I have 3 Janomes (one is a 90's Kenmore, but was made by Janome) and they are all great machines. I wouldn't hesitate to buy a Janome new or used, as long as you know it's not been abused.
If you're on a tight budget, don't forget about vintage machines. A lot of those are all steel and are very easy to maintain on your own, and would probably hurt the dogs and the hallway more than the dogs and hallway could ever hurt one of those steel beasties! I don't like modern Singers but I have few from the 50's and earlier and they are really and truly built like tanks (pretty much literally). Kenmore is another brand I really trust - Kenmore sewing machines were made by a variety of manufacturers but so far every Kenmore I've had has been rock-solid (I currently own 3, by 3 different makers - one from the 40's, one from the 50's, and one from the 90's; the one from the 50's is my favorite - it's a real beast, talk about a tank...). It's too bad Sears/Kenmore don't still make sewing machines!