Dog: $40/year vet bill, $15/month food, maybe, $5/month toys, treats, other
my philosophy is "if it costs less than a dollar it doesn't count, so I spend lots of money on walmart's 88 cent toys and on dollar tree toys"

Cat: $2.50/month litter, $5/month food, a few replacement toys and sleeping baskets a year

Fish: Filter media and test kits $30/year, Decoration budget $50/year, Food $10/year, + camera batteries, extra tanks, nets, treatments, conditioners, water

I probably spend more on my fish than any other pets. I get a LOT of clearence items so I tend to spend more than I think.