After he’s grounded by an injury, a high-flying bachelor is saddled with two wide-eyed orphans as they come face-to-face with the dangers and beauty of the outside world.
There's a dog in a very small crate on the back of a freight bicycle, which seems cruel. Also, depending on your stance, the fact that a large number of ducklings are taken to the back of a restaurant to be killed and served may be considered abuse, perhaps especially since they realise what's about to happen and are terrified.
We see poultry served at a restaurant, and so do our protagonists, which is terrifying for them, as they themselves are birds. Various bugs, worms etc. are eaten by other animals. (Besides that, an evil pallas cat dies.)
A male goose is consistently called "Mommy" by a duckling who imprints on him. It's done in innocence, not malevolently, and eventually the gander grows to be sort of proud of the moniker. At one point, two male cranes are called "Ladies". I'm not entirely sure whether it's meant as an insult or said due to a misunderstanding.
A pair of ducklings are abandoned by an adopted parent goose (one calls him "Mommy" consistently, including during the abandonment scene). The parent goose tries to but doesn't actually do the leaving, only because his broken wing prevents him from succeeding. A duckling explicitly says "You were going to abandon us!" and then they choose to leave him.
There's a dog in a very small crate. A herd of ducklings are trapped in the back of a restaurant, metal gates having been closed behind them. A duckling gets his head trapped in a hole in a log. There may be more claustrophobic scenes, but I can't think of them.
Well, maybe... The main antagonist throughout the movie, a pallas cat with one bright red eye, has two personalities that argue amongst themselves, much like Gollum in the LOTR movies. The most aggressive one of these personalities might conceivably be interpreted as a demonic entity inside the cat.
Hmm... A herd of ducklings who believe that they're going to a nice place are in reality taken to a restaurant to be killed and eaten. They don't realise where they're being led before it's too late - when they get there, a metal gate is closed behind them.