Not true! Many adoptive families have pets and there are known benefits to having pets in a family. 

The exception would be if your pet(s) were dangerous for children to be around. Your agency will need to determine that your pet is safe to be around children, and there may be some children for whom being around pets will be unsuitable (for example, because the child is allergic, or cannot conduct themselves safely around pets). On rare occasions, the number or type of pets in the household may require further consideration.