Distichiasis

[t-time]

Just wanting some info about distichiasis in relation to breeding and mode of inheritance.

I'm aware it's quite common in several breeds.

The reason I ask is because, Distichiasis is mentioned as occurring in Havanese in ONE US Hav health paper written some 10 years ago but the condition seems to have either been brushed under the carpet or not given any heed since.

Those of you with breeds which suffer Distichiasis - is it a major consideration in your breeding choices? Do you/would you still breed with a dog who has had a known case of Distichiasis?

Any good websites about the condition would also be appreciated.

Thanks in advance

[Gigit]

Just wanting some info about distichiasis in relation to breeding and mode of inheritance.

I'm aware it's quite common in several breeds.

The reason I ask is because, Distichiasis is mentioned as occurring in Havanese in ONE US Hav health paper written some 10 years ago but the condition seems to have either been brushed under the carpet or not given any heed since.

Those of you with breeds which suffer Distichiasis - is it a major consideration in your breeding choices? Do you/would you still breed with a dog who has had a known case of Distichiasis?

Any good websites about the condition would also be appreciated.

Thanks in advance

I just Googled it, lots of sites come up, you need to go through them. A great one is the images on the google list.

[Sandra777]

It is extremely prevelent in Staffordshire Bull Terriers and no I would not knowingly breed from an affected dog if other choices were available, but it would depend on the size of the gene pool and this differs from breed to breed

AFAIK it is a dominant gene with incomplete penetrance, which makes it a right sod of a thing to get rid of - it only has to come from one parent and it may or may not be apparent in an affected dog.

It does come in various forms and the dog with a couple of soft eyelashes suffers no illeffect, but my understanding is that this dog could throw pups with an eyeful of short bristly eyelashes.

[cowanbree]

It is definitely genetic and I take it very seriously, had to eliminate one of my imports because of it. I would excuse the odd one or perhaps even two eyelashes very occasionally but any more than that is desexed in this house.

ETA when I am looking for a stud it is one of the health questions I ask and yes would eliminate based on it

Edited January 27, 2010 by cowanbree

[Jed]

I wouldn't breed from a dog with it, and I try to check the line for things like this, which are not always poking you in the eye, so you have to be careful. (Sorry about the pun )

[Steve]

No way would I breed a dog which had this.

[t-time]

Thankyou folks!

It's a curious situation in our breed as there *were* a number of health problems reported in this study paper and to be honest, they seem to have just disappeared??

The Havanese Club of America is incredibly strict with their members' health testing with yearly CERF exams, heart, liver function, thyroid, hip & elbow scoring etc so you would *think* that something like Distichiasis would be reported in eye exams....

[ellz]

It can be very much a breed by breed thing.

In American Cockers it is generally considered to be "breeder discretion".

The preference is obviously to avoid it where possible but the gene pool is such that to do so means that you risk introducing "worse" issues if you dismiss any dog with the odd eyelash or two out of hand. And American Cockers have some pretty horrendous eye issues that make distichiasis look like childs' play.

Naturally, a dog with a severe distichiasis SHOULD be avoided by the plague, but it is generally accepted that a dog with one or two small eyelashes is relatively acceptable. And of course, there is no way that I (and I hope any other breeder) would consider using a dog with distichiasis on a bitch with distichiasis of ANY degree.

And if it is more than perhaps one or two small eyelashes, then no, I wouldn't breed from it.

[SoL]

Put simply, no. If I had a dog with certified distichiasis, then it is a genetic fault no matter what degree it is presented in and that dog IMO should not be bred from.

[ellz]

Should add that in Staffords, no, I wouldn't use a dog with distichiasis for breeding. The gene pool is large enough that quality dogs can be found without the issue.

Something I meant to mention with regards to American Cockers is that I have used a bitch with VERY mild distichiasis (ie 2 small eyelashes noted by an othalmologist in an otherwise healthy eye) twice in my breeding program and to date, none of her offspring or their offspring have shown distichiasis. And I'd imagine I would have found out by now if there were major issues....bad news spreads like bird shit, good news tends to not be mentioned.

[dancinbcs]

Just wanting some info about distichiasis in relation to breeding and mode of inheritance.

I'm aware it's quite common in several breeds.

The reason I ask is because, Distichiasis is mentioned as occurring in Havanese in ONE US Hav health paper written some 10 years ago but the condition seems to have either been brushed under the carpet or not given any heed since.

Those of you with breeds which suffer Distichiasis - is it a major consideration in your breeding choices? Do you/would you still breed with a dog who has had a known case of Distichiasis?

Any good websites about the condition would also be appreciated.

Thanks in advance

It may have just occurred in one line that has died out, or it make have been hidden.

Just because a condition once occured in a breed, it does not mean that it will always continue to occur. It also depends on the local gene pool in each country. Some conditions are common in one country but hardly ever seen in other countries in the same breed. The only way to really find out is to have DNA tests developed and used internationally.

My breed, Border Collies, probably do more DNA testing than almost any other as we now have three conditions we can test for. The genes for CEA and TNS have proven to be widespread throughout the breed worldwide. CL, however was mainly found in dogs here despite being traced to the most likely source, a dog imported from the UK, many years ago. Epilepsy seems to be a concern in BCs overseas, but pretty rare here and CPRA and PLL used to be listed in everything as known genetic problems in BCs but seem to have completely disappeared from the breed. Years of eye testing before the CEA DNA test became available failed to reveal any other eye problems in Australian BCs.

If a condition is reported in your breed, it is worth screening for but if no cases are seen in several generations then it probably never will be, unless you bring it in with an outcross. Dogs affected by genetic problems should not be bred unless the gene pool is so small that there is no option. Working out which parent the affected animal inherited the condition from can be difficult with dominant genes so avoiding breeding from the parents may be throwing the bay out with the bathwater. Without DNA tests the only solution to tracking down genetic defects, is good record keeping and absolute honesty between breeders.

[t-time]

Thankyou all on these interesting points of view.