Cataracts are one of the leading causes of vision loss in both people and animals. Rabbits are not exempt from suffering from this ocular pathology, which often leads to damage to the welfare of the animals that suffer from it. Fortunately, there are currently surgical techniques capable of solving this ocular pathology, which greatly improve the prognosis of treated patients.
Types of cataracts in rabbits
The lens is a biconvex lens present inside the eyeball that allows the focus of objects located at different distances. Under normal conditions, it is completely transparent, since 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 in the lens which is known as a cataract.
Cataracts can be classified according to various factors:
- Depending on the age at which they occur: they can be congenital (if the animal is born with them), juvenile or senile.
- Depending on maturity or evolutionary stage: they can be incipient, immature, mature or hypermature.
- Depending on their cause: they can be hereditary, metabolic, post-inflammatory, etc.
- Depending on the location: they can be anterior or posterior capsule, nuclear, posterior cortical, equatorial or axial cataracts.
Depending on their extension and degree of maturity, cataracts can cause different degrees of vision loss, so they represent a significant damage to the animals that suffer from them.
Cataract symptoms in rabbits
Cataracts in rabbits manifest themselves fundamentally with two clinical signs:
- Ocular opacity: depending on the degree of maturity of the cataract, the eye will have a more or less marked opacity.
- Vision loss: in rabbits, some of the behaviors that can be associated with the existence of a visual deficit are shocks with obstacles in their environment, reduced physical activity, lack of interaction or ignorance with other animals or keepers, and an increased tendency to be surprised or frightened when interacting with the environment.
Furthermore, cataracts can lead to other secondary eye pathologies, which manifest with specific symptoms. Therefore, 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), lacrimation, miosis (pupillary contraction), opacity of the cornea, including hyphema (deposition of blood in the anterior chamber) or hypopyon (deposition of white blood cells in the anterior chamber).
- Glaucoma: presents with eye pain, buphthalmia (increased eye size), corneal opacity, mydriasis (pupil dilation) and vision loss.
- Lens dislocation: presents with eye pain, tearing, blepharospasm (closed eye), aphakic crescent (moon-shaped silhouette) and abnormal movements of the iris and lens.
- Ruptured lens capsule.
Causes of Cataracts in Rabbits
In rabbits, the causes that can lead to cataract formation are:
- Infection by Encephalitozoon cuniculi: 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, both eyes are usually affected, that is, bilateral cataracts occur.
- Hereditary causes: especially in cases of consanguinity or inbreeding, due to crossings between related individuals. For this reason, cataracts in dwarf rabbits, and other breeds, are common when they come from irresponsible breeders. It is important not to encourage this and opt for adoption.
- High glucose levels: for example, due to poor nutrition (excess fruit or vegetables) or untreated diabetes.
Diagnosis of cataracts in rabbits
Diagnosis of cataracts in rabbits requires the following steps:
- Pupil dilation with tropicamide to be able to explore the entire lens.
- Backlight scanning, which allows you to clearly observe the opacity of the lens.
- Ocular ultrasound and electroretinography Although the diagnosis can be reached with the previous points, it will be necessary to perform an ultrasound and electroretinography to confirm that the Vision loss is due to the cataract and not to another eye condition.
Cataract treatment in rabbits
Medical treatments based on eye drops have not been shown to be effective in dissolving cataracts. This means that the treatment of this ocular pathology must be necessarily surgical Specifically, the surgery of choice consists of phacoemulsification, which consists of extracting the lens and replacing it with an intraocular lens.
It should be mentioned that the prognosis after surgery is very good, since between 90-95% of rabbits manage to recover the vision. For this reason, it is very important to go to the veterinary center at the first symptom of a cataract in the rabbit, or any other he alth problem. In this other article you will find the most common diseases in rabbits and their symptoms.
