Dr. Douglas Schar and Dr. Anatoly Vinokur
Wong Mau…. The Mother the Burmese Breed
Breeding Healthy Burmese Cats
When I decided to breed Burmese cats, I discovered that some American Burmese had become dangerously inbred. The famed cat geneticist, Dr. Leslie Lyons did a study of purebred cats and concluded that the American Burmese breed was one of the most inbred cats in the world.
First of all, inbred is never a good thing. Not in animals and not in people. When you see the word inbred, see the word trouble. Inbreeding always brings health problems. In the American Burmese it causes immune system problems, breathing problems, kidney problems, and a whole lot more.
Finding out my favorite breed in the world was the most inbred breed was a real downer. I did not want to own a cat with health problems let alone pass sick cats onto pet owners. So, I looked into the situation. Why were they inbred, how did this happen?
Well, it turns out the Burmese breed was created in 1920 using one cat, Wong Mau, and a Siamese looking stud, Tai Mau. It was a genetics project looking at the brown gene carried by Wong Mau and thus, the breed was literally "created" using one cat, and all Burmese cats trace their roots back to her. So, the Burmese breed in the United States was started with two cats, and for almost 100 years the descendants of these two cats have been bred back to themselves. Virtually no new blood in 100 years, and Voila, you have an inbred breed of cat.
I don't want to be an alarmist. All purebred cats are inbred, it is the nature of purebred cats. You don't get one without the other. But, building a breed on one cat, breeding all the kittens that result from that one cat, to each other, for 100 years, does not pass the whiff test. Common sense indicates something bad is going to happen and it has. My original cats, born in the 1970's, lived to be 27 and 29. Today, I get kitten requests, every day, from folks whose Burmese cat died at at 2 or 8. Inbreeding may have worked for a long time, but, it is no longer working. The health of the cats is down, the size of litters and vitality of kittens is down, all indicators the breed is NOW in trouble.
My desire to breed healthy Burmese cats forced me to do some thinking.
And my thinking was pretty simple. If the breed was created with a handful of cats imported from Thailand, it could be fixed by importing a handful of cats from Thailand. And, that became my breeding plan. However, I am not a cat geneticist and before I moved ahead with my plan, I decided to contact an expert, Dr.Leslie Lyons. I repeat, I am not a geneticist and I thought it important to listen to the expert on the subject. That’s why we have experts!
Anyhow, what I learned from Dr. Lyons was that the ideal mix would be kittens with one American parent and one imported Thai parent. Basically, that meant kittens that were 50% American Burmese and 50% imported Thai cat. And, that is my breeding plan and my goal. Kittens coming from my cattery follow the genetic formula suggested by a world- leading expert. Now, these are not going to be show cats, because, the Thai imports do not fit the American show standard. They do not look like the contemporary American Burmese. They look like the Burmese cats you saw in the 1970's. But, they DO have the same personality! Thats the important part to me.
The important facts to hold onto are these. The American Burmese breed is dangerously inbred, and, I imported cats from Thailand to improve the health of my kittens. This is a common sense solution to the problem, but, it is also one that I ran by cat geneticist. And not just any cat geneticist, one of the worlds leading cat geneticists.
That is probably as much as you need to know, but, if you are really interested, you can read my email conversation with Dr. Lyons that resulted in my breeding plan.
Email Conversation with Dr.Leslie Lyons
Me: Hello Dr.Lyons, Thank you so much for getting back to me. I have read all your work and am really exciting to be in contact with you. And, I promise you this. I will intently listen and put your counsel into action. I have no agenda apart from insuring the survival of the Burmese breed. I do not show. I do not derive my income from this pastime. I just like the breed and am in a position to do something to help it. And, I am a scientist so the truth, however inconvenient, is still the truth.
After I got your email, I became more enthusiastic about working within the Burmese breed group. Starting a new breed one was not exactly high on my list, just a course of last resort. But, with a little help, I think I can stick with the Burmese. I like the breed. So, I have few questions for you. Please feel free to answer with two word sentences. As in, a yes or no will be just fine! I appreciate your time is of a premium.
1. The breeders that are open to using imported stock have the following plan in mind. They will produce 50% Thai x 50% Burmese hybrids and then breed these hybrids back to Burmese lines, to "bring the cats back to type". Effectively what that means is that the second generation will be 25% Thai 75% inbred stock, and that number will then drop to 12.5% Thai 87.5 inbred stock. In the span of four generations, the percentage of new stock will be so low as to be of little genetic significance. More over, breeding "back to type" means breeding back the flaws currently causing problems.
A. Do you think this breeding plan would make a difference in the long term?
Dr. Lyons, "I think it would be better to breed 50% Thai x 50 Burmese hybrids to other 50% Thai x 50% Burmese hybrids whenever possible, with a minimum threshold of 25% imported Thai blood."
B. Do you think this breeding plan would make a difference long term?
Dr. Lyons: "I think people should try different things. You have to balance the loss with the gain as you still want to be somewhat competitive. So, if some people do one thing and others do another – that is a good thing. Just so the hybrid cats keep getting used. If you select for good things – that may be selecting for some of the import genes and keep that percentage high."
2. I have bred animals my whole life and am well acquainted with hybrid vigor. In keeping with this experience, I mated a seriously inbred American Burmese cat to an equally inbred American Siamese cat and ended up with three litters of kittens with health problems. Though the parents were theoretically unrelated, a true "outcross", and I know for a fact they did not come from the same foundation cats, hybrid vigor did not occur.
Dr.Lyons, "Well, it is a game of numbers. Maybe these 2 cats were not a good mix, or just bad luck with the litter. Overall, hybrid vigor will be at the population level and not always for individual cats."
In keeping with this experience, I have my doubts about outcrossing American Burmese to inbred Burmese derived breeds(Tonkinese or Bombay). Its not that these breeds are derived from the Burmese, its the fact that these breeds themselves lack genetic diversity. These are two inbred breeds.
Dr.Lyons: "Any crosses will help – again – it is a population thing and a specific litter or breeding may not be a good combination."
When you breed a dangerously inbred cat to an entirely unrelated dangerously inbred cat, can you expect hybrid vigor? Is there any benefit to this type of breeding?
Dr.Lyons: "They are likely inbred at different genes – so – it is still an outcross. We do this all the time in mice and generally it works."
Ok, those are my two primary questions. Thank you so much for taking the time to read them. I am eager to create a breed plan that makes sense, and, am at a loss as to what is the best course of action. Ill do it, whatever it is, but, I need to know what to do!
Breeding Health Burmese Cats