Updated: May 2
The Lagotto Romagnolo, an ancient breed, is thought to be the foundation of many if not all of the modern non-shedding, hypo-allergenic breeds, including the Poodle, Maltese, Portuguese water dog and others. In spite of this, it nearly went extinct just a few decades ago when it was rescued from this fate by a group of concerned Italian Lagotto Lovers. At this time, there were few Lagotto around and thus the genetic diversity of the breed was very limited.
Fast forward to today and the Lagotto Romagnolo as a breed does not enjoy the Breadth of Genetic Diversity as most other dog breeds. To adress this it should be the goal of every Lagotto breeder to strive not only for improvements in the breed's health while conforming to the Standard, but to ensure the greatest genetic diversity possible, which when carefully selected will further the goal of improvement to the health of the breed as a whole.
Traditionally breeders keep a number of males and females of their chosen breed - the offspring of their own breeding program. These dogs are kept with the intention of using them in future matings. The result of this is that without the importation of outcrossed genetics, the diversity of the kennels group (population) becomes concentrated, increasing the chances for unwanted genetic traits and health issues creeping into the population.
This raises a question for concerned and responsible breeders for it brings into conflict two opposing goals, the desire to eliminate unwanted Genetic disorders and the need to maintain the broadest possible 'gene pool'. In an effort to eliminate diseases susceptible to the breed, an obvious goal would be to eliminate from any breeding program any dog that has an autosomal-recessive gene for a known genetic disorder common in the breed. The result is a gene pool of genetically strong dogs, unaffected by A-recessive genes. This gene pool would however be so small that in just a few generations it leads to a highly concentrated genetic population. In turn, this increases the fragility of the breed. Frequency-dependent selection is the hypothesis that as alleles become more common, they become more vulnerable. This occurs in host-pathogen interactions, where a high frequency of a defensive allele among the host means that it is more likely that a pathogen will spread if it is able to overcome that allele.
One simple way of viewing this is through the concept of Coefficient of Inbreeding. The coefficient of inbreeding is the probability of inheriting two copies of the same allele from an ancestor that occurs on both sides of the pedigree. It can also be seen in the fraction of all of the genes of an animal that are homozygous (two copies of the same allele). This is something that Lagotto Breeders in particular with a genetic bottleneck only several generations behind us should be aware of and strive to reduce. This will take time and will improve with successive generations through conscientious breeding programs.
There are now database tools available to breeders to assist in identifying genetic Coefficient and they may be consulted, however a careful review of the pedigree of each proposed mating pair can identify sound matches and those potentially resulting in greater unwanted homozygous alleles.
At Northwest Lagotto, we believe that while line breeding and inbreeding within a breeding program results in consistent, predictable traits, it reduces genetic diversity and thus results in weakening our beloved breed. For this reason, as a rule, Northwest Lagotto will outcross when selecting mating pairs seeking to improve the diversity and robustness of the breed as a whole and our own puppies in particular.