Improving Breed Soundness in the German Shepherd Dr. Karen Hedberg BVSc 2010
Improving Breed Soundness The subject is very large and wide ranging and can be looked at from many angles including :- 1. Time past, present, future 2. Breeding schemes 3. Perceived problems of the breed 4. Long term goals
When Breeding a litter Trying to breed better than you currently have. Aim to improve or at least maintain the health qualities of the parents in the puppies. Generally 1 puppy is retained at most, the rest are on sold generally as pets ie. around 1in 8-10 puppies kept for show/breeding, rest go out to the general public. The vast majority of our puppies go as pets, ideally to live long healthy lives.
The German Shepherd Standard GENERAL APPEARANCE FCI: The German Shepherd Dog is medium sized, slightly elongated, powerful and well muscled, the bones dry and the overall structure firm. WUSV: The immediate impression of the appearance of the GSD is of a dog slightly long in comparison to its height, with a powerful and well muscled body. The relation between height and length and the position and symmetry of the limbs (the angulation) is inter-related in such a way as to enable a far reaching and enduring gait. The coat should be weatherproof. A beautiful appearance is desirable, but this is secondary to his usefulness as a working dog. Excessive looseness of overall ligamentation is a major fault. Sexual characteristics must be well defined, i.e. the masculinity of the male and the femininity of the female must be unmistakable.
Overall appearance A true to type GSD gives an impression of innate strength, intelligence and suppleness with harmonious proportions and nothing either overdone or lacking. His whole manner should make it perfectly clear that he is sound in mind and body and has the physical and mental attributes to make him always ready for tireless action as a working dog.
GSD Colours ANKC Standards Presentation
FCI: Characteristics Usage: All round working, herding and service dog. [See also under General Appearance and Temperament.] WUSV: The main characteristics of the GSD are: steadiness of nerves, attentiveness, loyalty calm self-assurance, alertness and tractability, as well as courage with physical resilience and scenting ability. These characteristics are necessary for a versatile working dog.
Temperament FCI: The German Shepherd Dog must be of well balanced temperament, steady of nerve, self assured, absolutely free and easy, and (unless provoked) completely good natured, as well as alert and tractable. He must have courage, combative instinct and hardness, in order to be suitable as companion, watch, protection, service and herding dog. Comments: With an abundance of vitality he must be tractable enough to adapt himself to each situation and to carry out his work willingly and with enthusiasm. He must possess the courage and determination to defend himself, his master or his master s possessions should the need arise. He must be observant, obedient and a pleasant member of the household, quiet in his own environment, especially with children and other animals, and at ease with adults. Overall, he should present a harmonious picture of nobility, alertness and self confidence.
Definition of Breed Soundness Breed soundness is determined by assessing several areas: 1. Physical soundness. This relates to construction and health. Is the animal able to cope with the demands of ordinary life as well as stresses of heavy work in specialised areas if required? Health can relate to organ or system health e.g. reproductive soundness as well as problems such as heart function or joint soundness. 2. Mental soundness. This refers to the temperament, ability and aptitude of the animal to be of benefit in its chosen field. Different temperaments are required for the numerous fields of activity (or relative inactivity) that cover the wide range of dog types and diversity of use. The keenness to work that is admired in the working and utility breeds would be rather overpowering in many toy breeds. 3. Genetic soundness. This is reflected in many physically obvious attributes, as well as on cellular and hormonal levels, which may be less obvious. Recent developments have resulted in many more conditions being termed genetic in origin, however the means to readily remove these conditions from a breed are often not yet available. 4. Breed type. Before considering breeding, your dog or bitch should be typical of the breed ie. look like the breed. It should be above average in order to improve the quality of stock within your kennel.
Breed improvement schemes Breed improvement schemes, particularly with polygenetic conditions such as hip and elbow dysplasia, are reliant on producing consistent repeatable results such that that breeders can assess the relative value of their breeding stock against a breed mean, and more importantly, continue to do so over generations of breeding. In order to do this breeders need the following:- In order to do this breeders need the following:- Consistent and reliable means of assessment. Ease of accessibility of the screening process (usually local veterinarians) at reasonable cost. A means of developing a breed average or median. Ideally a means of assessing the relative genetic merits of different sires based on progeny results (particularly in the numerically larger breeds). A means of assessing improvements (or otherwise) of entire breeds over time. That is, are we improving, has all this hard work by breeders (and money) achieved the desired result?
Breed improvement schemes a long term approach needed Most breeds have more than one condition that they are trying to control at any one time. The more conditions one is looking at to control, the slower the overall rate of improvement. Thus the aim should be to take out the worst affected animals (of any one condition) but try and retain at least 75% of the population for breeding purposes. The more conditions one is aiming at, the higher this retention figure may need to be. Trying to clear every animal with the slightest abnormality will result in a drastically reduced population base and ironically, a higher chance of seeing new conditions as a result of this narrowing to the genetic base of the breed. Any breed improvement scheme must to be looked at in the long term. To alter or improve a breed average (ie. shift the entire population mean) takes consistent effort and several generations to see what has been achieved. Improving breeding stock within a kennel can be relatively easy, however a single breeder alone cannot improve an entire breed on their own. The greater the level of participation, the more likely the scheme is to work across a breed.
Population Spread Populations can be described by a bell curve which can apply to any feature you wish to look at, be it height through a breed, litter size, hip dysplasia (HD) scores and so on. With this curve, the top of the curve is the mean of the population factor being assessed eg. height with the extremes at either end of the scale ie. the shortest and tallest. If your breed has a height limit such as German Shepherds, while we wish to breed strong, well boned dogs (who generally are on the large end of the scale), we have to fit (or attempt to fit) the vast majority of dogs under the limit, so the breeders will usually discard the tallest and the smallest, and generally work with the medium to large range of the population. This same principle can be applied to any genetic problem within a breed. If the incidence of a problem is small across the whole breed, eg. affecting 5-10%, it can be fairly easy for breeders or clubs to say not to breed with affected animals. If however, the problem has a variable expression and/or a complex means (polygenetic) of inheritance, this can affect virtually every member of the breed eg. hip dysplasia, to some degree.
Bell curve population spread Diagram. A Bell curve population spread
Success of the hip scheme The GSDCA HD and ED scheme has been, when viewed from the long term, spectacularly successful. The breed hip average some 35 years ago was around 18. This has gradually decreased over the years to the current rolling breed mean 2004-2009 of 6.73 The non GSDCA GSD population s average is starting (slowly) to drop. The 2004-2009 average is 10.74 There are 4 main reasons for the success of the GSDCA Hip Scheme 1. Having a cut off point ( A stamp max 8/hip) 2. Regular publishing of sire averages 3. Breed survey and excellent show awards 4. Introducing compulsory HD/ED Xrays LRL in 2000
GSDCA Annual Count & Mean Count Mean 1/7/96 to 30/6/97 157 5.73 1/7/97 to 30/6/98 301 11.49 1/7/98 to 30/6/99 750 10.64 1/7/99 to 30/6/2000 647 11.35 1/7/2000 to 30/6/2001 566 9.98 Decreasing breed mean 1/7/2001 to 30/6/2002 529 9.64 1/7/2002 to 30/6/2003 511 9.88 1/7/2003 to 30/6/2004 514 8.22 1/7/2004 to 30/6/2005 487 7.02 1/7/2005 to 30/6/2006 443 6.66 1/7/2006 to 30/6/2007 399 6.26 1/7/2007 to 30/6/2008 456 6.28 1/7/2008 to 30/6/2009 415 5.95 1/7/2009 to 30/6/2010 410 5.65 1/7/1996 to 30/6/2010 6,585 8.62 Non GSDCA Dogs Averages 2004 (37) 13.05 2005 (56) 11.63 2006 (98) 10.44 2007 (149) 10.67 2008 (167) 10.31 2009 (158) 8.33 2010 total 2004-2009 10.74 Total 1998-2010 835 10.81
25 20 15 10 5 0 Average hip score relative to breeding Average Willis Hip Scores of German Shepherds by Year of Birth Dogs who became parents Dogs who haven't become parents 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 1977 1978 Willis Hip Score
GSDCA Elbow Scheme The elbow scheme is similarly improving, initially some 30% of all dogs were affected (early 1990 s) with quite a high percentage of these being grade 2 animals. Some states has even higher percentages. We are now at the point that Grade 2 elbows can shortly be eliminated from the breeding population. The overall percentage of heavily affected dogs has significantly dropped. We still need to watch this area and avoid doubling up on the problem. Relevant statistics are harder to obtain with Elbow statistics as a reasonable percentage of affected animals are not recorded as they are removed from the breeding pool very early on (between 4-9 months of age). We still have a slight problem collecting statistics from these dogs today. Across the board, the numbers of puppies that have severe hip or elbow conditions has dropped dramatically, to the extent that rarely are any puppies euthanaised for either condition in the current era (in my state at least!).
Overall picture The overall picture covers many aspects within each area and may have different slants within various breeds. Compromises often have to be made when balancing out the relative importance of different problems both within that animal and the breed as a whole. The overall picture should be remembered. Trying to eliminate all dogs with hip dysplasia (HD) did not work (attempted in both German Shepherds and Labradors) and the end result was a greatly reduced genetic pool. Cases of HD were still occurring and breeds no longer resembled the standard. The main aim today of most hip schemes is a gradual reduction in the breed average while at the same time allowing breeders to preserve valuable bloodlines and decrease the incidence of really severe HD. The inheritance of HD varies in different breeds. The higher the degree of inheritance, the more rapidly changes can occur within a breed when selecting for the characteristic. Also, a dog that has a good hip score, may not necessarily throw low scores in his progeny, while a litter brother with a slightly higher score may have a far lower progeny average.
Keep problems within perspective The most important point is to keep the problems a breed has within perspective. This means that if there is a minor problem that does not affect the animal's soundness, either as a working animal or its quality and length of life, it should be kept in proportion relative to other problems within the breed. *Genetic problems that result in a high incidence of blindness, crippling arthritis, a vastly shortened life span (eg. the storage diseases), or there is pain and suffering for both the dog and the owner (be it monetary or emotional stress), then efforts should be made by breeders and breed clubs to decrease the incidence of these problems.
Physical Soundness This relates to construction and health. Is the animal able to cope with the demands of ordinary life as well as stresses of heavy work in specialised areas if required? As covered in diet section earlier today, this breed should be grown slowly and steadily avoiding rapid weight gains, particularly between 12-24 weeks of age. The GSD is perceived as having several structural issues, brought about by breeders and judges selecting for excessive hindquarter angulations. The standard states Any tendency towards over-angulation of the hindquarters reduces firmness and endurance. The hocks are strong and should form a firm joint, the stifle joint should also be firm and not overangulated. The hindquarters overall must be strong and well muscled to enable the effortless forward propulsion of the whole body. Deep hindquarters, excessive toplines and looseness of ligamentation will continue to follow us if we do not adhere to a more moderate and sounder line. The standard actually calls for tightness of ligamentation and that excessive looseness of ligamentation is a major fault.
Mental Soundness This refers to the temperament, ability and aptitude of the animal to be of benefit in its chosen field. The main characteristics of the GSD are: steadiness of nerves, attentiveness, loyalty calm self-assurance, alertness and tractability, as well as courage with physical resilience and scenting ability. These characteristics are necessary for a versatile working dog. The temperament of the GSD is one of its hallmarks. It is the quintessential all round working and companion dog. If our great breed is to continue well into the future we must guard and promote stable temperament as a core issue for breeding. Temperament is a highly inherited characteristic. Again temperaments have improved greatly over the last 20-30 years. While the temperaments are much more stable, there is concern of loss of working ability ie. firmness of character. Equally, we have to produce sound puppies that make excellent family pets. Dogs that are too hyper do not make great pets great destruction is often the result.
Genetic soundness The GSD has quite a number in inherited diseases, many of which do not have specific DNA tests or even the mode of inheritance determined at this time. There are a large group of immune based conditions affecting the skin, gut and overall health in the GSD. Work is currently going on both here and overseas to see if genetic markers or specific genes can be isolated, tests developed. Once tests are developed we can start reducing the incidence of these diseases occurring.
GSD DNA tests New DNA tests are appearing almost daily. Several DNA tests for GSD diseases exists. Dwarfism autosomal recessive condition. This test allows us for the first time to identify carriers. Carriers can still be bred with ideally only to normal partners. Puppies that are being retained can be tested and choices made (if needed) to select the normal or clear puppy to breed on with. Degenerative myelopathy autosomal recessive. This test identifies a major risk factor. Quite a few breeds carry the mutation. Dogs carrying two copies of the abnormal gene have a high risk for developing DM. Older GSD anywhere between 5-10% of dogs over 8 years of age can develop this condition. Care should be made to differentiate this condition and cauda equina.
Determining whether a fault or defect is inherited: 1. Does it affect more than one member of a litter? Obviously the larger the litter the more likely you are to get a significant result. 2. Has it recurred in a repeat mating, or in matings that are genetically similar? 3. Are there ancestors in common? 4. Test breeding can be carried out to see if the fault reappears (preferably not where the problem is well recognised).
Understanding the mode of inheritance The major task facing any breed inherited disorder, is establishing the mode of inheritance. If you are lucky, it may affect a single gene, with a recessive/normal pattern, and if you are really lucky, there may be a DNA marker or specific gene test found that can identify all three states of the gene ie. affected, carrier and normal. This still allows a breed club to keep its genetic pool and breed the problem out within two to three generations if they want to. Of the recognised diseases, more than half are believed to be single gene defects, and around 70% of these being inherited as in a simple autosomal recessive mode of inheritance. Much work is being done to isolate genetic markers or the specific gene that causes these diseases. By studying dog breeding populations and related individuals carrying or being affected by the disorder, the abnormal gene or its marker may eventually be isolated (after a lot of hard work).
Breed Selection selection of Breeding Partners Breed preferences and aims do change over the years, some more quickly than others, especially in the 'younger' breeds. Nothing is static particularly where genes are concerned, nor should it be. Gradual changes within breeds and lines are desirable when aiming at improvements in soundness or working ability. Selection for Desirable Traits Selection for Desirable Traits Obviously, breeders will try to select the more desirable characteristics of the breed, but some of these characteristics may well have variable methods of inheritance. Some of these characteristics (eg. coat colour) have fairly well documented genes, so that you can plan with reasonable accuracy what colours you may expect to obtain within the litter before you even mate the bitch. As time goes on, and more characteristics are sorted out genetically, the breeder will be able to predict what a proposed mating will produce as far as type, colour or shape.
Selection against Undesirable traits (faults) When trying to select for desirable characteristics, you are at the same time trying to reduce or eliminate the undesirable characteristics eg. hip dysplasia, entropion (in turned eyelids), eye defects etc. Many genetic faults have well documented studies sorting out the mode of inheritance of that genetic disorder. Where the fault is a simple recessive, it is relatively easy to reduce the incidence of it in your lines, but unless there is a simple DNA test to determine the carriers, the fault can be very difficult to completely eradicate. Breeders and clubs with the long term interests of the breed at heart are setting up schemes to test for the worst genetic faults (ie. those that are detrimental to the health, comfort and mobility of the animals) and reduce the incidence of these faults. The more breeders participate in such schemes, the quicker the overall standard of the breed will improve.
Selection Potential Selection potential is a term that appears every now and again, and refers to how 'heavily' an animal is selected for breeding compared to the rest of the population. This usually refers to the reduced number of individuals, particularly males, which end up being bred versus the total male population available. With dogs, because they can have multiple offspring at one time (ie. a litter) and can reproduce at a comparatively early age, a fairly high selection potential can apply. When selecting a puppy in a litter, a breeder usually has 4-6 puppies to choose from rather than just a single offspring as in many species (eg. the horse). This means that rapid genetic 'improvements' are possible. With the smaller breeds, there is usually a small litter size as well (1-4 puppies), so the rate of genetic improvement is slower.
Selection potential cont. What this means in real terms to a breeder is that as far as stud dogs are concerned, there is a very high selection potential on the exceptional males. Average or mediocre dogs receive very few bitches compared to the very good dogs. Only about 10% of male dogs are used at stud, compared to about 40-50% of the bitches used for breeding. Breeders are willing to breed mediocre bitches to very good dogs, but very few people are willing to use mediocre dogs. In the long run, a few males will end up having a fairly large effect on the breed, whereas a bitch has to be heavily bred from and be an exceptional producer to have the same effect, which by sheer numbers, places the bitches at a disadvantage. A well used stud dog can be out and producing 60-80 puppies during the same time as a bitch is producing one litter of 6-8 puppies. Before you decide to breed your bitch or dog, make sure that she/he is a relatively sound animal in type, temperament and structure. If there are major genetic faults within your breed, at least try to discover them before breeding your bitch or allowing your dog to be used at stud. As stated earlier, determine why you wish to breed a litter from that animal. Hopefully it is because you want to breed a better one for yourself, but the litter should also be as sound as you can make it for the sake of all the other owners of the puppies from that litter.
Inbreeding and Line breeding Inbreeding and Line breeding Inbreeding and line breeding are often thought to be totally different types of matings by many novice breeders. Inbreeding is generally considered by the older breeders to be close or incestuous breeding, whereas line breeding is thought to be where the common ancestors are slightly further removed. People differ in opinion as to where each one starts and stops. Basically it is all one and the same thing, only the degree varies. Inbreeding (or line breeding) is where an animal appears more than once on a pedigree. If this occurs after the fifth generation, the effect is held to be negligible. When inbreeding, the animal being doubled up or inbred upon and should be a very superior individual, having qualities which hopefully he/she transmits strongly. By inbreeding on this animal, or set of animals (eg. a particular set of litter mates), you are trying to set or fix a type.
Inbreeding cont. Genetically, you are trying to make the offspring homozygous for certain features, so that the offspring will: (a) Exhibit the desired characteristic. (b) Reproduce the characteristic consistently. Inbreeding of any degree results in the doubling up of an individual's genetic makeup. With increasingly close inbreeding, or heavy saturation of a particular individual, there are various consequences that may appear. As you double on the good points, you double your chances of producing the bad points, some of which may have been hidden until the individual was inbred upon. Increasing homozygosity - As increasingly more points becoming homozygous, your 'type' will stabilise, but the potential for change is reduced. As the chances for change are reduced, so are the factors that affect survival and reproduction.
Inbreeding cont. The effects of heavy inbreeding include:- (a) Reduced litter size in bitches; reduced percentage of viable (normal) sperm in males. (b) Reduced survival rate; offspring are more susceptible to infections or changes of climate. The ability to adapt to these changes is reduced by too many factors becoming homozygous i.e. both parents have donated the same form of the gene, therefore the ability to change is reduced. (c) Reduced lifespan for the same reasons as above. (d) Decreasing mental instability as the animals become more and more highly strung or neurotic. **To summarise, inbreeding is useful in helping to establish a type and should be done only on exceptional individuals. If grave faults appear on a regular basis, do not continue. For the average breeder, the best results of inbreeding (line breeding) generally occur using the third and fourth generation ie. grandparents and great-grandparents.
Where to go from here Breeders every where are facing increasing pressures to breed for soundness and for the welfare/health of the progeny/puppies that are produced. We are being pushed in many directions due to decreasing size of backyards, time available to follow hobbies such as dog showing and increasing intervention by legislation and welfare issues. We must all become very proactive in the service of this wonderful breed. We must continue to push health and welfare of the breed, we must push that legislation is fair and reasonable and not just towards to registered population of dogs (as we are the most findable!). While we have achieved great results in the area of temperament, hip and elbow statistics, we must continue to be very vigilant in order that this great breed can continue into a healthy future for generations down the line.
Areas that need attention Health hopefully there should be some breakthroughs in DNA technology in the area of immunology within the next few years. There are a large number of health concerns that relate to the immune system in the GSD. Temperament and willingness to work while temperaments have improved they still need attention. Working ability is the reason behind the GSD s wide usefulness and utility. Unless we can keep these really sound, the widespread use of the GSD throughout the world will decrease. With that drop, survivability of the breed into the future drops as well. Firmness of ligamentation and some overangulation of the hindquarter need to be addressed. We need to hand the breed on in as sound a state as possible so that it endures as the great all round sound working and family dog.
Summary Dedicated dog breeders must become 'relative' experts in many areas if they wish to produce sound healthy dogs. These areas include feeding and nutrition, housing and kennel management, basic genetics, disease control, breeding aspects (mating and whelping) as well as understanding the problems within their breed. All this is in addition to attempting to breed the next world beater for the show ring! Beautiful, healthy dogs who are sound in temperament and body, are the aim of all dedicated dog breeders. The end result is often a compromise of various factors, including economic ones. Where soundness relates to the dog's quality of life, we must make honest attempts to decrease the incidence of any problems. Where definitive tests exist that reduce the incidence of disease and/or improve soundness within the breed; breed clubs should try to incorporate such disease testing where feasible. The more we know of all the factors affecting our breeding stock (construction, inherited diseases) before breeding a litter, the better equipped we are as breeders to find solutions to problems and hopefully reduce the number of unsound dogs being produced. It has benefits for all, particularly for the dogs. * Remember when breeding, aim for soundness and reliability as the age of guarantees is upon us. Lawsuits abound!
Different Types of Matings There are several different types of mating systems that are used; quite often two or more systems are used simultaneously. The first two types of matings are often done without particular emphasis on pedigrees. The following systems are related to the pedigrees of the parents. 1. Type to Type Matings This is where the body and structure of both parents are similar in type. Generally one parent is the better animal (usually the dog), and you are attempting to correct minor faults while still retaining the same general body type. This system works very well, particularly if the parents are 'typical' of the litters from which they came ie. the parents are not 'one offs' or flyers. Where information on the rest of the litter is not available, the parents should be typical of the 'bloodlines' (ie. typical of the lines behind the parents). 2. Corrective fault matings This is where the 'types' of the parents are not necessarily similar, but one parent is particularly good in various areas while the other parent is weak. The resultant progeny will range in type between both parents, as will the fault you are trying to correct. This type of mating is generally done when trying to upgrade the quality of your stock. One generation of this type of mating will usually not be sufficient to remove the problem or it may merely hide it until the next generation.
Outcrossing Outcrossing is where new bloodlines are introduced into a pedigree. Technically this means that no common individuals appear in the first 5-6 generations. Outcrossing enables new genes and gene combinations to occur where they are often much needed particularly if the parents themselves are heavily inbred (but of different lines), the results can be very good. The trouble with outcrosses, particularly with heavily inbred dogs, is that the genetic variation has been lost to such an extent that the first generation produced may be a total loss as far as the show ring is concerned. The value is often seen in the next generation, when they are crossed (not too closely) back into either parent's line.
5. Line Combinations Line combinations are where certain bloodlines 'nick' well together. The lines do not necessarily have to be inbred in themselves. They may either be sire lines, or less commonly, bitch lines. When this occurs, the lines 'blend' together favourably. This is a well known phenomenon in racehorses, Greyhounds and German Shepherds. Good combinations are generally based upon exceptional sires or brood bitches with an effect that extends through their descendants. It is well worth keeping this in the back of your mind when outcrossing or inbreeding.
6. Prepotent dogs and bitches These animals are generally those exceptional producers, whether male or female, whose effect continues beyond their own generation. Prepotent dogs or bitches always throw their own type, whatever dog or bitch that they are put to. Prepotent can occasionally refer to particular virtues or faults that a dog or a bloodline produces with characteristics showing up in the majority of the offspring. Prepotency is held to be a very good sign in a stud dog. The most prepotent animals are, in my opinion, those that are from a very strong male and female family. If a stud dog comes from a good male line but the bitch line is weak (little of note has been produced), then the dog will probably not produce well, especially to average and below average bitches. The best sires are those that come from a very strong female family as well as a good male line, particularly if both are fairly prepotent animals. This way the sire should produce reasonably good results, even to the poor and mediocre bitches. The best brood bitches are those that come from prepotent bitches of strong family type. Occasionally sires may not produce an outstanding male, but the bitches from this sire may be of very good type and soundness and go on to produce offspring far above expectations. These sires are known as brood bitch sires and, while their male line may not persist, the effect of the sire is carried strongly through their daughters. The best brood bitches are by these sires and out of a good producing bitch family, ie. the bloodline is being continually upgraded. As a tip, when choosing a bitch puppy out of such a litter, go for those that most closely resemble the mother's type. If the bitches line has not yet 'firmed' its type, go for the sire's type in the offspring.