Enteric Flagellated Protozoa in Turkeys
Steven Clark
Alpharma Animal Health, Inc., Fort Lee, New Jersey, USA steven.clark@alpharma.com
Koen De Gussem
Alpharma Animal Health, Inc. Antwerp, Belgium koen.de-gussem@alpharma.com
John Barnes
North Carolina State University, College of Veterinary Medicine, Raleigh,
North Carolina, USA John_Barnes@ncsu.edu
Several types of protozoa are associated with
enteric disease of turkeys. Protozoal enteritis can present with general signs,
including dehydration, loss of appetite (off-feed), loose droppings and watery
intestinal contents. Flagellated protozoa include Cochlosoma, Tetratrichomonas,
Histomonas and Hexamita. Coccidia Cryptosporidia and Eimeria are
non-flagellated protozoa of turkeys. Cochlosoma and Hexamita have recently
been associated with enteritis, primarily in young turkeys, especially in the
summer months. There are field reports of co-infections with Cochlosoma and
Tetratrichomonas, or Cochlosoma and Hexamita, or flagellated protozoa and
Eimeria.
Cochlosoma anatis is an enteric flagellate protozoan. It is about the same size as the turkey’s red blood cell. Microscopically, it is will have a rapid, spiral movement. Cochlosoma organisms are found in the villi of the jejunum (upper small intestine), and attaches to the mucosa by means of a sucker-apparatus. C. anatis is associated with significant production losses in turkeys.
Hexamita meleagridis, now called Spironucleus meleagridis, is another enteric protozoa. Hexamita is smaller than a red blood cell. It has a characteristic torpedo, fast, straight movement and has a narrow, elongate appearance on the microscope slide. Hexamita is found in the crypts or lumen of the upper small intestine (duodenum, jejunum, and ileum).
Tetratrichomonas gallinarum, another common flagellate protozoa of turkeys, is larger than a red blood cell. Microscopically, Tetratrichomonas has a jerky motion and is found in the ceca. Trichomonads have an undulating membrane and are plump, pyriform in shape. Unless found in high numbers, Tetratrichomonas, commonly referred to as “Trich”, probably does not cause clinical disease.
Blackhead (Histomonas) is caused
by Histomonas meleagridis, a flagellated protozoan. The bird ingests
embryonated ova of cecal worms (Heterakis gallinarum) that contain Histomonas.
Protozoan infections can be diagnosed in the laboratory from fresh intestinal
mucosa scrapings; each organism has a distinctive microscopic appearance.
Recent research has reported the negative effects Cochlosoma has on bird
performance. Biosecurity and sanitation are essential steps in controlling and
preventing flagellated protozoan infections. Chlortetracycline,
oxytetracycline and tetracycline have FDA-approved label claims for the
control of hexamitiasis. In the USA, both nitarsone and roxarsone have been
used successfully in the field and research settings to control enteritis
caused by flagellated protozoan.