A number of tests are available for the Lancashire Heeler. Two or more of these tests purchased as part of this bundle will be discounted.
- Collie Eye Anomaly associated with the NHEJ1 gene
- Primary Lens Luxation associated with the ADAMTS17 gene
- Progressive retinal atrophy associated with the PRCD gene
Collie Eye Anomaly
Collie Eye Anomaly/Choroidal Hypoplasia (CEA/CH) is a developmental defect of the eye. Specifically, the abnormal development of the choroid – an important layer of tissue under the retina of the eye – in which there is a decrease in the development of the blood vessels. Puppies can be diagnosed by an ophthalmologist as early as 6-8 weeks of age. As the puppies get older the tapetum (the reflective layer at the back of the eye) develops and this can hide the signs of CEA. This phenomenon is called “go normal”, but it does not mean that CEA goes away or gets better. Affected dogs can also develop optic disc coloboma and retinal detachment.
Primary Lens Luxation
Primary lens luxation (PLL) is a painful and potentially blinding inherited eye disease that typically affects dogs between 3 and 8 years of age and in many breeds is caused by a single nucleotide substitution in the ADAMTS17 gene. PLL is the term given to the spontaneous displacement or movement of the lens from its normal position within the eye, as a result of rupture of the lens zonules that hold the lens in its normal position. The zonules are a network of tiny fibres that attach the edge of the lens to the ciliary muscle that circles the eye, in the same way that springs attach a trampoline to its frame. Following zonule rupture the lens usually moves to the anterior chamber at the front to the eye where it can cause damage and rapid onset glaucoma by obstructing the drainage of fluid out of the eye resulting in an increase of pressure within the eye. Glaucoma can cause irreversible vision loss if not treated quickly. PLL is invariably bilateral (occurs in both eyes), although a period of several weeks or months might separate luxation of the two lenses. Clinical signs of PLL include sudden onset of eye pain, clouding of the cornea (the front of the eye will look blue), redness of the “white” of the eye and a reluctance to exercise. PLL should be considered an emergency and veterinary assistance sought immediately.
Progressive retinal atrophy (PRCD type)
Progressive retinal atrophy (PRA) is the most common form of inherited disease affecting the retina in dogs. Genetically different forms of PRA, caused by mutations in different genes, affect many breeds of dog with each form usually affecting one or a small number of breeds. PRA is characterised by progressive degeneration of the retina at the back of the eye and leads to vision loss and blindness.
Progressive Rod Cone Degeneration (PRCD) is a form of PRA and was one of the first PRAs for which a genetic variant was identified. PRCD is different than most forms of PRA in that the variant has been found in a large number and diverse range of breeds.