Because a cat’s innate nature refuses to allow them to show illness (a sick cat was easy prey for a cat’s natural predators in the wild), you may not initially notice when your pet is less than 100%.

Any obvious pain or distress is cause for concern, as is a change in behavior (your normally friendly cat bites you, growls at you or hides from you without reason.)

Whenever something is amiss, get your cat to the vet pronto – by the time you can notice a problem it is usually much more serious than what your cat is showing.

If in doubt, call your vet – they may be able to help over the phone, or may need to see your cat in the office for a thorough exam to eliminate a serious illness.

You might want to purchase a good emergency first aid guide for cats - here's an affordable ebook we recommend: 

If your cat’s fur begins to look dull and unkempt, instead of smooth and glossy, this may be a sign of ill health. When a cat stops grooming up to standard, they are usually ill and a trip to the vet will be necessary.

Cats, like people, can get gingivitis and periodontal disease. Inflamed gums cause bad breath when bacteria get between the tooth and gum. Not only can bad breath be an issue, but also bone loss - which eventually results in tooth loss. Because cats don’t grind their food like humans do, they need their pointy little molars to help slice, shred and rip their food.

Feline flu virus can cause severe inflammation, which can cause bad breath and drooling.

Your cat needs crunchy foods (and maybe a tartar control treat or two) to help keep his or her gums in good shape.

Wheezing sounds when breathing can be very serious. Your cat may have asthma, or heart problems that result in fluid building in the chest. Either way, wheezing when breathing is something your vet needs to check out.

Weight loss in a cat usually points to a problem. Cats do lose weight as they enter their senior years, but if the weight loss is sudden, take your pet to the vet. If your cat is eating normally yet still losing weight, he or she may be experiencing kidney or thyroid problems. A vet can determine this with tests and prescribe medication if need be.

All cats try to cough up a hairball now and then. Providing cat grass for indoor cats will help, and letting your outdoor cat munch grass outside helps to bring these tightly wound balls of hair up. But if your cat is vomiting persistently, get them to a vet pronto.

Sometimes the little darlings will snitch food from someplace else and not want their regular food for a day or so, or may just be tired of the same-old-same-old. This is not cause for concern. If your cat is off their food for a longer time than this, there can be a whole range of medical reasons why – get them to the vet.

When your cat has an increase in appetite or thirst, this could indicate thyroid, liver or kidney problems and needs to be checked by a vet. If your pet cries for food, then refuses to eat it, this could indicate a serious underlying condition and needs a vet’s attention, as well.

If there is either an increase or a decrease in how often your pet uses their litter box, there could be a blockage or other serious problem brewing. Also, if your cat cries out when trying to urinate, this could indicate a serious problem In either case, have your vet check your cat over.

If your cat has been eating normally and not snacking on something questionable, diarrhea can be the symptom of an infection, a parasite or other serious problem – a visit with your veterinarian may be in order.

Diarrhea can be caused by:

• inappropriate diet (milk in adult cats)
• internal parasites (roundworms, tapeworms, lungworms, whipworms, hookworms, heartworms, toxoplasma, giardia)
• tumors
• food allergies
• drug reactions
• hyperthyroidism
• infections - bacterial or viral

If your cat's third eyelid, or "haws" is noticeaby covering the lower, inner portion of the eye, this may be an indication of digestive upset. If your cat loses weight or drags its bottom across the floor, these also may be indications that something is amiss. Again, a visit with your veterinarian may be warranted.

Fleas or ticks are the usual culprit when your cat starts scratching themselves like a maniac, and are readily treatable with preparations from your vet or a reputable pet store.

Allergy can be another cause. Your vet can help with this.

If a cat starts licking in one spot more than usual, take a look – cats lick wounds to help them heal.