Final answer:
Parasites that enter the body through gaps in the skin can prevent offering salon/spa services, but fungal parasites and certain bacteria and fungi may not.
Step-by-step explanation:
Salon/spa services may prevent offering their services if the conditions are caused by parasites that enter the body through several places that are not covered by skin. Examples of such parasites include pathogens that cause infections of the skin and eyes, as well as parasites like hookworms that live inside the host organism. However, conditions caused by fungal parasites and certain bacteria and fungi that can multiply in animal tissues are not examples that would prevent offering salon/spa services.