First of all, the best thing to do is to have your cat micro-chipped by your vet, this will provide a record of ownership (whichever of you owns the other :-) ) should your little friend go missing.
However, as micro-chips are invisible to the naked eye and can only be detected by means of a scanner it is not always evident that your pet has a home unless he or she is scanned, so my personal choice is to also put a collar on.
Many people do not agree with collars on cats due to the possibility of the collar becoming caught in a branch or something else and the cat being unable to escape. For this reason I would only ever use a safety collar for outdoor cats.
Furthermore I would not ever use an elasticated collar, although these are sometimes described as safety collars. The reason for this is that although the elastic would 'give' and possibly the cat could get out of the collar, there is also the danger that it may catch a paw in the actual collar while trying to escape. This can cause horrendous injuries to the neck if the cat is not found and taken to a vet, the collar can become embedded in the flesh of the cats neck, and sometimes the paw can become caught throught the collar, resulting in a deep cut, or worse, the loss of a limb.
So, by all means use a safety collar on your cat but do consider that the best ones to buy are those with a safety clip which will pull undone should your cat become caught.
In addition to this, if you allow your cat out at night or in the dark, do consider a reflective collar, better still keep your kitty indoors safely at night, away from dark roads and possible cat-nappers.
To avoid small injuries to your pet, be aware of the sharpness of some of the highly decorated and fashionable collars that are available these days, some of the 'bling' can damage little paws and get caught in coats.
One more thing to consider, along with the collar to show puss has a home - a tag or barrel with your phone no. and postcode. If you have a particularly sociable cat he or she may be less likely to get 'adopted' by a neighbour if it looks as if he has a loving home already.
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