I would call them & ask how long you get & how much, whether there's somebody in the pool etc, from what I've heard you won't want him swimming for 20mins straight off anyway as this could do more harm than good.
I enquired a while back as we have 2 pools near us, one charges £70 for 4 swims up to ½ hour & they suggest once a week, this is a small pool with jets. Another place is a much bigger pool & charge £16 for 1 dog/£18 for 2 but this is just a fun type swim, fetching toys etc, although would need an assessment first at £16 per dog.
We've recently found out Harry has mild HD & muscle wastage round his back end like your Henry & the vet recommended seeing the physio & our 1st appointment is on Friday (£49) I know people that have been to the same place, the 1st appointment is 45 mins but I was told we'll probably have exercises to do at home 2-3 times a day & probably won't swim for the first week or 2 & the exercise will gradually be increased, I'm expecting only a couple of minutes swimming for a start, I know when Bibathediva took Lola she had to do slow lead walks to build up the muscle.
Hydro pools are set at a certain temperature so yes I'd imagine the cold water could have been the problem.
I shall be claiming on the insurance, but will possibly continue to take him maybe just once a month once the physio & vet are happy that he's build up enough muscle, will see how things go on Friday, but if you want any more info just ask as I may find out more over the next few weeks
