Picking up my Old English Sheepdog on Saturday and don't want to offend the breeder so thought I'd ask here. Is 19% COI too high? looks like it was a half sibling mating. A bit worried about health issues.
The breeder is very good and her dogs are show dogs so I'd be very surprised if there's anything to worry about, but wanted to ask here instead of possibly offending her.

I have never really been into COIs but looking it up, it says 19% is high.   5% being best.  However, I have no problem with half sibling matings, provided the 'outside' half isn't at all close.  With novice breeders, it's been recommended that they take the advice of an experienced breeder (same breed) before going ahead.

If your breeder did this mating to keep something herself, and if she's showing and well known within her breed, I doubt she'd risk producing something that's going to have lots of nasties going on.

Why not ask her (re you notice a half sibling mating in your new pup's pedigree .....)  Lots of breeders do close matings from time to time, to fix type but they know to go out next time (with the offspring).   If she's worth her salt, why would she take offence?

Good luck!

The breed average CoI for Old English Sheepdogs in 5.1%, so 19% is quite high. However a litter between 2 top-quality dogs, both fully tested, giving a high CoI is usually a better bet than a littter from 2 unrelated but poorer-quality animals, even though the CoI is much lower.

If you put the names of the parents into the Kennel Club's Health test checker you can find out whether they are fully health tested with good results, and if so then there is less to be concerned about.

They are fully health tested I've seen the results. Breeder has told me it's to enhance breed type and good temperaments

I wish it was possible to edit answers written here long after the expiration date to be able to do this.

Just to add to my earlier comment, I didn't worry about COI with my breeding plans for two main reasons -

1.  I was more concerned about conformation and type and -
2.  Knowing my breed meant for the most part that I knew what health problems there were in certain bloodlines and so which to avoid.  Obviously unless two lines had not been bred together before when the unexpected could come out of the woodwork.

Moving to N.America and starting my breeding activities out there,  meant I had to breed stud dogs available in N.America, with my British stock (based on type) and it was the opposite when we returned to the UK with our by then American/Canadian and UK bloodlines, any stud dog we used back here barely doubled up on my stock.  Mainly because by then, I wasn't able to find any stud dogs who carried lines back to our UK foundation stock, other than way back.

ps   I had fun doing 10-generation pedigrees on both our foundation bitch, and then a later dog we bought from the UK to Canada.

Good breeders know their lines and know what's okay to double up on or not. Linebreeding doesn't create problems, it brings out what exists = making it more likely to appear. So without any health conditions lurking in the lines there shouldn't be a problem. One of my most special dogs ever was 19% COI. She was perfect in every possible way; temperament, looks, health, and lived until 14. If you're worried, ask the breeder. They should know the health of parents, grandparents and ideally more, know how long they lived etc. The mark of a good breeder is that a pedigree is not just a piece of paper with names on, they are actual dogs the breeder has knowledge about.