to prevent digestive upsets. Introduce one new food at a time and if it seems to upset the rabbit in the next 24-48 h exclude it from the diet. Try to feed smaller quantities of numerous different foods, rather than larger quantities of a few foods. This gives the rabbit a variety, and also helps to achieve a balance of other minerals.

The vast majority of rabbits on a hay and veggie diet manage fine, and get through a mound of fresh food their own body size daily. Hay and water must always be available.

Finally, it is vital to ensure the phosphorus intake doesn’t exceed the calcium. Discuss your rabbit’s diet with your vet, and expertise is also available from nutritionists employed by feed companies in the UK and US.

Red urine

Bloody urine is rare in rabbits and rodents. Cases of bloody urine in rabbits often turn out to be normal rabbit urine which is simply a deep red colour due to the extretion of plant pigments within the diet. True cases of blood in the urine (haematuria) are often due to stones/sludge within the urinary tract, cystitis, uterine adencarcinoma, polyps or abortion.

Bloody urine in rabbits may be rare, but red urine is not. Owners who pay close attention to what is in their rabbits litter tray will be familiar with the variation of colour that normal rabbit urine can be.

Red urine is observed in rabbits, and is almost always caused by plant pigments and does not affect the animals health. Vegetables such as cabbage, broccoli and dandelions will often result in the excretion of red urine. Normal rabbit urine will vary from a pale yellow or clear colour, through various orange and brown colours, right up to a deep red colour. Rabbit urine may also look cloudy due to the presence of calcium carbonate being excreted within the urine. Red urine is not a medical problem and usually returns to normal within one to three days, although it has been seen to take as long as three to four weeks before the urine returns to the pale yellow colour.

Dark and/or very strong smelling urine can result from heat stress or dehydration, so always ensure that your rabbit has plenty of fluids, especially in the warmer months of the year when they may appreciate a water bowl to drink from as well as a water bottle. If your rabbit frequently has dark or very strong smelling urine then it may be worth discussing this with your veterinary surgeon.

For obscure reasons red urine may occur due to any of the following:

  • While on antibiotics
  • At the first cold snap in autumn
  • After eating fir leaves
  • After eating carrots, spinach or other veggies containing beta carotene
  • Eating cabbage, broccoli and dandelions, especially if the rabbit isn’t used to eating these

If your rabbit appears well in themselves; is eating and drinking normally, active and bright, producing lots of normal droppings then do not panic when you observe a change in colour of your rabbit’s urine. Monitor the situation and if it doesn’t resolve then speak to your vet for advice. If your rabbit seems unwell in anyway then always consult your veterinary surgeon as soon as possible.

Blood in the urine is also known as haematuria.

True haematuria can occur due to disease anywhere within the urogenital system. An unspayed female rabbit might show a bloody discharge from her vulva, or drops of blood after urination, which could be confused with urine; either of these occurrences could be a sign of uterine cancer. An un-neutered male rabbit could have genital cancer or trauma which could cause blood to appear in his urine in either case you should take your rabbit to see your vet immediately.

Other causes or haematuria may result from calcium stones or sludge anywhere within the urinary tract system (kidneys, ureters, bladder or urethra), cystitis, polyps or even abortion. All of these conditions need urgent veterinary attention as most are painful to the rabbit and life-threatening if not given immediate veterinary care.

When we see red urine, most of us worry about a bladder or urinary tract infection. However, actual blood in the urine is usually difficult to see with the naked eye. When due to kidney disease, straining to urinate may not occur, but straining is the most common sign of urinary bladder disease.

A rabbit straining to urinate assumes an unusual stance, that is, he sits for an unusually long period of time on the tip toes of the back feet, with the tail very high in the air. If you notice your rabbit is straining, you should immediately change the litter box so you can determine if he is producing urine or not.

Cloudy/white urine

Rabbits metabolise calcium very differently from other mammals such as dogs and cats. Whereas dogs and cats will only absorb the amount of calcium their body needs from their diet, rabbits absorb all of the calcium within their diet and excrete the excess through the urinary system. This is why rabbit urine is often observed as being cloudy or white in colour.

Passing cloudy urine can be normal for rabbits which are fed a high calcium diet or those rabbits which are slightly dehydrated. However, rabbits who are fed a high calcium diet are much more likely to develop stones or sludge deposits within their urinary system, which often require corrective surgery and can be impossible to rectify.

Therefore it is recommended that rabbits are not given calcium supplements unless specifically stated by a veterinary surgeon and are not fed excessive amounts of alfalfa hay or vegetables high in calcium; carrot tops, spinach, water cress, kale or dark cabbages, etc.

It is not necessary to take your rabbit to the vet for the condition of red (pigmented) urine, unless your rabbit is showing any other symptoms.

If you notice urine that is red or pink (orange is OK) and there are no other symptoms, you could wait until the next available appointment at your vets to ask them to test the urine for blood.

If your rabbit is straining to urinate, he may only produce a drop or two of urine at a time because of the frequency with which he is attempting to urinate, if this is the case you should make an appointment for your rabbit to see your vet on the next available appointment. However, if your rabbit is straining and isn’t producing any urine at all, there could be a blockage, which is an emergency and you should take your rabbit to see your vet immediately to determine if there is a blockage. If there isn’t a blockage your vet may want to perform further tests to find out what the problem is.

Yes, your vet can test a urine sample (urinalysis) to determine if there is blood within the urine.

If haematuria is diagnosed then your vet will want to determine exactly what is causing the blood in the urine.

This may involve taking x-rays of the abdomen to look at the bladder and associated ureters and urethra to look for stones or sludge, which show up very well on x-rays.

A urine sample may be taken and tested for bacterial growth and to determine what antibiotics would be most effective.

If your rabbit is an entire female then the vet may do an ultrasound examination to look at the reproductive tract for any sign of tumours. If any growths are located then it is advisable to take chest x-rays to look for any spread of the disease before embarking upon any surgery.

Blood tests may also be used to assess kidney function and to look at the blood cells.

Rearing orphan rabbit kittens

Handrearing a rabbit kitten or kittens can be an extremely rewarding experience but is not a job to be taken on lightly. The task ahead is difficult, exhausting and there is no guarantee of success. However hard you try, you are a poor substitute for a kitten’s natural mother and despite the best efforts of human volunteers the death rate among orphaned kittens is often high.

Rabbit kittens can require hand-rearing if they are true orphans due to maternal death, or because the mother is unable to feed her kittens. Kittens only suckle once every 24 hours, at night and only for 5 minutes or so – they are left in the nest for the rest of the time and ignored by their mother. This avoids drawing attention to the nest (a survival strategy).

Mothers with a new litter can take 24 hours to start producing milk. If the kits have not been fed for 48 hours then mis-mothering can be diagnosed. Unfed kits will have thin tummies and wrinkled skin. Check also that the kits have pink rather than blue skin colour. They will also cry if they are not being fed.

Occasionally a mother will abandon one or more kittens in the litter. The kitten may look perfectly normal but the chances are that it has some serious defect which would prevent it from living a full and active life. Letting it die may seem cruel but it is nature’s way and in these situations it may be kinder to ask your vet to put the kitten to sleep. If a litter of wild baby rabbits is found, it is wrong to assume that they have been abandoned – the mother is probably out hunting or watching from a hiding place. Leave the kittens where they are. If you disturb them or move them from the nest, you will reduce their chances of survival.

The most common causes of failure and death are pneumonia due to inhalation of milk into the lungs and diarrhoea due to failure to establish a normal gut flora (the mother’s milk is not only the best source of nourishment but also provides the gut bacteria essential for their digestion).

Kits under 7 days will need to be kept at 27-30°C (an airing cupboard will do). Their fur will grow when they are about 7 days old. Baby rabbit’s eyes open between 10 and 12 days and they can hear by the fifth day. Place kits in a box, e.g. a shoe-box, lined with hay, maternal fur (rabbits will pull their fur before giving birth to make a nest), soft cloths or fleece veterinary bedding. Temperature can be lowered after 7 days if the kits are thriving.

Rabbit milk is highly concentrated and commercial substitues available are Esbilac, Climicat and Lactol (although full cream goats milk and evaporated milk (e.g. Carnation) diluted 50:50 with water have also been used). Ask at your Veterinary practice for supplies. The commercial preparations are recommended and should be prepared according to the manufacturer’s instructions. A probiotic, e.g. Protexin, Avipro, and multivitamins, e.g. BSP drops, should be added to the milk, following the manufacturer’s instructions.

Made-up milk can be stored for 24 hours in a refrigerator but the milk should always be given at body temperature and can be tested on the back of the hand before it is given. Use Milton’s fluid to clean teats, bottles and syringes, rinsing in water before use.

Nursing bottles with teats available for kittens, or syringes can be used. Teat feeding is best as it carries less risk of aspiration pneumonia. If fed by syringe you cannot generally revert to teat feeding as the suckling reflex is lost after about two days. If using a syringe, administer the milk very slowly to minimise the possiblity of aspiration.

Hold the kit on your lap with its head gently restrained between the thumb and second finger, and the first finger placed on the top of the head. If using a sryinge, this should be gently inserted through the side of the mouth behind the incisor teeth. Stop between mouthfuls to allow swallowing. Once accustomed to being fed, the rabbit will refuse milk when it is full.

Feed the baby rabbit between 3-6 times a day. 4 times a day is usually adequate with a break of 6-8 hours overnight. Weigh the kit regularly and increase the volume and/or frequency of feeds if they are failing to gain weight. As a rough guide, new born kits consume about 2 ml/day, increasing to:

  • Day 4: 10 ml/day
  • Day 7: 13 ml/day
  • Day 10: 15 ml/day
  • Day 14: 22 ml/day
  • Day 21: 27 ml/day – starting to nibble hay and use water bottle
  • Day 27: 30 ml/day – eating hay
  • Day 30: 20 ml/day – well established on hay
  • Day 35: weaned! Eating mainly hay, and a small amount of solids (concentrates) and wild plants/vegetables.

A water bottle should be introduced when the kits are about 3 weeks old. Probiotics should be added to the water.

After each feed, wipe the kit’s bottom with a damp cloth or cotton wool to stimulate urination and defecation (the mother’s tongue usually does this). This will need to be done until the rabbit is about 10-14 days old.

Weaning is a critical period and it is important that only hay is introduced first. The rabbits should be well-established on hay before small amounts of solid food (concentrates) and vegetables are introduced.

Kidney problems

Like other mammals, rabbits possess two kidneys. The kidneys are essential for filtering out toxins from the body and excreting them via the urinary system. There are many potential problems which can affect the kidneys, with varying degrees of severity.

Rabbits produce alkaline urine and rely heavily on renal excretion as the major route of getting rid of any excess calcium within the diet. A rabbit’s calcium metabolism is completely different when compared to that of other mammals because blood calcium levels reflect their dietary intake. This means that if the diet consists of too much calcium, this alone can cause problems. Furthermore, the rabbit depends greatly on kidney function to regulate the metabolism of calcium in the body. The calcium that is eliminated via the kidney can precipitate the urine forming crystals that give the rabbit’s urine its typical creamy appearance.

There are numerous reasons why a rabbit’s kidneys may fail or the efficiency of them may lessen. Unlike the liver, kidneys do not possess any regenerative powers, so once the kidneys have been damaged or disease has become apparent, the damage cannot be reversed.

Renal failure is when the kidneys fail to filter the toxins and waste products from the blood properly. Acute renal failure happens over a short period of time, but clinical symptoms may involve reduced appetite and reduced urine production, which may go on to a cessation of appetite and urine production altogether. The rabbit may become depressed, dehydrated and grind its teeth in a painful manner (bruxism). Secondary gastrointestinal problems may also arise.

Clinical examination may reveal enlarged kidneys and uraemic odour from the rabbit’s mouth.

Acute renal failure is often due to the ingestion of a harmful substance; these commonly include lead batteries, anti-freeze and nephrotoxic drugs.

Treatment involves aggressive fluid therapy to correct the dehydration and in the hope that the toxins can be flushed from the body in time before any long-term damage is done. However, the longer the problem has gone untreated, the poorer the prognosis. All potentially toxic drugs should be discontinued immediately.

Unlike acute renal failure, chronic renal failure may develop over many days or weeks, and the clinical signs may go unnoticed for some time.

Clinical signs can include weight loss, gradual reduction in appetite, increased urine production and increased water consumption. The rabbit may lose body condition and generally look ‘unwell and scruffy’.

A clinical examination will detect small ‘shrivelled’ kidneys which may feel irregular in shape. A blood sample is invaluable in these cases as it may show an increase in some parameters which may be indicative of a kidney problem. In particular, examination of the blood may show elevated creatinine, although urea is unlikely to be raised until over 50-70% of kidney function has been lost.

Potential causes of chronic renal failure include E. cuniculi infection, bacterial infections, sludge/stones within the kidneys and renal tumours.

Treatment is aimed at treating the underlying cause of the renal failure, whilst supporting the rabbit’s kidneys and ensuring they remain hydrated and their gastrointestinal tract doesn’t go into stasis.

Pain relief is also recommended, but all non-steroidal anti-inflammatory drugs (NSAIDs), such as Metacam® (meloxicam; Boehringer Ingelheim) or Rimadyl® (carprofen; Zoetis) must not be given due to their harsh nature on the kidneys.

A prognosis will depend on the severity of the kidney damage and the underlying cause of it. If this cannot be corrected/managed, then the prognosis is extremely grave.

This has been reported in rabbits whereby small, multiple cysts have been located in the kidneys. Most rabbits with the condition show symptoms of chronic renal failure by the age of 2-3 years, which is often inherited. It has many similarities to polycystic kidney disease seen in humans and cats.

These seem to be an incidental finding in rabbits and have often been diagnosed on ultrasound examination whilst looking for other problems.

Cysts don’t seem to cause any impairment to the function of the kidneys, and treatment is not required.

Some rabbits may be born with only one kidney, which can affect both bucks and does. The rabbit may show no symptoms and lead a perfectly normal life, however, if their one kidney becomes disease in any way, and its function is compromised, then the rabbit’s prognosis is grave.

This is the term given for the surgical removal of one kidney.

If one of a rabbit’s kidneys is diseased to the point where it is causing the rabbit pain or problems, then it is possible to remove the diseased kidney. The surgery is a major undertaking and serious consideration should be given to the rabbit’s welfare and long-term prognosis before proceeding.

If the rabbit’s other kidney is diseased or not working properly, then the prognosis is extremely grave.

Excessive drinking and urination

Drinking and urinating more than normal is medically called polydipsia (poly = many; dipsia = drinking) and polyuria (poly = many; uria = urine). Thirst and urine production are a delicate balance controlled by interactions between the brain and the kidneys. Increased urination stimulates thirst, as the body’s overall hydration decreases and stimulates thirst mechanisms in the brain. Sometimes the opposite can be true when excess thirst triggers urination, as can be seen with diseases like diabetes when the body tries to dilute toxins by drinking more and the diluted blood then stimulates increased urination.

A rabbit with polyuria and polydipsia will have increased water intake and increased urine output.

The water bowl might become empty more frequently and there might be more instances of urine production; the urine might appear lighter in colour and less concentrated, or the rabbit may be partially incontinent.

On average rabbits will drink 50-150 ml/kg/day, so a large 5 kg rabbit will normally drink up to 750 ml each day, so anything over that could be abnormal. Similarly, normal urine production is about 120-130 ml/kg/day, so a large 5 kg rabbit will urinate as much as 650 ml per day, so anything over that may be abnormal.

The causes of polyuria and polydipsia can vary, but can include:

  • Diabetes or insulinoma (a tumour of the pancreas)
  • Renal (kidney) disease
  • Hepatic (liver) disease
  • Drugs, large quantities of sodium chloride
  • Behavioural problems

Other conditions like dehydration can stimulate thirst, but if the rabbit is dehydrated it will usually have decreased urine production. Similarly, rabbits can have incontinence from things such as bladder stones or bacterial infections, or it might spray in territorial/behavioural display, but this doesn’t necessarily mean the rabbit is producing more urine.

Psychogenic polydipsia may lead to polyuria. The condition may be behavioural or due to a physical problem and can only be deemed a cause of polydipsia and polyuria once other causes have been ruled out.

Rabbits with dental disease may try to fill themselves up on water, if eating is too painful; the rabbit will drink excessively in an attempt to feel full, which in turn will lead to increased urination. These rabbits will lose weight, condition and appear miserable.

Bored, lonely or stressed rabbits may take comfort in drinking, especially from water bottles, as rabbits often like to ‘play’ with the ball-bearing in the tip of the bottle, leading to polydipsia and polyuria.

As there are many different causes for polyuria and polydipsia, your vet will need to thoroughly evaluate the clinical signs and carry out some diagnostic tests to narrow down the root of the problem.

Blood tests and urinalysis are the most common and will assess kidney function, liver function and the presence of excess blood glucose, as is frequently seen in diabetes. This can usually be done quickly with a day stay in hospital and results are usually back within a few days if samples are sent to an external laboratory.

If bladder/kidney stones are suspected, radiographs or ultrasonography might also be required. This usually requires sedation and a day stay in hospital.

Treatment of polyuria and polydipsia depends on the cause.

For diabetes, it is important to treat the underlying cause which may include weight loss.

For bladder stones, surgery and a change of diet may be needed.

For kidney and liver disease, the rabbit may need to be admitted to hospital for fluid therapy and supportive care as well as further investigations to determine if the condition is reversible.

The living environment of rabbits suffering from psychogenic polydipsia and polyuria will need a thorough review, a physical examination should also be performed to determine the cause and best course of treatment.

Each problem will need to be addressed individually.

To help prevent the incidence of disease that can lead to polyuria and polydipsia, ensure that the rabbit is happy and healthy. The environment should be safe, secure and non-stressful. Ensure the housing offers shelter as well as space where the rabbit can exercise and exhibit normal behaviour.

The rabbit’s water bowl should be large enough to provide at least the daily water requirement, and water should always be clean and fresh.

Food should be suitable and not contribute to obesity or bladder/kidney stones.

Provide environmental enrichment, such as places to hide, nesting material, toys to play with, wood for chewing, herbs to browse and soil to dig in.

Prevent overcrowded housing that can be stressful and promote unnecessary spread of disease. This includes reducing the likelihood of territorial aggression by avoiding housing the rabbit in close quarters with other that are un-neutered or of the same sex.

Ensure prevention of disease by having your rabbit seen at least once a year by your vet for an all over check-up and dental examination.

Provide rapid treatment of disease by consulting your vet at the first sign of any abnormal signs such as lack of appetite, changes in drinking or urination, changes in activity level, hair loss, scratching, excessive grooming, drooling, teeth grinding, changes in hair coat, faecal soiling, flystrike, limping, among others.