RE: What if your pet grows and grows and grows ...
Pet owners should always research well and be prepared before they get any pet at all. The most often case I have heard is large snake species were ditched by their owners when they got too big to be "liked" by their old 'buddies". Big cats such as tiger, lion, panther, leopard, etc. too, they can be extremely cute when they were little, but the time of such "happiness" is short consider how fast they can grow into something big and dangerous, and it is sad to "jail" them once they get older just because who they are, or rather what they are.
Having a 150kg pig as pet is something unique lol. Consider the fact it is food for much of the world. From the look of it, I think this pig is a little over-weighted (yes, for a pig) lol.
If you look at the rest of the photos in the source news link, you might notice the family is actually still quite happy.
But of course, they could be posing for photos just for the news. If they are truly happy with their over-sized pet, I am also happy for them.