Congenital Hypothyroidism with Goiter (CHG) and Primary Lens Luxation (PLL) .

The two most common breed specific genetic health issues that found and or tested by breeders of Tenterfield Terriers are:

Congenital Hypothyroidism with Goiter, commonly referred to as CHG and Primary Lens Luxation referred to as PLL .

CHG is a autosomal recessive defective gene that only affects young puppies in the the first 2-8 weeks of their life. Affected dogs lack an enzyme that is important in the production of thyroid hormone which is necessary for the normal development and metabolism of dogs.The symptoms consist of feeding difficulties, loss of co-ordination, loss of the ability to regulate their own body temperatures, eyes and ears fail to open and growth is very stunted. Puppies born with CHG very rarely survive long enough to receive their first vaccinations either by demise or euthanasia.

So what does this mean for you as a potential puppy owner? Alaula Tenterfield Terriers would never sell an affected puppy exhibiting any of these symptoms. As all of our puppies are vet checked before sale, this horrible disease would be identified by us (and our vet) as the disease is clinically obvious .

As responsible breeders we are obligated by the ANKC code of Practice to do all we can to identify and eliminate inheritable diseases and we do this by making informed breeding choices through testing our bitches and dogs for these genetic diseases. Research has shown that as an autosomal recessive gene, to end up with an affected pup you need to obtain a double up of the defective gene. That is, both parents must be carriers. Consequently, if only one of a breeding pair is a carrier, they will never produce an affected pup, but will produce puppies that may be carriers. Carrier puppies do not develop the disease themselves and will not exhibit any abnormalities throughout their lives but can pass the gene mutation on to the next generation. Therefore if breeders are mating a carrier to a clear, this will result in approximately 50/50 ratio of carrier & clear puppies.  We therefore ask if you are considering buying a breeding bitch or dog please talk further to us further, about this gene and your options for testing your puppy.

PLL is an inherited eye condition that affects many breeds of dogs. Lens luxation refers to the lens being in an abnormal position inside the eye which is associated with an inherited degeneration of the zonules, or the thin ligaments that suspend the lens in place behind the iris (the coloured part of the eye) and in front of the vitreous (a clear, gel-like substance). In affected dogs the zonular fibres which support the lens breakdown or disintegrate, causing the lens to fall into the wrong position within the eye. If the lens falls into the anterior chamber of the eye, glaucoma and loss of vision can quickly result.

Clinical signs in terriers are usually not seen until the dog is in middle age, and include a sudden onset of pain (squinting, tearing etc), redness, and cloudiness of the cornea. Treatment of PLL is aimed at reducing the fluid pressure within the eye and preserving vision in acute cases, then removing the lens surgically. Blind eyes may be removed to treat pain.

As responsible breeders we are obligated by the ANKC code of Practice to do all we can to identify and eliminate inheritable diseases and we do this by making informed breeding choices through testing our bitches and dogs for these genetic diseases. Genetic testing is available for the screening of breeding animals, so that two carriers (or any affected animals) are not bred. Although the disease is treated as a recessive one, carrier animals will also occasionally develop lens luxation ( between 2%-20% statistics as per Tenterfield Terrier Club of QLD ) which is why all dogs in our breeding program, at present, have been genetically tested and classified as clear.

Alaula Tenterfield Terriers offer both PLL & CHG testing of your puppy through Orivet Genetic Pet Care, as an extra charge. Orivet are a leading genetic testing organisation who offer an extensive range of genetic services to Breeders, Veterinarians and Pet Owners worldwide.

We can also offer puppy owners who are looking at breeding, Orivet’s Full Breed DNA Profiles  which cover breed specific genetic screens for diseases & traits that are relevant to the Tenterfield Terrier as well as your puppy’s colour genetics.

 

 

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