Symbiosis: living together There are 5 types of symbiotic relationships

Predator/prey This is a short term relationship where one being benefits at the expense of the other

Phoresis: The smaller member of the relationship is mechanically carried about by the larger.

This moraxella bovis is transported from cow to cow on the sticky foot pads of the face fly

Mutualism: Both organisms benefit.

Commensalism: One being benefits and the other neither benefits nor is harmed

Parasitism: An association exists between two organisms of different species in which one member lives on or in the other other member and may cause harm.

Parasitiasis When a parasite is present and potentially pathogenic but the animal does not exhibit outward clinical signs

Parasitosis: When a parasite is present on or within the host and does produce obvious injury or harm to the host.

Ectoparasite: If the parasite lives on the body of the host

Endoparasite: If the parasite lives within the body of the host

Erratic or Aberrant parasite: When a parasite wanders from its usual site of infection into an organ or location it does not ordinarily live

Incidental Parasite: When a parasite occurs in a host that it normally does not live.

Facultative Parasite: A “free living” (non parasitic in nature) can become parasitic in certain hosts.

Pelodera is a free living nematode that lives in superficial layers of soil as a non- parasite, but, it can penetrate the skin of domestic animals

Obligatory Parasite: A parasite that must lead a parasitic existence. These are not capable of leading a free living existence

Periodic Parasite: A parasite that does not have to live on or in a host but must make short frequent visits to obtain nourishment.

Pseudoparasite: Living creatures or objects that are not parasites but may be mistaken for parasites

Each parasite has its own lifecycle, this is the development of the parasite through its various lifestages. Every parasite has at least one definitive host and may have one or more intermediate hosts.

Definitive host: The host that harbors the adult, sexual or mature stages of the parasite.

Intermediate Host: The host that harbors the larval, juvenile, immature or asexual stages of the parasite

Homoxenous : a parasite that will only infect one type of host. Stenoxenous: a parasite with a narrow host range Euryxenous: a parasite with a broad host range Zoonosis: any disease or parasite that may be transmitted from animals to humans