Dacryocystitis in Rabbits

Dacryocystitis refers to infection and inflammation of the tear duct. It is a common problem in the rabbit and is often a primary reason for presentation to the veterinary hospital.

Although the main signs are caused by a bacterial infection there are usually much deeper underlying causes.

Diagnosis

Clinical signs are often enough – a white purulent discharge from eyes and/or nose. This often sticks to the fur causing hair loss and may cause skin ulceration in these areas. The condition may be uni- or bi-lateral. If in doubt, pressing the skin just under the eye results in pus being squeezed up the lachrymal duct and onto the eye surface. The opening to the lachrymal duct is generally large (though may become constricted in chronic cases) and is found in the lower eyelid, just superficial to the third eyelid.

Underlying Causes

Although rare underlying causes include such problems as foreign bodies, the vast majority of cases result from dental disease.

The lachrymal duct is very tortuous in the rabbit (this combined with the solid nature of rabbit pus explains the frequent blockages of this duct) and runs over both premolar and incisor roots.

Dental disease resulting in tooth root infection and osteomyelitis of the surrounding bone will, therefore, frequently involve the tear duct.

Investigation

Given the major underlying causes it is essential that all cases receive a full dental investigation including radiography of the skull.

"Given the major underlying causes it is essential that all cases receive a full dental investigation including radiography of the skull."

In some cases contrast media can be placed into the tear duct allowing the site of blockage to be determined.

Treatment

If possible underlying dental problems should be corrected. If the incisor roots are the cause then these teeth may be removed.

With the frequent finding of osteomyelitis it is important that medium- to long-term systemic antibiosis and analgesia (non-steroidal anti-inflammatory drugs are often effective) are instigated.

Unlike many rabbit abscesses tear duct infections do lend themselves to regular flushing. Cannulae may be inserted into the opening of the tear duct and anti-microbial solutions may be instilled into the duct. Dilute pus may be seen exiting the nose. In some cases the duct may be so blocked that the solution will not flush through. Repeated flushing may be successful especially after use of systemic drugs. Instillation of proteolytic enzymes may also assist in breaking down solid pus.

Antibiotic-containing eye and skin creams/gel may also be used to reduce peri-ocular irritation.

Therapy is likely to be prolonged and recurrences of dacryocystitis are common owing to the nature of the underlying dental disease.