The Parson Russel is a breed of small white dog that is known to have originated from the fox terriers of the 18th century. This dog is formally known as the Jack Russell Terrier in the states.These dogs were used as a small game hunting dog particularly for red fox. The breed has a weatherproof coat that can be broken or smooth and is white, white with black or can have brown markings. It is a clean breed and does not need frequent bathing, but the broken coat needs to be hand stripped. It is a feisty and energetic dog, suited to sports. However, this breed suffers from a range of health issues, mainly relating to eye disorders. Eye conditions which affect the breed include primary lens luxation which causes the zonular fibres to be abnormal and which begins to disintegrate in affected dogs. The fibres help to support the lens of the eye, and their disintegration can cause the lens to fall in a wrong location within the eye. In case the lens fall in the anterior chamber of eyeball, a secondary glaucoma can occur, causing loss of vision. Some of the other eye conditions which appear in the breed include corneal dystrophy, cataracts, posterior vitreous detachment, and progressive retinal atrophy. Some of the other minor health concerns are patella luxation, prone to dislocation of the kneecaps, deafness, Legg Perthes which is a disease of the hip joints in smaller breeds of dogs. The average lifespan of this breed is between 14 to 15 years.