Parasites come in all shapes and sizes. Some of them can live in their host without causing symptoms whilst others cause debilitating and sometimes fatal disease. A few episodes ago, we talked about lungworm in cattle. While lungworm can affect other species as well, like deer and buffalo, they tend to be closely related to cattle. However, other parasites make a habit of infecting different species as part of their lifecycle. Rather than having a free-living life cycle, which leaves them at the mercy of the elements, they take up residence in an intermediate host. Here they are relatively safe and can busy themselves preparing to infect their definitive host where another round of reproduction will take place.

A good example of these types of parasites are Echinococcus, a genus of Cestodes which are more commonly known as tapeworms. This type of tapeworm tends to use livestock as an intermediate host and predatory species, such as canids, as their definitive host. They have an important role in human health too. If a person eats an Echinococcus egg, the parasite can infect them as if they were the intermediate host, causing severe disease. This ability to cause disease in a wide variety of species means that control measures must encompass all affected species in order to provide adequate protection.

Marisol Collins is coming to the end of her PhD, during which she has worked on the HyData Project to investigate the distribution of Echinococcus granulosus in the UK. This has involved looking at the potential for Echinococcus transfer in different populations of canids including hunting hounds and zoo animals