Ichthyosis (Jack Russell Terrier Type) is an inherited condition of the skin affecting dogs. This condition is characterized by parchment like scaling of the skin generalized over the whole body, but easily visible in the non or lightly haired regions of the abdomen. Present from birth, scaling skin can persist into adulthood and may result in secondary infections including ear infections. The pads of the feet may show signs of skin overgrowth and nails may be soft. Ichthyosis (Jack Russell Terrier Type) does not typically cause hair loss. Treatment focuses on reducing complications and improving the health of the skin through oral and topical medications.
Genetic testing of the TGM1 gene will reliably determine whether a dog is a genetic Carrier of Ichthyosis (Jack Russell Terrier Type). Ichthyosis (Jack Russell Terrier Type) is inherited in an Autosomal Recessive manner in dogs meaning that they must receive two copies of the mutated gene (one from each parent) to develop the disease. In general, carrier dogs do not have features of the disease but when bred with another carrier of the same Mutation, there is a risk of having affected pups. Each pup that is born to this pairing has a 25% chance of inheriting the disease and a 50% chance of inheriting one copy and being a carrier of the TGM1 gene mutation. Reliable genetic testing is important for determining breeding practices. In order to eliminate this mutation from breeding lines and to avoid the potential of producing affected pups, breeding of known carriers to each other is not recommended. Dogs that are not carriers of the mutation have no increased risk of having affected pups.
There may be other causes of this condition in dogs and a normal result does not exclude a different mutation in this gene or any other gene that may result in a similar genetic disease or trait.
Credille KM, Minor JS, Barnhart KF, Lee E, Cox ML, Tucker KA, Diegel KL, Venta PJ, Hohl D, Huber M, Dunstan RW. Transglutaminase 1-deficient recessive lamellar ichthyosis associated with a LINE-1 insertion in Jack Russell terrier dogs. Br J Dermatol. 2009 Aug;161(2):265-72. Epub 2009 Apr 24.
Lewis, Ford, Kwochka. Characterization and management of a Jack Russell terrier with congenital ichthyosis. Vet Dermatol. 1998 Jun;9(2):111-118.