The Dogs Trust in Bridgend says over 600 dogs arrived at the centre last year - a record high.
Staff believe the struggling economy has played a part, but added many people simply don't realise the time and money needed to care properly for a pet.
They have urged would-be owners to think long and hard before committing to a dog.
More top news
A family has issued an appeal to help find their missing pet turkey - in case he gets gobbled up as someone's Christmas dinner.
A blustery start to the weekend with sunny spells and scattered showers.
Welsh Secretary Stephen Crabb has launched an attack on Labour leader Ed Miliband, saying he "doesn't give a toss about Wales".