Have you ever suffered from conjunctivitis or ‘sore eyes’? Did you know that your dog or cat can also be similarly afflicted?
Conjunctivitis is an inflammation of the conjunctiva, a thin mucous membrane lining the inner surface of the upper and lower eyelids, and both sides of the third eyelid. Conjunctivitis is one of the most commonly diagnosed ocular disorders in cats and dogs.
Causes and Risk Factors
Cats in multi-cat households, catteries and free-roaming cats are more at risk. Other risk factors include cats with underlying systemic viral infections, such as feline leukemia virus (FeLV), feline immunodeficiency virus (FIV) and feline herpes virus (FHV), and bacterial infections such as chlamydophila felis and mycoplasma. Cats with abnormal eye conformation, eye trauma and upper respiratory infections tend to have concurrent conjunctivitis.
In dogs, breeds that are predisposed to abnormal eyelid conformation, keratoconjunctivitis sicca (dry eye) and pannus (chronic superficial keratitis) are more prone to conjunctivitis. Other risk factors include canine distemper virus and canine adenovirus in non-vaccinated dogs, dogs with skin allergies, ear infections and exposure to environmental irritations.
Conjunctivitis can occur unilaterally (in one eye) or bilaterally (in both eyes) depending on the cause. Usually in cats, unilateral conjunctivitis is related to trauma, topical irritants, intraocular tumours or uveitis, whereas bilateral conjunctivitis is related to systemic disease or infection.
In dogs, unilateral and bilateral conjunctivitis can be related to allergies, infections or underlying ocular or systemic disease.
Common presenting symptoms include painful red eye, excessive blinking, increased discharge from the affected eye, swelling from fluid build-up around the eye and follicle formation due to irritants. Sometimes, there may be excessive rubbing of the affected eye and the third eyelid may be protruded.
A complete ophthalmic examination includes checking for evidence of other ocular diseases. For instance, the disease may not be in the conjunctiva but in other parts of the eye. Once verified, the veterinarian will conduct a complete eye examination. Fluorescein dye application is a common test, which involves spreading a fluorescein stain on the surface of the eye to make scratches, ulcers, and foreign material stand out under light.
Conjunctival swabs can be done for bacterial and fungal culture and sensitivity. Conjunctival scrapings for cytologic evaluation in diagnosis for bacterial or fungal infection, and intra-cytoplasmic inclusions in conjunctival epithelial cells in diagnosis of canine distemper infection may also be considered. It is crucial to examine for foreign materials that may have gotten caught in the lids or eyelashes. A Schirmer tear test and checking of intraocular pressure may be necessary to rule out dry eye and glaucoma as a contributing factor to conjunctivitis.
As there are many possible causes for this disease, the course of treatment will be determined by the cause. In the event of a bacterial infection, topical and oral antibiotics will be prescribed. For allergic, follicular or plasma cellular cause of conjunctivitis, topical corticosteroids or corticosteroid and antibiotic combination may be prescribed, tapered slowly based on response to treatment.
In cases of recurrence, it may be necessary to address contributing factors, such as atoppu and food allergies. An elimination diet may also be recommended if dietary allergies are suspected; regular food will be cut back to the minimum or changed, and then different foods will be gradually added to the regular diet to test whether the source of the reaction is food based.
If a large amount of eye discharge is noted, it is important to gently clean and flush the eyes with saline prior to any topical application. If both eye drops and ointments are prescribed, do apply the drops first. If several eye drops are prescribed, wait several minutes between the applications of each.
An Elizabeth collar to protect the eyes from scratching or rubbing can be helpful for the healing process and must be kept on at all times until complete recovery. If the condition deteriorates or your pet is unresponsive or developing an adverse effect to the treatment, do contact your veterinarian for advice.