Collie eye anomaly

Currently, the most common disorder known in the breed is a non-progressive genetic mutation called Collie Eye Anomaly or CEA. It can cause a number of vision problems, including loss of depth perception, blurred vision and, in rare cases, total blindness. It is estimated that nearly 90% of dogs genetically affected by the CEA mutation either show no physical signs of the disorder or the psychological symptoms are very mild.

Heart murmur

Heart murmurs have been reported in several dogs in Japan, enough for Japanese breeders to start testing their breeding dogs. To put it simply, we talk about a heart murmur when the blood flow in the heart causes a disturbance. They can be divided into several types, such as stylotic (a murmur when the heart contracts), diastolic (a murmur between heartbeats), and continuous (a murmur during the entire heartbeat cycle). From there, they are graded on a severity scale from one to six, with one being the least severe and six being the most severe.

Hip dysplasia

Based on current American and European results, this breed is also prone to hip dysplasia. It is a complex, multifactorial trait that affects a large percentage of both purebred and mixed breed dogs. Dogs prone to hip dysplasia are born with normal hips, but quickly develop subluxation of the femoral head. Degenerative joint disease typically occurs in the first year of a dog's life. 

Idiopathic / epileptic seizures

It is a genetic disorder in which seizures occur for no identifiable reason. A seizure is a sudden excessive electrical discharge of neurons in the brain. This results in a rapid series of involuntary contractions of an otherwise voluntary muscle. In dogs, symptoms typically appear between the ages of 6 months and 6 years. It is an incurable disorder.