I am not a vet but I do know that dry food is bad for cats. Most of it - unless it is the very best from specialty pet stores - is full of grains and nasty by-products that can cause all kinds of problems including allergies, obesity and diabetes. All dry food is - well - dry. Cats are desert animals and were meant to get their water from their prey. They do not have a strong urge to drink water and can be dehydrated easily. A good quality canned food is much better then any dry food. You might need to move them over to wet food slowly - some older cats don't like to change. Avoid the cheap, grocery-store foods - they are basically dry food with added water. The main ingredients should be a named meat - chicken, turkey, beef, etc. No by-products or mystery meat.
I have always fed my cats a combination of "megabrand" wet and dry food (neither store nor premium), and I always have fresh water available.
Cats, like people, will eat what they like.
Our vet in Ohio (we were at Wright-Patterson AFB from 11/91 - 4/96) recommended Science Diet. All 3 kitties picked out the SD nuggets and ate only the Purina (we tried mixing the 2 to gradually introduce the "healthier" alternative).
Every cat I've owned has lived 16 years or better, save one who succumbed to anaphylactic shock at the Science Diet vet's clinic at 6 1/2.
All "Name Brand" foods are formulated to meet the basic needs of a cat in good health.
As for the hair pulling, that is behavioral...look to your life, which affects kitty. Have there been any changes or new stressors??? BTW, yelling will only make matters worse.
My wife and I have been re-socializing an older (10 1/2 when we got her) feral cat. Persistent, consistent kindness has done remarkably well...
Your young kitty can eat regular cat chow, but your senior kitty should be on a senior cat chow. Older cats need a little different nutrition than young cats so you should definitely feed a "senior" food to the older kitty.
I have always fed my cat dry food only. He vomits wet food. He also vomits many of the "expensive" dry food, so I feed him Friskies Indoor Cat Chow lol - he loves it and does not vomit it up! :) Hard food is actually much better for cats' teeth as wet food will rot their teeth earlier and unless you brush their teeth yourself, they will need dental care in their lifetime.
You are right that cat food can be full of nasty byproducts, but to be perfectly fair, most human food is full of the junk too. All packaged products (ketchup, soda, etc.) are allowed to have a certain percentage of bug parts in it! How's that for an eew-factor? :)
2 of my cats do not eat cat meat AT ALL! So basically live on dry food. I rang the vet to ask if this is normal because I never knew it to be before, and she said yes because they are eating and drinking. But we do give them tuna and fresh fish at least 3 times a week as too much can make them ill. The reason I think they are not eating cat meat is their back teeth havent delevoped so they cannot congest the jelly... This has happened to my neighbours cat...
One of the cats who doesnt eat meat has a bald patch which I found she has a flea allergy... This might be the case to yours I dont know? my kitten is only 9 wks old and cannot have flea treatment as said by the vets!!
Take them to the vets and get them checked over
The behavioral difference you are seeing in your cats have nothing to do with diet and everything to do with their age difference. A 14 year old cat is just not going to have the same energy and interests as a 4 year old cat anymore than a teenager and a senior citizen will have the same interests and activities. I have 3 senior cats (aged 10-14) and 2 kittens. They eat the same food but their behavior is totally different based on their ages.
The fur pulling may be a stress reaction in your older cat. Yelling at her adds to that stress. If there is no underlying skin problem, I would suggest leaving her alone.
I must agree with the comments above made by oregpsnow about dry food.
Dry food not only leads to dehydration but is also FULL of preservatives and fillers that aren't beneficial to a cat....its survive vs. thrive!!!
I must remark on the total misconception that dry food is good for teeth and can food rots teeth, where in the world did that ever surface from? a dry food company?
that is totally wrong, there is no food that will rot teeth.
and since most dry food is swallowed and not chewed it is hardly the benefit to teeth that company's claim.