Newfs are highly intelligent, thinking dogs, problem solvers, and know when to protect and not to, they are not "needy" depends on if you buy from a breeder who doesnt care and lets them go at six seven weeks or a breeder who is there training those pups from day one, imprinting training, and working them thru ten weeks.
much of a newfs personality is shaped by the owner and the dog in the household it comes home to.
some can be needy if the other dog is domineering, aggresive, or if it is not well adjusted.
much training must go into the young BOISTEROUS newfoundland pup
it is a WORKING DOG
and needs a lot of excersise, preferably walking in sand, or in water, swimming, walking against the current in a river or up hills.
building up muscle is key to healthy joints along with keeping them thin and trim, do not be set on a huge newf, they are not mean to be huge.
if you want that get a mastiff or great dane.
No matter the testing you never know if joint problems will arise,
the odds are out of a litter of six pups two or three wont pass ofa
doesnt mean they wont function normal healthy sound lives, they dont walk on their xrays, it doesnt matter, cross referencing or not, the odds are the same, we have it in humans, it still is a mystery, everyone is trying to find the magic formula, but it is not there, as it is so polygenic in nature, and there is more than a small genetic componant, i have always believed growth rates are what contribute hugely to the factors of bad joints, and lack of correct excersise at crucial ages.
diet plays a huge role, as well as the environment they live, slippery floors?
allowed to run amuck the house?
keeping those feet shaved out?
if not they slide all over and wahh lahh, not good for joints at all.