As far as leaving dogs goes - I agree with the advice that others have said.
But there may be maybe elderly dog owners who can't get out enough that you could help out when not working .
Rescued pets can indeed have some issues but way better to give them a good shot at a life.
Worst of all are pets from puppy or kitten farms - they always seem to be mental.
Pedigree pets also often are metal from inbreeding. (EDIT: Oops - I meant mental)
I always wanted a cat but didn't really want the responsibility and was happy to fuss over neighbour's cats (who always recognise a mug who will fed them treats).
However my cat Tigger turned up as a stray who was living rough and fighting all the local cats when competing for their food.
It didn't take long before he just didn't leave anymore and lived permanently in my garden till I let him stay in the house when I was there.
Over the years that he's been here he's become very settled although he hates me playing guitar.
Some of you may have met him at the workshop.
Oddly enough his physique has changed a lot since he no longer lives rough and fights for food (and we had him neutered too)
Before , when we met him he was called "fatneck" or "Whingey Meow-stink" (Yngwie Malmsteen) both due to looking like Mike Tyson and having a whiney meow and being a smelly stray

Now he's slim and no longer smells.....APART FROM FARTING
