For The Health of Your Mini...

A new column dedicated to addressing the health concerns of the MBTCA membership.

If you have an article that you feel might be pertinent to this column, please submit it to the editor before the ad deadline for the issue in which you would like it to appear

Recorded, March 15, 2002

Louisville, KY

Transcribed by: Renges Fabris

Guest Speaker: Liz Hanson,

Assistant to Dr. Gary Johnson

University of Missouri, Department of Pathobiology

Speaker: The initial work that we had been doing on the lens luxation project in mini bulls kind of got stymied because of the small gene pool that mini bulls have and many of the markers that we worked with were uninformative. Basically, that means that everyone we tested had the same genotype. We can’t sort out one from the next in terms of effected dogs vs. unaffected dogs. Looking at the genetics we can’t find anything that is linked. We have now added other breeds that also have lens luxation problems. The grant that we just had approved by the AKC Health Foundation is to look not only at lens luxation, but also glaucoma. It seems that often times these run together. As I’m sure we are all aware, lens luxation can cause secondary glaucoma, and sometimes glaucoma can cause the lens to luxate. So not knowing, in some cases, which came first, we decided to study both of these together. Right now we are looking at samples from 14 different breeds and we are hoping that if we can crack this nut in one place, it will help us move along in another.

Audience: My partner and I haven’t had anything luxate yet. If we got the people who bought our puppies, and get all the puppies and the parents sampled, would that help your research so far.

Speaker: The thing that will tell us the most is whether these dogs are related to dogs that have luxated. The animals that we most want to sample are effected dogs, their full siblings and their half siblings. Also, the parents and the grandparents if they are still alive. Grandparents are useful if we can get them. I know this is not always possible when you have a late onset problem like this. If the dog had been used for breeding prior to luxating, we would like samples from all the puppies and the other parent as well. The lines where there hasn’t really been any problem, and they don’t appear to be related to any dogs that have a problem, they probably are not going to tell us a whole lot, unfortunately.

Audience: How do you get a DNA sample?

Speaker: We prefer to use a blood sample. I know it’s much quicker and easier to use a cheek swab, but it doesn’t give use much DNA to work with. The last thing we want to do is get halfway there and run out of DNA. So we ask for a blood sample. If the dog is having surgery, we’ll take whatever “spare parts” there are (laughter) because that’s a mountain of DNA if we can get a tissue sample. If a dog is being euthanized, we would like to get a tissue sample, preferably from the spleen. We don’t need the whole thing…just about a thumb size chunk. That would be more DNA than all the researchers in the world could use. We at least need blood samples in a purple top tube. Right now, when you’re getting ready to go in for a heartworm test, this is an ideal time to be sampling these dogs. Just get a little bit more blood and send it in. Contact puppy buyers and other people that you know and advise them when they go in for heartworm testing on their dogs that they should also get the dog sampled for this project.

Audience: I understand that glaucoma and lens luxation are two separate diseases. But if your dog starts luxating, it can shift the lens and that can interfere with drainage…

Speaker: Right. A luxated lens can interfere with drainage.

Audience: But then that’s not actually glaucoma?

Speaker: That would be secondary glaucoma.

Audience: If a dog has glaucoma and it is predisposed to lens luxation, the pressure of glaucoma can cause the zonules to weaken further and further along to lens luxation. Is that common?

Speaker: Yes. That is why we are looking at these two diseases together, because one can predispose the dog to the other. Initially, when we started on this, we thought that you guys with the mini bulls were experiencing strictly lens luxation, and we went merrily along our way with that assumption. And then we found out that you’ve also got glaucoma. We thought we kind of had a spectrum here with Basset Hounds having only glaucoma and you guys only having lens luxation and a lot of breeds that were experiencing different levels of these diseases in between. However, now we have a few Bassett Hounds that have luxated.

Audience: But a dog that has glaucoma won’t necessarily get lens luxation. And a dog that has lens luxation won’t necessarily get glaucoma. Right?

Speaker: Right. That’s why it is important to keep us updated as you send samples in. We really need to know what’s going on as the dogs age. We’ve had people whose dogs were sampled two or three years ago that have contacted us and told us that the dog luxated or it’s being treated for elevated pressure. If we think we’ve got a link marker, but we don’t have the right phenotype (if we don’t know that your dog has luxated) we might pass up a marker by saying that these are all normal dogs so this can’t be the correct marker. So it is very important that we are updated as to what is going on with the dogs as you have them checked every year. We have to have those updates, or we are going to pass up the correct marker.

Audience: I guess you are really familiar with glaucoma?

Speaker: I’m not an ophthalmologist. My role is to be a liaison between the scientists and the breeders. I have Standard Schnauzers. I started in this with some epilepsy research. I’ve had Standard Schnauzers for 26 years and another breeder and I got hit with epilepsy. Not wanting to give up all that work, we looked for someone to help us. After about a year of bringing samples to Doctor Johnson, he said “You know, you just need come work for me”. The epilepsy research is the other big project we are working on. We have a lot of other smaller dog projects. I fit into this because I’m a dog breeder; I’m an exhibitor. I’m here showing this weekend. I know what all you folks are going through when something like this hits. Any one of these inherited diseases can devastate a breeding program. I also have a background in science and veterinary medicine, although I am not a vet. I can work between in trying to help get the samples that we need into the researchers and get the results of the research back to you. Dr. Johnson is the gene jockey. He is the molecular geneticist and works on that end of it. But whatever project we are working on, we collaborate with an expert in that field. So, we have several neurologists that we work with in the epilepsy research; we have the opt homology staff at Missouri, and we are hoping to get a research consortium going there as well. In the epilepsy research, we have four universities working together and we are hoping to get something similar to that going with the eye research.

Audience: I had my dog tested at an eye clinic held in conjunction with the Montgomery County all-terrier show. When I took her in, I took her directly from the show to the clinic. I took her on a choke lead. She was playing with everything. When he did the testing on her eyes, her pressure was up. I don’t remember who the ophthalmologist was…it was in Pennsylvania. I immediately panicked because I was told that glaucoma and lens luxation were one-in-the-same disease. I immediately went out and got Xalatan because that is what he recommended. When I got home, I went immediately the University of Florida, to Dr. Galett and Dr. Biros. I wouldn’t take her off Xalatan even though they kept telling me to do it for almost a year because I was afraid my dog would have a glaucoma attack and that she would be in terrible pain. Finally, after almost a year the doctor told me to take her off. I did, and she never developed glaucoma. He told me don’t ever go in and have your dog tested under those conditions. It’s like being strangled or hanged…your eye pressure goes up. That’s what happened in this case.

Speaker: When you run into a problem, it never hurts to get a second opinion.

Audience: So…when you take your dog to be tested, take them in a crate, or carry them in?

Audience: I was asked by Roz Clamper, who is a bull terrier breeder-judge, to mention that her standard bull terrier developed glaucoma and has sub-luxated. Would this be of interest to your studies?

Speaker: Yes. Definitely. With this new grant that is looking at both lens luxation and glaucoma, it is fully funded, and I think your club contributed to that. We had several clubs that did contribute to the grant, and it is open to any breed that has the problem. So, we are definitely interested in other breeds.

Audience: Of course, standard and miniature bull terriers are very closely related. It’s almost a shame to call them a different breed. They’re not really a different breed. Only in the United States.

Speaker: Are there any other reports of standard bull terriers that have luxated first?

Audience: I don’t know about luxated first, but I talked to Dr. Vainisi about standard bull terriers that he has seen with glaucoma.

Speaker: Yes. We would definitely be interested in this data. Wednesday, before I drove here, I interviewed an ophthalmology candidate coming from Missouri who is one of Dr. Galett's post doc students. He is either going to NIH to study glaucoma using animal models for human glaucoma, or come to Missouri. I tried to lay out all the things that we are doing in Missouri and the reasons why it would be best to come to Missouri. He seemed pretty excited about the things we are doing. So we hope he will come because it will help us out quite a bit.

Audience: I was under the impression that the miniature bull terrier picked up the lens luxation when the standards were crossed to the Jack Russell Terrier in order to get the size down, although we don’t know this for sure. Are Jack Russell's taking part in this study?

Speaker: Yes. We are just starting. And, it is the non-AKC Jack Russell people that are more excited about it than the AKC people…there is such a split in that club. But they got past the idea that the AKC was involved and decided they could work with the Canine Health Foundation. We are getting quite a few Jack Russell Terrier samples in the last few months. Because lens luxation seems to be primarily in a lot of the true terrier breeds, it is possible that there is a founding mutation that is behind the luxation that is behind most, if not all, of these breeds. We have quite a few samples from the Tibetan Terriers, which are not true terriers, but they have luxation. They believe that it came from one individual dog in England. In the 40s or 50s, if you got two or three British judges to say that is was…then it was. They found this dog on a wharf. It looked like a Tibetan Terrier. These judges said that if it walked and talked like a Tibetan Terrier, then it’s a Tibetan Terrier. And all of the Tibetan Terriers with lens luxation can be traced back to this one animal. The club sort of did the outcross that is useful to use. We don’t have as many samples as we would like to from the families. But it’s getting better. We get little spurts of Tibetan Terrier luxation families.

Audience: Is lens luxation on the increase?

Speaker: It’s hard to tell if it is on the increase or if there is better awareness and better openness about it.

Audience: I recently had a lens luxation case; my husband is a former Welsh Terrier breeder. Up until recently, I had never heard of lens luxation in Welsh Terriers.

Speaker: All of the Welsh Terrier samples we have are glaucoma. I don’t think we have any that have lens luxation cases in Welsh Terriers.

Audience: If you go to there website, there is mention of lens luxation in Welsh Terriers. I find this interesting, because I have never heard of it in Welsh Terriers.

Speaker: It is very hard to know how much of this is because it is occurring more, or if its because people are more willing to talk about it. Dog people thump each other over the head with any little bit of dirt they can find. I think a lot of things have been hidden and not talked about, so you just stop with that part of the line and move on to something else and just don’t mention it. I think we are getting better about talking to each other about these things. None of us can make informed decisions without information. We have to talk to each other. No one plans to produce a problem…but it happens. We are dealing with living things, and things go wrong.

Audience: Is there any feeling about whether lens luxation is a recessive?

Speaker: We haven’t run the statistics on that. Ned Patterson, who is working with us on epilepsy research from the University of Minnesota…he is a wiz at statistical modeling. He is going to take a look and see if he can come up with numbers. Just looking at pedigrees without analyzing the numbers, it looks like a simple recessive, but we haven’t proven that.

Audience: From a conversation with Dr. Gallant, I understood, that it was recessive.

Speaker: Like I said, at-a-glance, looking at it, it seems to be recessive. There are a lot of things that can effect this. We don’t know for sure yet.

Audience: We have two dogs that are about 8 and 9 years and are both clear but have produced five puppies, four of which have sub-luxed. So, you think you have a clear dog…they are both clear…no lens luxation, no glaucoma, but out of five puppies from two breedings, two have luxated and two have sub-luxated. This really destroys your comfort level. You’re so careful. You wait so long to breed them….

Speaker: We really encourage people to get samples from their puppies before they are placed, and then get a larger sample later. Do the puppies before they leave so you have the whole family. We are also doing a general DNA bank for several breeds. We charge $10.00 per sample and it is stored forever. If we ever decided to close up shop, we would give plenty of notice so that your sample could be moved to another organization. If there is DNA needed at another university or organization, we could send samples elsewhere. So it might be a good idea just to sample everyone and get it stored. We may never use it, but we’ll have the ones that are really important, even if they have died since, it will help us to close up the holes in these pedigrees and move this project along. Eventually, when we do have markers from DNA tests and you can genetically clear both the parents and the grandparents, then you won’t have to test all the puppies, you will already know what the genotype is.

(End of tape)