The animal's need to roam in search of a mate, decreasing the chances that your pet will become lost, get
into fights with other animals or be hit by a car.
They can cause traffic accidents or damage to vehicles, get
into fights with other animals, get lost / injured / killed, produce unwanted litters (if not altered), damage neighbor's property, etc..
A dog or cat that isn't neutered has a natural instinct to roam, making him more vulnerable to acquiring illnesses, becoming injured, getting
into fights with other animals, and even becoming lost or missing.
Prevention: Not always preventable, but can minimize risk by keeping surroundings free of harmful items (such as barbed wire, metal lawn edging, metal plant supports), keep pets from running unrestricted to avoid getting hit by car or getting
into fights with other animals.
If a cat stays closer to home, however, he may have less chance of catching diseases from other cats or getting
into fights with other animals.