While generally recognized as a very healthy breed, there are several health issues that one should know about when purchasing a Toy Fox Terrier. Reputable breeders should be open about their breeding stock and share what they know about the breed. While no one can guarantee against unforeseen imperfections, being knowledgeable and asking questions will help you find the healthiest puppy possible.
Medial patella luxation, or kneecap luxation, may be congenital (present at birth) or acquired. Patellar luxation is a dislocation of the kneecap. The congenital form is most common in the toy and miniature breeds and may occur simultaneously with other pelvic limb deformities. While the definitive sequence of events which leads to or allows these deformities has not yet been established, the age at which the syndrome occurs does play an important role in the severity of the degenerative changes in the joint. All dogs should be screened for this prior to being bred.
Demodectic mange is the result of a microscopic mite multiplying out of control. The majority of dogs have demodex mites on their skin in small numbers. The mites are acquired in puppies at birth from contact with their mothers. Most of the time, these mites cause no problems at all. Demodectic mites can be found in small numbers in the hair follicles of all normal dogs. In dogs with nemodicosis (the skin disease caused by the microscopic parasitic mite) these mites multipy and large numbers inhabit the skin and hair follicles causing the dog to have a moth eaten appearance.
Demodectic mange can occur in one of two forms, localized and generalized mange. The localized form most often appears in dogs under 1 year of age and is usually brought on by stress or puberty. The first sign is a thinning of hair around the eyelids, the lips, the corners of the mouth and the front legs. The patches of hair loss can occasionally be confused with ringworm. Mite removal/reduction normally consists of creams, dips, and cleansing shampoos. Most puppies will "self cure" as their immune system matures. Adult onset demodicosis generally occurs in dogs over the age of 5 years and is often associated with internal disease or cancer. Localized demodicosis is the mildest form. Usually only a few areas of hair loss on the head or front legs occur. Most dogs with the localized form recover completely. Plan to visit your vet for the proper course of action.
This condition is generally a disease of small breeds and is often confused with congenital hip dysplasia. Legg-Calve-Perthes disease is due to the aseptic death of the head of the femur. This causes wearing and promotes arthritic changes. Thus, after the condition has progressed for some time it is difficult to diagnose whether the resulting degenerated joint is a manifestation of hip dysplasia or Legg-Calve- Perthes. Both conditions are considered congenital and have no known cure other than surgery to prolong the useful life of your pet. Animals with Legg-Calve-Perthes disease should be eliminated from any breeding program.
von Willebrand's Disease (vWD)
Canine von Willebrand's disease is an autosomal recessive genetic disease in which affected animals suffer a condition which makes them more likely to bleed abnormally. This is similar in symptoms to Hemophilia in humans. This can lead to life threatening consequences in situations such as accidental injuries, spaying, or neutering. Because it is an autosomal recessive disorder, "Carriers" of the disease can show no outward signs of vWD, yet can pass the gene along and perpetuate the disease through breeding. Ultimately, the result is more affected animals.
Congenital Hypothyroidism with Goiter (CHG)
Carrier status does NOT affect a spay/neutered pet. Only when breeding does Congenital hypothyroidism with goiter (CHG) become a potential problem. Carriers of this disease should be identified & bred carefully to Clear tested dogs to eliminate producing Affected (affected=puppies displaying the disfiguring effects of the disease). Breeding Carrier to Carrier dogs together can and does produce Affected offspring in approximately 25% of a litter ... and ... 50% of the litter will be Carriers ... 25% will be clear. Affected puppies of CHG do not move around as much as normal pups, and the head may appear large in comparison to the body. If nursing care is given and they survive as long as 3 weeks, the eyes do not open, the ear canals remain very small, and the hair coat is abnormally bristly. By the second week of age, a swelling on the underside of the neck can be felt and continues to enlarge with time. Delay in lengthening of bones in the legs, spine, and face causes dwarfism. Eventually, even with treatment, the goiter continues to enlarge and constrict the airway. Affected puppies usually die or are euthanized by the age of 3 weeks.