Gametocytes in bird blood. These are malaria-like protozoa transmitted by the bite of infected simulid or black flies.
Gametocytes in bird blood. These malaria-like parasites are transmitted by the bite of infected hippobosid flies (wingless). The black pigment covering the gametocytes is hemozoin a metabolic biproduct produced by malarial parasites.
Babesia canis trophozoites
Piroplasms that usually occur in pairs in the erythrocytes. The bovine form was erradicated from the U.S. but similar organisms can be found in horses and dogs.
Theileria spp ring stages in erythrocytes
Blood protozoa commonly found in deer and cattle. Cytauxzoon felis in cats is similar in appearance when in erythrocytes. The following images show schizont stages of C. felis in endothelial macrophages easily found in lungs and spleen impression smears.
Ehrlichia ewingii morula in canine neutrophil
Ehrlichial organisms are seen in monocytes and granulocytes in dogs. This parasite is in a neutrophil and is not the same as E. canis that infects monocytes. This parasite produces a less severe disease that is often associated with lameness.
Anaplasma marginale in bovine erythrocytes
Rickettsial agent transmitted by ticks.
Hemobartonella felis on feline erythrocytes
Rickettsial agent that forms chains of organisms across the surface of the erythrocyte. Mode of transmission in question.
Other related images:
Operculated fluke egg (Paragonimus kellicoti)
Lung fluke of dogs and cats. Eggs can be found in feces by flotation unlike other types of flukes. Tracheal washings can also be checked for eggs. Dogs and cats get the parasite by eating infected crayfish.
Life cycle stages:
Adult flukes representatives of other trematode families of veterinary importance
Acanthocephalan egg (Macracanthorhynchus hirudinaceus)
Thorny-headed worms are not nematodes. They differ in several anatomical ways. Dung beettles are intermediate hosts for the swine parasite named above. The dog parasite Oncicola canis also uses beetles but paratenic hosts such as poultry may be involved in transmission.
Pseudophyllidian egg (Diphyllobothrium latum)
The eggs of pseudophyllidian tapeworms are operculated on one end and can be confused with fluke eggs which are similarly operculated. This egg has a small knob-like structure on the end opposite the operculum which differentiates it from a fluke egg.