One thing we usually don't have to watch out for back home in Sweden are grass seeds. However, here in Spain and Portugal, the dried seeds can easily be a source of infection causing inflammation and painful swelling when they enter your dog's skin. Their pointed head and arrow-shaped fibres enable them to cling on to fur and then pierce and enter your dog's skin :-(
Make sure to thoroughly check your dog’s body, especially after walking through fields of long grass. In the little movie, we see Anna removing a seed which got stuck in Ronja's skin.
P.S. Thanks for the nice lady in Evora's pet shop who pointed this out to us when stocking up on dog food.