821 LINE-BRED OR ILL-BRED
LINE-BRED OR ILL-BRED?
by David Hancock
"The most remarkable feature in the Laverack breed of setters is the extraordinary extent to which in-breeding has been carried, as shown in the pedigree of Countess, given by Mr Laverack in his book on the setter. By examining this carefully, it will be seen that every animal in it is descended from Ponto and Old Moll..."
Those words from Stonehenge's Dogs of the British Islands of 1878 support the old adage that line-breeding is successful in-breeding. But what would have happened further 'down the line'? A highly-skilled breeder like Laverack had the knowledge and the stock to in-breed wisely! Unwise or inexperienced in-breeding creates the problem. It may well be more harmful than plain bad breeding.
In the past decade a number of extremely important inquiries have been conducted into dog-breeding in England. 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.
Greater Scrutiny
In-breeding 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.
Over-use of Sires
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 2,197 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.
I strongly support the view recently expressed by four veterinary scientists at the Ontario Veterinary College which read: "The advantages of hybrid vigour in a pure-bred line could be realised in a carefully controlled breeding program making use of outcrosses." The American veterinary surgeon Leon Whitney found fifty years ago better disease resistance in his crosses between two pedigree breeds. Also in north America, a study by Scott and Fuller (1964) indicated that the high puppy mortality characteristic of matings within a breed was greatly reduced when two different breeds were crossed. Another study by Rehfeld (1970) showed that the frequency of neonatal death in pure-bred beagles increased with the degree of inbreeding.
Seeking Uniformity
Most pedigree dog breeders resort to close line-breeding when they realise that such a programme is more likely to produce uniform animals of predictable merit. Then to their dismay, a few animals having recessive disorders begin appearing in the line-bred progeny. When the first abnormal puppy is born, the initial reaction is to deny that anything heritable is at fault in their line. It is regarded as a freak and the puppy disposed of. When further abnormal births occur, the cover up continues.
The veterinary profession and geneticists know well that in-breeding is usually accompanied by an increase in defects: smaller litter sizes, increased post-natal mortality, general lessening of body size, lower reproductive performance, less robustness and behaviourial problems. It is not inbreeding per se which brings about these defects but the presence of deleterious recessive genes which are being carried in the stock. Yet it is consistently argued by pedigree dog breeders, and regrettably even by some with veterinary training, that our pedigree breeds of dog are just as healthy, virile and robust as any cross-bred dog, mongrel or mutt. This is in spite of the weight of empirical evidence, especially from north America, over the last fifty years in particular. There are of course plenty of perfectly healthy pedigree dogs and far too many ill-kept mongrels and pitiful pi-dogs in the world. It is in the area of planned dog breeding where action can and must be taken to conserve the famous breeds handed down to us.
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. As successful an experienced hound-breeder, Martin Scott MFH wrote in Hounds magazine, Vol 30, 2014: "Line breeding is when you multiply the number of ancestors in the pedigree of the sire and the dam - ideally you should be breeding back to the best workers. To avoid getting into problems that might occur by breeding too close, the practise should not be any closer than the fourth generation as problems will arise if you do go closer than that. At the same time it is better to alternate the tail male of the sire and dam as well, so as to avoid both having the same tail female line." I have never heard a show breeder providing such advice. 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.