Need help understanding screening results

[shoff]

First, I'd like to say my 12 year old boxer crossed the rainbow bridge not too long ago. He developed cardiomyopathy at a young age and then an aggressive form of prostate cancer. (He was not neutered because at the time, they didn't recommend boxers with cardiomyopathy undergo anesthesia.) I didn't know any better when I got him and would like to do my best to avoid this in the future. I'm looking at 2 breeders now, but I'm not sure. So I was hoping someone could hep me determine which is best or if I should keep looking.

This is the first breeder.

Sire
OFA CERTIFIED
Echo Normal
Hips Good
Elbows Normal
ALBA Holter 2 singles 1/17/11
ALBA Holter 0 singles 2/27/12
Alba Holter 13 singles 6/7/13

Dam
OFA Certified
Echo Normal
Elbows Normal
Hips Good
DM At Risk
She says she was holtered but didn't post results

My concern with this litter is that the Dam is at risk for DM and the sire wasn't tested. Would that concern you? Also, is it concerning that the sire had 13 singles on 6/7/13? Also, would you buy from a breeder who didn't test thyroid or CERF?

SECOND BREEDER

From the breeder. He didn't send me OFA links.

Sire had good results on his echo, good results on his holter, ARVC - Negative , DM- Clear.

The dam has good results on her echo and holter. Will be doing ARVC and DM after the pups are weaned. I can say her 5 year old full sister is ARVC- Heterozigous. Both of her parents were fully health tested no ARVC or DM and both are still living at 9 AND 7.

What does it mean that a full sister is ARVC - Heterozigous? Plus, should I be concerned that hips weren't tested? And no thyroid?

Are either of these good candidates?

Thanks!

 

[Cami]

What does it mean that a full sister is ARVC - Heterozigous?

She carries one copy of the gene that is known to cause ARVC. This does not mean she will or will not go on to develop ARVC just that she has one copy of the gene which was inherited from one of her parents.

The one dog with 13 singles which was an increase from previous testing may or may not be an issue. A holter only tests for a "moment in time". It could be that nothing presented in previous tests or it could be a pattern and this dog is going to go on an develop ARVC (increasing number of PVC's). Those numbers are nowhere needing treatment or even to give an ARVC diagnosis.

Here is further reading on DM and what "at risk" means:
Orthopedic Foundation for Animals

 

[shoff]

Thanks. I'm confused. If her 5 year old full sister is ARVC Heterozigous, how can both of her parents have no ARVC? Wouldn't the sister have gotten the gene from her parents? And since it's a full sister, then how can the parents show no ARVC?

 

[shoff]

One more question on the DM. Is it appropriate/ethical/safe to breed an at risk dog with a carrier? Wouldn't the puppies be either at risk or carrier or as well?

 

[Cami]

Just because they carry the gene (and passed it on) does not mean they have or will go on to develop the disease. It could also be that they have not developed it yet.
There are two genes which have been found to cause ARVC however there are likely many more genes which also cause it. A dog can be "clear" of these two specific genes yet still develop ARVC.
I was just at my girls cardiologist this week and was talking about getting her tested. I sent away for the test kit but haven't done anything with it yet.
It was the cardio's viewpoint that even if we test her and she is shown to be Heterozigous it won't change our treatment plan at all. She has ARVC and we know this. Testing won't give us additional answers....if she were Homozygous (2 copies of the gene) then she more than likely would have a more severe form of the disease (faster progressing perhaps or just more VPC's). Out of 1400 Boxers tested only 8% carried two genes. Most with a DX of ARVC carry one.
More about testing here:
http://www.akcchf.org/news-events/library/articles/boxerupdate0410.pdf

I'm not a breeder but I would not want a pup from an at risk dog and a carrier. My girls dad is a carrier but her mom is clear. I won't test her since I just don't want to know and her chances of going on to develop the disease is pretty low. A carrier has a pretty low chance of developing the disease and an at risk dog has a higher risk but still not a guarantee it will develop the disease.

 

[shoff]

Thanks, Cami! That's very helpful! I noticed some breeders tested their dogs for ARVC and others don't. Do you think it's necessary to find a breeder who tests for it or is a holter/echo enough?

 

[Cami]

IMO a holter is enough to test for ARVC. An echo would be to check for stenosis which is important but not mandatory.