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.
How is the rabbit's reproductive tract different to 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.
What is pseudopregnancy?
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.
What is endometrial cystic hyperplasia?
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.
What is hydrometra?
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.
What is pyometra?
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.
What is pregnancy toxaemia?
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.
What is uterine neoplasia?
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.