Phil,
We all have some health issues as we age. If you had to cancel your May trip,, plan another one as soon as possible. Sorry to hear about your dog issues. Get them corrected and take him out there. Do some day trips soon. Life is short so enjoy it. Do not dwell on the obstacles. Revel in the fact that you can still take your dog and go out there. The best way to keep in shape to go on trips is to go on trips.
Two friends flaked out on me this week on a June trip. We have been planning for 4 months. Oh well. Not my monkeys, not my circus.