Playing Feline Matchmaker

Picking the Right Pairs for Your Breeding Program

Lucy Drury

If you are new to the world of show cats, do you want to know how to make a veteran breeder wince? Make an obvious fuss over their beautiful cats, ask a lot of good questions about their breed, tell them how you’ve never seen this breed before, how much you love it, that you’ve only had rescue cats until now, and then follow up with this question: “Do you sell any kittens for breeding?” Even if that breeder is the type who loves to get newbies off to a great start, the response you should receive might be the offer of an altered kitten or cat to show so you can learn about the breed, along with a brief discussion of what goes into planning and building a quality breeding program – particularly how to pick the right sire and dam for your first litter.

A Breed Standard? What’s That?

Where does one begin, though, when deciding who the lucky feline couple will be? Studying the breed standard is a great place to start. A breed standard is a set of observable physical characteristics (i.e., the phenotype) that a group of experts have defined by describing those characteristics with carefully chosen words. Both new and experienced breeders need to have a solid understanding of what that standard is for their chosen breed. For the most part, writing a breed standard is a somewhat arbitrary and artistic exercise, and standards between the various pedigreed cat registries can and do vary, even if they are calling a breed by the same name. Furthermore, standards can be changed by their governing bodies (the breed councils) as circumstances dictate.

You may have some trouble convincing a new – or even an experienced breeder – that following the breed standard is a necessary requirement. “I don’t care about show quality,” one breeder might say, “so why do I have to worry about the breed standard? I’m just breeding them to sell as pets.” That is a breeder to absolutely avoid!

The truth of the matter is, if that particular breeder is not going to pay any attention to the breed standard, then they cannot claim they are producing kittens in the interest of breed preservation! They are just randomly breeding domestic cats … something the Cat Fanciers’ Association does not endorse. That does not mean there isn’t room for individual interpretation, as standards are full of words that are more qualitative than quantitative in nature. Clearly, though, if a breed standard calls for a broad, rounded ear and the cat you are considering adding to your breeding program has a narrow, pointed ear, it is probably not the one you want, no matter how much you love its color and temperament. While there may be disagreements between experienced, knowledgeable breeders as to what the ideal looks like (e.g., how round is too round and how broad is broad enough), few standards have measurably quantifiable characteristics. So, while there are often distinctive looks from cattery to cattery, they all still arguably meet the standard. This highlights the need to show your breed and observe the winning cats if you really want to learn about the standard. It is not enough to read the standard and have other people show the cats for you. As one veteran judge stated, “You can read a standard all day and not know how to interpret it correctly until someone who understands the breed goes over it with you with one or more live examples of the breed.” Visiting other catteries of your breed is helpful, but your perspective will be narrower unless you also attend and keenly observe at cat shows.

I’ve Learned the Breed Standard – Can I Go Buy That Kitten on Facebook Now?

Not so fast. You have a few more critical things to consider. That kitten may look perfect and be a beautiful, sweet example of the breed – for now. What do you know about the parents?  Do you know what they looked like as kittens?

Even more important: what do you know about the parents’ pedigrees and health screens? While it’s always a good idea to ask for those even if you are buying a kitten as a pet, it becomes vitally important to know about ancestry and inheritable health issues in the breeding lines when contemplating the purchase of a breeding animal. Ask to see veterinary records of the parents and test results for screens in breeds with known inheritable defects, such as Hypertrophic Cardiomyopathy (HCM) and Polycystic Kidney Disease (PKD). Having a parent genetically test as a carrier for an inheritable defect may not automatically disqualify a kitten for your breeding program, but you will want to test the kitten for the defect before you make any final decisions. If the kitten tests positive, then you have a difficult decision to make, particularly if everything else is “right” about the kitten. For example, that beautiful girl who would make a perfect match with your best boy tested as a carrier for pyruvate kinase deficiency (PK def). As a carrier only, the kitten will never develop this disease as it is a recessive gene – the kitten must inherit the defect from both parents to develop the disease itself. If the other parent is not a carrier, then none of the kittens will be develop the disease; however, statistically, half the kittens produced by the pair will also be carriers.

Why even consider the kitten, then? Why pass on an inheritable defect if you know it’s there?

Genetic Diversity

That question leads us to our next point when selecting parents: genetic diversity. The more closely related the parents are, the more chance you have of producing a kitten with an inheritable health issue. In a prior issue of CatTalk, we discussed the Coefficient of Inbreeding (COI), how to calculate it, and how it can be useful in selecting parents, so we won’t rehash those issues here, except to say that the lower the COI, the less closely related the pair. The difficulty with COI, however, is it doesn’t always tell the whole story, particularly if it is only calculated from a four-generation pedigree. Go back a few more generations, and you might find a lot of the same names behind those great-grandparents. By its very nature, breeding pedigreed animals is a form of inbreeding. In most cases, a breed was determined by a group of humans getting together and segregating animals of the same species by observable characteristics long before genetic testing was “a thing.” Breeds and the written standards that go with them are arbitrary, human-manufactured classifications. Breeders who are competing at shows or are simply striving to breed the “perfect” specimen of their breed will often deliberately select for recessive traits (such as dilute colors or classic tabby), or will strive to have only homozygous forms of a dominant trait (where both copies of the gene are dominant). These decisions greatly narrow the available animals for their breeding pool. Such a reduction of genetic variance in a population created by a reduction in the original number of animals available to reproduce is called a population or genetic bottleneck.

While this can fix desired traits in your lines, keep in mind that it also increases the risks of rare but deleterious mutations manifesting themselves in a population. The effects of population bottlenecks in dogs has been well-studied and documented. Heart disease, blindness, cancers, hip dysplasia, cataracts and other genetic defects are a result of declining genetic diversity in a population. ^1,2 New breeders who are choosing their foundation cats need to be particularly wary of this problem. It does not take long for a prolific and popular stud to leave his mark on a population, good and bad, so pedigrees need to be researched thoroughly beyond the four-generation chart to determine whether a potential breeding pair might be more closely related than the COI as calculated from four generations might suggest. Genetic diversity is so important to a viable population that using carriers of certain defects as one parent may be acceptable if using that cat in your breeding program helps the genetic diversity overall.

If there’s not a wealth of pedigree information beyond four generations, what then? Pick your pair and hope? Not necessarily, if you’re willing to spend a few bucks. Given how costly it can be if you don’t get a good match, genetic testing can be well worth the investment. At least one genetics lab offers comprehensive genetic trait, disease and diversity testing for less than $100. The diversity testing will compare the diversity of your cat’s genetic makeup to the average for their breed and the cat population at large. It will also do test comparisons of potential mates if the owners wish to participate. The more diverse the genetic makeup, the better the match, at least from a genetic health perspective.

What’s Your Blood Type?

An oft-overlooked trait when selecting breeding pairs is blood type. Just as in humans, incompatible blood types between mother and offspring can be deadly. One of the most dangerous scenarios occurs when a blood type “B” queen is mated with a type “A” tom and gives birth to type “A” kittens. “B” queens carry naturally occurring anti-A antibodies, which are present in the colostrum with all the other maternal antibodies. Unfortunately, the anti-A antibodies attack and destroy the kitten’s “A” red blood cells. If this blood type pairing is known and not immediately managed at birth, the condition is almost always fatal – unless the kittens are removed from the queen and hand fed for the first 24 hours. It is best to avoid the scenario if possible and pick parents of compatible blood types.

Does Color Matter?

When it comes to selecting your breeding pairs (except for your personal preference), probably not. Consult your breed standard. What does it say? What colors are allowed?  What outcrosses are allowed?  If the breed standard says it’s okay, it’s okay. If it’s not, it’s not. This goes for any trait. Remember what we discussed at the beginning of this article: a breed standard is a set of observable characteristics determined by a group of people knowledgeable about the species and breed being described. Yes, I know, your favorite breed may be one that allows most colors and patterns, but you could well discover that some breeders won’t allow you to breed their cats of one color to a cat that expresses a different color or even possibly carries certain colors and patterns based on their pedigree, because they believe cats of certain colors are not “pure” representatives of the breed, despite what the breed standard says.

Since the purpose of this article is to help the reader make quality decisions regarding breeding pairs and not prove or disprove the genetic ancestry of a breed, consider this: the more genetically diverse a population is, the more genetically healthy it is. That means less structural issues, less cancer, less autoimmune diseases, healthier and more viable litters. The benefits of a genetically diverse population are well-studied and documented. By breeding pedigreed cats, a breeder is already lowering the genetic diversity by excluding all other breeds from their breeding program. Add in the obvious reasons for exclusion – health defects, bad temperament, poor type – and you narrow it down even further. Beyond that, a breeder wants to sell you a kitten and requires a contract which further restricts you from using potential breeding partners for your kitten based on criteria that has nothing to do with the health of the future litters or maintaining the breed standard. Think carefully before putting yourself in this form of bondage, particularly if you are just starting your breeding program. Research the pedigrees of the cats in the cattery carefully – not just the kitten you are thinking about buying, but its relatives, too. Is there evidence of a lot of inbreeding? Are you going to be able to easily find an unrelated mate that meets the restrictions? If the answer is “Yes” to the first and “No” to the second, you should find a breeder who is less restrictive. Even if you are not a fan of a certain color, some of your kitten buyers will be, so let go of the ones you don’t like rather than trying to purge the color from your pedigrees.

These are just a few of the considerations a breeder should think about when selecting a breeding pair. A good mentor who will look at potential candidates then frankly critique and discuss them with you is an invaluable resource. Producing healthy kittens should be the main consideration in choosing parents, followed by good temperament and good type, while color and pattern should be the last things considered. As many breeders have put it, you have to build the house before you paint it.

References

 

1. Lindblad-Toh, K., Wade, C. M., Mikkelsen, T. S., & Karlsson, E. K. (2005). Genome sequence, comparative analysis and haplotype structure of the domestic dog. Nature, 438(7069), 803.
2. Marsden, C.D., Ortega-Del Vecchyo, D., O’Brien, D.P., Taylor, J.F., Ramirez, O., Vilà, C., Marques-Bonet, T., Schnabel, R.D., Wayne, R.K. & Lohmueller, K.E. (2016). Bottlenecks and selective sweeps during domestication have increased deleterious genetic variation in dogs. Proceedings of the National Academy of Sciences, 113(1) 152-157.