Calculating the COI, or inbreeding level, is an integral part of planning a healthy litter and usually the first step in the process of mate selection.
Inbreeding is both good and bad, it is necessary if you want to make a unique breed of anything, dogs, canaries, peas, whatever. Some breeders refer to it as inbreeding only when they breed together close relatives such as mother-son, father-daughter or brother-sister. Others refer to line breeding which is making sure that a particular dog is in the pedigree of the planned litter as many times as is possible, thereby breeding on that "line" to bring in its traits to your pups and lastly there is out-crossing which means that the sire and dam of the litter are not closely related although they are of the same breed. Inbreeding, line breeding, out-crossing are all inbreeding if the COI is above 0.0%. I personally do not use any of these terms as they are misleading.
In almost every planned litter, there will be some level of inbreeding. It is very rare that two dogs with at least a few complete generations of parents on their pedigree, won't have at least one common relative in ten or more generations.
Your dog and every other dog in existence is either not inbred because their COI = 0.0%, or it has a score above 0.0% which means it is inbred to a lesser or greater degree (COI = Coefficient of Inbreeding, is a very long and difficult mathematical equation to figure out how closely related dogs are, it is best done with a computer program made for this purpose or a math genius).
In order for a breed to become a breed, some inbreeding has to be done. Low levels of inbreeding provide the typical fixed basic features of a breed, such as color, fur, body dimensions, ear and tail type, and all the other things that allow us to identify a dog as belonging to that breed. High levels of inbreeding over a prolonged period can create more uniform breed specimens. To the not so involved breed person, ten dogs of the same breed may look identical, but those breed enthusiasts which have been involved on a higher level for many years, can usually identify one dog from another without too much trouble.
However, in most every breed there are usually a few kennels that have "fixed" their "look" to such a consistent level, that identifying any dog in their lineup from another is problematic for even an experienced eye. This can be done by either using a persistent inbreeding schedule over many generations or by repeating litters many times over many generations. Inbreeding is not a quick fix and you can just as easily fix traits you don't want.
The level of inbreeding that is acceptable in a breed depends on a few things, the most relevant are the breeds’ average COI level and any serious genetic health issues the breed may have. 12.5% and above is generally regarded as being high, or higher than GRAS (generally regarded as safe). In some breeds, the breed wide COI average is so high, it is not possible to get a COI for a litter that is GRAS. In those breeds, lowering the COI levels of planned litters should be a priority, or at least not creating litters with a higher than breed average COI. The goal should be a COI of 6.25% for each planned litter, as is possible.
Keeping the COI low should give enough breed similarity to the planned pups, while still allowing for a diverse pool of genes to draw from for future litters, which will benefit health, temperament and the purpose of a breed through the years ahead
So what does all this mean to you? If your dog has a COI of 0.0%, it is not inbred, this usually happens only when you breed two parents that are not from the same breed together. If your dog has a COI of 0.1%, it is inbred. Keeping the level under 12.5% is in the best interest of a breed's future health and welfare. But in order to avoid doubling up the risk of a serious health concern in a planned litter, it may be necessary to go a little bit over the GRAS limits occasionally. It is probably not wise to go over 16% (a 25% increase from 12.5%), no matter what you are wanting to avoid, the chance of doubling up something additionally not desirable, also increases the higher the COI level goes up.
Now if you missed that salient tidbit, the chances of reproducing something good or bad are about equal, no matter the COI level. That is, if you breed with a lower COI, you might have less of a chance to reproduce something bad, but you also have less chance to reproduce what you want. If you breed with a higher COI you might have a better chance to reproduce what you want, but you also have a better chance to produce what you don't want just as easily. This applies to external features, as well as diseases. Now how to rectify this trade off into a win-win situation, that is, keep the COI level low and still get the good features you want in the planned pups?
If you know the two parents you plan to use in detail and have studied their visible features well (and have passing health tests for both), if you like what you see, chances are you will like what you see in their pups. If other dogs that are very closely related to the chosen parents also have these same features, that is, their parents, grandparents, siblings, other offspring they may have previously had, also have good fur, correct tail, pricked ears, etc., then the chances get better that your pups will have these too. It's an educated gamble, but what you see in the parents and those relatives close to the parents, are the most likely choice of features that will be available for the pups in your litter too, regardless of inbreeding levels. Inbreeding to high levels does not guarantee you will get what you want in your litter anymore than low inbreeding does.
Getting what you want in a litter goes far beyond the inbreeding level! The inbreeding level is a gauge to help determine the possible gene pool diversity available in a breed, it is not very helpful in getting the features you want in your litter. As the breed average level goes higher, the dogs in the breed start to show symptoms of inbreeding depression, the COI level is similar to a gauge of health in a breed. Those breeds that have a high breed wide COI average usually have common health and reproduction problems which are difficult to avoid in every litter.
So to further put this into action, if you have a bitch you want to breed and you have several males in mind that give a COI below 12.5% preferably, pick the males that will also give you the best chance to avoid major health issues, then from those final choices, pick the males that will improve the faults of your female and have family members that also have those same good qualities. In rare breeds which are spread out over the globe, this is not an easy task! However the more popular breeds can also have difficulties in finding suitable mates, this is not an uncommon problem to most dog breeds today.
If you want to learn more about COI's, their calculation, what the percentages mean and what can happen when they get too high in a breed, check out the article on the COI Info Tab on this blog.
If you have any questions or concerns, please post in the comments section or send me a private email: mudicompass@gmail.com
Thanks for reading!
