The damage that invasive species can cause to the environment and the economy are well known, but impacts on human health have been much less analysed. However, invasive species can cause impacts ranging from psychological effects, phobias, discomfort and nuisance to allergies, poisoning, bites, disease and even death. Invasives experts Giuseppe Mazza and Elena Tricarico of the University of Florence, Italy say that in addition to these direct effects, some work in more indirect ways. Humans are menaced by alien invasive species affecting the services provided by ecosystems. “These services are vital to our well-being: changes may decrease the availability of drinking water and of products from fisheries, agriculture and forestry, alter pollination and impoverish culture and recreation,” say Mazza and Tricarico.
Dogs, just like humans, can have problems with learning, memory and attention, particularly as they get older. Several tests of cognitive ability in dogs have been used in research with a particular focus on the effects of ageing. What is less well understood is how diseases affect these cognitive abilities. In an article in CAB Reviews, Lena Provoost, Margret Casal and Carlo Siracusa discuss how changes in behaviour, such as loss of appetite, house soiling or changes in sleeping are often the first indicators to the pet’s owners that there is a problem. The team from the School of Veterinary Medicine at the University of Pennsylvania say that while those changes could be caused by mental decline, they could be secondary effects of other medical causes, such as pain from infection swellings or kidney disease.