Here is the full list of all 21 Loot Hound achievements.
Discover every loot item
Solve the Buxton Wheat Field mystery
Complete 5 loot sets
Maximise a skill for two different dogs
Find 7 loot items guarded by animals
Complete 3 loot sets
Find 7 loot items in rock
Find 7 loot items in enclosed spaces
Find 5 legendary loot items
Complete 1 loot set
Escape the park patrol
Find 7 rare loot items
Own 3 dogs
Own 2 dogs
Find 8 uncommon loot items
Find a new loot item in Scavenger Hunt mode
Find 10 common loot items