A parasite is an organism that lives in or on an organism of another species, and benefits by deriving nutrients at the others expense
Endoparasites
Helminths
Cestodes
Trematodes
Nematodes
ectoparasites
fleas
itching, allergies, blood loss
mites
itching and inflammation
lice
itching and inflammation
ticks
blood loss, local reactions, disease vector
flies
tissue damage
nematodes
roundworms
resides in intestines, skin and respiratory tract
cattle lungworm
Coughing, pneumonia and death
large roundworm
Parascaris equorum in horses
Intestinal blockage
trematodes
flatworms
tissue damage in liver and reproductive tract
liver fluke
chronic anaemia in sheep resulting in sudden death
cestodes
tapeworms
meat borne diseases
protozoa = single celled eukaryotic organisms, either free living or parasitic, which feed on organic matter such as other microorganisms or organic tissues and debri