11/01/2015
In my efforts of continuing education I am currently enrolled in the Institute of Canine Biology course Understanding Hip and Elbow Dysplasia. It is an all encompassing curriculum that includes genetics, environment and practical methods at improving odds of hip and elbow displasia. My future litters will benefit from this course. I am willing to invest both my time and money to learn from experts and not just hearsay from other breeders or misinformed philosophies.
Here is the link to the course overview if anyone is interested:
http://www.instituteofcaninebiology.org/understanding-hip--elbow-dysplasia.html
Hip Dysplasia
by Donna Patterson
Disclaimer: I am neither a vet nor a geneticist, and I am presenting information that I have read, heard, or studied. While I will quote references I don’t pretend to have all of the answers and am only intending to shed some light on different things that I have learned.
Hip Dysplasia is a developmental orthopedic disease. All puppies are born with normal hips. Yes, you read that correctly, ALL PUPPIES ARE BORN WITH NORMAL HIPS. The dysplastic dog over time will exhibit abnormal development of the ball-in-socket joint that makes up the hip. It’s the snowball kind of affect that once the socket does not fit together tightly, wear on the surface begins, causing friction, straining the joint capsule, damaging the cartilage, causing inflammation and the pain associated with arthritis.
Hip dysplasia is not arthritis though. It may eventually cause arthritis, but it is not arthritis. It is thought to be a polygenetic inheritable trait. Meaning it is caused by not just one gene, but by multiple genes, which must combine for a dog to become dysplastic. Because polygenic inheritance is so complex, in addition to involving multiple genes, polygenic inheritance also looks at the role of environment in its development.
In the beginning I didn't even think about hip dysplasia, nor have any knowledge about where to get the information. That worked out to my first BRTs breeders advantage and I've spend the past 8 years of so trying to help novice dog people learn about health checks,and how to use the OFA website. Back in 2004 when I became involved with the BRTs the rate of dysplastic dogs was 48.8%. Even though breeders talk a really good game, the current rate is 43% overall with 40% born between 2006-2010, so some improvement has been made during those 10 years but at the current rate it would take another 25 years to bring us into the range of the Rottweiller. The Rottweiler rates used to be comparable to the BRT, however their parent club initiated stringent breeding guidelines and their rate is now 15% dysplastic..
In fact, I suspect the rate of dysplasia is even higher because I know some breeders just look at the xrays and decide not to even send them in for evaluation, so we will never know the true incidence of dysplasia in the breed.
I used to think that it was so easy that if people just bred good hips to good hips, we could improve the breed in just a few generations. Well that was naive, but there does have to be a constant move to improve on what we have. I still feel like the priority needs to be to continue breeding up. The OFA has enough information and statistics to know that if you want to improve on your results you don't breed failing hips and elbows, nor do you breed the only dog of a litter who might have passed when everything else has failed. Below is the OFA Breeding Guidelines concerning hips and elbows.
OFA's Recommended Breeding Principals
I would have to say that in the Black Russian Terriers looking for a familial history of 75% passing is difficult to find. So I would think that the family history above 50% would be about as good as you could expect. Twenty years ago in this country there were so few BRTs that it might have been necessary to include dogs who either did not have passing grades or who didn't have a familial history of passing. That is really no longer the case.
The illustrations below are examples taken from the OFA of dogs currently being bred of offered for breeding. I believe that I have removed all of the identifying information. In this first example you see a dam who has passed all of the recommended testing bred to a sire with bad hips. Of the first litter only 5 puppies are showing and of these puppies only one has passed hips, so 4 more dysplastics BRTs as a result of this one breeding. It isn't a breeding I would have done to start off with, but certainly would not have repeated given these first results.
Hip Dysplasia is a developmental orthopedic disease. All puppies are born with normal hips. Yes, you read that correctly, ALL PUPPIES ARE BORN WITH NORMAL HIPS. The dysplastic dog over time will exhibit abnormal development of the ball-in-socket joint that makes up the hip. It’s the snowball kind of affect that once the socket does not fit together tightly, wear on the surface begins, causing friction, straining the joint capsule, damaging the cartilage, causing inflammation and the pain associated with arthritis.
Hip dysplasia is not arthritis though. It may eventually cause arthritis, but it is not arthritis. It is thought to be a polygenetic inheritable trait. Meaning it is caused by not just one gene, but by multiple genes, which must combine for a dog to become dysplastic. Because polygenic inheritance is so complex, in addition to involving multiple genes, polygenic inheritance also looks at the role of environment in its development.
In the beginning I didn't even think about hip dysplasia, nor have any knowledge about where to get the information. That worked out to my first BRTs breeders advantage and I've spend the past 8 years of so trying to help novice dog people learn about health checks,and how to use the OFA website. Back in 2004 when I became involved with the BRTs the rate of dysplastic dogs was 48.8%. Even though breeders talk a really good game, the current rate is 43% overall with 40% born between 2006-2010, so some improvement has been made during those 10 years but at the current rate it would take another 25 years to bring us into the range of the Rottweiller. The Rottweiler rates used to be comparable to the BRT, however their parent club initiated stringent breeding guidelines and their rate is now 15% dysplastic..
In fact, I suspect the rate of dysplasia is even higher because I know some breeders just look at the xrays and decide not to even send them in for evaluation, so we will never know the true incidence of dysplasia in the breed.
I used to think that it was so easy that if people just bred good hips to good hips, we could improve the breed in just a few generations. Well that was naive, but there does have to be a constant move to improve on what we have. I still feel like the priority needs to be to continue breeding up. The OFA has enough information and statistics to know that if you want to improve on your results you don't breed failing hips and elbows, nor do you breed the only dog of a litter who might have passed when everything else has failed. Below is the OFA Breeding Guidelines concerning hips and elbows.
OFA's Recommended Breeding Principals
- Breed normals to normals
- Breed normals with normal ancestry
- Breed normals from litters (brothers/sisters) with a low incidence of HD
- Select a sire that produces a low incidence of HD
- Replace dogs with dogs that are better than the breed average
I would have to say that in the Black Russian Terriers looking for a familial history of 75% passing is difficult to find. So I would think that the family history above 50% would be about as good as you could expect. Twenty years ago in this country there were so few BRTs that it might have been necessary to include dogs who either did not have passing grades or who didn't have a familial history of passing. That is really no longer the case.
The illustrations below are examples taken from the OFA of dogs currently being bred of offered for breeding. I believe that I have removed all of the identifying information. In this first example you see a dam who has passed all of the recommended testing bred to a sire with bad hips. Of the first litter only 5 puppies are showing and of these puppies only one has passed hips, so 4 more dysplastics BRTs as a result of this one breeding. It isn't a breeding I would have done to start off with, but certainly would not have repeated given these first results.
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This second example is a sire being offered for Stud. You can see that although this sire did pass his hips with a Fair rating, there is nothing else in his family line that has, neither mother, full or half siblings. This would be an example of the OFA calling not to breed the one dog out of the litter to pass if the rest of the family history did not pass.
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This example is of a dog who has good hips. His father had Mild hips and his mother had Fair hips. But if you look at what he has produced, not one of his offspring (and there are many more than what is listed here) have passed.
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I could (and probably have) spent weeks going over Kennel histories in the OFA. So there are some that are easy reads. You can look at a kennel that shows their first submission to OFA back in the late 1990's. So you know that dogs have been being bred for about 20 years, yet they only show 15-20 total dogs listed on OFA, and a lot of those listed are missing either hips or elbows. It indicates that either the breeder does is not committed to health testing, has not made much improvement in what they are breeding over that long time span, or does not share results openly for public information. You can look at whole kennel lines and see a complete history of breeding bad hips or bad elbows or both with no genetic progress being made. Breeders just love their line breeding, however if you look at this whole kennel and see these kinds of results then it's time this breeder abandon this line breeding and bring in fresh and better genetic material.
It's very hard to make intelligent decision about lines when so little information is available.
Given the poly-genetic nature of dysplasia and the high BRT fail rate, you need to assume that all BRTs carry some of the genetic material that produces dysplasia. That's why even when you breed your passing to passing, you can still produce dysplastic dogs and that is the part that is so frustrating to me. I worked on behalf of the BRTCA Health Committee for 6 month setting up a study with Cornell University to study hip dysplasia in the BRT with the hope of finding a genetic marker that produces dysplasia. It was set up as a totally anonymous study, you submitted blood samples and OFA results directly to Cornell...the club was not involved either in the collection of the samples, nor in sharing of the information and was of no cost to participants other than the blood draw from their vet. Any idea how many people participated? ...28 at last count. In a breed where we have such a high failure rate, only 28 people could find the time to work on the research. How can people in all good conscience continue to breed dysplastic dogs and not even be concerned enough to participate in research to find the problem? Did your breeder participate?
Environment
Now we all know that dysplasia has a genetic component. It also has an environmental factor. The important thing to know is that environment alone won't make a dog dysplastic. There are many breeds with a very low instance (less than 3% of dogs born between 2006-2010), Whippet, Saluki, Italian Greyhound, Borzoi, Siberian Husky, German Shorthaired Pointer, Shelti, Lasha Apso, Kerry Blue, Rhodesian Ridgeback, Dalmatian, Collie, Bull Terrier. You have to know that given all of these low numbers that all of these dogs were not raised in the ideal environment, yet they have the good genetic background that they don't develop the disease.
EARLY WEIGHT GAIN
In 222 German shepherds born consecutively, 100 were dysplastic, and the prevalence of hip dysplasia at 1 year had a direct correlation with their weight at 60 days of age. The heavier dogs, that is, the heaviest males and heaviest females at 60 days of age, had the highest incidence of hip dysplasia at maturity.
These data suggested a number of indirect genetic factors influencing the rate of hip dysplasia. There was an extensive study done on Labrador Revriever puppies. The Kealy study published in 1992 was based upon 48 8-week-old Labrador Retriever puppies. These puppies were sex-matched littermates randomly assigned to two groups: the first group was fed ad libitum (as much as they wanted, when they wanted to eat); the second group was fed the same feed until they were 2 years old, but in amounts of only 75 percent of what the first group consumed ad libitum. Thus for every puppy fed ad libitum, there was a same-sex littermate on a restricted diet. This rigid protocol gives this study great respectability and credence. The accompanying chart gives the findings in tabular form. Note the tremendous increase in normal animals at two years of age when kept on a restricted diet for those two years. This ought to more than suggest that overweight animals are at risk for phenotypic expression of canine hip dysplasia.
Radiographic Evaluation Method Group 1 Group 2
Free Feeding 75% of the Free Feeding Amt
Dysplastic Normal % Normal Dysplasitic Normal % Normal
OFA 16 8 33% 7 17 71%
Additional studies have shown that limited food intake and slow rate of body growth beneficially affect the development of hip and elbow joints in growing and adolescent dogs (Riser et al., 1964; Kasström, 1975; Hayes et al., 1979; Kealy et al., 1992; Kealy et al., 1997; Sallander et al., 2006).
It appears that the amount of calories a dog consumes and when in the dog's life those calories are consumed have the biggest impact on whether or not a dog genetically prone to hip dysplasia will develop the disease.
Experimentally, it has been shown that obesity can increase the severity of the disease in genetically susceptible animals. It stands to reason that carrying around extra weight will exacerbate the degeneration of the joints in a dog; including the hip. Dogs that may have been born genetically prone to hip dysplasia and are overweight are therefore at a much higher risk of developing hip dysplasia and eventually osteoarthritis.
Another factor that may increase the incidence of hip dysplasia is rapid growth in puppies during the ages from three to ten months. Experimentally, the incidence has been increased in genetically susceptible dogs when they are given free choice food. In one study, Labrador Retriever puppies fed free choice for three years had a much higher incidence of hip dysplasia than their littermates who were fed the same diet but in an amount that was 25% less than that fed to the free-choice group.
Feeding a diet that has too much or too little calcium or other minerals can also have a detrimental effect on the development of the hip joint. However, with today's complete and balanced dog foods this has become a rare occurrence. The practice of feeding home-made dog foods is popular with some dog owners. These diets must be carefully monitored for proper nutritional balance; not only for calcium and the other essential minerals but for all nutrients.
Exercise:
Exercise may be another risk factor. It appears that dogs that are genetically susceptible to the disease may have an increased incidence of disease if they over-exercised at a young age. But at the same time, we know that dogs with large and prominent leg muscle mass are less likely to contract the disease than dogs with small muscle mass. So, exercising and maintaining good muscle mass may actually decrease the incidence of the disease. Moderate exercise that strengthens the gluteal muscles, such as running and swimming, is probably a good idea. Whereas, activities that apply a lot of force to the joint are contraindicated. An example would be jumping activities such as playing Frisbee.
The Norwegian School of Veterinary Science in 2012 conducted a study which shows very definite links between the environment in the puppy's first 3 months and the incidence of HD. Puppies that had free exercise on outdoor ground (without stairs) had a lower incidence of HD than puppies raised indoors with no access to free exercise.
Many breeders will advise against exercising a pup to prevent the development of orthopedic conditions. Nonetheless, veterinarians believe that gentle, low impact exercise can be beneficial for pups, but that all forced exercise beyond what a puppy would normally do should be avoided. I call it "free play". Veterinarians maintain that running (forced running not free play) should be avoided until a puppy is physically mature, and that puppies should stay away from high impact sports such as jumping and agility. Both of these activities are believed to be traumatic on a puppy's immature joints.
There is a really excellent series done by John C. Cargill, M.A., M.B.A., M.S. and Susan Thorpe-Vargas, M.S. It is eight parts and a lot of research, but I would suggest it to anyone interested in expanding their knowledge of Hip Dysplasia. You can find a link to the study here
under the Bone and Joint Section http://www.midnightriderbrts.com/interesting-health-links.html.
Conclusion
So what do I do with my puppies? It's fine to do a lot of study and research, but somehow you need to combine it all together into some useful plan. Here's what I do:
So does all of this stuff work? I don't know....like I said I'm not a geneticist, a vet or a research specialist. I just know that I want my dogs to have the best chance that they have of being HD free so I kind of combine everything I know and do it all! Maybe it works as well as gris-gris putting chicken bones in a bag and shaking them up (I'm from New Orleans), or throwing salt over their shoulders as they go out the door. But for whatever reason, or a combination of all of them, I'll take the results I've gotten so far.
It's very hard to make intelligent decision about lines when so little information is available.
Given the poly-genetic nature of dysplasia and the high BRT fail rate, you need to assume that all BRTs carry some of the genetic material that produces dysplasia. That's why even when you breed your passing to passing, you can still produce dysplastic dogs and that is the part that is so frustrating to me. I worked on behalf of the BRTCA Health Committee for 6 month setting up a study with Cornell University to study hip dysplasia in the BRT with the hope of finding a genetic marker that produces dysplasia. It was set up as a totally anonymous study, you submitted blood samples and OFA results directly to Cornell...the club was not involved either in the collection of the samples, nor in sharing of the information and was of no cost to participants other than the blood draw from their vet. Any idea how many people participated? ...28 at last count. In a breed where we have such a high failure rate, only 28 people could find the time to work on the research. How can people in all good conscience continue to breed dysplastic dogs and not even be concerned enough to participate in research to find the problem? Did your breeder participate?
Environment
Now we all know that dysplasia has a genetic component. It also has an environmental factor. The important thing to know is that environment alone won't make a dog dysplastic. There are many breeds with a very low instance (less than 3% of dogs born between 2006-2010), Whippet, Saluki, Italian Greyhound, Borzoi, Siberian Husky, German Shorthaired Pointer, Shelti, Lasha Apso, Kerry Blue, Rhodesian Ridgeback, Dalmatian, Collie, Bull Terrier. You have to know that given all of these low numbers that all of these dogs were not raised in the ideal environment, yet they have the good genetic background that they don't develop the disease.
EARLY WEIGHT GAIN
In 222 German shepherds born consecutively, 100 were dysplastic, and the prevalence of hip dysplasia at 1 year had a direct correlation with their weight at 60 days of age. The heavier dogs, that is, the heaviest males and heaviest females at 60 days of age, had the highest incidence of hip dysplasia at maturity.
These data suggested a number of indirect genetic factors influencing the rate of hip dysplasia. There was an extensive study done on Labrador Revriever puppies. The Kealy study published in 1992 was based upon 48 8-week-old Labrador Retriever puppies. These puppies were sex-matched littermates randomly assigned to two groups: the first group was fed ad libitum (as much as they wanted, when they wanted to eat); the second group was fed the same feed until they were 2 years old, but in amounts of only 75 percent of what the first group consumed ad libitum. Thus for every puppy fed ad libitum, there was a same-sex littermate on a restricted diet. This rigid protocol gives this study great respectability and credence. The accompanying chart gives the findings in tabular form. Note the tremendous increase in normal animals at two years of age when kept on a restricted diet for those two years. This ought to more than suggest that overweight animals are at risk for phenotypic expression of canine hip dysplasia.
Radiographic Evaluation Method Group 1 Group 2
Free Feeding 75% of the Free Feeding Amt
Dysplastic Normal % Normal Dysplasitic Normal % Normal
OFA 16 8 33% 7 17 71%
Additional studies have shown that limited food intake and slow rate of body growth beneficially affect the development of hip and elbow joints in growing and adolescent dogs (Riser et al., 1964; Kasström, 1975; Hayes et al., 1979; Kealy et al., 1992; Kealy et al., 1997; Sallander et al., 2006).
It appears that the amount of calories a dog consumes and when in the dog's life those calories are consumed have the biggest impact on whether or not a dog genetically prone to hip dysplasia will develop the disease.
Experimentally, it has been shown that obesity can increase the severity of the disease in genetically susceptible animals. It stands to reason that carrying around extra weight will exacerbate the degeneration of the joints in a dog; including the hip. Dogs that may have been born genetically prone to hip dysplasia and are overweight are therefore at a much higher risk of developing hip dysplasia and eventually osteoarthritis.
Another factor that may increase the incidence of hip dysplasia is rapid growth in puppies during the ages from three to ten months. Experimentally, the incidence has been increased in genetically susceptible dogs when they are given free choice food. In one study, Labrador Retriever puppies fed free choice for three years had a much higher incidence of hip dysplasia than their littermates who were fed the same diet but in an amount that was 25% less than that fed to the free-choice group.
Feeding a diet that has too much or too little calcium or other minerals can also have a detrimental effect on the development of the hip joint. However, with today's complete and balanced dog foods this has become a rare occurrence. The practice of feeding home-made dog foods is popular with some dog owners. These diets must be carefully monitored for proper nutritional balance; not only for calcium and the other essential minerals but for all nutrients.
Exercise:
Exercise may be another risk factor. It appears that dogs that are genetically susceptible to the disease may have an increased incidence of disease if they over-exercised at a young age. But at the same time, we know that dogs with large and prominent leg muscle mass are less likely to contract the disease than dogs with small muscle mass. So, exercising and maintaining good muscle mass may actually decrease the incidence of the disease. Moderate exercise that strengthens the gluteal muscles, such as running and swimming, is probably a good idea. Whereas, activities that apply a lot of force to the joint are contraindicated. An example would be jumping activities such as playing Frisbee.
The Norwegian School of Veterinary Science in 2012 conducted a study which shows very definite links between the environment in the puppy's first 3 months and the incidence of HD. Puppies that had free exercise on outdoor ground (without stairs) had a lower incidence of HD than puppies raised indoors with no access to free exercise.
Many breeders will advise against exercising a pup to prevent the development of orthopedic conditions. Nonetheless, veterinarians believe that gentle, low impact exercise can be beneficial for pups, but that all forced exercise beyond what a puppy would normally do should be avoided. I call it "free play". Veterinarians maintain that running (forced running not free play) should be avoided until a puppy is physically mature, and that puppies should stay away from high impact sports such as jumping and agility. Both of these activities are believed to be traumatic on a puppy's immature joints.
There is a really excellent series done by John C. Cargill, M.A., M.B.A., M.S. and Susan Thorpe-Vargas, M.S. It is eight parts and a lot of research, but I would suggest it to anyone interested in expanding their knowledge of Hip Dysplasia. You can find a link to the study here
under the Bone and Joint Section http://www.midnightriderbrts.com/interesting-health-links.html.
Conclusion
So what do I do with my puppies? It's fine to do a lot of study and research, but somehow you need to combine it all together into some useful plan. Here's what I do:
- Select from the best genes that I can find. I would never pick a puppy if I could not verify that the sire and dam had good hips and look at the overall results of the line to make sure I was happy with what I saw.
- I do not feed my puppies raw. I feed only a very high quality kibble (Orijen Large Breed Puppy) for the first 6 months. After 6 months they go to adult kibble supplemented with Turkey Necks and some raw feeding. I do not feel that I have the expertise to make sure that the puppy is getting all of the nutrition he needs with raw feeding in the right mix of calcium/phosphorous . I would never use a calcium supplement unless it contained the recommended offset of phosphorous (If you want to use a supplement check out Sure Grow for a mixture of Calcium/Phosphorous/Vitamin D/Vitamin A). I want to encourage slow growth and I do this feeding at the bottom end of the recommend amounts and not over-supplementing.
- I always keep my puppies at a low weight. I don't care that a fat little puppy is really cute, nor if I'm showing mine in the ring and my puppy looks skinny compared to the rest. I keep them purposely lean until they are over 2 years of age.
- I don't have stairs in my house, but I have just 2 stairs off of my deck to the back yard. I carry the puppies up and down even just those 2 stairs until I can no longer carry them. Constantly going up and down stairs are not good for developing joints. After that I try to make sure that they don't take a flying leap off of them. Doesn't always work, but I do try.
- Every surface in my house is a non skid surface. My tiled kitchen/pantry/laundry room is covered with cheap area rugs. You could get better ones, but they are puppies after all and will have accidents. My husband hates them, but for 2 years they stay down. My hardwood hall ways are 100% covered in rug runners (purchased from Lowe's by the 50' roll with rubber backing). These stay in place for 2 years. It's funny to see a little puppy sliding around on the floor. It isn't however, good for the joints.
- We don't do any forced exercise until after the age of 2. They run and play all they want, but no road training, no agility jumping. For the first 4-6 months I didn't let the older dog run wild in the yard with the puppy. BRTs play very rough and I didn't want the 130 pound dog running over the 20 pound dog. They play together in the house, but only supervised outside and a quick voice correction if the older dog starts getting too rough.
- I don't allow them to jump. As puppies they are never allowed to jump on people....not only isn't it good for the hips but it also isn't good that they get in the habit on jumping on people because what is acceptable for a 20 pound dog is not at all acceptable for a 130 pound dog.
So does all of this stuff work? I don't know....like I said I'm not a geneticist, a vet or a research specialist. I just know that I want my dogs to have the best chance that they have of being HD free so I kind of combine everything I know and do it all! Maybe it works as well as gris-gris putting chicken bones in a bag and shaking them up (I'm from New Orleans), or throwing salt over their shoulders as they go out the door. But for whatever reason, or a combination of all of them, I'll take the results I've gotten so far.