related term: spinal dysraphism What is spina bifida? Normally, the spinal cord is surrounded and protected by the vertebrae of the spinal column. In spina bifida, there is defective fusion of the vertebral arches during embryonic development, so that the vertebrae are incomplete. The abnormalities range from only nonfusion of a small part of one or a few vertebrae, to most of the vertebral arch being absent on several adjacent vertebrae with protrusion of the spinal cord and/or its lining (meninges) through the defect. In the first case the dog will have no medical problems, but with more severe defects there will be clinical signs associated with the area of the spinal cord that is affected. Spina bifida may occur anywhere in the spinal column but is seen most often in the lower back region (caudal lumbar spine). Both genetic and environmental factors (toxins, nutritional deficiencies during pregnancy) can produce spina bifida. How is spina bifida inherited? The condition is thought to be inherited, but the mode of inheritance has not been identified. What breeds are affected by spina bifida? English bulldog, other breeds sporadically For many breeds and many disorders, the studies to determine the mode of inheritance or the frequency in the breed have not been carried out, or are inconclusive. We have listed breeds for which there is a consensus among those investigating in this field and among veterinary practitioners, that the condition is significant in this breed. What does spina bifida mean to your dog & you? Most often, spina bifida occurs in the lower back region (caudal lumbar spine). The clinical signs vary with the extent of the defect. With a mild defect, you will likely never know there is an abnormality unless your dog has x-rays that show the area. When the spinal cord itself is affected, you will see signs in the hind end ranging from weakness and incoordination to paralysis and urinary and fecal incontinence. With a severe defect (absence of several adjacent vertebral arches with protrusion of spinal cord), signs are generally evident very early, when pups start to walk. How is spina bifida diagnosed? In severe cases in young pups, your veterinarian may recognize the condition on physical examination. Diagnosis is confirmed by x-ray. With a mild defect, your veterinarian may find this abnormality incidentally when an x-ray is performed. For the veterinarian: Absence of the vertebral arch or failure of fusion of dorsal spinous processes in one or more vertebrae may be evident on plain radiographs, and may be seen as an incidental finding. Neurological signs may or may not be present depending on the extent of the defect. Most commonly, spina bifida occurs in the caudal lumbar spine, with clinical signs consistent with a transverse myelopathy from L4 to S3 spinal cord segments. How is spina bifida treated? There is no effective treatment for dogs with spinal cord malformations. No treatment is necessary for dogs in whom spina bifida is discovered incidentally on radiographs. Reconstructive surgery may be helpful for mildly affected animals. FOR MORE INFORMATION ABOUT THIS DISORDER, PLEASE SEE YOUR VETERINARIAN. Resources LeCouteur, R.A., Child, G. 1995. Diseases of the spinal cord. In S.J. Ettinger and E.C. Feldman (eds.) Textbook of Veterinary Internal Medicine, pp. 629-696. W.B. Saunders Co., Toronto. Copyright © 1998 Canine Inherited Disorders Database. All rights reserved. Revised: October 30, 2001. This database is a joint initiative of the Sir James Dunn Animal Welfare Centre at the Atlantic Veterinary College, University of Prince Edward Island, and the Canadian Veterinary Medical Association. |
What is hemivertebra? This is a condition where there is abnormal bony development of one or more of the vertebrae - the bones that make up the spinal column. The main part of each vertebra should look like a spool when seen from the side. A hemivertebra looks like a wedge or triangle. Hemivertebra can occur in dogs that have other kinds of vertebral malformations as well. Whether the condition causes problems for the dog depends on what part of the spinal column is affected, and whether there is compression of the spinal cord. How is hemivertebra inherited? The condition is autosomal recessive in the German short-haired pointer and German shepherd. The mode of inheritance is unknown in other breeds. What breeds are affected by hemivertebra? Hemivertebra occurs in the German short-haired pointer and the German shepherd. It is seen most commonly in screw-tailed breeds (Boston terrier, bulldog, French bulldog, and pug), where the kinked tail is the result of hemivertebrae in the tail region. For many breeds and many disorders, the studies to determine the mode of inheritance or the frequency in the breed have not been carried out, or are inconclusive. We have listed breeds for which there is a consensus among those investigating in this field and among veterinary practitioners, that the condition is significant in this breed. What does hemivertebra mean to your dog & you? A hemivertebra does not necessarily cause problems for your dog, unless it causes compression of the nerves (the spinal cord) within the spinal column. This may occur in two ways - the abnormally shaped vertebra may put pressure on the spinal cord directly, or it may be an unstable "weak link" in the vertebral column. Spinal cord compression causes back pain, weakness or inability to get up or walk, and usually requires surgery. How is hemivertebra diagnosed? Radiographs (x-rays) are necessary to diagnose hemivertebra. Your veterinarian may discover that your dog has hemivertebra while taking x-rays for another purpose. If your dog shows signs of spinal cord compression (back pain, weakness, or inability to get up or walk), special x-ray techniques (such as a myelogram) will show if the compression is caused by a hemivertebra. How is hemivertebra treated? Unless your dog has spinal cord compression, there is no need to treat hemivertebra. Where there is spinal cord compression, your dog will probably need surgery. FOR MORE INFORMATION ABOUT THIS DISORDER, PLEASE SEE YOUR VETERINARIAN. Resources Bailey CS, Morgan JP. 1992. Congenital spinal malformations. Veterinary Clinics of North America Small Animal Practice. 22(4):985-1015. LeCouteur RA, Child G. 1995. Diseases of the spinal cord. In EJ Ettinger and EC Feldman (eds.) Textbook of Veterinary Internal Medicine, pp. 629-696. WB Saunders Co., Toronto. Copyright © 1998 Canine Inherited Disorders Database. All rights reserved. Revised: April 23, 2002. This database is a joint initiative of the Sir James Dunn Animal Welfare Centre at the Atlantic Veterinary College, University of Prince Edward Island, and the Canadian Veterinary Medical Association. |
What is hip dysplasia? The hip joint is a "ball and socket" joint: the "ball" (the top part of the thigh bone or femur) fits into a "socket" formed by the pelvis. If there is a loose fit between these bones, and the ligaments which help to hold them together are loose, the ball may slide part way out of the socket (subluxate). With time, as this occurs repeatedly, other degenerative changes in the joint occur (also called osteoarthritis) and your dog will become painful, lame and weak in the hind end. This disease is progressive; that is, it gets worse with time. How is hip dysplasia inherited? The mode of inheritance of this disease is polygenic (caused by many different genes). Scientists do not yet know which genes are involved, or how many genes. Factors that can make the disease worse include excess weight, a fast growth rate, and high-calorie or supplemented diets. What breeds are affected by hip dysplasia? Hip dysplasia is the most common inherited orthopedic disease in large and giant breed dogs, and occurs in many medium-sized breeds as well. When obtaining a dog from a large or giant breed, you should ask the breeder about hip certification in their breeding dogs, and for several generations back. For many breeds and many disorders, the studies to determine the mode of inheritance or the frequency in the breed have not been carried out, or are inconclusive. We have only listed breeds for which there is a strong consensus among those investigating in this field and among veterinary practitioners, that the condition is significant in this breed. What does hip dysplasia mean to your dog & you? While there is a severe form of hip dysplasia that affects young dogs (less than one year of age), signs of this disease are most common in older dogs. The loose fit at the hip joint will be present in young dogs, but it may take years for the other changes (such as osteoarthritis) to cause pain. Your dog may be painful after exercise, have difficulty with stairs, or even have difficulty getting up. You may only notice this once in a while, but over time you will find it getting worse. There is no cure, but your dog's pain and lameness may be reduced by making sure that s/he is not overweight, restricting exercise, and using pain-relieving medications and/or alternative therapies such as acupuncture. Large and giant-breed dogs are more likely to get hip dysplasia later in life if they are overfed and gain weight quickly as puppies. If you have such a puppy, you may be able to reduce the chance of future hip dysplasia by careful feeding. Your veterinarian can help you determine the right body weight and diet for your dog. How is hip dysplasia diagnosed? Your veterinarian will probably suspect hip dysplasia if your large or giant breed dog has pain or lameness in the hips. Your vet will take x-rays to evaluate the general fit of the femur and pelvis, and to look for any osteoarthritic changes in the hip joint. Usually sedation or anaesthesia is required to ensure proper positioning of the dog. In order to see how much looseness there is in the hip joint, your veterinarian may take special stress or distraction radiographs. For the veterinarian: There are several established scoring systems to evaluate radiographs for the presence of hip dysplasia. The Orthopedic Foundation for Animals evaluates a standard ventrodorsal view with hips extended and stifles rotated internally. Radiographs are scored based on degenerative joint changes and evidence of subluxation. Dogs must be 2 years of age in order to be certified by the OFA. The PennHip method uses a quantitative measure of joint laxity (based on distraction and compression views) to determine the Distraction Index (DI), as well as the standard hip-extended view, to evaluate a dog for hip dysplasia (see Smith and McKelvie,1995, below). Dogs may be evaluated by this technique as young as 16 weeks of age. How is hip dysplasia treated? The degree to which the hips are dysplastic does not always correlate with the amount of pain. Some dogs with very bad hips radiographically are less painful than others whose x-rays show only minor changes. Although there is no cure for hip dysplasia, there are ways to manage the pain. Your veterinarian will work with you to keep your dog comfortable. Treatments include anti-inflammatory drugs and/ or alternative therapies such as acupuncture. Nutraceuticals such as glucosamine may also be helpful. Controlling exercise and maintaining your dog at an appropriate weight, are important in managing the pain. Your veterinarian may suggest surgery (such as hip replacement) if the pain is severe, and/or can not be controlled by medical treatment as above. FOR MORE INFORMATION ABOUT THIS DISORDER, PLEASE SEE YOUR VETERINARIAN. Resources Leighton EA. 1997. Genetics of canine hip dysplasia. JAVMA 210(10):1474-1479. Martinez SA. 1997. Congenital conditions that lead to osteoarthritis in the dog. Veterinary Clinics of North America Small Animal Practice. 27(4):735-758. Richardson DC. 1995. Developmental orthopedics: Nutritional influences in the dog. In EJ Ettinger and EC Feldman (eds) Textbook of Veterinary Internal Medicine, p. 252-258. WB Saunders Co., Toronto. Smith GK, McKelvie PJ. 1995. Current concepts in the diagnosis of canine hip dysplasia. In JD Bonagura (ed) Kirk's Current Veterinary Therapy XII Small Animal Practice p. 1180-1188. WB Saunders Co., Toronto. Describes PennHip technique. Smith GK. 1998. Advances in diagnosis of canine hip dysplasia. ACVIM-Proceedings of the 16th Annual Veterinary Medical Forum. p. 569-571. Swenson L, Audell L, Hedhammar A. 1997. Prevalence and inheritance of and selection for hip dysplasia in seven breeds of dogs in Sweden and benefit cost analysis of sceening and control program. JAVMA 210(2):207-214. Copyright © 1998 Canine Inherited Disorders Database. All rights reserved. Revised: November 28, 2002. This database is funded jointly by the Sir James Dunn Animal Welfare Centre at the Atlantic Veterinary College, University of Prince Edward Island, and the Canadian Veterinary Medical Association. |
What is patellar luxation? The knee cap (patella) normally fits into a groove in the thigh bone (femur). The patella slides up and down in this groove as the leg bends and straightens. Patellar luxation means that the knee cap has slipped out of the groove. There are several reasons why this happens, including malformation of the groove. Luxation may happen only occasionally, or may happen continuously. The knee cap may pop back into the groove on its own, or your veterinarian may need to push it back into place. Your dog will be lame when the patella is out of place. Over time your dog may develop other degenerative joint changes, such as osteoarthritis. How is patellar luxation inherited? The mode of inheritance is not yet known. Some researchers think that this disease may be polygenic. What breeds are affected by patellar luxation? This disease is inherited in the following breeds: miniature and toy poodle, Yorkshire terrier, pomeranian, Pekingese, chihuahua, Boston terrier, basset hound, shih tzu, silky terrier, and lhasa apso. (Patellar luxation may also occur in any breed as a reult of trauma.) For many breeds and many disorders, the studies to determine the mode of inheritance or the frequency in the breed have not been carried out, or are inconclusive. We have listed breeds for which there is a consensus among those investigating in this field and among veterinary practitioners, that the condition is significant in this breed. What does patellar luxation mean to your dog & you? When present, the condition is usually evident in young dogs by around 6 months of age, but if mild it may go unnoticed until the dog is older. When the knee cap is out of place, your dog will be lame and may refuse to bear weight, or his/her knee may be "locked". The severity of the condition varies widely. In mild cases, the knee cap may only slip out of place occasionally, causing your dog to "hop" for a few steps, and then it may slide back into the groove on its own. In severe cases, the knee cap slips out of place more often, or is never in a normal position. It may not go back into the groove on its own and your veterinarian may need to push it back into place. As a result of patellar luxation, your dog may develop other degenerative joint changes, such as osteoarthritis. If your dog has a mild case of this disease, you may not notice the actual luxation, but your dog may eventually develop pain due to osteoarthritis. How is patellar luxation diagnosed? Your veterinarian will diagnose this disease based on physical examination and palpation. He/she may take radiographs to see if your dog has other problems (such as osteoarthritis) as a result of this disease. How is patellar luxation treated? The treatment and long term outcome (prognosis) depend on the severity of disease (how often the knee cap slips out of place, and how easily it slips back into the normal position), and whether there are other problems such as osteoarthritis. Moderate or severe cases often require surgery to make sure that the knee cap stays in the groove in the femur, and to prevent painful osteoarthritis. Exercise restriction is important for a period after surgery, and the results are usually very good. For the veterinarian: Patellar luxation may be classified in four grades, with grade I being the most mild. Mild patellar luxation may be discovered as an incidental finding. Severe cases in growing dogs may result in limb deformity. Surgery is usually recommended in moderate or severe cases to stabilize the patella and correct the underlying anatomic deformity. Surgical correction may or may not stop the progression of degenerative joint disease, and reluxation is a possible complication of surgery. FOR MORE INFORMATION ABOUT THIS DISORDER, PLEASE SEE YOUR VETERINARIAN. Resources Martinez SA. 1997. Congenital conditions that lead to osteoarthritis in the dog. Veterinary Clinics of North America Small Animal Practice. pp. 261-290. Schrader SC . 1995. Differential diagnosis of nontraumatic causes of lameness in young growing dogs. In JD Bonagura and RW Kirk(eds.) Kirk's Current Veterinary Therapy XII Small Animal Practice p. 1171-1180. WB Saunders Co., Toronto. Copyright © 1998 Canine Inherited Disorders Database. All rights reserved. Revised: April 23, 2002. This database is a joint initiative of the Sir James Dunn Animal Welfare Centre at the Atlantic Veterinary College, University of Prince Edward Island, and the Canadian Veterinary Medical Association. |
related terms: OCD, osteochondrosis of humeral condyle, fragmented medial coronoid process, ununited anconeal process, incongruent elbow What is elbow dysplasia? The term elbow dysplasia refers to several conditions that affect the elbow joint: osteochondrosis of the medial humeral condyle, fragmented medial coronoid process, ununited anconeal process, and incongruent elbow. More than one of these conditions may be present, and this disease often affects both front legs. An affected dog shows forelimb lameness and elbow pain. These conditions may actually be different manifestations of a single disease process, osteochondritis dissecans (OCD) . OCD is abnormal maturation of cartilage (the specialized connective tissue from which bone develops). While this in an inherited defect, environmental factors such as diet, activity, and trauma also have a role in the development and progression of the disease. Osteochondritis dissecans (OCD): A fragment of cartilage peels away from the bone, within the joint. Osteochondrosis of medial humeral condyle: OCD develops on the elbow end of the humerus (the long bone in the front leg above the elbow). Fragmented medial coronoid process and ununited anconeal process: The coronoid and anconeal processes are small bones which fuse with the main part of the ulna as the animal matures. (The ulna and the radius are the two bones which make up the front leg between wrist and elbow). These terms describe the condition where those processes either break off from the ulna, or fail to fuse normally. Incongruent elbow: The bones which form the elbow joint grow at different rates and do not fit together properly. How is elbow dysplasia inherited? This is a polygenic condition (more than one gene is necessary to cause the disease), although it is not currently known how many or which genes are responsible. Environmental factors such as over-feeding, which causes fast weight-gain and growth, can also affect the development of this condition in dogs that are genetically predisposed to it. What breeds are affected by elbow dysplasia? Many large breed dogs are affected, and elbow dysplasia is more common in males than females. Affected breeds include the basset hound, Bernese mountain dog, bloodhound, Bouvier des Flandres, chow-chow, German shepherd, golden retriever, Great Pyrenees, Irish wolfhound, Labrador retriever, mastiff, Newfoundland, rottweiler, St. Bernard, and weimaraner. Other large breed dogs may be affected as well. For many breeds and many disorders, the studies to determine the mode of inheritance or the frequency in the breed have not been carried out, or are inconclusive. We have listed breeds for which there is a consensus among those investigating in this field and among veterinary practitioners, that the condition is significant in this breed. What does elbow dysplasia mean to your dog & you? Lameness usually starts insidiously at 7 to 10 months of age. It is present every day, and may be most obvious when you dog first gets up, or starts to walk or run. The prognosis (the likely outcome) depends on how far the disease has progressed when treatment begins. Good clinical results (ie. your dog will not be painful) are usually seen if treatment starts early, before osteoarthritis (degenerative changes in the joint) has developed. If left untreated, your dog's pain and lameness will gradually get worse. How is elbow dysplasia diagnosed? The initial lameness may be very subtle with this condition, and it may be some time before it can be documented or diagnosed. Your veterinarian will suspect elbow dysplasia if you have a young, fast-growing, large breed dog (especially those breeds listed above), with forelimb lameness and elbow pain. S/he will perform a physical exam and watch your dog walk or run to confirm which limb, and which joint, is painful. X-rays are necessary to diagnose elbow dysplasia. Your veterinarian will probably x-ray both elbows, because this disease is often present in both sides even if your dog is only lame on one side. If possible, s/he may do a CT scan; this technique will show certain bone fragments better than plain x-ray films. How is elbow dysplasia treated? Surgery is usually recommended to remove a bone or cartilage fragment. If unequal bone growth is the problem, surgery may help to relieve the pressure at the joint. Medical management recommendations include monitoring the diet (to avoid excess weight gain and fast growth), and controlling exercise. Medications such as non-steroidal anti-inflammatory drugs may help with pain relief. "Chondroprotective agents" such as glucosamine may also be prescribed. FOR MORE INFORMATION ABOUT THIS DISORDER, PLEASE SEE YOUR VETERINARIAN. Resources Abstracts of the 7th Annual Meeting of the International Elbow Working Group. 1996. Veterinary Comparative Orthopaedics and Traumatology. 9(2):58-71. Bennett D, May C. 1995. Joint diseases of dogs and cats. In EJ Ettinger and EC Feldman(eds). Textbook of Veterinary Internal Medicine, pp. 2032-2077.WB Saunders Co., Toronto. Schrader SC. 1995 Differential diagnosis of nontraumatic causes of lameness in young growing dogs In JD Bonagura (ed.) Kirk's Current Veterinary Therapy XII, pp. 1171-1180. WB Saunders Co., Toronto Copyright © 1998 Canine Inherited Disorders Database. All rights reserved. Revised: April 23, 2002. This database is a joint initiative of the Sir James Dunn Animal Welfare Centre at the Atlantic Veterinary College, University of Prince Edward Island, and the Canadian Veterinary Medical Association. |
