The charges sound reasonable, I do some dog sitting as a sideline to gardening and charge the same rate £12.50 per hour for the established clients - due to being too busy new clients are £15.  However it may be that here in the London commuter zone we are able to charge more.

The only down side to dog sitting is the worry of losing the dog,  especially if taking it on a walk,  one place has 4 dogs  and trying to do gardening whilst keeping a watchful eye on them all is surprisingly stressful.

Whatever you do, do not undercharge for your time,  there are lots of people with no time who want help with little jobs like you suggest.  I could not do any house sitting as I have too many domestic responsibilities at home but just do hours during the day - for instance last week  the client who normally works from home had to go to Bristol so he was out from 6a.m. to 8p.m.,  but often it is only a couple of hours needed during the day. In order to catch people like that it might be better to separate the house sitting and dog sitting in the advert so people who are only away for a few hours don't think you only do an overnight service.

One other question is can you get insurance for it just in case the worst happens.

It's worth talking to an insurance broker about what cover might cost as it could give an awful lot of peace of mind - my gardening cover is under £70 per year.

Sort of related to the dog-sitting I came across a business called pet pavilions in central London, they are seeking to expand in to Battersea,  I dread to think what they charge for looking after dogs but charging extra to shampoo the mutt sounds like a good way to charge even more. Interesting that just walking one dog is a special one to one client experience.

http://www.petpavilion.co.uk/