Lead cows, pigs, and sheep through the Nether portal.
You cannot lead dogs through, but these animals can be lead to your new nether farm. You can also bring villagers through the portal. Even though it's not likely you are going to use them much, they are very handy when you are low on a special material.
"It is impossible for a player to use a Nether portal while on a horse. It is possible however, to enter the portal on the horse and then dismount, sending the horse through the portal on its own, or use a lead to position the horse, then push it through the portal."
You cannot ride a horse into the end.
Skeleton Horses fit really well in the Nether!
A skeleton trap horse is a hostile skeleton horse spawned from a fraction of lightning generated naturally by a thunderstorm (0.75–1.5% chance on Easy, 1.5–4% on Normal, and 2.25–6.75% on Hard, depending on regional difficulty).
Spawning. Zombie horses may be created by the /summon command or with their spawn egg. When using a spawn egg, 20% spawn as foals. In Bedrock Edition, zombie horses can be spawned with a spawn egg.
Sometimes a horse can glitch and can't go through a nether portal whether the horse is in the overworld or in the nether. ... If you touch the portal while being on the horse the cooldown on the horse is RESETED UNECESARILY.
Chicken jockeys, like spider jockeys, cannot pass through portals. Zombified piglin chicken jockeys can spawn from portals in the Overworld. A normal chicken jockey may spawn in the Nether if a zombified piglin calls a normal zombie as reinforcement.
Unlike horses, all donkeys have the same movement speed and jump strength, although speed potions can be used on the donkey and travel via the Nether can make the donkey easily the pack animal with the fastest practical way to travel in Minecraft.
What you can do instead, is to seat the cat next to the portal (on a block level with the portal so you don't have to push it "uphill" and nudge it into the portal. The cat will teleport to the Nether, and you can follow into the Nether - the cat will likely be sitting inside the portal.
Bedrock Edition and Nether portals
In the Bedrock Edition 1.5 tamed wolves will always follow the owner into the Nether and back through the portals, even if they are not in sight or even if they do not have access to the portal.
You can live entirely in The Nether now, but beware the neighbors. The latest big update to Minecraft is the long-awaited overhaul for the hellish Nether dimension. The dangerous, lava-filled endgame area has been pumped with new enemies to fight, blocks to craft with, and biomes to explore.
Mobs. ... Skeletons, chickens, and endermen are the only Overworld mobs that can naturally spawn in the Nether; in Java Edition, baby zombified piglins may spawn as chicken jockeys.
Zombie jockeys have a very small chance to spawn (1%), either naturally or by a Zombie Spawn Egg.
Baby Zombies can spawn naturally in the Overworld, but they only have a 5% chance to spawn. The player can also spawn one with a Zombie Spawn Egg. Baby Zombies can also be found riding a Chicken, creating a Chicken Jockey.
It is impossible for a player to use a Nether portal while on a horse. It is possible however, to enter the portal on the horse and then dismount, sending the horse through the portal on its own, or use a lead to position the horse, then push it through the portal.
Though speed can vary, white horses offer the best chance to be the fastest. They are typically faster than their counterparts who might jump higher or have a lot more health. Breeding two fast horses will also result in a fast foal.
The optimal breeding scheme is that you start with two parent horses and breed them, and if the foal is stronger than the weakest parent horse, replace the weakest parent horse with the foal. Each time a foal is produced counts as "1" breeding attempt, regardless of whether it replaces a parent or is discarded.
Where to Find Skeleton Horses. In Minecraft, skeleton horses occur in the game when a regular horse is struck by lightning. If you are having trouble finding a skeleton horse, you can summon a skeleton horse using a cheat or you can use a spawn egg.
Surprisingly, skeleton horses in Minecraft do not eat anything. They are undead mobs, and players cannot feed them. Players can only restore the health of the skeleton horse. They can throw down potions on skeleton horses to regenerate their health.
Where to Find Zombie Horses. In Minecraft, zombie horses do not spawn naturally in the game, so you must spawn one using a zombie horse spawn egg or you can summon a zombie horse using a cheat.