As they say, "if you are a hammer, every problem looks like a nail" - if you are a gun enthusiast, then I guess every situation calls for a gun - preferably a big one.
The OP's question was not "What type of gun should I take when hunting bear" but what sort of "defensive tools" would be appropriate to guard against the risk of dangerous animals while wild camping in Europe........
.....Back to the OP's question - the risks are incredibly small but since bears (regardless of the statistical evidence to the contrary) are perceived as the most dangerous things in the woods here is some feedback from someone who lives in European "bear country". Last year I spent some time listening to a presentation by a Rumanian lady keen to introduce the Brits to her fine range of rustic cuisine which included her delicious bear sausages. When asked about the dangers of living in "bear country", she replied that sometimes the younger kids get a bit frightened when out foraging if they find a bear on the opposite side of the bush they are collecting from but they weren't a serious danger.
IME badly behaved dogs are the biggest nuisance/threat in the UK - I've been bitten (mauled?) at least 4 times over the last few years (enough to draw blood/tear clothes but nothing serious) and always feel more comfortable with a walking pole when out and about though I do like the look of Mors' bear bat.
Safe travels and watch out for those cows.