His dog became a missing dog.
1. He should have used a dog lead.
2. He should have tied the dog with a dog lead.
3. He should have tied a dog lead to the collar of the dog.
4. He didn't used the leash. He should have walke the dog with the leash on the collar.
5. He didn't used the leash. He should have walke the dog after having the leash attached to the collar of the dog.
(Which expressions are suitable? Do you have more useful expressions?)
His dog became a missing dog.
His dog went missing.
His dog was missing.
His dog ran away.
His dog got lost.
1. He should have used a dog lead.
2. He should have tied the dog with a dog lead.
3. He should have tied a dog lead to the collar of the dog.
All are OK.
4. He didn't use the leash. He should have walked the dog with the leash on the collar.
5. He didn't use the leash. He should have walked the dog after attaching the leash.
He didn't use the leash. He should have walked the dog with the leash on.
I have fixed the errors in 4 and 5 and added one more possibility.
All of the expressions you provided are suitable for discussing the importance of using a dog lead or leash to prevent a dog from becoming missing or running away. Here are some additional expressions you can use to convey the same idea:
6. He should have kept the dog on a leash.
7. He should have secured the dog with a leash.
8. He should have had the dog on a leash at all times.
9. He should have walked the dog while holding the leash.
10. He should have ensured the dog was properly restrained with a leash.
These expressions emphasize the importance of using a leash to keep the dog under control and prevent it from going missing. Additionally, other common practices to consider for keeping a dog from becoming missing include ensuring a secure yard or enclosure, using microchipping and identification tags, and providing proper training to the dog for recall and listening to commands.