Travelling with pets can be done. Through air, train and route it depends entirely on the distance that one wants to cover. If it is intercity travel or travel via Road ( by car etc) can be considered as an option. However, when it when it's Interstate or in country, It's not practical as long-distance travel on road is difficult for the pets.
There are options available to transport by air, however that is considered as very expensive, and not all cities has an airport. Also, not all airlines except pets in their cargo, record So when it comes to destination that is remote, train can be the best option.