Sparky, the sick male cat living at my place for the time being. Later on, I have to take him to the vet again. His leg is still swollen but his condition is much better.
Maybe the vet can see today whether the cat has any spider or scorpion bites because this is what probably happened. In Israel there are plenty of little spiders which look harmless. But what they do is they can crawl into your bed or just bite you somewhere without you even noticing it. However, some animals or humans are allergic and the spot where the spider bit you is swelling. In addition to that, one gets a high fever and I have heard about people who were rushed to hospital because they were in life danger.
Those spiders are not everywhere but they can be in a garden in the middle of town. My guess is that they are mostly in the countryside. Just like snakes.