Spironucleus (Hexamita) spp. (2)

Question 1

How do you identify?

Answer 1

Smaller than Giardia

2 nuclei

2 sets of 3 anterior flagella and 2 posterior flagella

Trophozoites vary in shape
- Average size: 6.9 x 3.4 micro m

Cysts

 - Ovoid to round
 - Average size: 5.5 x 4.5 micro m

Question 2

Explain the life cycle

Answer 2

Same as Giardia

Flagellates alternate in life cycle between motile trophozoite and nonmotile cyst

Birds vs. mammals

Large vs. small intestine

Droppings from carrier birds

Contamination of shoes or equipment carries fecal material to one location from another

Many bird carriers

Question 3

What is the site of infection?

Answer 3

Large intestine

Question 4

Describe the pathogenesis

Answer 4

Rapid weight loss

Infectious catarrhal enteritis - inflammation of mucous membranes

Young birds affected

Losses can be severe in birds 3-5 weeks old

Resistance develops with age

1/3 of recovered birds become carriers

Primary infection source: droppings from carrier birds

 - Buildup of organism through several broods of poults
        - Exposure of following brood overwhelming

Indirect transmission
- Fecal material carried from one location to another via shoes/
equipment

Free flying birds may be carriers

Primary symptoms
- Listlessness
- Foamy/watery diarrhea with rapid weight loss (“dehydrating
effect”)

Survivors remain stunted

Huddle together near heat and cry/chirp constantly (as though in pain)

Convulsion due to lowered blood sugar precede death

Dehydration/Emaciation - principal gross lesions

Muscles dark and gray

Loss of muscle tone in intestine

Intestinal contents usually thin/watery

Question 5

How do you diagnose?

Answer 5

Depend upon history

Symptoms

Microscopic examination of intestinal contents

Definite diagnosis
- Typical flagellated organisms detected in intestinal contents

Most flagellate organisms in ceca do not cause disease

Question 6

How do you treat and prevent?

Answer 6

Dimetridizole in water for 12 days effective

Good management

Hygiene

Young bird raised away from other birds of different age groups

Avoid sharing pens among batches of birds

Thoroughly cleaned/disinfected pens and equipment between batches
- Leave unoccupied as long as possible

Question 7

What are the hosts?

Answer 7

Domestic and wild fowl

Turkeys

Quail

Ducks

Partridges

Pigeons

Spironucleus (Hexamita) meleagridis: Turkeys
Spironucleus (Hexamita) columbae: Pigeons

Ring-necked Pheasants - heavy losses

Chickens - not apparently affected