Change in routine:
Cats are creatures of habit, they like to know when they are going to be fed when you will be home from work and where to find their litter tray. Any changes around the home or to their routine can throw them off balance and result in a stressed cat who possibly develops undesirable behaviours (such as inappropriate urination). Some cats are fine, but many don't like change.
Older cats especially need things kept fairly simple and routine. Senses begin to diminish in old age and they are especially sensitive to changes.
Well, most cats don't anyway. Some are more friendly than others and need constant attention. When selecting a cat, it is always a good idea to consider your current situation. Are you out of the house for long periods of time? If so, a more independent cat may be better. Do you want a cat who will follow you around the house and "help" you, or would you prefer one who is content to snooze by a window and doesn't need much attention?
Many cats owners will attest to the fact that the moment they sit down at the computer to study, pick up a newspaper, talk on the phone, it's virtually a cue for your cat to come along and start demanding attention. This may include sitting on the above-mentioned computer, newspaper, weaving in and out of your legs or just flopping on the floor at your feet with the expectation that you immediately stop what you're doing and give the cat a stroke.
A cat's sense of hearing is by far superior to ours. They don't like loud noises, sudden noises, bangs and crashes, high pitched sounds. Many pet owners have noticed how fearful cats become on fireworks night.
A few breeds including the Toyger, Bengal, and Turkish Van are said to like it, but the majority of cats would prefer to avoid water at all costs.
Who does like their food cold? Well okay, cold pizza for breakfast is pretty nice but most of us enjoy our food warmed up, it makes it more palatable. This is the same for cats. Not all cats mind eating food straight out of the fridge, but if yours turns his nose up, try microwaving it for 30 seconds, remember to stir it up prior to giving it to him to avoid hot spots.
Most cats dislike a trip to the vet and who can blame them? I can't say I'm a fan of visiting my doctor either, even though they are both there to help us. Nobody really likes to be poked and prodded. Unlike humans, though, cats don't understand that the vet is there to help. It really can be quite a stressful time for your cat. Getting him used to the vet from a young age is important. He will need to accept his cat carrier, being transported in a car (or however you get to your vet), and being handled by strangers.
A spray of Feliway on the hands can help relax a nervous kitty. This is a synthetic version of the "feel good" pheromones the cat has on his cheeks, it helps to calm him down.
In extreme cases, you can look for a vet who does house calls, but this has its limitations. Obviously, it's fine for things like general check-ups, vaccinations etc., but for more complicated conditions, surgery etc., he will still need to visit the vet's office.
Similar to the vet, minus the poking and prodding. Most cats dislike change, and that includes being taken out of their home environment. Different smells, sounds, routine, people all work against your cat. They do eventually seem to begrudgingly accept the boarding cattery but be prepared for the sulks when you bring him back home.
Being stared at:
Direct eye contact with a cat is seen as a dominance issue and most cats don't like it. However, if you want to win your cat over, you can try looking at him and blinking very slowly, if he returns your stare with a slow blink, he loves you.
Back to eye contact, have you ever wondered why your cat is immediately attracted to the one person in the room who doesn't like cats? That is because generally people who don't like cats won't make eye contact with them, so they are seen as non-threatening. The cat lover, on the other hand, sits down, stares your cat directly in the eye and calls him over. Most cats don't like that, and will opt for the non-threatening person who's sitting in the corner hoping the cat will ignore him.
Dirty litter trays:
Cats are fastidiously clean animals and do not like to use a dirty litter tray. Many will find alternative places to go to the toilet if their litter tray isn't kept clean. It should be scooped out at least once a day, and thoroughly emptied out once a week. As a rule of thumb, have one tray per cat, plus one spare.
While we're on the subject of litter trays, cats also don't like to eat where they go to the toilet, so make sure your litter trays are kept away from food and water bowls.
Who hasn't had a mighty battle with their cat to get them to swallow a pill? It's almost as if they sense what's about to happen, we talk to them soothingly, approach them and they run for the hills. It's as if they know that "come here Kitty" voice means they will soon be having a tablet shoved down their throat. I can't say I would enjoy having somebody do that to me either, but again, it's just one of those necessities in life.
Read here for more information (and video) on how to pill a cat.