L2-HGA

L-2-HGA (L-2-hydroxyglutaric aciduria) in Staffordshire Bull Terriers is a neurometabolic disorder characterised by elevated levels of L-2-hydroxyglutaric acid in urine, plasma and cerebrospinal fluid. L-2-HGA affects the central nervous system, with clinical signs usually apparent between 6 months and one year (although they can appear later). Symptoms include epileptic seizures, “wobbly” gait, tremors, muscle stiffness as a result of exercise or excitement and altered behaviour. The mutation, or change to the structure of the gene, probably occurred spontaneously in a single dog but once in the population has been inherited from generation to generation like any other gene. The disorder shows an autosomal recessive mode of inheritance: two copies of the defective gene (one inherited from each parent) have to be present for a dog to be affected by the disease. Individuals with one copy of the defective gene and one copy of the normal gene – called carriers – show no symptoms but can pass the defective gene onto their offspring. When two apparently healthy carriers are crossed, 25% (on average) of the offspring will be affected by the disease, 25% will be clear and the remaining 50% will themselves be carriers. The mutation responsible for the disease has recently been identified at the Animal Health Trust. Using the information from this research, we have developed a DNA test for the disease. This test not only diagnoses dogs affected with this disease but can also detect those dogs which are carriers, displaying no symptoms of the disease but able to produce affected pups. Carriers could not be detected by the tests previously available which involved either a blood or urine test detecting elevated levels of L-2-hydroxyglutarate or magnetic resonance imaging. Under most circumstances, there will be a much greater number of carriers than affected animals in a population. It is important to eliminate such carriers from a breeding population since they represent a hidden reservoir of the disease that can produce affected dogs at any time. Breeders will be sent results identifying their dog as belonging to one of three categories: CLEAR: the dog has 2 copies of the normal gene and will neither develop L-2-HGA, nor pass a copy of the L-2-HGA gene to any of its offspring. CARRIER: the dog has one copy of the normal gene and one copy of the mutant gene that causes L-2-HGA. It will not develop L-2-HGA but will pass on the L-2-HGA gene to 50% (on average) of its offspring. AFFECTED: the dog has two copies of the L-2-HGA mutation and is affected with L-2-HGA. It will develop L-2-HGA at some stage during its lifetime, assuming it lives to an appropriate age. Carriers can still be bred to clear dogs. On average, 50% of such a litter will be clear and 50% carriers; there can be no affected produced from such a mating. Pups which will be used for breeding can themselves be DNA tested to determine whether they are clear or carrier. Results of mating with different diagnoses of the disees - Clear x Clear: All puppies clear by birth. – Clear x Carrier: 50% of the puppies are clear, 50% are carriers. – Clear x Affected: All puppies are carriers, but non are affected - Carrier x Carrier: 25% clear, 50% carrier, 25% affected.. – Carrier x Affectet: 50% carrier, 50% affected – Affected x Affected: All puppies will be affected.

PHPV

PHPV – Persistent Hyperplastic Primary Vitreous This is another inherited cataract, although it is a much more complex condition and it is much more difficult to tell how it is inherited in pups. During a puppy’s development, certain blood vessels are needed to help develop the eye. In ‘normal’ pups, these blood vessels disappear after they are no longer needed (usually within a few weeks during development) in puppies with PHPV the vessels don’t disappear and can cause eye problems. PHPV is congenital (this means that it will be present at birth) and can be detected in puppies as young as 6 weeks old. The condition is not progressive – this means that once it’s detected and manifests itself it will not get worse as the puppy grows older. Dogs can be affected very mildly or quite severely, and if it is present in a breeding dog, there is no way to know how badly pups will be affected in a litter. If the Dam or Sire has mild PHPV the pups could potentially have a much worse strain of the illness. This is why it is essential to ensure that all breeding dogs are screened for the illness along with HC and L2–HGA.

HC 

Hereditary Cataracts (also called Juvenile Cataracts) Hereditary Cataract in Staffordshire Bull Terriers has been recognised as an inherited condition since the late 1970’s. Affected dogs develop cataracts in both eyes at an early age. The condition is not congenital, so the lenses are normal at birth but cataracts appear at a few weeks to months in age, progressing to total cataract (and resulting blindness) by 2 to 3 years of age. The mutation, or change to the structure of the gene, probably occurred spontaneously in a single dog but once in the population has been inherited from generation to generation like any other gene. The disorder shows an autosomal recessive mode of inheritance: two copies of the defective gene (one inherited from each parent) have to be present for a dog to be affected by the disease. Individuals with one copy of the defective gene and one copy of the normal gene – called carriers – show no symptoms but can pass the defective gene onto their offspring. When two apparently healthy carriers are crossed, 25% (on average) of the offspring will be affected by the disease, 25% will be clear and the remaining 50% will themselves be carriers The mutation responsible for the disease has recently been identified at the Animal Health Trust. Using the information from this research, we have developed a DNA test for the disease. This test not only diagnoses dogs affected with the disease but can also detect those dogs which are carriers, displaying no symptoms of the disease but able to produce affected pups. Under most circumstances, there will be a much greater number of carriers than affected animals in a population. It is important to eliminate such carriers from a breeding population since they represent a hidden reservoir of the disease that can produce affected dogs at any time. The test is available now and information on submitting samples is given below. Breeders will be sent results identifying their dog as belonging to one of three categories: CLEAR: the dog has 2 copies of the normal gene and will neither develop Hereditary Cataract, nor pass a copy of the Hereditary Cataract gene to any of its offspring. CARRIER: the dog has one copy of the normal gene and one copy of the mutant gene that causes Hereditary Cataract. It will not develop Hereditary Cataract but will pass on the Hereditary Cataract gene to 50% (on average) of its offspring. AFFECTED: the dog has two copies of the Hereditary Cataract mutation and is affected with Hereditary Cataract. It will develop Hereditary Cataract at some stage during its lifetime, assuming it lives to an appropriate age. Results of mating with different diagnoses of the disees - Clear x Clear: All puppies clear by birth. – Clear x Carrier: 50% of the puppies are clear, 50% are carriers. – Clear x Affected: All puppies are carriers, but non are affected - Carrier x Carrier: 25% clear, 50% carrier, 25% affected.. – Carrier x Affectet: 50% carrier, 50% affected – Affected x Affected: All puppies will be affected.

HD

Hipdysplasia Hip dysplasia occurs when there is abnormal development in the hip joint. Cartilage in the joint degenerates and releases a large amount of enzymes into the joint. These enzymes further destroy and prevent the formation of new cartilage. With cartilage that can no longer help cushion and support the joint, movement can become increasingly difficult and painful. Hip dysplasia is mainly found in large dogs, but can affect all dogs no matter the size or breed. It also has been known to lead to a degenerative joint disease known as osteoarthritis which can add more pain and inflammation than is already present.

Grade: Description:

A/B Normal

C Mild HD

D Moderate HD

E Severe HD

ED 

Elbow Elbow dysplasia is a term used to describe a general incongruency of the elbow joint. The elbow itself is a complex joint composed three major bones, the humerus, radius, and ulna, joining together. Elbow dysplasia is seen most often in young, fast growing, large and giant dog breeds. It will normally affect both elbows with one being slightly worse than the other, though unilateral cases are also seen. Elbow dysplasia consists of 4 conditions: joint incongruity, ununited anconeal process, fragmented coronoid process, and osteochondrosis. One or more of these conditions may be present in cases of elbow dysplasia. Joint Incongruity In joint incongruity the elbow joint does not fit together properly. This is normally due to the bones not growing at the same rate causing the conformation of the elbow to be incorrect. This increases the wear and tear of the joint and will most likely lead to general arthritis. Ununited Anconeal Process (UAP) The anconeal process is a hook like projection which connects the humerus and the ulna. In normal development the process is fused with the ulna between 20-24 weeks. In UAP the anconeal process does not fuse with the ulna. It is held mostly in place by ligaments but does not provide the amount of stabilization as it should. This makes the joint very unstable and can cause pain. Fragmented Coronoid Process (FCP) In a fragmented coronoid process, this area of the ulna degrades or breaks off. The coronoid process of the ulna helps hold the humerus in place as well as helping distribute the dog?s weight through the joint. The fragmented process causes pain and can lead to other problems in the joint. Osteochondrosis (OCD) In osteochondrosis the bones and cartilage in the elbow joint do not form correctly. Instead of being a thin layer of cushion, the cartilage is abnormally thick. This creates problems because the synovial fluid, which provides the cartilage with its nutrients, cannot reach the entire cartilage. It results in cartilage being broken down. In many cases parts of the cartilage will separate from the underlying bone. This can either happen as a flap of cartilage or it can come completely loose and be floating in the joint. This causes pain and swelling of the joint.

Grade: Discription:

0/A Normal

1/C Mild ED

2/D Moderate ED or a primary lesion

3/E Severe ED

Demodicosis 

Demodex canis is a mite that is present in small numbers in the skin of most healthy dogs. Nursing puppies acquire the mite from their mothers during the first few days of life, and in most dogs there will never be any associated problems. In some dogs however, the normal balance is disrupted due to an immune defect. The mites multiply by the thousands in the hair follicles causing inflammation, in a condition called demodicosis. Demodicosis may be localized – that is, confined to 1 or more small discrete scaly reddened areas of hair loss, most commonly on the face or front legs. This is usually seen in pups of 3 to 6 months of age, and most cases resolve spontaneously. Alternately, generalized demodicosis may develop, at anywhere from 3 to 12 months of age. It is important to note that demodicosis is not infectious, to other pets or to people. The mite is present in small numbers in the skin of healthy dogs, but the condition of demodicosis only develops in some animals, who are believed to have a defect in their immune system. Demodicosis may be localized – a mild disorder confined to 1 or more small scaly reddened areas of hair loss, most commonly on the face or front legs. This is usually seen in pups of 3 to 6 months of age, and most cases resolve spontaneously. Generalized demodicosis on the other hand can be one of the most severe skin diseases in dogs. It starts out with local lesions that instead of disappearing, get worse and spread, generally on the head, legs and body. Secondary infections of the hair follicles occur, and large scaly crusted patches form which may eventually cover most of the dog. The deep skin infections can be complicated by resistant bacteria. Some dogs only develop demodicosis on the feet (demodectic pododermatitis). These lesions commonly become infected, are painful, and can be quite difficult to treat successfully.