Is the word cachorros the same in Brazilian and European Portuguese?

No

While the spelling and the literal meaning of the word are the same, there is a significant difference in typical usage. In Brazilian Portuguese, "cachorro" is the standard, everyday word used to refer to a dog of any age. In Continental Portuguese, "cão" is the standard and most natural word for a dog. In Portugal, while "cachorro" is understood, it is much more frequently used to refer specifically to a puppy or a young dog.

Brazilian Portuguese Examples

1. Eu adoro cachorros. (I love dogs.)
2. O meu cachorro é muito brincalhão. (My dog is very playful.)
3. Você viu aquele cachorro correndo na rua? (Did you see that dog running in the street?)
4. Nós vamos levar os cachorros para passear. (We are going to take the dogs for a walk.)
5. Cuidado, esse cachorro pode ser bravo. (Be careful, this dog can be aggressive.)

Continental Portuguese Examples

1. Eu adoro cães. (I love dogs.)
2. O meu cão é muito brincalhão. (My dog is very playful.)
3. Viste aquele cão a correr na rua? (Did you see that dog running in the street?)
4. Nós vamos levar os cães a passear. (We are going to take the dogs for a walk.)
5. Cuidado, este cão pode ser bravo. (Be careful, this dog can be aggressive.)