Around $200/month. That's only on dogs. Let's see. Here are my other expenses:

Fish:
Food-$25( includes pellets, flakes, and bloodworms)
Betta Food- $7


Birds:
Toys: $10
Food- $20
Accessories- $15


Hermit Crabs:
Sponge: $5
New Shells: $7


Dogs:
Food- $50
Grooming Supplies- $20
Toys- $15
Treats- $10
Other Necessities(sp?)- $30


That's only for about a month. Now add all that together and multiply it by 12 and add around $200 for vet bills and medication(ie. frontline and heartguard) and you will have how much I spend on my pets.