The vet had to sedate my cat before he could examine her.
My cat had to undergo sedation before she could be examined at the vet's.
この場合、次のような言い方ができますよ。
ーThe vet had to sedate my cat before he could examine her.
「獣医は彼女を検査する前に鎮静剤を与えなければいけなかった」
to sedate で「鎮静剤を与える」
ーMy cat had to undergo sedation before she could be examined at the vet's.
「うちの猫は動物病院で検査してもらう前に鎮静剤の投与を受けなければいけなかった」
to undergo sedation で「鎮静剤の投与を受ける」
ご参考まで！
Before the checkup, the vet would need to sedate to her as she will be very aggressive.
My cat would need to be sedated before the check up, otherwise she will go wild.
獣医さんか猫ちゃん、どちらを主語にするかによって表現を替えられます。
「Before the checkup, the vet would need to sedate to her as she will be very aggressive.」
診察の前に、私の猫は狂暴なので獣医さんは鎮静剤を使わなくてはならないだろう
「My cat would need to be sedated before the check up, otherwise she will go wild.」
私の猫は診察の前に鎮静剤を打ってもらう必要がある、さもなくば彼女は暴れてしまうだろう。
参考になれば幸いです。
カナダ 
日本 
