Gutters should get cleaned at least twice a year or more. Also to ensure that they get cleaned properly you might want to have a professional clean them or if you don't want that then you can always clean then yourself.
Horses can get by without any grooming at all. However, it is good to at least look the horse over every day to check for injuries and such. You should also groom a horse, at least the saddle area,...
The NFPA recommends a chimney be cleaned at least once a year. The creosote buildup is not good for a household or the environment and poses a greater risk for fire. All chimneys are different and...
A rabbit cage and hutch should be cleaned out at least once a week. If your rabbit is a dwarf then maybe 1-2 weeks. Giant rabbits are supposed to be cleaned out every 5 days!
You should never store a dirty firearm. They should be cleaned after every use, especially if you're firing ammunition with corrosive primers. It's not absolute necessity that you clean them every...