This week, Jethro was brought to the clinic under protest. Jethro is a male poodle, quite elderly, but still sprightly despite his age. It was clear that Jethro did not want to be at the veterinary clinic. What was also very obvious was that Jethro knew where he was by sense of smell alone, for Jethro’s eyes were completely opaque. He was blind.
With some coaxing from his owner, we got Jethro up on the examination table where we could have a better look at his eyes. I was informed that Jethro had been suffering from eye problems for some years. Sometimes his condition improved; other times, he regressed. This happened to be one of his bad patches.
Under examination, I could see that the cornea of both Jethro’s eyes had gone completely white and opaque. There were also clear signs of a ‘dirty’ seepage from both eyes. A fluorescent stain test on his eyes turned up negative which meant that the problem had not involved the deeper layers of the cornea and also that there was no sign of any perforations or ulcers. Jethro has chronic superficial keratitis.
Chronic superficial keratitis (CSK) is an inflammation of the cornea – the transparent layer that envelopes the eye. The condition is also known as pannus which comes from the Latin term for cloth and which describes the visual quality of the change to the cornea.
CSK is not one of those clear cut cases but is generally thought to be an immune-mediated disease. This means that an abnormal change in the cornea has occurred at the cellular level. This change triggers the natural defence mechanism of the dog’s immune system. The immune system then attacks the dog’s own cornea just as if it were foreign tissue. The result is an inflamed cornea that progressively becomes more and more cloudy, leading to partial or total blindness.
The disease usually affects both eyes. It generally starts with whitish-pink abrasions developing at the outer or lower parts of the cornea. Left untreated, this whitish inflammation will gradually spread. If the condition is left to progress uncontrolled, the inflammation can become organised with dark pigmentation leading to complete blindness.
CSK generally occurs in middle-aged dogs, but has also been known to occur in dogs as young as three-years of age depending on the breed. In fact, certain breeds have been found to be pre-disposed to contracting this disease. Besides poodles, such as Jethro, the German Shepherd is particularly noted for its predisposition. However, dachshunds, border collies and even cross-breeds can suffer this condition.
Environmental factors, for example smoke, are thought to be one reason why a dog’s cornea might flare up. But it is also thought that ultraviolet light from the sun is a primary factor in causing CSK and in aggravating the existing disease. The basis for this belief came about when vets found that canines such as shepherd dogs that work on mountainous regions, that is in high altitudes with intense sunlight, are more at risk of developing CSK. Malta may not be a mountainous region, but we’re certainly not lacking UV radiation.
As a dog owner, there are several symptoms that should alert you to a possible problem with your dog’s eyes: unusual tearing from one or both eyes, raw red eyes, squinting, and pawing at the eyes. You should also look out for your dog’s avoidance of bright light.
On the eyes themselves, the appearance of your dog’s third eyelid either filming over its eyes, or increasing in thickness or redness, or developing ‘bubbles’ or losing their natural colour should alert you to a possible problem.
Another symptom to watch out for is an accumulation of whitish fatty deposits at the corner of your dog’s eyes. Failing all of the above, any form of cloudiness whatsoever should have you visiting your vet urgently as your dog’s eyesight could be at risk.
Your vet will carry out a routine physical and eye examination of your dog. He or she might opt for a fluorescent eye stain test to determine whether the cloudiness is likely to be CSK or due to unrelated factors. Other tests may be carried out depending on the severity of the case. Your vet will then administer the required treatment.
Research for a cure for CSK is still ongoing, so it is important to be aware that this disease is a lifelong condition requiring ongoing treatment. Medication will not cure the disease, but it may halt its progression and improve the wellbeing of your dog. You should also regularly take your dog to your veterinarian for check-ups and to avoid relapses.
Jethro’s corneas were both fully clouded over. There was also some sign of infection and a course of eye medication was duly prescribed. His history shows that when his eyes are medicated regularly and with consistency, his eyesight slowly improves, so advice was given in this regard. Hopefully, Jethro’s eyesight will soon be much improved and for the long term.
thisweekwiththevet@gmail.com
Dr Martin Debattista is a veterinary surgeon.