Dogs and cats often have sore eyes caused by dryness.

Soreness can be brought about by a variety of causes, but it is usually mild and easy to cure. Your pet's eyes may feel sore, for instance, when a foreign body gets into their eyes, when they come into contact with irritating substances or when they produce insufficient or poor tears.

Irritation is often linked to problems with dry eyes.


Cats and dogs with dry eyes

Dry eye syndrome, also known as keratoconjunctivitis sicca (KCS), can affect cats and dogs when they do not produce enough tears or their tear balance has been upset.

These animals' tears have three layers:


The outer layer is oily due to its lipid composition and is secreted by the sebaceous glands in the eyelid. Its function is to delay evaporation and keep the surface of the tear stable.


The middle layer is mostly water, produced by the orbit glands and the nictitating membrane. This layer contains elements such as protein, salts, glucose, urea and growth factors, and supplies the cornea with oxygen, nutrients and lubrication.


The inner-most layer contains mucin from the goblet cells in the conjunctiva, whose mission is to adhere the tear to the corneal epithelium.

These three layers are stratified on the corneal surface to take care of lubrication, protection and nutrition. They also contain immunoglobulins and enzymes, such as lysozymes, providing protection against infections.

Keratoconjunctivitis sicca is more commonly found in dogs than cats. The aim of treating it is to combat the cause, replace or restore tears, contain inflammation and fight infection. If the cause of the condition is immunomodulated, as is often the case, it is advisable to use immunosuppressants.

Whatever the cause, it is crucial to keep your dog’s and cat’s eyes clean and free from infection because their eyesight is vital.

It is always a good idea to use a suitable eye cleaner such as Ocucan Toby and apply artificial tears with hyaluronic acid such as Ocucan Rufus. If your pet has dry eyes, good eye care is even more important as they are more likely to suffer from bacterial infections and corneal erosion.



Depleted tear production can be caused by congenital conditions and usually stems from stunted tear gland development, a problem often found in small breeds like Yorkshire Terriers. Infections can also cause tear problems, such as canine distemper, as can pharmaceuticals such as sulphamides and long-term use of atropine. Other causes include neurogenic disorders due to injuries in the facial nerve and immunomodulated problems, which are frequently seen in Maltese dogs, West Highland terriers, shih tzus and lhasa apso breeds.

Clinical symptoms

The most telling sign is mucous or mucopurulent discharge along with diffuse conjunctival reddening, superficial corneal neovascularisation, corneal cell infiltrations and pigmentary keratitis. This can be diagnosed by performing the Schirmer test, especially when the animal has pink eye and rheum, and by measuring tear break-up time.

Early diagnosis and treatment is vital for a good outcome.

Whatever the cause, it is advisable to use moisturizing drops (artificial tears) containing hyaluronic acid such as Ocucan Rufus to help restore the tear film and repair the damage on the surface of the eye.

Sore eyes can also be a sign of more serious pathologies, so it is always recommendable to seek advice from a vet.

Some of the visible signs and symptoms to look out for and see whether your pet is suffering eye soreness or discomfort include: redness, itchiness (causing the animal to scratch its eyes with its paws, which can make it worse), excess rheum, teary eyes, reluctance to being exposed to light, pigmentation and neovascularisation of the cornea, etc.


Why do pets cry?

Teary eyes can be a sign that the animal's tears are not working properly.

The tear film is a coating that is mainly intended to keep eyes suitably hydrated to ensure good eyesight. It also has the task of protecting eyes from external threats. Tears are constantly being renewed which helps to protect eyes from pollen, dust and any other harmful substances.

Excess tear production can occur when your pet's eye calls for that protective function to remove a foreign body or to counteract the presence of another substance that is irritating the animal's eye. This defence mechanism that comes into play when an aggression occurs is often not enough because a dog's tear production capacity is limited. That is why we recommend artificially providing a saline solution with a similar pH, tonicity and composition to the tear film, which involves using an eye cleaner such as Ocucan Toby or artificial tears like Ocucan Rufus, which have been formulated specially for this purpose.

Both products are bottled in aseptic conditions and contain hyaluronic acid. They are free from irritating substances and designed to keep your pet's eyes healthy and provide instant relief.