My cat has hairballs. What's an affordable hairball food or medicine?

A high quality food of science diet, royal canin, iams, or purina are great brands. Iams makes a hairball control. You can also purchase hairball medications/supplements and use your favorite food.

Yes, depending on the food. Most of the brands that claim to have efficacy against hairballs have some kind of formulation that has added fiber designed to help hairballs to pass. Some foods are more effective than others at this (stick to Science Diet, Royal Canin, or Purina for over-the-counter non-prescription diets). These are not usually prescription diets and are almost always ok to feed as a maintenance diet to normal, healthy cats.

There are hairball diets that you could try out to see if Moose will try them out. Most are available from local pet stores. You can try mixing it in with his regular food, or transitioning to it completely if he enjoys it. You can also try to hide the paste or treats with something "tastier" such as a bit of warmed up boiled chicken- cats tend to go for things that are smelly rather than tasty, and the smell of the chicken may mask the scent of the hairball medicine enough to encourage him to try it.

Laxatone or PetroMalt are recommended. If he will allow, try to brush him daily to reduce shedding. https://www.petco.com/shop/en/petcostore/product/tomlyn-natural-laxatone-cat-hairball-eliminator https://www.petco.com/shop/en/petcostore/product/sentry-petromalt-malt-flavored-hairball-relief

Do not combine foods, this causes GI upset. Brands of food I recommend include Royal Canin, Hill's Science Diet, Purina Pro Plan, and Iams. I recommend these foods because they run their own feeding trials, meet AAFCO standards, and have veterinary nutritionists on staff. They are the only four brands to do this. I think an indoor cat formula would be best for Storm. As for water, get a pet water fountain. It provides a constant source of fresh water, and encourages cats to drink. I have one for my cats, and they love it. Don't change litter if he has one he likes. Cats are very picky about litter, and a change in litter can lead to them not using their box.

The following food is one of the best for hairball problems: https://www.royalcanin.com/products/royal-canin-feline-health-nutrition-indoor-intense-hairball-34-dry-cat-food/2534 bear in mind the vomiting might be caused by the hyperthyroidism rather than caused by the hairballs.

Brushing her may be the missing step in reducing her hairball production. If she will tolerate a shedding tool, use one to get the majority of the loose hair off her and then use a soft brush daily. My cats tolerate a natural bristle brush very well, it's a brush meant for people and they're pretty inexpensive. The more hair you can get off her, the less she'll ingets while grooming. Also, get her a tube of hairball medicine, the most common brand is Petromalt. Most cats like the flavor so it's easy to give, but if she doesn't take it easily wipe a bit on her face or paws so she has to groom it off. This helps move the hair through and out the other end rather than her vomit them up.