703 LINE-BRED OR ILL-BRED
LINE-BRED OR IN-BRED?
In the past year in Britain a number of extremely important inquiries have been conducted into dog-breeding. Each one has expressed concerns about breeding to close relatives in pedigree breeds. The Bateson report recommended the establishment of an Advisory Council to address the issue. The cross-party Parliamentary Group’s findings also recommended greater scrutiny of dog breeding practices of such a nature. But for a century or so, close breeding to certain lines or sires has been accepted practice amongst pedigree dog breeders. In her informative book Advanced Labrador Breeding, published by Witherby in 1988, Mary Roslin Williams, herself a successful breeder of both show and FT champions, wrote: “to produce a strain of good ones, you must carry out a degree of line-breeding, possibly even using the dangerous practice of mild inbreeding in special cases. Top breeders hate the moment they have to use a complete outcross.”
She defined line-breeding as “a gathering of lines leading back in three or four generations to a known good dog or bitch or very often to one or two good dogs and bitches, with the rest of the pedigree filled with outcross names.” The famous Golden Retriever breeder Mrs WM Charlesworth warned against brother-sister matings but liked bitch to grandfather unions and favoured bitch to nephew matings. In the notorious TV documentary ‘Pedigree Dogs Exposed’ in 2008, the chairman of the Kennel Club was pressed on this matter and understandably looked visibly distressed when asked if he would consider having children with his granddaughter. Cousin to cousin unions are the closest ones we humans are legally permitted.
Inbreeding is coming under greater scientific scrutiny as inheritable defects in pedigree dogs increase. One researcher in America found that in dog breeds there is a decline in the average life span of around 7% for every 10% increase in inbreeding. Dwarfism has been found in Pointer litters at inbreeding coefficients of 13 to 37%, whereas unaffected litters rated 0 to 24%. In a Foxhound pack, the conception rate with sperm of inbred dogs was 73% against 87% with outbred ones; average litter size was 7 against 9 and 4 against 6 at weaning. The sperm count was 70 against 367.
Swedish research shows that their pedigree dogs in 60 breeds had an average inbreeding coefficient of 14%. Most dog breeds with good-sized populations have a coefficient of inbreeding of 4-5%. Professional breeders of production animals such as cows, pigs, goats, sheep and horses consider that a coefficient of inbreeding of around 9% is risky. Why do breeders of production animals seek healthier animals than dog-breeders? Is it not mainly based on market value related to beef and milk production? Show dogs have no performance rating, just breeder-whim appearance. The Germans have a word for reckless breeding leading to discomfort, disease and a shorter life for the pedigree dog. It is 'qualzucht', cruelty breeding, or more literally, 'torture breeding'. When a geneticist, himself in Boxers, finds it necessary to pose the question: Are there any Boxers that are truly free of heart murmurs? we have much to think about. He himself was brave to outcross for the naturally docked tail - and why not?
Uninformed outcrossing is not the answer; there has to be research as well as vision. Leading geneticist Professor Steve Jones has stated that for pedigree breeds of dog 'a universe of suffering' is ahead with continued inbreeding. Fellow geneticist Bruce Cattanach has written: '...inbreeding has been ingrained in dog breeder psyche from the beginning and is hard to break, even when it is possible to show that it is not the most successful way to breed'. He went on to state that some pedigree breeds may well become extinct in our lifetimes without intervention, advising outcrossing to other related breeds. But who will listen to him; dogma will prevail and not just lurchermen will wonder at such folly - and such damage to long-established breeds. One of the weaknesses of the otherwise quite excellent Bateson Report into the state of pedigree dog-breeding in Britain was that it didn’t gather any valuable evidence on the genetic size of each registered breed. This report uses the expression ‘closely related breeding pair’ when discussing the mating of dams with sires, but doesn’t define what closely related actually means.
Inbreeding will not cause inherited problems if the problems are not present, in the genes, in the first place. The genetic size of a breed is crucially important; some ancient breeds are inbred and some relatively newly-created breeds are not. But breeding practices decide whether a breed founded a century ago is inbred or genetically diverse. Much can depend for example on the over-use of prize-winning sires. In 2010 a magnificent Hungarian Vizsla won best in show at Crufts; he had been a highly successful prize-winner since arriving here in 2005. During his first four years in this country, he produced 827 offspring, 517 being first generation from him. In that period just under 5,000 Vizslas were newly registered, which means that he sired more than 10% of the newly registered Hungarian Vizslas in Britain. The over-use of a top dog can end up contributing to a narrow genetic pool, which, without mandatory health clearances, can lead to an increased potential for inherited disease.
The German Shepherd Dog Champion Ludwig of Charavigne (1959-1972) produced 2197 offspring, but because no health records are maintained alongside details of ancestors by name, who knows what defects he passed on? The famous Canadian racehorse stallion Northern Dancer (1961-1990), which won the Kentucky Derby in 1964, went on to sire 645 foals in 23 seasons, truly a sire of sires. But his offspring were judged on their performance not just their handsomeness. It’s worth noting that since then stallion owners have played on not having Northern Dancer blood in their stock, fearing accusations of breeding too close. Experts within dog breeds have argued that puppy-farms are the source of much unskilled inbreeding and there is truth in that; the need is for all breeders to be aware of the problem - or be regulated into compliance.
David Balding, Professor of Statistical Genetics at Imperial College, London, has advised: “Inbreeding is not the only cause of canine health problems, and perhaps not even the worst, but it is the easiest problem to fix…Find out the coefficient of inbreeding for a puppy before buying it…at least make sure that the puppy has four different grandparents, not one of them directly related to another.” The Finnish Kennel Club publishes the coefficient of inbreeding for dogs registered with them on its website, our KC must now do the same.
Inbreeding Depression is an acknowledged cause of small litter sizes, shorter lives and a reduced immune system in pedigree dogs. Dr Ian Ramsey of the University of Glasgow has stated: “Inbreeding leads to certain genes being concentrated in particular breeds, or even lines within breeds, and a lack of variation follows…However, dogs’ genes also determine how well their immune systems are at recognising their own bodies. If the ‘bad’ genes that stop a dog’s immune system recognising its own body are, accidentally, concentrated along with the ‘good’ genes for a certain coat colour, physical size, etc., then the dog will have an inherited tendency to suffer from autoimmune disease. This dog may well pass this tendency on to its puppies.” He went on to point out the only way of avoiding this is to avoid inbreeding as much as possible – accepting that as you do so a greater variation in other things will be introduced. Breeders can choose, their dogs cannot.
Of course, breeds were created and then isolated by inbreeding, that is how their breed-type was established and then sealed. But a closed gene pool when there are acknowledged problems in a breed, whether through a falling-away in virility or harmful morphological exaggerations, seals the problem in the breed’s genotype. Bruce Cattanach was right to state that inbreeding is encased in the dog breeder’s psyche. Crossbred dogs are considered inferior or a threat to breed purity by the diehards, scorning all empirical and scientific evidence to the contrary. The defiant phrase ‘We’re not having scientists telling us how to breed a dog!’ is not the brightest declaration of the age, an age in which livestock breeders welcome scientific advice and have been accepting it gratefully for half a century. Skilled informed breeders of sporting dogs have long bred for performance and initially all breed-type was rooted in function. Breeders of sporting and working breeds of pedigree dog may not want to utilise their dogs’ innate field capabilities but if they don’t respect a breed’s function, only its appearance, then the outlook for them in a rapidly changing canine world – and, more importantly, for their dogs – is bleak.
(This article was first published in Country Life a year ago; David’s latest book, his eighth, entitled The World of the Lurcher was published by Quiller in July 2010.)