I bred my first litter last spring, and somewhere near the end of the process realized how much I had to learn about good breeding practices and how important it was that I did learn. A novice breeder like myself who breeds one litter of puppies a year bears the same responsibilities for those pups as does the established breeder who breeds a number of litters a year. However, the unfortunate truth of the matter is that we novice, small-time breeders often don't have the knowledge or the facilities to bear those responsibilities easily. Our limitations make it all the more important that we try to produce sound terriers.
In an effort to gather some information on good breeding practices, I turned to my past issues of True Grit and found some excellent resources. In the June, August and October '91 issues there are a number of articles on genetic science as it relates to dog breeding. The August and October '91 issues also include Nancy Breakstone's discussion of the Breeder's committee's clarification of the JRTCA's then existing policy on inbreeding. What follows here is based on my reading of these articles and discussions with some of the knowledgeable people I have the good fortune to be acquainted with. It is directed toward folks in a situation similar to mine, that is, those of you who are just beginning to breed litters, but who are serious in your commitment to the Jack Russell Terrier.
It seems to me that there are three general areas that must be considered when we evaluate a pair of terriers in order to decide if each member of the pair should be bred and if so to decide if they should they be bred to each other: we evaluate each terrier's outward appearance and temperament; we study their pedigrees, and we consider the degree and kind of inbreeding (if any) that we will allow with regard to our goal for the breeding.
First, it is important to look at each individual as dispassionately as possible. What are her faults? Does she have any defects? Faults are aesthetic flaws while a defect is a genetic malformation or disease which severely affect the dog's health, soundness, structure and/or temperament. Because we register individual terriers who must be veterinarian certified for soundness prior to registration, it is unlikely that even the most novice among us would consider breeding an individual who was obviously defective. Unfortunately, possible defects can show up after a terrier is registered. Does your tough little dog show signs of back end lameness at the end of a long day in the field? Does your bitch chew her paws into a bloody mess in the fall? Situations like these can make for pretty tough decisions, especially for the novice breeder who owns a small number of treasured terriers.
The distinction between fault and defect is not always clear, especially when one is evaluating a working terrier. For the working Jack Russell, size, substance, eye shape, coat and of course, work style are directly related to function. Additionally, your hunting territory and quarry will figure largely in your considerations. To complicate matters more, even among the more experienced breeders there is strong disagreement as to what constitutes a defect: some would not breed an animal with a level bite, others would not breed a terrier which stood too far back to bay, still others would not consider either of these characteristics to be defects of structure or temperament.
After you have decided that an individual terrier is, generally speaking, of the caliber to be bred, it then falls upon you to decide how to breed it. If you are just getting started , it is likely that you obtained your terrier from an experienced breeder. She will be your greatest resource at this time. While you should know your terrier inside and out with regard to its development from puppyhood, your breeder should know the terrier's genetic history. She will have tracked your dog's ancestors through a variety of breeding combinations, and thus will be able to tell you the sort of combination that will stand the greatest chance of producing puppies free of defects and conformational faults.
It is likely that every terrier, no matter how perfect its outward appearance, no matter what its breeding, carries the genetic potential for some sort of defect. A recessive gene for a given defect will only appear if it is paired with another recessive gene of the same sort. The experienced breeder who has proven stud dogs and a number of good brood bitches will have learned that crossing individuals with particular pedigrees will produce certain problems in the puppies. This does not necessarily mean that your breeder is responsible for giving you a genetic true confessions. Sometimes it is possible to determine which ancestor is responsible for a defect or fault. Then, in the case of a defect you will avoid doubling up on that ancestor at all costs. Many times it is next to impossible for the breeder to determine which particular ancestor is responsible for the recessive gene. She may then advise you in general terms to avoid a cross, but will be unable to give you specific information as to why it should be avoided.
Our status as novice breeders does not excuse us from taking responsibility for learning the genetic history of our animals. As we prove ourselves to be reliable and sensible breeders, we will gain access to knowledge of the pedigrees of an increasing number of terriers. Further, we have the responsibility to inquire about the terriers we breed to and to follow up on the puppies we breed. Nancy Breakstone has a number of suggestions for those who are selecting a stud dog. She recommends:
- Get a pedigree, see it, don't just have it read to you over the phone.
- Send your pedigree to the owner of the stud dog. Ask if she has bred to familar lines and if so, what the outcome was. Most important, were the puppies healthy and registerable? Then, what were the puppies' conformational characteristics?
- If the dog has never been put to your bitches lines, ask for the names of people who have bred to the stud dog, and then ask them about their litters. (You should be particularly interested in the occurrence and rate of occurrence of problems and strengths common to the litters.)
Finally it is important to consider the general goal of your breeding program with regard to the amount of inbreeding that this breeding will involve. When you look at the pedigree of the terriers you are considering for a cross, you will need to evaluate the degree of inbreeding the cross would involve. If the two have ancestors in common, you are considering an inbreeding. The number of ancestors in common and their closeness to the breeding pair in the pedigree will determine the degree of inbreeding. You are considering a linebreeding when you consider the pedigrees with the goal being to find a particular ancestor common to both individuals in order to increase the likelihood that the puppies will resemble that ancestor. (Linebreeding is a special form of inbreeding.) When the pedigrees of a breeding pair show no ancestors in common within six generations then you are considering an outbreeding.
Serious breeders, novice or not, are engaged in an effort to produce outstanding individuals, individuals who will pass on their positive, dominant traits to their offspring. Some breeding programs, programs that involve higher degrees of inbreeding, can contribute to the appearance of such an outstanding individual. BUT, the unhappy truth is that such programs can also cause reduced fertility, increased health problems, and defects in other offspring. In the articles I have read, any discussion of inbreeding always includes a discussion of culling similar to the following: "It takes some skill to successfully practice inbreeding. Since the risks are great, you must be prepared to cull by spaying or neutering all of the weak and inferior animals." Oh, if it were that simple. It doesn't take a lot of time around dogs to gain an awareness of the sadness and suffering connected with these "weak and inferior animals." Also, culling does not necessarily involve a convenient spay/neuter contract. Defective puppies often present the breeder with a choice between extensive medical treatment and euthanasia.
The club office receives many inquiries about line breeding and inbreeding. The JRTCA will not accept any terrier that is inbred according to the JRTCA inbreeding definition. No father/daughter, mother/son, or brother/sister matings are permitted. Half brother/half sister matings are permitted only once within three generations if there is an ancestor that is common to both the sire and a dam (a generation is defined as the complete lineage of both the sire and the dam.) Many of us who breed litters don't realize that this inbreeding policy still allows fairly close breeding of relatives in our terrier families. Genetically speaking, the positive side of this is that we are free to increase our chances of producing those characteristics we all treasure in our terriers: intelligence, keen hunting ability, small chests, strong heads, good coats... happy, healthy warriors. The negative side of this is that we are also free to increase our chances of producing the genetic defects that are the worst nightmare of those who choose to preserve, protect and work the Jack Russell Terrier.
In closing, I would like to say that, after only one litter, I am all to aware of the thought, work and luck involved in producing good puppies. Evaluating breeding stock, understanding pedigrees, and establishing worthwhile goals for a breeding program are activities that cannot be successfully carried out by an individual. It has to be a collaborative effort. The breeder from whom I got my terriers provides me enormous amounts of help and support, as do other friends. As a result of their generosity, I have come to believe that the more we can appreciate each others' efforts, understand each others' mistakes, and respect each others successes, the more we will promote the welfare of our terriers.
Written by Margaret Wheeler