Boxer Breed Council - Hip Dysplasia

Hip Dysplasia

By Walker Miller BVMS DBR MRCVS (Walkon Boxers)
Published in Boxer Quarterly July 2001

To Download a Copy of Hip Dysplasia in Dogs A Guide for Dog Owners by John Foster Click Here

This is a disease that affects the hip joints of larger dogs. Certain breeds seem to be more susceptible than others and those that come to mind are, GSD, Labradors, Rottweillers and Golden Retrievers. In my opinion it is not a major problem in the British Boxer but it is always talked about.

Let’s begin by eliminating some of the myths that have existed over the last 50 years. Unilateral or one-sided HD does not exist as a disease therefore can only be due to an injury. For many years it was believed that HD was a totally hereditary problem, well this is not true, I am sure there is genetic impact from both parents but there is also a huge environmental influence as well. Therefore whether or not HD is genetic or not, it does have systematic or environmental implications as well which means it can be prevented and controlled.

HD is characterised by abnormal development (dysplasia) of the hip joint, which consists of the round ball of the femoral head, which fits into the socket of the pelvis called the acetabulum. The rounder the femoral head can be and the deeper the acetabulum are the two major advantages to a good hip joint, which will last the wear and tear of the dog’s life.

Other factors come into this such as the angle that the two components meet and also the type of edge (in length and depth) the curve of the acetabulum has. The disease is caused by a mismatch of growth of the hip joint and the soft tissue, i.e. non-bony structure, round about the joint, which holds the joint together as one unit. There is a joint capsule that is an envelope of connective tissue (strong collagen or stringy fibres) round the acetabulum and femoral head. The strength and tightness of this also has a strong bearing on the function of the joint. If the dog is unfortunate enough to dislocate its hip this round ligament must break and the joint capsule will stretch and then the function of the joint is impared for the rest of the dogs life and arthritis is much more likely to set in, in older age. The mechanical strength of the joint capsule is related to the collagen content and the composition of it. In children with congenital hip joint dislocation the collagen composition of the joint capsule has been shown to be abnormal and I’m sure this is one of the causes of HD in dogs. There are different type of collagen and dogs which have a high collagen type III : I ratio in the joint capsule have weak capsules. A study was done, albeit a small study, and the collagen type was examined between two groups of dogs. One of the groups were breeds with a high prevalence of HD on x-ray and the other group were greyhounds, it was found that was found that the greyhounds had a much lower content of type III : I than the other group. One theory is therefore that a major factor in HD is poor quality, low strength collagen in the joint capsule and ligaments. This is thought to be caused by too little ascorbic acid or vitamin C.

In eight litters of dysplastic German Shepherd parents or parents that had produced dysplastic offspring, there were no signs of HD when the bitches were given mega doses of ascorbate during pregnancy and the pups were kept on a similar regime until they reached a year old. I must establish the actual dose for the boxer.

We have now established that HD is a genetically mediated disease which is also majorly influenced by environmental factors such as the size and breed of the dog, rate of growth, type of feeding used, type and duration of exercise and also other existing skeletal disorders, e.g. back deformities, pelvic disorders, injury and bone or joint abnormalities of the fore limbs.

The disease is diagnosed by signs of lameness, pain, abnormal gait, inability to climb stairs easily, falling over when turning quickly and also of course, by x-ray of the hips. The hips are best x-rayed with the dog sedated and lying on its back with both hind legs extended straight out behind and rotated slightly inward. This is the position used by the kennel club for interpretation of the kennel club hip dysplasia scheme. One thing that has been established is that there is no correlation between radiographic appearance of the hip joints and degree of lameness or disability.

HD is usually a gradual, progressive disease in young dogs with a reduced range of joint movement. The muscles of the forequarters are usually well muscled due to the shifting the majority of the weight forward. A bunny hopping gait is quite characteristic of the disease as it is a bilateral condition. Acute signs are seen in affected animals less than one year old and more chronic signs are seen in older animals.

The pain in the hip is caused by inflammation of the joint by erosion of the cartilage of both the femoral head and acetabulum. There is an increase of fluid within the joint and thickening of its joint capsule and this encourages joint stability. There are a number of preparations available on the market and these do help the healing of the joint in the young animal and in some cases I have seen, these have certainly helped greatly. One product I have used is Synoquin and have had very good results along with strict rest and very little exercise. The muscle development over the quarters and rear end is very slow due to most of the weight on the front end and this causes poorer soft tissue support of the joint and makes the condition worse. The femoral head and the neck of the bone are remodelled due to the abnormal stress on the joint and one gets a very flattened femoral head and a thick neck to the femur with extra bone being laid down there. As said before if there is gross remodelling of the hip joint there is no certainty that the dog will show any signs of lameness in its lifetime.

Treatment is usually conservative to begin with and this means strict cage rest and very little exercise, certainly only in the back garden. This prevents too much remodelling of the hip joint as it develops and allows a better hip joint to form. High doses of vitamin C as mentioned could help and also some Synoquin to allow proper development of the joint fluid and bone. Be very careful with feeding, feed a well balanced food and do not allow the dog to become fat, as this will add extra stress to the joints. Non-steroidal, anti – inflammatory drugs can be used to ease the pain such as Metacam or Rimadyl. I find the latter to be more useful for this condition in young dogs, but in older dogs I use the former. It may be that Rimadyl is used twice daily so the owner of a young dog thinks it will help to medicate twice daily and it is the owners reasoning only. In older dogs over eighteen months old if the animal is very lame and pained then surgery can be preferred. A complete hip joint replacement can be done but this is a specialist job and is therefore expensive. Careful immediate after care is essential following surgery. One hip only is operated on at any one time the other can be operated on six to twelve months later if required.

Prevention can of course be carried out and therefore x-raying of both parents is a good start and only breed from low scored parents, certainly those with hip scores less than twenty in the kennel club hip dysplasia scheme. Extra vitamin C to pregnant bitches and young pups is certainly worth a try. Reduced exercise, certainly in early life is a good idea to allow correct joint development of all the joints and prevent abnormal remodelling of the more stressful joint such as the hip joint. Starting training and full exercise at twelve months of age and not six months will help. With conservative treatment about 75% of lame dogs become sound to satisfactory by twelve to fifteen months of age. If corrective surgery is required a significant improvement will be seen in 70% of dogs.

I hope this helps you understand this complicated disease, which I am sure is not fully researched. My opinion is that it is still not a major problem in our breed but lets be cautious. The boxer is a very muscular breed and this will hide a lot of problems for a while. Try vitamin C in pregnant bitches and let’s see what this does to hind movement.





Hip Dysplasia By Walker Miller BVMS DBR MRCVS (Walkon Boxers) Published in Boxer Quarterly July 2001 To Download a Copy of Hip Dysplasia in Dogs A Guide for Dog Owners by John Foster Click Here This is a disease that affects the hip joints of larger dogs. Certain breeds seem to be more susceptible than others and those that come to mind are, GSD, Labradors, Rottweillers and Golden Retrievers. In my opinion it is not a major problem in the British Boxer but it is always talked about. Let’s begin by eliminating some of the myths that have existed over the last 50 years. Unilateral or one-sided HD does not exist as a disease therefore can only be due to an injury. For many years it was believed that HD was a totally hereditary problem, well this is not true, I am sure there is genetic impact from both parents but there is also a huge environmental influence as well. Therefore whether or not HD is genetic or not, it does have systematic or environmental implications as well which means it can be prevented and controlled. HD is characterised by abnormal development (dysplasia) of the hip joint, which consists of the round ball of the femoral head, which fits into the socket of the pelvis called the acetabulum. The rounder the femoral head can be and the deeper the acetabulum are the two major advantages to a good hip joint, which will last the wear and tear of the dog’s life. Other factors come into this such as the angle that the two components meet and also the type of edge (in length and depth) the curve of the acetabulum has. The disease is caused by a mismatch of growth of the hip joint and the soft tissue, i.e. non-bony structure, round about the joint, which holds the joint together as one unit. There is a joint capsule that is an envelope of connective tissue (strong collagen or stringy fibres) round the acetabulum and femoral head. The strength and tightness of this also has a strong bearing on the function of the joint. If the dog is unfortunate enough to dislocate its hip this round ligament must break and the joint capsule will stretch and then the function of the joint is impared for the rest of the dogs life and arthritis is much more likely to set in, in older age. The mechanical strength of the joint capsule is related to the collagen content and the composition of it. In children with congenital hip joint dislocation the collagen composition of the joint capsule has been shown to be abnormal and I’m sure this is one of the causes of HD in dogs. There are different type of collagen and dogs which have a high collagen type III : I ratio in the joint capsule have weak capsules. A study was done, albeit a small study, and the collagen type was examined between two groups of dogs. One of the groups were breeds with a high prevalence of HD on x-ray and the other group were greyhounds, it was found that was found that the greyhounds had a much lower content of type III : I than the other group. One theory is therefore that a major factor in HD is poor quality, low strength collagen in the joint capsule and ligaments. This is thought to be caused by too little ascorbic acid or vitamin C. In eight litters of dysplastic German Shepherd parents or parents that had produced dysplastic offspring, there were no signs of HD when the bitches were given mega doses of ascorbate during pregnancy and the pups were kept on a similar regime until they reached a year old. I must establish the actual dose for the boxer. We have now established that HD is a genetically mediated disease which is also majorly influenced by environmental factors such as the size and breed of the dog, rate of growth, type of feeding used, type and duration of exercise and also other existing skeletal disorders, e.g. back deformities, pelvic disorders, injury and bone or joint abnormalities of the fore limbs. The disease is diagnosed by signs of lameness, pain, abnormal gait, inability to climb stairs easily, falling over when turning quickly and also of course, by x-ray of the hips. The hips are best x-rayed with the dog sedated and lying on its back with both hind legs extended straight out behind and rotated slightly inward. This is the position used by the kennel club for interpretation of the kennel club hip dysplasia scheme. One thing that has been established is that there is no correlation between radiographic appearance of the hip joints and degree of lameness or disability. HD is usually a gradual, progressive disease in young dogs with a reduced range of joint movement. The muscles of the forequarters are usually well muscled due to the shifting the majority of the weight forward. A bunny hopping gait is quite characteristic of the disease as it is a bilateral condition. Acute signs are seen in affected animals less than one year old and more chronic signs are seen in older animals. The pain in the hip is caused by inflammation of the joint by erosion of the cartilage of both the femoral head and acetabulum. There is an increase of fluid within the joint and thickening of its joint capsule and this encourages joint stability. There are a number of preparations available on the market and these do help the healing of the joint in the young animal and in some cases I have seen, these have certainly helped greatly. One product I have used is Synoquin and have had very good results along with strict rest and very little exercise. The muscle development over the quarters and rear end is very slow due to most of the weight on the front end and this causes poorer soft tissue support of the joint and makes the condition worse. The femoral head and the neck of the bone are remodelled due to the abnormal stress on the joint and one gets a very flattened femoral head and a thick neck to the femur with extra bone being laid down there. As said before if there is gross remodelling of the hip joint there is no certainty that the dog will show any signs of lameness in its lifetime. Treatment is usually conservative to begin with and this means strict cage rest and very little exercise, certainly only in the back garden. This prevents too much remodelling of the hip joint as it develops and allows a better hip joint to form. High doses of vitamin C as mentioned could help and also some Synoquin to allow proper development of the joint fluid and bone. Be very careful with feeding, feed a well balanced food and do not allow the dog to become fat, as this will add extra stress to the joints. Non-steroidal, anti – inflammatory drugs can be used to ease the pain such as Metacam or Rimadyl. I find the latter to be more useful for this condition in young dogs, but in older dogs I use the former. It may be that Rimadyl is used twice daily so the owner of a young dog thinks it will help to medicate twice daily and it is the owners reasoning only. In older dogs over eighteen months old if the animal is very lame and pained then surgery can be preferred. A complete hip joint replacement can be done but this is a specialist job and is therefore expensive. Careful immediate after care is essential following surgery. One hip only is operated on at any one time the other can be operated on six to twelve months later if required. Prevention can of course be carried out and therefore x-raying of both parents is a good start and only breed from low scored parents, certainly those with hip scores less than twenty in the kennel club hip dysplasia scheme. Extra vitamin C to pregnant bitches and young pups is certainly worth a try. Reduced exercise, certainly in early life is a good idea to allow correct joint development of all the joints and prevent abnormal remodelling of the more stressful joint such as the hip joint. Starting training and full exercise at twelve months of age and not six months will help. With conservative treatment about 75% of lame dogs become sound to satisfactory by twelve to fifteen months of age. If corrective surgery is required a significant improvement will be seen in 70% of dogs. I hope this helps you understand this complicated disease, which I am sure is not fully researched. My opinion is that it is still not a major problem in our breed but lets be cautious. The boxer is a very muscular breed and this will hide a lot of problems for a while. Try vitamin C in pregnant bitches and let’s see what this does to hind movement.