Buying puppies as Christmas presents could lead to the deaths of thousands of dogs in the New Year, say animal welfare experts.

Last year, councils put down 20,000 stray dogs across the UK, at the cost of �21m to the taxpayer.

Many of the casualties were abandoned by owners who could not cope after puppies were bought as Christmas presents.

The National Canine Defence League says that in a normal year it sees a 20% increase in January on the hundreds of dogs brought into its shelters.

But the situation this year is likely to be far worse.

Launching its annual A Dog is for Life, Not Just for Christmas campaign, the NCDL said its rehoming centres were already running out of places.

Of 160 kennels at its Kenilworth centre in Warwickshire, for example, only two remain empty - way above normal levels.

The reasons for the unusual overcrowding are not clear, but it is bound to get worse after Christmas and the charity fears it will be unable to cope.

"We just do not have enough room, the kennels are very full," a spokesman said.

"We are worried about how we will be able to deal with the inevitable flood of Christmas casualties that we get each year and want to reiterate that dogs should not be given as presents."

The campaign was first launched 21 years ago by NCDL officials horrified at the number of dogs abandoned in the New Year.

Older pets are often ditched in favour of new puppies and young animals can be dumped by owners who find themselves unable to cope.

NCDL asked anyone thinking of buying a puppy as a Christmas present to think again.

And it asked anyone finding it difficult to cope with a new dog to try to hold on until the New Year before bringing it into one of its centres.