Canine Glaucoma is described as either primary or secondary, depending on whether it comes from a genetically inherited mutation or another cause.

Primary Glaucoma

Primary glaucoma’s have been traced to mutations of the ADAMTS10 and ADAMTS17 genes which can be detected by canine DNA testing companies such as Embark. If breeders were to test all of their breeding pairs, in theory these types of glaucoma could be entirely eliminated. Sadly, because they derive from a gene mutation, they are incurable and can only be treated temporarily either through topical eye drops or more invasive procedures such as laser destruction of the tissues that make the fluid inside of the eye. Within the category of primary (inherited) glaucoma, there is “Primary Open Angle Glaucoma” (POAG) and “Primary Angle Closure Glaucoma” (PACG) which describe the physical changes that prevent fluid from properly draining from the eye. Open-angle glaucoma is more common and develops slowly over time, while closed-angle glaucoma is a more sudden onset and is considered an emergency.

Primary glaucoma is most commonly seen in certain breeds, including the American Cocker Spaniel, Basset Hound, Chow Chow, Shar-Pei, Norwegian Elkhound, and Siberian Husky.

Secondary Glaucoma

Secondary glaucoma in dogs is caused by an underlying condition that leads to increased pressure within the eye. Some common causes of secondary glaucoma in dogs include:

  1. Inflammation: Inflammation in the eye, such as uveitis, can cause fluid to accumulate and increase pressure within the eye.
  2. Trauma: Any injury to the eye, such as a puncture or blunt force trauma, can damage the drainage structures within the eye and lead to glaucoma.
  3. Tumors: Tumors within the eye or surrounding tissues can obstruct the normal drainage of fluid from the eye and lead to increased pressure.
  4. Lens luxation: When the lens of the eye moves out of position, it can block the normal flow of fluid and lead to increased pressure.
  5. Inherited conditions: Certain breeds of dogs, such as Cocker Spaniels and Basset Hounds, are predisposed to developing glaucoma due to inherited structural abnormalities in the eye.
  6. Other conditions: Other underlying conditions such as cataracts, retinal detachment, and intraocular hemorrhage can also cause secondary glaucoma in dogs.

It is important to identify the underlying cause of secondary glaucoma in dogs in order to provide appropriate treatment and prevent further damage to the eye. If you suspect your dog may be suffering from glaucoma or any other eye condition, it is important to seek veterinary care promptly.