What Does COI Mean?


COI stands for Coefficient Of Inbreeding and is the calculation used to determine the level of inbreeding on an idividual dog or puppy.
The higher the number for COI the closer the dog or puppy was inbred. 
A very low COI reflects that that dog or puppy was “outcross” bred, meaning the parents of the dog or puppy had little or no common ancestors. A low COI breeding should really appeal to those individuals leaning towards obtaining a designer breeds (mutts) as basically a COI of less than 10% would be the equivalent of a mutt breeding, but with the beauty, health and characteristics of a purebred and a breeder’s health guarantee and support.
I get asked all the time how we achieve reds that hold their colour.
In order to achieve dark red colour a breeder has to start with the dark red colour.
You can’t take two light coloured dogs and achieve dark red colour that is going to hold.
You can’t take a light coloured Poodle and breed it to a dark red Poodle and achieve dark red pups that will hold colour 
UNLESS it is a linebreeding on dark red ancestor which will usually be a Majestic dog or VERY old Palmares Lines.
Which will mean a COI of 6% or greater on the litter. 
Line breeding on a dark red Poodle ancestor will “bring forth” that dark red gene. 
Because very few breeders are concentrating on “Colour Breeding”, finding “real” dark reds that hold their colour 
and have passed all OFA testing, is near impossible in 2010 and will continue to be impossible
Until more breeders stop using fading reds, apricot and creams in their red programs.
Buyers will find that the only “real” dark reds they can find as of 2010 will have a 10-generation COI of 6% and up. 
Once red breeders start concentrating on “Colour” (assuming OFA’s are completed of course) THEN
we can acheive colour from outcross breedings like breeders are doing with the more common colours.
Red breeders need to concentrate on health testing of course…but also on colour breeding.
Our BEST breedings of producing that rich Dark Irish Setter Reds have been 10-generation COI = 7.18% 
My BEST Dark Brown breeding with exceptionally sweet temperaments in 1980’s was a 10-generation COI = 15.27% (now in 2010 it is 1.11% or less)
You can see these reds and browns on our web page as pups as adults that have held their colour 
and are exceptionally healthy, completing all OFA health testing and DNA testing available.
COI is a great “tool” to assist breeders, but breeders CAN’T ignore genetics and expect to get results.
High COI percentages of over 20% increase the probability that genetic defects will be carried from common ancestors on both sides of the pedigree and will match up to cause the actual genetic disease or defect in the animal.
Many other problems of a high COI also affect dogs, such as Autoimmune disease and inbreeding depression symptoms, which result in reproductive and longevity issues.
A COI of 12.5% is equivalent to a half brother to half sister mating or a grandparent to grandchild mating. This breeding is the most common practice for breeders wishing to achieve consistency in type or to “cement” certain traits. As a result the litter should be fairly uniform in type & temperament which is the goal for anyone breeding for show. 
This breeding is usually referred to as a “line-breeding” and is one of the 
BEST breedings to achieve PERFECTION.
A COI of 25% is equivalent to a parent-child or brother to sister mating. This type of breeding is really not recommended by anyone. It is a very “tight” breeding and is usually referred to as “inbreeding”. A breeder could either get really amazing healthy great looking pups as a result, with pups that will have great genotype (ability to reproduce its self) and great phenotype (the pup will visually appear close to ideal for its breed) for the desired breed type, OR the opposite and look poorly and be very skiddish, hyper, aggressive, unhealthy pups as a result. So this breeding will either produce the best or the worst traits of their parents.
Ideally, the COI of a litter should not exceed the average COI of the two parents. It is highly recommended to avoid a COI in excess of 20%.
Some genetically inherited diseases and faults in Purebred and Mutts alike, are:

  • Hip and elbow dysplasia
  • Patella Luxation
  • Epilepsy
  • Eye disease such as: cataracts, Collie Eye Anomaly (CEA) and 
 Progressive Retinal Atrophy (PRA) 
Cancer 
Allergies and skin problems
  • Retained testicles
  • Autoimmune diseases
  • Bad bites and missing teeth
  • Unacceptable colors
  • Temperament problems such as shyness and aggressiveness

Inbreeding depression symptoms are seen as the loss of viability or function resulting from excess inbreeding. Sometimes these syptoms are very subtle and gradual and are often blamed on diet, pollution and other environmental factors. While these factors may also contribute, it is the dogs genes that make it more susceptible.
The most frequently seen inbreeding depression signs are:

  • Chronic poor health/poor keepers
  • Higher incidence of disease in a line (or breed) of one or more diseases
 than is seen in the breed or canines as a whole
  • Higher incidence of immune system diseases
  • Unusually small litter size
  • Difficulty in getting and keeping bitches pregnant
  • Bitches that abandon a litter or are poor mothers
  • Bitches that kill or damage puppies intentionally or by lack of care 
Studs that are indifferent to a bitch in standing heat 
Studs that cannot breed without help 
Low sperm count
  • Earlier average age of death in a line or in the general breed population

All of these factors make it incredibly important that you do the COI calculation on any planned litter. Keeping the breed healthy is easier than cleaning it up after the fact. COI calculation can give the breeder an indication of how inbred a dog or litter will be. Knowing this percentage will enable you to make the best choices towards reducing inbreeding in your dogs.
Today the emphasis should be put on health, temperament and working ability if purebred dogs are going to survive into the next hundred years. Active concern for health should be your number one breeding goal, because without health, you have no dog.

Leave a Reply

Your email address will not be published. Required fields are marked *