Rubulavirus
If not vaccinated against mumps, susceptible individuals catch the disease by breathing around an infected person who has coughed or sneezed, releasing their contaminated saliva. Those who have had mumps are usually immune to future infections of the disease. Children have the highest risk of catching mumps, and it is rare for an adult to contract mumps. The incubation period for mumps can range from a couple weeks to a month, while the illness period is a few weeks. The swelling of the salivary glands is caused when the virus travels from the respiratory tract to the salivary glands and multiplies within the glands, causing the glands to swell.
Mites of livestock
The clinical manifestation of infestation with psoroptic mites is usually called mange and sometimes scabies, but the skin disease of sheep caused by "Psoroptes ovis" is often known locally as sheep scab. This species may affect its hosts severely enough to reduce their gain in weight. Costs to farmers of controlling sheep-scab in Britain were at £8 million (US$12 million) annually in 2005. Transmission between hosts is readily accomplished by contagion during flocking contact and also on fomites such as scraps of sheep's wool because these relatively large and robust mites can survive for one to two weeks off their host. "Psoroptes ovis" infests the superficial layers of the skin. Irritation of the outer skin by the mite's mouthparts and saliva results in a complex form of cutaneous hypersensitivity and inflammatory exudation of serum and fresh cells. The mites feed on this moist exudate. The skin loses its hair (depilation) at the sites of infestation and this may be extensive. As a result of the movement of the mites into areas of fresh skin, large scabs accumulate on the raw skin left behind. The mites cause intense pruritus (itching). In cases of heavy infestations, the host grooms compulsively, aggravating the depilation, and it may become mentally distressed. "Psoroptes ovis" infests sheep worldwide and can be a serious welfare and animal-production problem for sheep farmers.
Infestations of cattle with mites of the similar genus "Chorioptes", in combination with "Sarcoptes" mite infestation, has been shown to cause a failure to gain body weight by 15.5 kg to 37.2 kg over a two-month period compared to cattle without the mites.