Why doesn't my cat use the litter tray?

i have 2 cats 1male 18mths-good as gold, the other is female 9mths approx, the problem i have is she goes toilet out of the litter tray but right next to it or sometimes she will go on my dogs bed. i clean the litter every day as they both use it but nothing works, i regularly buy new litter trays but it dont make... show more i have 2 cats 1male 18mths-good as gold, the other is female 9mths approx, the problem i have is she goes toilet out of the litter tray but right next to it or sometimes she will go on my dogs bed. i clean the litter every day as they both use it but nothing works, i regularly buy new litter trays but it dont make a differance, she's been doing this ever since i got her at surposedly 9wks but she has always been small- but does anyone have advice on how to stop her doing this as its horrid now and i cant afford to kep buying new dog beds all the time as washing them makes no difference as the only other option i have is to take her to a rehoming center but i bought her for life so don't want to dump her on them so to speak as they need the room for more needy cats. please help!
12 answers 12