Hereditary Cataracts, Early-Onset Cataracts, Juvenile Cataracts

Affected dogs will first show a cloudy haze in their pupil that becomes progressively more milky blue to crystalline in appearance. Vision will become progressively worse, and dogs may start bumping into furniture, be more hesitant on steps, and run into walls or doorways.

While cataracts are typically a disease of the aged dog and can be associated with other eye diseases (these would be termed secondary cataracts), mutations in the HSF4 gene cause cataracts to form at an accelerated rate in comparatively young dogs (approximately 2-7 years of age).

Veterinarians will examine your dog’s eyes, and may use a light or lens to assist in the diagnosis. Please note that there are other ocular diseases that are commonly mistaken for cataracts so be sure to have your dog evaluated by a veterinarian.

Surgical correction by a veterinary ophthalmologist is currently the only treatment available to restore your dog’s vision. The other alternative is careful monitoring and lifestyle changes to make your dog’s blindness more manageable.

Talk to your vet about your dog’s hereditary cataracts result so you can work together to plan regular eye exams and monitoring.

Schedule veterinary eye exams to track any changes in the lens and discuss whether a referral to a veterinary ophthalmologist may be helpful.

Watch for signs of vision changes, such as cloudy eyes, bumping into objects, or hesitation in dim light, and contact your vet if you notice any of these signs.

This mutation was first identified in the Australian Shepherd.

Penetrance: Breed will determine whether or not the mutation of HSF4 has incomplete or complete penetrance. Australian Shepherds with one or two copies of the mutation may or may not develop cataracts as other genetic and environmental factors play a role in contributing to the disease. Please remember that there are other genetic and environmental causes of cataracts, and your dog may develop cataracts even with two normal copies of the HSF4 gene.

Gene

HSF4

Inheritance type

dominant

Clinical category

Ophthalmologic

Citations

1. Mellersh et al 2006a
2. Mellersh et al 2009

• Australian Shepherd
• Australian Shepherd
• Miniature/MAS-type Australian Shepherd