Cases- In these days, I keep seeing rabbits presented for epiphora (excessive tear production/ overflowing) on a daily basis. The record of rabbits with eye problem that I see was up to 5 on the same day. Rabbit owners bring in their rabbits and note the periocular hair is wetted and their rabbits seem to be crying. Many of them are caused by obstruction of the nasolacrimal/tear duct. The reasons of blockage range from infection, inflammation or tooth root elongation which impinges on the tear duct. Obstructed tear duct is usually filled with inflammatory cells and debris. Owners may report their rabbits have nasal discharge or sneezing as the affected tear duct can cause irritation at the nostril opening. They can also have secondary pyoderma around the periocular area where there are hair loss, matted fur, crusting, foul smelling etc. Sign of tear overflow depends on whether the obstruction is partial or complete. Owners report rabbits have on and off clear discharge from the affected eye for a few days then self recovered. However, complete obstruction presents with constant and persistent clear to milky ocular discharge. Regarding physical examination, at first I check for white discharge at the medial canthus as this may indicate dacryocystitis. Depending on how long the problem has been present before rabbits are brought in for consultation, for chronic individuals, constant moisture can cause hair loss, skin reddening, ulceration and secondary bacterial infection of the surrounding skin. Second, I perform a skull symmetry examination to check for possible dental abscess or overgrown tooth roots- especially the upper jaw. There are 2 main potential dental problems causing a nasolacrimal duct issue which are overgrown upper incisors or cheek teeth. The nasolacrimal duct is running in close association with them. Sometimes, I do see rabbits with milky ocular discharge from the eye which suggests Fluorescein stain is applied onto each eye to check for the nasolacrimal duct patency. Normally, the dye should reach the nostril in 10-15 seconds if they are not obstructed. Once no contrast is seen after 10+ seconds, an obstructed tear duct is diagnosed. In order to relieve the obstruction, nasolacrimal flush is performed which is a minor procedure. Topical local anaesthetic eye drop is administered. Then a 24G soft intravenous catheter is introduced into the tear duct orifice at the inner side of the lower eyelid. Irrigation with sterile saline may dislodge foreign material and thick white exudate as shown in the following pictures taken during consultation. If successful, rabbits may sneeze out part of the dislodged material. Next step of further diagnostics include skull radiography, dacryocystorhinography which allow investigation of possible dental involvement. Whenever imaging is needed, sedation is warranted to ensure a still patient for a clear image to be captured. For persistent infection problem- bacterial culture and sensitivity will be needed to select the most suitable antibiotic for my patients. Topical eye drop with antibiotic and anti-inflammatory are prescribed for home use. Patients are needed to recheck or duct reflush every 3 days, 7 days or 2 weeks depending on the severity. Owners should keep their rabbit facial fur clean and dry in order to treat the pyoderma associated. I have seen owners self administering over the counter eyedrop from the pharmacy without consulting their rabbit veterinarian. However, nasolacrimal obstruction normally does not respond to just antibiotic eyedrop. I have also seen owners wait and see the eye problem for a month or so before presenting their rabbits to me. Once the complete obstructed tear duct has been scarred and narrowed due to infection, flushing is likely to fail and the affected rabbits may have life-long ocular discharge and periocular skin problem. It is strongly advised to get your rabbits checked once you have noted there is excessive |
