Depends usually on the value of the horse and what one's plans would be should a horse that had LOU be unable to work to the level one had intended it for.
I paid a reasonable amount for Dizz and she has LOU: I bought her to BSJA. The other two were much cheaper and do not have LOU.
Personally I don't insure for it now although I did for a couple of years some time back.
The reasons I stopped were:
- it hikes the premiums dramatically
- I heard too many horror stories of insurance wriggling out of paying
out eg. claiming it was probably a pre-existing condition that had not
been picked up at vetting, etc
- some companies require the horse to be PTS or will only pay 60% if
you don't
Fortunately I have never had a LOU situation as the two I have retired due to slight lameness are both veterans and wouldn't be covered anyway.