They are not a public health pest as they do not transmit or carry diseases, however Slugs can be annoying if iinside your property or on your crops,

The word slug is also often used as part of the common name of any gastropod mollusc that has no shell, a very reduced shell, or only a small internal shell, particularly sea slugs and semislugs.

Control is generally with DIY garden centre products, always rea dthe label though as they products can be hamrful to pets.