Corneal Injuries - Rabbit

Injuries

Corneal injuries may be repaired as in other species with 6/0 or 8/0 Polyglactin 910 (Vicryl®; Ethicon) and supportive post-operative therapy administered as required. Cat scratches may lead to endophthalmitis and are treated with topical applications of antibiotics. Clean surgical wounds may be treated with topical antibiotics and corticosteroids.

Abrasions

Corneal abrasions are occasionally encountered in pet rabbits usually as a result of injury on straw bedding (barley awns) or from injuries sustained from being chased by dogs or children. These can be confirmed by the instillation of fluorescein drops followed by examination with and without a cobalt blue filter over the light source after the excess fluorescein has been flushed away. Treatment is as for other mammals - repeated topical applications of antibiotics following sensitivity testing or, in the event of antibiotic sensitivity testing not being available, utilising an agent known to include Pasteurella multocida in its spectrum of activity. From clinical experience I prefer aqueous ophthalmic solutions preferably those containing hydroxypropylmethylcellulose (hypromellose), to ointments for the treatment of corneal injuries and abrasions and I recommend that applications should be repeated hourly or more frequently, but care must be taken not to cause stress with such frequent handling. Refractory cases can be treated surgically by surgical debridement of the ulcer margin and temporary tarsorrhapy or a nictitans flap (I prefer to place sutures through the cartilage of the membrana nictitans rather than attempt to pick up the very fine conjunctival epithelium of the membrana which tends to tear very easily in this species).

Lipidosis

Corneal lipidosis has been observed by myself in rabbits and presents the same clinical appearance as in dogs and cats. Other than to assess the liver function of the subject and alter the diet accordingly, I regret that I can offer no clinical advice. Lawton (1993) reported the occurrence of corneal dystrophy due to cholesterol clefts which he asserted are both dietary and hereditary (clinical work-up includes blood testing for cholesterol and triglycerides and the treatment involves dietary adjustment).

Oedema

Corneal oedema can occur with glaucoma and indolent ulceration. If thermal keratoplasty is required, Williams (2006) warns that the thin nature of the rabbit cornea makes this a delicate procedure.

Dystrophies

Corneal dystropies are reported (Williams 2006).

References

• Lawton M P C (1993) Procs BVZS Autumn Meeting ZSL 4/12/93
• Williams 2006