If your Vet has just diagnosed uveitis in your canine friend, you may be wondering what this condition is and how it manifests? Well you are not alone, uveitis is a common eye condition affecting both cats and dogs. This article aims to cover what uveitis it, how to recognise it, the most common causes and management options.
Table of contents
What‘s uveitis?
Inflammation inside the eye is called uveitis. ‘Itis’ means inflammation and therefore uveitis is inflammation of the ‘uvea’. That might not help, until we explain that the uvea is a structure within the eye which comprises the ciliary body, iris and choroid. Together, these have multiple roles including adjusting to different levels of light or distances to enhance vision.
Uveitis can be further categorised into anterior or posterior uveitis and this reflects the location of the inflammation. If the ciliary body and iris – near the front of the eye – are affected, this leads to anterior uveitis. In contrast, if the choroid – further back – is affected, this leads to posterior uveitis. Panuveitis is the term used to describe inflammation both in the anterior and posterior chambers at the same time.
What are the clinical signs?
Uveitis is a painful condition and the clinical signs you may see in your dog are generally related to ocular pain. The degree of ocular pain your dog experiences is dependent on the severity of the uveitis.
Clinical signs may include blepharospasm (squinting), rubbing, redness or cloudiness of the eye and ocular discharge. A dog with uveitis (especially in severe cases) may have an extremely ‘blood shot’ appearance to their eye and they may experience photophobia (avoiding bright lights). Additionally, in some cases owners may recognise that their dog’s vision is reduced. These clinical signs are also quite generic and can also be associated with many other eye conditions such as corneal ulceration and glaucoma. Therefore, it is always important to seek Veterinary advice if you notice any of these signs in your dog.
What causes canine uveitis?
There are many causes of canine uveitis and these range from primary or secondary causes. The following list will state some of these differentials (this list is not exhaustive):
- Glaucoma – in glaucoma patients, they experience a dangerously high intraocular pressure (inside the eye) which is extremely painful. If left untreated it can lead to complete blindness.
- Conjunctivitis
- Dry eye (keratoconjunctivitis sicca)
- Lens luxation (displacement)
- Trauma
- Corneal ulceration – a reflex uveitis is a common secondary condition to corneal ulceration.
- Diabetic cataracts
- Immune-mediated
- Infectious
- Neoplasia – neoplastic causes of uveitis include primary intraocular tumours such as uveal melanoma. Non-primary tumours including metastatic tumours can also cause uveitis. Neoplasia is usually more common in older patients.
- Idiopathic
So, what will my Vet do?
Uveitis can be a frustratingly difficult eye condition to diagnose and treat and your Vet may carry out a diagnosis of exclusion.
Your Vet will take a thorough history and will perform a full general examination including an ophthalmic examination. Your Vet may also carry out further diagnosis during the consultation including taking intra-ocular pressure measurements to check for underlying glaucoma development.
The initial aim in any uveitis case is to reduce inflammation and to provide analgesia (pain relief), therefore symptomatic treatment is usually given straight away. This is achieved by starting them on oral pain relief such as a non-steroidal anti-inflammatory medication as well as topical anti-inflammatory eye drops. Your Vet will likely gently place a drop of orange/green fluorescein dye into your dog’s eye first to check for any damage or signs of ulceration to the cornea (the most outer surface of the eye).
When the ciliary body and other parts of the uvea are inflamed, it causes the ciliary muscle to spasm. This creates a very constricted pupil which leads to ocular pain and discomfort. Once it has been stabilised that the pressure within the eye is within normal limits, your Vet may apply drops of atropine directly to your dog’s eye to dilate the pupil and to further reduce their ocular discomfort.
Whilst the above information provides some management for uveitis patients, one of the most important factors is investigating and managing the underlying cause. This investigation process may include blood work and an ophthalmology referral to determine the cause, prognosis and management options. Depending on the underlying causes, recurrence may also be likely. Severe cases of uveitis can result in irreversible blindness!
Conclusion
To conclude, uveitis is a painful ocular eye condition that should be identified and dealt with quickly. The treatment options are greatly dependent on the underlying cause.
Further reading:
- Understanding uveitis in the canine and feline eye – VetCPD
- Managing uveitis in dogs and cats – Today’s Veterinary Practice
- Is It Possible for Dogs to be Short-Sighted?
Discussion