Simplify the following text for a Grade 4 native English-speaking person.
Original: When Lightning Bar was about five days old Pollard was afraid that he had leg problems and was buck-kneed , and considered putting the colt to sleep .
Simplified: When Lightning Bar was about 5 days old , Pollard was afraid that he had leg problems and was buck-kneed . Pollard thought about putting the young horse to sleep .