Eye problems

Rabbit Cataract Causes, Symptoms and Treatment

Josie F. Turner
By Josie F. Turner, Journalist specialized in Animal Welfare. July 7, 2022
Rabbit Cataract Causes, Symptoms and Treatment

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Cataracts are one of the leading causes of vision loss in both human and animal medicine. Rabbits are not exempt from this ocular pathology, but they can be more difficult to diagnose. Although their eye placement means they struggle seeing objects right in front of them, they have acute vision from far away. In the wild this allows them to spot predators, but their vision is similarly important in the domestic environment. Fortunately, although cataracts can cause blindness, there are treatment options available in many cases.

At AnimalWised, we look at rabbit cataract causes, symptoms and treatment. This will help you to observe your rabbits and find out whether they are suffering from this specific pathology.

You may also be interested in: Canine Uveitis - Causes, Symptoms and Treatment
  1. Types of rabbit cataracts
  2. Symptoms of rabbit cataracts
  3. Causes of rabbit cataracts
  4. Diagnosis of Cataracts in Rabbits
  5. Treatment of cataracts in rabbits

Types of rabbit cataracts

The lens of a rabbit's eye is biconvex. This allows the rabbit to focus on objects located at varying distances. Under normal conditions, it is completely transparent, as it must allow the passage of light rays to the retina. However, when there is an alteration in the metabolism of the lens, an opacity appears. It is this opacity that we know as cataracts in rabbits.

Rabbit cataracts can be classified based on various factors:

  • Age when they occur: they can be congenital (if the animal is born with them), juvenile or senile.
  • Maturity or developmental stage: they can be incipient, immature, mature or hypermature.
  • Underlying cause: they can be hereditary, metabolic, post-inflammatory, etc.
  • Location in the eye: they can be anterior or posterior capsule, nuclear, posterior cortical, equatorial or axial cataracts.

Depending on their extension and their stage of development, cataracts can cause different degrees of vision loss. They can cause significant damage to the animals that suffer from them and result in blindness of the affected eye(s).

You can find out more background information on how rabbits see with our comparison of rabbit and human vision.

Symptoms of rabbit cataracts

Cataracts in rabbits two main clinical signs which guide a veterinarian to diagnosis:

  • Ocular opacity: depending on the degree of maturity of the cataract, the eye will have a more or less marked opacity. This presents in a cloudy area on the rabbit's eye which can be of varying size.
  • Loss of vision: some rabbit behaviors associated with the existence of a visual deficit are collisions with obstacles in their environment, reduced physical activity, lack of interaction or ignoring other animals or people. They will also likely have an increased tendency to be surprised or frightened when interacting with their environment.

In addition to the opacity of the lens, cataracts can influence the development of secondary ocular pathologies. These manifest in various symptoms. It is common for rabbits with cataracts to present other clinical signs associated with the following complications:

  • Uveitis: presents with blepharospasm (closed eye), hyperemia (red eye), tearing, miosis (pupillary contraction), corneal opacity, hyphema (blood deposit in the anterior chamber) or hypopyon (white blood cell deposit in the anterior chamber).
  • Glaucoma: presents with eye pain, buphthalmia (increased eye size), corneal opacity, mydriasis (pupil dilation) and vision loss.
  • Lens dislocation: occurs with eye pain, tearing, blepharospasm (closed eye), aphakic crescent (moon-shaped silhouette) and abnormal movements of the iris and lens.
  • Rupture of the lens capsule: can put the rabbit in danger of various other complications including retinal detachment.

As you can see, a rabbit cataract is only one of the possible ocular diseases from which this rabbit can suffer. Learn more with our article on common eye problems in rabbits.

Rabbit Cataract Causes, Symptoms and Treatment - Symptoms of rabbit cataracts
Image: rabbitsdiscapacitados.com

Causes of rabbit cataracts

In rabbits, the causes that can cause the formation of cataracts are:

  • Encephalitozoon cuniculi infection: this is a microsporidium capable of infecting rabbits during the fetal period. The larva enters the lens as it is forming and causes a cataract to form. In these cases, bilateral cataracts occur, i.e. both eyes are usually affected.

  • Hereditary causes: especially in cases of consanguinity or inbreeding, due to crossbreeding between related individuals. For this reason, cataracts in dwarf rabbits and certain other breeds are more common when they come from irresponsible breeders. It is important not to encourage this practice and opt for adoption.

  • High glucose levels: for example, due to inadequate nutrition (excessive fruit or vegetables) or untreated diabetes.

Learn more about rabbit diet with our article on fruits and vegetables suitable for rabbits.

Diagnosis of Cataracts in Rabbits

Diagnosis of cataracts in rabbits requires the following diagnostic tests:

  • Dilation of the pupil: tropicamide is used to enable examination of the entire lens.
  • Back-illuminated examination: this allows the opacity of the lens to be clearly observed.
  • Ocular ultrasound and electroretinography: although the diagnosis can be reached with the previous tests, it will be necessary to perform an ultrasound and an electroretinography to confirm that the loss of vision is due to the cataract and not to another ocular alteration.

Treatment of cataracts in rabbits

Medical treatments based on eye drops have little efficacy in dissolving cataracts. This means the treatment of this ocular pathology must rely on surgical intervention. The specific surgery required to treat the rabbit cataract is phacoemulsification. This involves the removal of the lens and its replacement with an intraocular lens.

It is worth mentioning that the prognosis after surgery is very good. Between 90-95% of rabbits manage to recover their vision. For this reason, it is very important to go to the veterinary center at the first symptom of a rabbit cataract or any other health problem. In this other article you can learn more about the most common diseases in rabbits and their symptoms.

This article is purely informative. AnimalWised does not have the authority to prescribe any veterinary treatment or create a diagnosis. We invite you to take your pet to the veterinarian if they are suffering from any condition or pain.

If you want to read similar articles to Rabbit Cataract Causes, Symptoms and Treatment, we recommend you visit our Eye problems category.

  • Ashton, N., Cook, C., & Clegg, F. (1976). Encephalitozoonosis (nosematosis) causing bilateral cataract in a rabbit. Brit. F. Ofthal., 60(9), 618-631.
  • Sanchez, R., Everson, R., Hedley, J., Dawson, C., Lam, R., Priestnall, S., Garcia, A., de Miguel, C., & Seymour, C. (2018). Rabbit with naturally occurring cataracts referred for phacoemulsificaction and intraocular lens implantation: a preliminary study of 12 cases. Vet Ophthalmol, 21(4), 399-412.
  • Wagner, F., & Fehr, M. (2007). Common ophthalmic problems in pet rabbits. Journal of Exotic Pet Medicine, 16(3), 158-167.
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Rabbit Cataract Causes, Symptoms and Treatment