It has to be a cat owner's worst nightmare - Puss fails to return home. It is even worse for owners of indoor cats; an indoor cat may panic if it escapes into the unfamiliar outdoors. Though outdoor cats are most at risk of becoming lost, e.g. if chased, abducted and dumped, or by climbing into a cat, indoor cats can sometimes escape, especially if your home is broken into by a burglar or a door is left open when a tradesman calls.
Many people don't bother to search for a lost cat, assuming it can take care of itself or has gone wild. Those cats may wander for days, disoriented and frightened. The lucky ones are adopted or rescued, but others cannot fend for themselves and die or are killed as pests. Some join feral cat colonies. Many are accidentally shut inside shed or garages which are opened only now and again.
A neutered (desexed) cat is less likely to stray than an unneutered cat. A collar and ID tag (or a microchip) could swiftly reunite you with your lost pet. Make sure you have clear colour photos of both sides of your cat and its face (a 'portrait' photo). You may need these for 'Lost Cat' posters or to prove ownership if someone has adopted or stolen your pet. Though you may put 'Lost Cat ... answers to name of Gemma' many cats don't answer to their name if it is spoken by a stranger,
If your cat goes missing, first search all parts of your house. Look in boxes, closets, washing machines, under beds etc. Then search the immediate environs - outbuildings, sheds, garages and hedges. You may need to carry wire-cutters to free your cat if you live in an area where snares are likely. Take some photos with you so that you can more easily describe your cat to people you meet. Check the 'Lost and Found' columns of local newspapers and cards placed in shop windows or on community notice-boards.
Let people know that the cat is missing. You could inform the police if you believe the cat has been stolen they may not take it seriously, but under English Law a cat is considered property. Community policemen will be more sympathetic than the town police station. Inform local vets in case the animal is, or has been, injured and is taken to a vet's surgery. Inform local schools since children are very observant of animals that they meet on their way to and from school. Contact local animal shelters and welfare groups.
Local councils (the 'Cleansing Department' or Environmental Health Officer) should keep records of dead animals they have cleared from the roadside (they may also store the body in a freezer for a short period of time before it is incinerated). If you live near to a railway, the nearest station may have records of animals found on the track. Speak to neighbours who may have seen your cat since it disappeared. It's surprising how many cats have a 'den' under a neighbour's shed or have second homes. Have a word with any delivery people or roundsmen who have regular rounds in your area.
Advertise the fact that a cat has gone missing. Put up posters if possible. Put cards on local noticeboards, in shop windows (a small weekly fee will be charged), church noticeboards (a donation to funds may be required), at the local school and local filling station. Posters and notices are more effective if they have a photo of the cat. Put them wherever people congregate, but beware of any local regulations prohibiting unauthorised notices. Put 'Lost Cat' notices through people's doors, asking them to check inside their shed, garage etc. Put your name and address on all notices.
Contact the local newspapers; most have a 'Lost and Found' section or may be able to print a picture and small article about the missing cat (especially if it is valuable or extraordinary in any way). Contact your local radio station and, if you have one, your local TV station. If you believe your cat may have climbed in a car or truck and hitch-hiked to another area, advertise in a national cat publication. Very valuable cats have sometimes had their stories reported on national news and national teletext services.
If your local animal rescue groups have a lost and found section on the internet, supply a photo for that. A donation may be required. Sites for lost cats exist, but they may not cover your area or even your country. They are also difficult to keep up to date.
Offer a reward to motivate people; there is no need to specify the amount. The drawback of this is that you may be presented with a procession of cats (some taken from elsewhere) by people wanting to claim the reward. These people work on the theory that all tabby cats look the same (or all Siamese cats look the same etc) and owners won't be able to tell the difference. Such people will not return the cat to where they found it, leading to another lost cat.
The earlier you report a missing cat, the more likely you are to find it. Be aware of your cat's habits, e.g. what time does it normally return from hunting expeditions or visits to neighbours?
When you are reunited with your cat, inform any authorities who were asked to look out for him. Remove any posters or notices, especially those which offer a reward otherwise you will end up paying out money to everyone who finds your cat sitting on your doorstep.
Don't give up to soon. Cats have been known to return home after long absences, having been adopted as a stray or after hiking long distances home after accidentally riding in a car. I know of one cat which was reunited with its rural owner after being found at a London Railway Station - the cat had decided to explore the guard's van when the train stopped at its local station; luckily it was microchipped and had a collar. I have reunited a Havana with its owner after a separation of 6 months. This indoor-only cat was trapped during a trap-neuter-return campaign at a factory the other side of town. The owner worked at the factory. Somehow it had managed to get into the garage and had travelled to the factory in the engine compartment of its owner's car.