Congenital or juvenile cataract in a rabbit

 

 

Esther van Praag, Ph.D.

 

 

Warning: this file contains pictures that may be distressing for people.

 

The word cataract comes from the Latin “cataracta”, or from the Greek katarraktēs, meaning waterfall. It refers to a decrease of the transparency of the eye lens, which can be partial or affect the whole lens. Consequently, a reduced amount of light passes through the lens. The ability to focus and clarity of eyesight will decrease with time. This is accompanied by a loss of sensitivity to contrast. The ability to see objects is little affected when light is intense and the lens is only partially affected, but can lead to full blindness when the opacity of the lens is total and affecting both eyes. 

MediRabbit

Five month’s old rabbit with a healthy eye and a clear eye lens.

Mario Beuchat

Six week old rabbit that developed a juvenile cataract.

In rabbits, the onset of cataract is linked to several causes such as age, eye trauma, metabolic disorders or a toxic action, or is related to the presence of the protozoan parasite Encephalitozoon cuniculi (click here for more details). In young rabbits, the onset of cataract has often a congenital origin. Two types of inheritance have been observed:

·           Simple recessive inheritance. The young rabbits presented a slight opacity of the posterior face of the lens. The opacity gradually increased and was total at the age of 5 to 9 weeks. Interestingly, progression of the disease was slower in animals fed a dry diet, compared to those fed a diet rich in water (e.g., fresh vegetables).

·           Incomplete dominant inheritance, with a penetration of 40 to 60%. This type of cataract develops only in one eye. 

Unfortunately, there is only little information available on this disorder affecting young rabbits.

In young rabbits aged 29 days and 6 weeks: 

Mario Beuchat

Mario Beuchat

In a 6 week old rabbit: bilateral juvenile cataract (both eyes are affected):

Mario Beuchat

Mario Beuchat

Juvenile cataract affecting a few months old rabbit, Harlequin (Japanese) breed: 

Michel Gruaz

Michel Gruaz

Treatment

There is no treatment for cataract in rabbits

Acknowledgements

Thank you to Dr. Flavien Beuchat (Clinique Vétérinaire du Vieux-Château, Switzerland), to his father Mario Beuchat, and to Michel Gruaz (Switzerland) for sharing their pictures and their permission to use here. Thank you also to Dani Tomlin for her help.

Further information

Ehling U. Untersuchungen zur kausalen Genese erblicher Katarakte beim Kaninchen. Z. Konstitutionsl. 1957; 34, 77-104.

Gelatt KN. Congenital cataracts in a litter of rabbits. J Am Vet Med Assoc. 1975; 167:598-9.

Nachtsheim H, Gurich H. Erbleiden des Kaninchenauges. I. Erbliche. Nahtbandchentrubung der Linse mit nachfolgendem Kernstar. Z. Menschl. Vereb. Konstitutionsl. 1939; 23, 463-483.

Munger RJ, Langevin N, Podval J. Spontaneous cataracts in laboratory rabbits. Vet Ophthalmol. 2002 Sep;5(3):177-81.

Weisse I, Niggeschulze A, Stotzer H. Spontaneous congenital cataracts in rats, mice, and rabbits. Arch Toxicol. 1974; 32:199-207.

   

e-mail: info@medirabbit.com