A year of HW prevention at our vet is $56.
The annual exam and shots and fecal is $75.
Heartworm test is $25.
That's just the very basic, per dog. Every time they go to the vet for something else, like if they are sick, seems like it's at least $100. If they would need dentals that would cost upwards of $300 each. I also don't buy conventional flea/tick prevention.
I have no idea how much I spend on food! But it isn't much per dog. For 6 dogs I probably spend $50-$75 a month.
And then there are the extras! I buy a lot of little things - cookies, toys, Nature's Miracle, etc. Probably $50-$150 per month!