by Emma Vickers
One of the things we most love about our chihuahuas are surely their expressive eyes, yet precisely because of their large, prominent nature, owners should be on the lookout for corneal ulcers, a very painful condition that can occur through injury and other causes.
What is the cornea?
The cornea is the external layer of the eye; it has many functions, including keeping bacteria and harmful objects away from the inner layers of the eye such as the iris and pupil. The cornea comprises four layers: the epithelium (the outermost layer), the basement membrane, the stroma (the thickest of the layers) and the Descemet’s membrane (the inner most layer)
What is a corneal ulcer?
A corneal ulcer is a wound or trauma caused to the eye by being scratched, punctured, etc. The injury can be caused by anything from twigs and dried grass to ingrown eyelashes, chemicals, debris, heat, smoke, infection or lessened tear production. Corneal ulcers can be very easy for dogs with prominent eyes to develop. The breeds which are most at risk are the brachycephalic breeds (which have flat noses and prominent eyes). These include Boston Terriers, Pugs, Boxers, Pekingese, Bulldogs and Shih Tzus. Even dogs with longer noses, however, can suffer from this injury if their eyes are prominent.
What are the symptoms of a corneal ulcer?
Corneal ulcers are a very painful conditions so that if your Chihuahua develops an ulcer, you will notice it immediately through his behavior. Your dog will probably begin scratching at his eye with his paw, shaking his head in an odd manner, or squinting. The eye can also begin to tear more than usual or display unusual redness; it can also release a discharge or display cloudiness. If your Chihuahua displays these symptoms, do not wait to take them to the vet; corneal ulcers can cause blindness and the more your dog scratches at his eye, the worse the ulcer can become. This condition should be considered an emergency and dealt with promptly.
The nature of the treatment chosen by your vet will depend on how deep/large the corneal ulcer is. The vet will probably begin by applying a fluorescent stain, which will enable them to identify the number and size of the ulcers (there can often be more than one). Your vet may also perform a test for tear production and/or test any discharge to check for any possible bacterial or viral causes. In the case of superficial ulcers, the usual treatment involves antibiotic drops or ointments and optical pain medication. Your vet may advise you to use the latter sparingly, since some numbing medications can interfere with the healing rate of the eye. In addition to applying an ointment, you will probably be told to place an Elizabethan collar on your Chihuahua, to stop him from scratching his eye and worsening its condition. Many people give up on the Elizabethan collar too early, since it can be uncomfortable for a dog to wear for so many days straight (your vet may advise you to keep it on your dog for a week or more). Yet just one scratch can set back the healing process and even create a deeper or larger ulcer so it is vital to follow your vet’s advice to the letter. If you worry about excessive itchiness or hardness of the collar, shop online for soft, padded collars, which are available in a number of sizes and which will enable your Chihuahua to feel much more comfortable than in a standard collar. It is also important that you administer the medication in the way prescribe by your vet, without missing doses. If the corneal ulcer fails to heal, your vet will refer you to a veterinary ophthalmologist, who may decide to apply a lens (to speed up healing) or who may decide that surgery is needed. Because of the possible expense involved, it is also advisable to guard yourself with a sound pet policy that covers eye conditions and specialist and emergency care. Procedures which may be required include conjunctival flaps or grafts, sutures or a corneal transplant, all of which may incur a significant expense but are well worth it, since it involves saving your dog’s vision.
Prevention of Corneal Ulcers
Try to avoid allowing your Chihuahua to play in or roll around in areas with dried twigs, which can be sharp and cause perforations. Check your pet’s eyes every day to make sure they are not tearing excessively or that no colored discharge or redness is present. Finally, if you have the slightest suspicion that your Chihuahua may have a corneal ulcer, seek prompt attention to avoid infection and/or further injury.