This was Cape of Good hope Lock, so wide and deep. We had just started to go up, dog was crossing lower lock gate when it fell in.
You have to make quick decisions in these situations. A slow fill of lock was a good option but dog swam up side of boat, in small gap between boat and lock with danger of getting squashed. I dropped paddle and whent down ladder, encouraged dog to front of boat but could not lift out, wet and slippery.
Big audience by this time. You have to decide if they are the sort of people who can be trusted to come down a lock ladder. Two came down, one was possibly the owner. I thought they could hold dog while I went back up to slowly fill lock, but instead together we pulled dog onto front deck. Filled lock, dog shook itself off and walked away as if nothing had happened. Biggest danger was that dog only just missed Gillie (steering) when it fell in.
Nasty lock that one, it is in effect a public footpath and many users have had a few beers, it needs a bridge.