What is Horner's Syndrome in Dogs?

While there are still some aspects of the condition which remain a mystery, we do know that Horner's Syndrome in dogs is a neurological disorder which manifests itself ophthalmologically. Its origin can be a trauma applied to the head, a bite from another dog or animal, otitis, neoplasia or others. In terms of neoplasia (i.e. abnormal growths), the prognosis is generally not good. There are so many possible causes of Horner's syndrome in dogs that it is often the case that it will remain idiopathic, meaning that the result is never known.

We can generally define Horner's Syndrome as a problem which prevents the correct contraction of facial muscles due to a communication failure in the nervous system. It can be unilateral or bilateral depending on whether it affects one or both eyes. It is possible for any dog to suffer from Horner's syndrome, but it should be noted that some dogs such as the Golden Retriever are more predisposed to it than other breeds.

As we have said, the symptoms of Horner's syndrome in dogs can manifest itself in either one or both eyes. They include:

• Drooping of the upper eyelid (palpebral ptosis).
• Permanently contracted pupil (miosis).
• The third eyelid, also known as the nictitating membrane, prolapses. This means it becomes visible when the eye is open which is abnormal.
• The eye seems smaller or sunken (enophthalmia).
• The eye may appear red as you would get with conjunctivitis.

All of the above symptoms should be fairly noticeable to pet owners, but they do overlap with other conditions. Uveitis is one such pathology with which it is commonly confused. As soon as one of them manifests, we advise a trip to the veterinarian. While it could be something which is relatively treatable or benign, there is also the chance of something which can seriously affect their well-being. If this is the case, the earlier the diagnosis, the better chance of a positive prognosis.

To reach a suitable diagnosis a complete neurological and ophthalmological assessment is required. This may require x-rays, ultrasounds and maybe even a CT or MRI scan if deemed necessary. This may cos money or require your pet insurance to kick in. However, it will depend on your country and/or region.

To know how to treat Horner's syndrome in dogs, the cause must first be determined. For example, if the cause of Horner's syndrome is otitis, then treatment if this inner ear infection is required. As we have, seen, however, this is not always possible. Not knowing the cause isn't always the worst case scenario, however. In some instances the condition can spontaneously correct itself without much intervention, although rest and appropriate care does play a major factor. On the contrary, some cases are irreversible. Again, this is why going to see a specialist is so imperative for an appropriate diagnosis and treatment plan.

Depending on the cause, you will not always be able to prevent Horner's syndrome in dogs. However, there are certain precautions which can be made to reduce the chances of it occurring. These include:

• Maintaining good hygiene of the ears. The ear canal in most breeds should look pink and not emit any odor.
• If there is an ear infection, we might see discharge, foul smells, inflammation, redness, heat or a discomfort which often makes the dog try to scratch their head against different objects. Take them to the vet as soon as these symptoms are spotted, otherwise it can become aggravated and affect the ear more profoundly.
• Take care when cleaning the ears. Doing it too harshly or incorrectly can indirectly lead to Horner's syndrome.
• Pay attention to a dog's relationship with other dogs. We must be careful when allowing our dog to approach another. We need to be careful when our dog interacts with other dogs as we cannot always know when an infection may be spread. We don't mean be worried when other dogs are around, but be careful if you see another dog with obvious signs of infection.
• Maintain a safe environment with our dogs and reduce the possibility of receiving trauma.
• Always walk a dog on a leash unless in specialized areas. This will help prevent a dog from escaping and indirectly developing Horner's syndrome.

Since ear-care is fundamental to prevent Horner's syndrome as much as possible, we recommend this article on how to clean a dog's ear step-by-step.

This article is purely informative. AnimalWised does not have the authority to prescribe any veterinary treatment or create a diagnosis. We invite you to take your pet to the veterinarian if they are suffering from any condition or pain.

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