If the litter box is not big enough for the cat and has not been cleaned for a long time, the whole litter will smell of urine and your friend will not want to use the litter box. In addition to cleaning, if their requests for attention and play are not met or if a second pet friend has come to the house, due to the stress, they leave urine and poop outside the litter box. A third factor is the season of heat and neutering is necessary as soon as the heat period passes. The most common urinary tract infection in cats is a condition called cystitis. They may not be using the litter box because they cannot control their urine. Due to being alone for a long time and a lack of affection, dogs generally protest their owner. If their daily routine is disrupted and they do not go out to toilet daily, it is natural for them to leave urine and poop in certain corners of the house.  Since older dogs, just like puppies, cannot control their urinary system, toilet pads can be used as a solution.