I live in the south and am so envious of that weather. We actually just bought a baby pool for the dogs and literally dump it every day because over night it becomes mosquito infested. I am going to cringe at my water bill at the end of the summer.erm . . . While I do feed my dog high quality food and bottled spring water* and use leftover meat and veggies for treats, I do not vaccinate yearly, nor do I use heartworm meds year round.
First of all, it's unnecessary to vaxx yearly. Most of the vaxxes last a lifetime. For example, what's the difference between a 1 year rabies vaxx and a 3 year rabies vaxx? Chemically, nothing. The manufacturer decided to test the 1 year vaxx for 3 years, it worked, so they sell a 3 year variety. The truth is, most vaxxes last at least 10-15 years, i.e., the lifetime of the average American dog.
Secondly, in a climate like Chicago and Northeastern PA, it is completely unnecessary to treat for heartworms year round. Heartworms are only a problem when misquitoes are present. Misquitoes aren't present in PA from October to May. Even when misquitoes are present, the heartworms won't grow unless you get 2 solid weeks when the temperature gets above 80F every day and never falls below 57F. In PA, that's usually June through September.
There are heartworm maps where you can find reported incidences of heartworm in your area. In mine, there are, on average, 5 reported cases a year. Mind you, that's just where the vet was who reported it, not where the dog was infected. A good many people in the Northeast own rescues transported from shelters in the South. All 5 of those dogs could have been infected in the South, then transported up north and diagnosed.
Anyway, this is all with the blessing of my vet, and from the experiences of my mother and grandfather, who did the same and never had a dog with rabies or heartworm.
*I'm not totally crazy. Even I can smell the chlorine in the tap water, I wouldn't expect a dog to drink it.
I have to stay up on all vax just because my guys get kenneled a few times a year and also I foster and even though they all UTD before they enter my house, I prefer not to take the chance.
My dogs get good quality food, fresh water daily (I have a filtered bowl but only one will go near it), regular exercise, fish oil, monthly baths (unless otherwise needed), nail clippings and ear cleanings and they do get bones to help keep their teeth cleaned. So far no major problems that I could have prevented.