Genetics is a subject that frightens most people. Don’t let it frighten you, because if you are going to breed you need at least a basic knowledge of genetics. If you do not have this knowledge, you will breed by trial and error. Some of those errors can be fatal for the pups and disastrous to you as a breeder.

Genetics is simply the law of inheritance and every time you breed a selected pair, you are practicing the art or science of genetics.

All the answers for the problems of dog breeders are not available due to the large gaps in the knowledge and research in dog genetics. There are some things that are true in genetics regardless of the species. This is that genes are the basic components that carry information for specific traits from generation to generation. If a gene is defective or missing then the information carried by that gene must be defective or missing. Very simply put there are Dominant genes, Recessive genes, and very rarely Mutant genes.

Genes are connected to each other on long strands called chromosomes. These are usually "paired" with one of each pair donated by each parent.

Every species has a distinct number of chromosome pairs, which never varies within that species. Humans have 23 pairs, cats have 19 pairs and dogs have 39 pairs. Similar species tend to have similar or identical numbers of Chromosomes. If there is an uneven number of Chromosomes genetic problems can occur. There are two instances of this, which most people will be familiar with. One is the horse (64) and the donkey (62), when bred together they produce the mule with 63 Chromosomes, this invariably means the mule is sterile. The other is a Downs Syndrome child who has one extra Chromosome.

The dog, wolf, dingo, coyote and jackal have the same number of Chromosomes. What is even more remarkable is the size and types of the Chromosomes in these species are identical. That is the fundamental reason why these species can interbreed. There are some 25,000 or more pairs of genes in the dog. These genes are attached to the 78 individual Chromosomes. It is the large number of Chromosomes in the dog that accounts for the numerous different sizes, shapes and breeds, to have spread and adapt to the many climates throughout the world.

Good breeding practice means the conservation of all the genetic material that is good in the hope that eventually we can breed dogs that are entirely good at least from a genetic point of view. This is where your basic knowledge of Dominant and Recessive genes needs to be studied and applied. Notes should be kept on all litters carefully and methodically and you will learn something new with every litter you produce.

You start by learning the golden rule of genetics and it is If a trait appears in any puppy that is not evident in its parents, that trait must be a recessive gene trait. You will begin to recognise the recessive genes without a lot of studying or effort and you will find it interesting exciting and fun.

Another thing to remember is that Recessive genes always breed true and so do Mutant genes.

Some of the Recessive genes we all see from time to time in our breed are, undershot/overshot mouths, parti colours, ring neck, sox and stockings and masks, long legs, long coat, timidity, light eyes and liver or blue pigment, curly tail, and patella luxation. There are many more, some are potentially dangerous or lethal for example hydrocephalus, cryptorchidism, kinked tail, epilepsy, harelip, cleft palate, inverted vulva to name just a few.

It is important for you to know that these problems must be bred out, they can not just be cut out. The reason for this statement is that both parents had to be carriers of the Recessive gene for a puppy to show it. Therefore unless you could have the parents desexed and all of their offspring and their entire families the gene responsible is being carried and passed on by some of them.

If both sire and dam are only carriers of a recessive gene, you can expect to see, in a litter of 5 pups, 2 completely normal, 2 normal but carriers and 1 showing the recessive gene trait.

To sum up and finish this presentation I would like to give you some examples to demonstrate Recessive genes in action:

• A long coat to a long coat can only produce long coats.
• A parti-colour to a parti-colour can only produce parti-colours.
• A patella luxation to a patella luxation can only produce patella luxation.
• A non-black pigment to a non-black pigment can never produce black pigment.
• A soft or dropped ear to a soft or dropped ear will only produce soft or dropped ears.

And finally, remember that if one parent shows a Recessive gene trait that is the only gene that parent can give its offspring. The reason for this is that Dominant genes can, and do, mask Recessive genes but Recessive genes can only breed true i.e. as they are. It is therefore genetically impossible for two Recessive genes to ever produce a dominant gene.

The message to push home is that the genetically perfect dog is a myth. Everybody carries something. The objective is to avoid crosses between dogs that carry the same harmful thing.

This presentation has been very much simplified and avoids the technical and scientific language to introduce the subject in a way that I hope was still informative and interesting. Thank you for your attention and I hope I have sparked your curiosity on the subject of Canine Genetics.

Lynda O’Hello.

Q. What is a parti-colour? A. A white dog with spots, patches or splashes of colour.

Q. Are dew claws recessive? A. Yes although they are not a simple recessive.

Q. Do geneticists know the pathway of gene inheritance. A. They cannot yet trace a defective gene to a single donor although they have identified about 400 genes in the dog. They can test animals and tell if they are carrying a defective gene for some traits but not necessarily, where that gene started in the line.

Q. Is the albino gene present in dogs, e.g. if a pup at 8 weeks. has pink pads, pink nose and red eyes but has cream patches on a white coat, could it be an albino. A. The cream patches preclude it from being a true albino as the cream denotes some pigment. However there are degrees of albinism and this may be an instance of it or it may be a puppy with weak pigment and ruby eyes.

Q. What is a true monorchid and can you breed it out. A. Monorchid is a term invented by dog breeders to denote one testicle undescended, however the correct term would be unilateral cryptorchid. In a cryptorchid one (unilateral) or both testicles (bilateral cryptorchid) have not descended through the inguinal canal and are trapped within the body cavity. A true monorchid has only one testicle in the body whether it is descended or not. One has to be very careful in diagnosing this condition because some dogs may not have both testes in the scrotum until 18 months of age. The testicle that has not descended may be free of the body cavity and under the skin in or near the groin. The evidence available from research on dogs states that this is almost certainly not genetic. It is more likely that it is the result of arrested development, it may be on a very short vas due to trauma of some sort and it may be a developmental problem. It can be bred out of a line but it takes many generations of careful breeding and recording results.

Q. How can you tell what genetic defects are in a line and where would you get the information to breed it out.

A. This is something that is very difficult to answer because people do not want to say that they have produced a problem. I try to tell breeders there is no shame in producing it because you didn't create it. Once we accept that we begin to move forward. Breed clubs should have all the information available as to what the significant genetic defects are common for the breed. They should have advice to assist breeders in understanding the basic principles of inheritance and this knowledge when applied begins to breed the problem out. The Breed club is one step, other breeders another, vets know genetics very well and there are some quite good books on the subject although most would find them very heavy reading.