Australian Shepherd Age Calculator

A genetic mutation in the MDR1 (ABCB1) gene that causes the blood-brain barrier to be permeable to certain drugs, leading to potentially fatal neurotoxicity from common medications. Approximately 50% of Australian Shepherds carry at least one copy of this mutation. Affected dogs can have severe or fatal reactions to ivermectin (in some heartworm preventives), loperamide (Imodium), and several chemotherapy and sedation drugs.

Prevention: DNA test your Aussie for the MDR1 mutation — this is non-negotiable for the breed. Inform every veterinarian, groomer, and caretaker of your dog's MDR1 status. Avoid ivermectin-based heartworm preventives (use alternatives like milbemycin at appropriate doses). Keep a card with your dog's MDR1 status in your wallet and on the dog's collar. The Washington State University Veterinary Clinical Pharmacology Lab maintains an updated list of drugs to avoid.

Symptoms: tremors, excessive drooling, blindness, disorientation, seizures, coma, death (in severe cases)

A congenital, inherited eye disorder affecting the development of the choroid (the blood vessel layer beneath the retina). The severity ranges from mild choroidal hypoplasia (which may not affect vision) to retinal detachment and blindness. CEA is present from birth and does not progress in most cases, though severely affected dogs can lose vision. It is caused by a recessive gene and is detectable by DNA testing or ophthalmologic exam at 6-8 weeks.

Prevention: DNA testing for the CEA/CH mutation is available and should be performed on all breeding stock. Responsible breeders avoid mating two carriers. Have puppies examined by a veterinary ophthalmologist at 6-8 weeks of age, as mild cases are easier to detect before the choroid fully pigments and masks the lesion.

Symptoms: no visible symptoms in mild cases, vision impairment in moderate cases, retinal detachment in severe cases, abnormal eye exam findings at puppy check

Abnormal development of the hip joint causing pain, lameness, and progressive arthritis. Australian Shepherds have a moderate to high incidence of hip dysplasia, partly due to their active lifestyle placing demands on the joints from a young age. The condition can range from mild laxity causing occasional discomfort to severe malformation requiring surgical intervention such as total hip replacement.

Prevention: Source puppies from breeders with OFA Good or Excellent hip scores for both parents. Maintain a lean body weight throughout life. Avoid high-impact activities during growth (before 14-16 months). Provide joint supplements proactively and keep exercise consistent rather than sporadic weekend warrior sessions.

Symptoms: bunny-hopping gait when running, reluctance to climb stairs or jump, stiffness after rest, decreased activity level, limping or favouring one leg, narrow stance in hind legs, audible clicking from hip

A neurological disorder causing recurrent seizures without an identifiable structural brain lesion. Australian Shepherds have a higher incidence of idiopathic epilepsy than most breeds, with a suspected genetic component. Seizures typically first appear between 1-5 years of age and may range from brief focal seizures (twitching, staring) to full grand mal seizures with loss of consciousness and convulsions.

Prevention: There is no prevention for idiopathic epilepsy, but responsible breeding with health-tested lines reduces risk. If your Aussie has a seizure, stay calm, clear the area of hazards, time the seizure, and contact your veterinarian. Most epileptic dogs can be well-managed with anticonvulsant medications (phenobarbital, levetiracetam, potassium bromide) and lead full, active lives.

Symptoms: sudden collapse and convulsions, paddling of legs, jaw chomping, drooling or foaming, loss of consciousness, confusion after episodes (post-ictal phase), staring spells or focal twitching

Clouding of the lens of the eye that progressively impairs vision. Australian Shepherds are predisposed to hereditary cataracts that can appear at various ages, including juvenile cataracts that develop in young adults. The condition is bilateral (affects both eyes) and progressive, eventually leading to significant vision loss or blindness if untreated. Surgical removal and lens replacement is highly effective when performed by a veterinary ophthalmologist.

Prevention: Annual ophthalmologic examinations by a board-certified veterinary ophthalmologist can detect cataracts early. Source puppies from breeders who perform annual CERF/OFA eye exams on breeding stock. Early detection allows for surgical intervention before the cataract matures and becomes more difficult to treat.

Symptoms: bluish-white cloudiness in the eye, difficulty catching treats or toys, bumping into objects, reluctance to navigate in dim light, changes in eye appearance