Iris coloboma in the Australian shepherd dog breed

The Australian shepherd is a medium-sized dog from the Kennel Club’s pastoral group, and which is still widely kept as a working dog in Australia but that is also starting to gain traction as a popular pet all across the world, including within the UK.

Australian shepherds are good, versatile all-rounders, which have reasonably high intelligence and high energy levels too, and they love to spend time outside playing and running around. They love the company of people and don’t thrive without someone around and something to do, and the breed is a good fit for active, outdoors-y people who tend to spend most of their time with their dog.

Dogs of the breed also tend to be fairly heavy shedders too, which need a lot of grooming – particularly for dogs with an active, busy lifestyle that are apt to get messy regularly! However, the Australian shepherd is a great and very rewarding dog to own for the right sort of handler, and they are certainly worth considering as a pet if you love smart, active dogs that can learn lots of commands.

If you are considering buying an Australian shepherd, it is important to learn as much as possible about the breed and its core traits – and also, potential problems that can come with dogs of the breed too. Examining the breed’s general health and longevity is an important part of this, and whilst dogs of the breed tend to live between around 13-15 years on average, there is a reasonably long list of hereditary health conditions that can compromise the longevity and quality of life of individual dogs.

One hereditary health condition that the Australian shepherd has elevated risk factors for is called iris coloboma, and this is a disorder of the eyes. In this article we will look at iris coloboma in the Australian shepherd in more detail, to provide a basic grounding for prospective Australian shepherd owners. Read on to lean more.

What is iris coloboma?

Iris coloboma is caused by incomplete development of the iris of the dog’s eye, and exactly how pronounced the condition is can be highly variable. The colobomas themselves are congenital malformations of the eye that take the form of holes or gaps in the iris, which may present as large holes, individual slivers or slices, or little chips or notches on the inside edges of the iris.

Dogs with iris coloboma are born with the condition, and generally, will have only a negligible effect on the dog’s ability to see. However, acute and large colobomas can cause vision problems because they prevent the iris from contracting as it should in bright light, which causes the dog to squint in order to see comfortably. This in turn can decrease the dog’s field of vision, and lead to eye strain and discomfort.

What sort of Australian shepherds might develop iris coloboma?

Iris coloboma is a hereditary health condition caused by a congenital defect, which leads to malformation of the iris itself. The exact mode of inheritance is unknown, but dogs that have a parent or close relative with the condition are more likely to have the condition themselves.

The vast majority of presentations of iris coloboma in the Australian shepherd breed occur in dogs with merle colouration, but it is not unheard of for the condition to develop in dogs of other colours too, and it is not yet known why merles get more than their fair share of cases.

The condition affects both male and female dogs equally frequently, and as mentioned, is present from birth.

What are the symptoms of iris coloboma?

Depending on how pronounced the coloboma is, you may be able to see it with the naked eye as a malformation of the iris that makes the pupil appear to be misshapen or have uneven borders. However, this is not always obvious and mild presentations of the condition are easy to miss.

A dog that squints a lot, particularly in bright light but in conditions that aren’t causing other dogs to squint is another indication.

Because puppies are born with their eyes closed, the visible indicators of iris coloboma won’t be present until the pup opens their eyes for the first time – and you should ask your vet to examine you pup and look at their eyes as an introductory check-up within a few days of first bringing them home.

Can iris coloboma be treated or cured?

Currently, there is no way to reverse or cure iris coloboma in dogs affected by it. The condition is not painful and often, won’t affect the dog’s vision acutely, but it can cause the appearance of their eyes to be rather unusual.

Australian shepherds with iris coloboma, even a mild version of the condition, should not be used for breeding because they can pass the condition onto their own offspring. If you are considering buying an Australian shepherd puppy, talk to the seller about the health of their breed lines and if any relatives of the litter you are viewing have the disorder themselves.