FOR ANY ILLNESS, OR IF YOUR CAT IS NOT ACTING NORMAL OR LOOKING ILL IN ANY WAY ALWAYS CONSULT A VET.
To tell first signs that any animal is off colour or unwell, always check the gums. If gums seem paler than normal then there could be a problem...consult a vet if you are at all unsure.
I will include as much as i can here, of course more will be added as i go along.

FELINE CALICI VIRUS AND FELINE RHINOTRACHEITIS (both now commonly as cat `flu`)
FCV is a herpes virus that can cause mouth, throat and node ulcers.
Both affect the upper respiratory tract, causing snuffles and sneezes.
It can be a killer especially in young cats or kittens or in ageing cats.
A combined vaccine is usually available to prevent this.

FELINE INFECTIOUS ENTERITIS (FIE)
This is a highly infectious virus and can be fatal, it attacks the bowels and central nervous system.
It should be vaccinated against and is usually incorporated into the same vaccine as FCV and FVR.

FELINE IMMUNO DEFICIENCY
This attacks the immune system and as yet there is no vaccine for it although the virus is quite rare.

FELINE INFECTIOUS LEUKAEMIA (FELV)
again this attacks the immune system, which in turn makes the cat prone to all other infections.
The virus is normally transmitted via blood.
Some cats are carriers and so show no signs of illness as they are naturally immune, but can still pass it on to other cats.

FELINE INFECTIOUS PERITONITIS (FIP)
This too can be fatal. Signs are that the abdomen will become very distended in the `wet` form. However there is a `dry` form of the disease which is harder to spot as it affects the nervous system.

PARASITES(see dermatitis)
Some obvious sign are, scratching, black specks in the coat.
The best treatment is from a vet as most flea powders, collars etc bought from pet stores are a waste of money and don`t really work.
Some flea collars can cause an allergic reaction around the neck as the chemicals are rubbing against the skin while the collar is on.
The whole house should be treated with a good house spray as well, also any other pets will need treatment.
Cats who are allergic to fleas will show hair loss, normally along the spine are to start with.

EAR MITES (see also ear problems)
Usually noticeable by inspection of the inside of the ear. You would notice a build up of brown wax which also has a smell to it. Also if the cat scratches its ears and shakes it head or hold the ear at an odd angle.
This is easily treated with ear drops from your vet.

FUR MITES or MANGE (see dermatitis)
Noticeable by balding patches often with scabby areas.
This can be confused as ringworm and so should be diagnosed by your vet who can give appropriate treatment.

TICKS
May show up with signs of dermatitis.
These have to be removed entirely. They have a mouth hook which embeds into the animals skin and so you can`t just pull the tick off.

The easiest way is to anaesthetise the tick first. Use a small amount of alcohol. This should work...then a pair of tweezers placed right under the head, should remove the pest.
Other wise seek the vets advice.

ROUND WORMS and TAPE WORMS
These are both internal parasites. Often the cat looks off colour, the coat may be out of condition and the stomach may be enlarged.
Diarrhoea or constipation may also be a sign.
Eggs of the worms are passed out in the cat faeces.
Tape worm eggs look like grains of rice.
Both types of worm can be treated by a vet, but it`s a lot easier to worm the kitten as soon as they are old enough to prevent infestation from the start. Afterwards, regular worming will keep them at bay.

CANCER
As with a lot of human cancers, this is sometimes hard to spot from the offset.
Breast cancer can be recognised b small lumps appearing in or around the nipple areas. If these are felt, then best get to a vet immediately, just in case.
The treatment is a mammary removal, normally preceded by a scan to check how far the cancer has spread.
Depending on how much is affected will depend on how much of the mammary tissue needs to be removed. If the vet is unsure about some lumps then a full mammary strip will be done to remove all suspect lumps, in some cases both sides will need to be removed.


ABSCESS
(see also Anal Glands)
Often they will appear after a cat fight or from an infected tooth etc..
Easy enough to spot as they are usually swollen, tender and full of pus.
Normally a vet will treat either with an injection of an antibiotic followed by a course of antibiotic liquid or tablets.
Although left untreated they can result in septicaemia.

ANAEMIA
Lethargy, pale gums and tiredness..(more than normal).
As with humans, this is a lack of iron in the diet.
There is also an infectious form known as feline infectious anaemia (FIA).
The vet can treat either condition,

ANAL GLANDS
These are situated each side of the anus. They can become infected or blocked.
They can be cleared by gently squeezing them with a wad of cotton wool soaked in warm water. Although unless you are sure of how to do this best let the vet take care of the problem. Also be aware that what comes out has a rather potent smell!!
Sometimes the glands get impacted and can cause an anal abscess, this can normally be cleared with a course of antibiotics.
If the problem is severe and recurring, the vet can recommend the glands be surgically removed.

ANAL PROLAPSE
The best way to describe this is that it looks like a raspberry coming from the cats anus. Sometimes caused by a lack of roughage in the diet.
Immediate veterinary treatment should be sought.

ALLERGIES
Skin, eye and breathing problems can all be signs of an allergy.
Hard to detect in a lot of cases so veterinary advice is the first port of call.

ARTHRITIS
Stiffened joins, sometimes lameness or swollen joints.
In mild cases a change of diet will help, but in more serious cases a course of steroids or anti-inflammatory drugs may help.

CONSTIPATION
If your cat is constantly straining, then this is probably the cause.
Mild cases can be treated with a simple change of diet with more fibre included.
Fur balls can also cause this if they have travelled that far down. The vet can suggest a good laxative or similar to help shift it.
If the constipation is more persistent and regular, then there could be an intestinal blockage or other condition and it should be investigated by a vet. Sometimes surgery can be the only treatment for a very serious blockage.
Constipation can also be a sign of Key-Gaskell Syndrome....affecting various parts of the nervous system.

EYE
Any abnormalities, such as weeping or the cat rubbing at the the eye could be an infection, or may have been a minor injury in a cat fight,
Anyway this should be checked by a vet as there could be a more serious infection, first sign of cat flu, chlamydia or Key Gaskell Syndrome. (see Key Gaskell Syndrome)
If a cats eyes are not reacting to light as normal, this can also be a sign of Key Gaskell Syndrome.

COUGHS AND COLDS
This can also be a sign the cat has lung worm and should be treated by a vet.
Sneezing, weeping eyes and coughing could mean the cat has contracted one of the cat flu viruses. Consult a vet straight away.
However, just a cough can mean that there is a fur ball waiting to come out.
If the cough is persistent, let the vet check it out as it could be a foreign body lodged in the throat.

BLADDER (see also kidney)
Cystitis can be contracted by male and female cats.
The most common sign is the cat straining when trying to urinate, often accompanied by a small amount of blood tinged urine.
Antibiotics should clear the problem.
Sometime Cystitis can be caused by the urine being too alkaline and the vet can suggest a suitable change of diet.
Also there could be an underlying kidney problem, so in any case a vet should be consulted.

DANDRUFF
Sometimes a change of diet to include more oily foods with do the trick.
Sometimes over grooming can cause this as it can make the skin over produce cells.
If there is a rash or an raw patches a vet should be seen as there could be mites.


DIARRHOEA
Sometimes a sign of toxoplasmosis.
If the cat seems healthy in all other ways try starving it for 24 hours, allowing only water.
If the problem still persists, consult a vet.

EAR PROBLEMS
Constant scratching of the ears can be a sign of mites, check for a dark coloured wax in there which is usually accompanied by a smell. This can be treated with ear drops.
There could also be a foreign body such as grass seed lodged deep in the ear, so consult a vet.

HAIR LOSS
This can be due to stress, mites, fleas or mange (which are also a type of mite). Treatment is nowadays quick and simple and reasonably inexpensive. Ask your vet for advice.

HAEMATOMA
A haematoma is a blood filled lump unlike an abscess which is pus filled.
often appearing on the ears after a fight. This should be treated by a vet.

HEART DISEASE AND STROKES
Most heart problems can start as the cat moves into old age although in some cases it can be a congenital condition, and so affect a younger cat.
Strokes can be triggered by shock. As with humans the degree of damage a stroke leaves, varies.
Depending on how severe the stroke is will depend on how well the cat recovers and as long as it is not left too disabled, should still be able to handle day to day living.

HEATSTROKE AND SUNBURN
Heat stroke can leave a cat with a slight twitching or even a more serious fit.
If you think the cat has had a little too much sun and showing signs of heatstroke, you should try to cool the cats paws down in cold water, to lower the blood temperature.
Sunburn can lead to skin cancer. Cats with less fur are more prone or pale and white furred cats are also prone to sunburn.
A sunblock for cats that regularly go out in full sun can be used. Ask the vet.

TEETH
Most cat teeth problems can be prevented by feeding the cat hard food as well as the moist stuff.
Giving the cat a harder food such as cat biscuits will help to clean the teeth and keep them plaque free.
There is also feline toothpastes on the market with can be used, but be prepared for a few scratches unless your cat actually enjoys it!

VOMITING
Cats often chew grass as a natural emetic, which makes it vomit and clean out the digestive system. This is normal and nothing to worry about, just like us taking a tonic.
Persistent vomiting could have an underlying cause for instance toxoplasmosis and should be checked out by a vet.
Vomiting can also be the result of eating or chewing a poisonous plants, a lot of plants are poisonous to cats that are safe for humans.
and toxic plants ( page 11)vomiting

vomiting see page 8