Moose are vegetarians in the sense that they don't intentionally eat meat. However, when they browse, they inadvertently eat whatever may be on the twigs/leaves/vegetation. So they end up eating spiders, insects, larva, and most notably snails and slugs. Where moose range overlaps white-tailed deer range, and slugs and snails are present, the accidental consumption of a slug or a snail can be fatal to a moose. A brain worm called Parelaphostrongylus tenuis (P. tenuis for short) carries out its regular life cycle by living in both a white-tailed deer and a slug/snail. P. tenuis doesn't hurt the deer (it is a natural host), but when a moose (an incidental host) accidentally eats a slug/snail that is carrying the parasite, P. tenuis ends up in a "dead end" host. The brainworm can't carry out its regular life cycle, runs amok in the moose, and causes the moose to walk around like a zombie (usually in circles) until it starves to death, gets taken down by predators, gets euthanized by wardens, or finds its way into traffic and gets hit.
I'm not sure about the presence or absence of P. tenuis in Sweden, but I can say with certainty that it is present in eastern Canada and northeastern United States.
(Some of that may not be 100% accurate. It's been a while and I may have overlooked something or remembered something slightly incorrectly.)
Duo does have a report button for those and they accept many different synonyms on lots of exercises so I don't see why you feel the need to explain such a thing as synonyms exist.
"On the whole" is uses basically the same as "by and large", "mostly", "for the most part", or perhaps even phrases like "all things considered".