What dry food should I feed older long-haired cats with hairballs?

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.

If she is doing fine on the Iams, I would keep her on it. It's a good quality food, and I personally like it and recommend it. Royal Canin is excellent as well. I don't recommend switching her food if she isn't having problems on it, there's no need for it :-)

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.

If he likes his current food then you can add in a hair ball medicine like catlax or laxatone. You can give this to him 2-3 times per week. If you don’t feel like you will be able to do that then I would go back to the food you were feeding before since it seemed to help. I like science diet, Royal canin, Iams, and eukanuba which all should have affordable hair all formula options. I hope this helps!

Science diet and Purina have very good cat formulas for cats. I would find one that is appropriate for your cats age and health status. For example, they make a hairball formula if that is problem or an over weight formula if weight loss is needed there is no benefit of feeding dry over canned, so it is personal preference for that.

Hello and thanks for using Petco Pet Education Center, formerly Petcoach! By IBS I am assuming you may mean inflammatory bowel disease (IBD) as this is common in older cats. Some prescription diets like Royal Canin Gastrointestinal canned or dry or hydrolyzed diets. The Science diet limited ingredient diets (d/d) can also be helpful. If you are looking for an over the counter diet I have had some success with Natural balance limited ingredient canned food. Canned diets are always preferred in cats so if you can feed Simon an all canned diet that would be better.

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.