Breeding & Health Testing

Our breeding program is currently in a period of restructuring (we got our first Bostons starting in 2001) and refinement. Our current focus for our program is our bloodlines, extensive health testing and keeping current with cutting edge research and genetic testing. Our focus continues to be on quality and not quantity.

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Our dogs are a blend of Canadian, American and European bloodlines. We have imported our dogs from reputable breeders in the United States and from many European countries. We do so, in order to promote genetic variability in our bloodlines. More specifically, to prevent homozygosity (homozygosity is having two identical alleles of a particular gene/genes). While breeding related animals produces more consistent and predictable traits (as a result of homozygosity), loss in vitality and vigor are also the result (Beuchat, 2015). Breeding related animals also reduces fertility, produces smaller offspring, early death and a shorter lifespan (Beuchat, 2015). That is, the higher level of inbreeding, the greater the detrimental effects (Beuchat, 2015). All things considered and weighing the benefits and risks, we aim to breed puppies/dogs with inbreeding coefficients (ICs) as close to zero as possible. It is recommended that ICs are calculated over at least 8-10 generations (the more the better though!) and preferably 5% and under (Beuchat, 2015). Our ICs are calculated on TEN GENERATIONS and therefore reflect higher than they would otherwise (i.e. if calculated over 8 generations). In the past, we have always regarded 6.8% inbreeding coefficient to be an upper limit (again, trying to keep as low as possible), as suggested in the agricultural research available to us at that time. With advancements in genetics in the Veterinary field however, we now consider 5% over 8-10 generations to be an upper limit. In addition to taking into consideration our dogs' ICs when breeding, we also consider and compare these percentages to their Genetic Diversity/Heterozygosity percentage, as determined by DNA. Interestingly, one dog can have a low IC and higher homozygosity percentage and another dog can have a high relative IC and have a lower homozygosity percentage. Cool, right??!! A breeder must consider ALL!! The typical range of heterozygosity percentage of Boston Terriers is betwen 31 - 37% (Wisdom Panel™). The higher the percentage, the greater the heterozygosity.
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As per Our Story page, we breed for the "total dog", with an emphasis on health and temperament, while breeding to standard. Given the pitfalls of "breeding for show titles" (i.e. breeding dogs closely related to achieve consistency and predictability) and that breeds are created by inbreeding to begin with, our focus remains on health and temperament first and foremost. Yes, one must also breed to standard and we feel that showing is important in maintaining the integrity of the breed standard and the breed as a whole. However, show wins isn't our sole focus. Indeed, we enjoy showing and try to get to shows when our family life allows. "The fewer generations used in calculating the inbreeding coefficient, the "better" (i.e. lower) it will appear to be. But this isn't an accurate assessment of the true degree of homozygosity in a dog, so it does not reflect the true level inbreeding depression and risk of genetic disease" (Beuchat, 2015).

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The inbreeding coefficient is the estimated level of inbreeding/homozygosity of a particular mating/breeding. The inbreeding coefficient is the probability of inheriting the same allele from an ancestor on both sides of the pedigree and the fraction of all of the genes of a dog that are homozygous (Beuchat, 2015). A low inbreeding coefficient has a lower risk, but supposedly also lower benefits, as it relates to consistency in type. A high inbreeding coefficient would produce more consistency in type of the puppies produced, but there would also be a significant loss of vigor and health (Beuchat, 2015). The detrimental effects of inbreeding start to become evident at 5%, with a significant loss of vitality and an increase in the expression of detrimental recessive mutations in puppies at 10% (Beuchat, 2015). An inbreeding coefficient of 10% is considered to be the "extinction vortex", in which smaller litters, higher mortality, and expression of genetic defects have a negative effect on the size of the population (Beuchat, 2015). Further, as the population gets smaller, the incidence of inbreeding goes up, culminating in a "negative feedback loop" that eventually drives a population to extinction (Beuchat, 2015).

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Again, in terms of health, an inbreeding coefficient of 5% or less is most ideal, as above that, there are detrimental effects and risks. Thus, a breeder needs to weigh these against anticipated benefits gained (Beuchat, 2015). Inbreeding coefficients of 5-10% supposedly will have modest detrimental effects on the offspring, while levels above 10% will yield significant effects - not just on the quality of the offspring, but on the breed as a whole (Beuchat, 2015).

A breeder can use the inbreeding coefficient to reduce the risk of genetic disorders in their puppies, as it's an estimate of the predicted loss of vigor and general health expected as a repercussion of the expression of recessive mutations (Beuchat, 2015). However, the inbreeding coefficient is NOT a measure of health. Rather, it's a measure of RISK, and with or without DNA tests, it's the best way to ascertain the level of genetic risk one takes when breeding (Beuchat, 2015).

However, every dog has many mutations, and one has no way of knowing about them if the dog has only one copy and it's not expressed. Thus, if one breeds two dogs with some of the same mutations, one can expect that the puppies will be homozygous for 25% of them (Beuchat, 2015). Many of these mutations may only have very few effects and one may not recognize these as a "disease". It's the accumulation of these few effects that causes the loss of vigor and vitality in inbred animals (referred to as "inbreeding depression") (Beuchat, 2015). DNA tests tell you only about one particular gene, which is known as a risk for a particular disease (Beuchat, 2015).

To breed healthy animals, one needs to consider ALL of the potential risks, and there are many more recessive mutations than the ones we have DNA tests for (Beuchat, 2015). This is why we're now running (now that the tests are available) Optimal Selection™ panels on our dogs. In the past, we have always at least certified patellas, heart (by auscultation) and Juvenile Hereditary Cataracts and then Degenerative Myelopathy and Hyperuricosuria when the tests came out. We have also tested for the piebald gene in the past (and continue to do so) as well, as it's been hypothesized to be the cause of congenital deafness in related breeds and progenitors of the breed (Bulldogs, Bull Terriers, etc.). Please note, there is no genetic marker for breed specific congenital deafness in the Boston Terrier to date, but we do test for Deafness and Vestibular Dysfunction in this panel. Indeed, there are many reasons for deafness, genetics aside. However, we will continue to screen our dogs and puppies, follow research and test for all possible causes. It's important to note that DNA testing is not diagnostic, nor does it absolutely guarantee that a dog won't get disease/illness. Rather, it's a measure of likelihood, based on a dog's DNA/genes and DNA tests can NEVER completely replace Veterinary examination, certification and testing!