Nails and claws grow throughout life, and are normally worn down to normal lengths by use.  However, many pets do not get enough wear of the nails or claws.  This can be because the animal does not exercise enough (due to old age, or housing that is too small), because a nail or claw is growing at the wrong angle and does not come into contact with a wearing surface, or because the surfaces the pet comes in contact with are too soft. 

-         A small dog that lives in a carpeted house and exercises on the lawn may be prone to overlong nails, whereas a Guide Dog that walks on pavements for much of the day has nails of an appropriate length

-         Wild rabbits spend much of their time digging, and move about constantly in search of food and safety.  A pet rabbit, particularly if confined all day to a hutch, moves about much less, and has a smooth, non abrasive wooden surface to the hutch, which does not provide adequate wear

-         Wild birds perch on branches of various diameters and textures, scratch surfaces, and move about constantly.  Caged birds spend all day on a smooth, uniform perch.

Long nails or claws need cut because if they are overlong they are more liable to break at the sensitive base which can be very painful, they can grow round in a circle and penetrate the pad (causing pain and infection), or they can cause the animal to have problems walking or perching correctly.  Overlong bird's claws can get hooked on cage bars, and small birds can lose a lot of blood from a broken claw, as they have only half a teaspoon of blood altogether.

Dew claws are on the inside of the front legs (and sometimes the back legs in some dogs).  These are the equivalent of the thumb, and are not in contact with the ground during normal walking.  They do get wear when the animal is scrambling, digging or climbing.  It is common in some puppies to get the dew claws removed when they are a few days old (ask your vet for advice about this, do not attempt to remove them on your own) to prevent future problems.  The dew claws may overgrow and penetrate the pad, while the other nails can be a normal length.  It is advisable to keep a close eye on dew claw growth.

You can cut your pet's nails at home if you buy appropriate good quality clippers and know how far back you can safely cut.  In some animals this can be obvious, in others with dark coloured nails, this can be very difficult.  If in doubt, ask your vet to clip the nails for you, or show you how.  If you cut too far back, you will penetrate the sensitive tissue of the nail, which is very painful, and can bleed profusely.  In animals with white nails, you can usually see the pink sensitive tissue inside the nail.  You must leave adequate clearance between the apparent end of this tissue and the place where you cut, bearing in mind that the clippers might cause pressure higher up than the place they are cutting.  Cutting the nails slightly longer, but more frequently, is preferable to cutting them too short and causing pain or discomfort to your pet.  Poor quality or blunt clippers can split a nail rather than cutting it cleanly, so have good clippers which are made specifically for animals.

You can help to prevent nail or claw problems developing by examining the nails regularly, cutting them or getting them cut by the vet if necessary, and providing adequate exercise or wearing surfaces for the animal to use.  You can walk dogs on pavements more often, rather than grass, provide rabbits with a larger run or a have a stone surface in part of the run, and put perches of different diameter and texture in the bird cage.

If your pet has a broken claw, a painful claw, or one which will not stop bleeding, you must see the vet.  Infections around the base of the claw are not uncommon in dogs and cats, and can cause swelling, pain and lameness.  This must be treated by the vet.