Nematode Parasites of Poultry

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(There is a lot more information about paraites in animals than there

is about parasites in humans. Reading about parasites in general will

broaden your education about parasites as most act similarly.)

 

 

 

 

http://edis.ifas.ufl.edu/PS012

 

Nematode Parasites of Poultry (and where to find them) 1

R.D. Jacobs, J.A. Hogsette, and G.D. Butcher2

 

Nematodes or roundworms are the most important group of helminth

parasites of poultry. This is due to the large number of parasitic

species (23) that cause damage to the host, especially in severe

infections. Roundworms are elongated, cylindrical and unsegmented.

They are covered with a tough, noncellular layer called the cuticle.

Roundworms have a well-developed alimentary tract. Most roundworms are

bisexual; that is, a single worm is both male and female.

 

Nematode Life Cycle

Each species of roundworm tends to infect a specific area of the

intestinal gastro tract. Different species of the same genus may

infect several different areas of the tract. In general, the different

species of roundworms have very similar life cycles. Adult roundworms

lay eggs inside the infected bird. The eggs are voided from the hosts

through the feces. The eggs incubate in soil before they become

infective. Roundworms may or may not require intermediate hosts. The

eggs or intermediate hosts must then be consumed by the avian host.

Once the infective agent finds its way back to its infective site, the

cycle is complete. An interesting example of this is the eye worm (

Oxyspirura mansoni ). The eye worm lays eggs on the surface of the

eye. These eggs are then washed down the naso-lachrymal duct and pass

into the intestinal tract of the host and are voided with feces. The

eye worm eggs must then be consumed by a cockroach, the intermediate

host. After an incubation period, the worm larvae becomes free inside

the body cavity and legs of the cockroach. After the cockroach has

been consumed by the avian hosts (chickens, turkeys, peafowl and

ducks) the eye worm larvae are released in the crop. They migrate up

the esophagus, tear ducts and back to the eye. The time required for

the cycle to be completed may be a few days or several weeks depending

upon the worm species.

 

Six infectious groups of roundworms are identified in this fact sheet.

The first three groups (large roundworms, cecal worms and capillaria)

are the more common, the remaining three groups (eye worms, gapeworms

and gizzard worms) are less common.

 

Prevention

The best method for controlling roundworms is prevention, which

includes sanitation of the area where poultry are kept, controlling

secondary hosts, keeping poultry age groups separated and keeping

different kinds of poultry separated. Secondary hosts include not only

insects such as beetles, roaches and grasshoppers, but also earthworms.

 

Problems associated with roundworms can be reduced if the hosts are

maintained on wire placed above ground level, thus preventing contact

with contaminated feces and/or intermediate hosts.

 

Symptoms

Symptoms of roundworm infections closely resemble symptoms of other

types of diseases. The presence of roundworms should be identified

prior to using chemical treatment. In all cases if chemical treatments

are to be used, manufacturers recommendations should be followed .

 

Large roundworms

Primary species : Ascarida galli

 

Location : Lumen of intestines

 

intestines .

Symptoms : Large roundworms are found in all ages of chickens, the

greatest amount of damage is in young birds under 12 weeks of age.

Unthriftiness, drooping of the wings, bleaching of the head and

emaciation are described. In adult hens, egg production can be

reduced. In heavy infections, large roundworms may move up the oviduct

and be found in hens' eggs, and sometimes large roundworms can be

found in the birds' feces.

 

Autopsy : Large numbers of worms can occlude the intestines and

penetrate the mucosa during growth causing injury, loss of blood and

permitting bacterial infection.

 

Treatment : Piperazine salts, continuous medication in feed with

Hygromycin B.

 

Cecal Worms

Primary species : Heterakis gallinae

 

Location : Lumen of cecal pouches

 

Symptoms : With heavy infection (500), especially in young birds,

listlessness, depression and unthriftiness are present. In production

birds, heavy infestation of cecal worms can adversely affect

production. Cecal worm eggs can be carriers of the blackhead organism

Histomonas meleagridis .

 

Autopsy : Large numbers of worms can cause thickening of the cecal

walls, hemorrhages.

 

Treatment : Phenothiazine as drug of choice, piperazine salts,

Hygromycin B in the feed and Levamisole.

 

Capillaria or Small Roundworms

Primary species : Capillaria amulata

 

Location : Embedded in the lining or mucosa of the esophagus, crop,

duodenum and small intestine .

 

Symptoms : Droopiness, anemia, muscular weakness, loss of appetite,

foul breath, emaciation, twisting of the neck and paralysis of the

legs are described.

 

Autopsy : To identify presence of small roundworms, scrape mucosa of

infected area, wash through a fine mesh screen, backwash into a large

glass jar. Identify worms suspended in the backwash. Inflammation and

thickening of walls are described.

 

Treatment : Levamasole in drinking water, Hygromyacin B in feed.

 

Eye Worms

Primary species : Oxyspirura mansoni

 

Location : Under the nictitating membrane of the eye and in the

naso-lachrymal duct.

 

Symptoms: Scratching of the eyes; can cause blindness.

 

Treatment : Physical removal of worm using local anaesthetic.

 

Gapeworms

Primary species: Syngamus trachea

 

Location : Inner lining of trachea

 

Symptoms : Respiratory distress and death may occur from asphyxiation.

 

Autopsy : Red worms can be found in trachea causing inflammation,

ulceration and accumulation of mucus in the trachea.

 

Treatment : None

 

Gizzard Worms

Primary species : Cheilospirura hamulosa

 

Location : Musculature of gizzard

 

Symptoms : Dullness, loss of appetite, emaciation, weakness and death

are described.

 

Autopsy: Presence of red worms attached to musculature of gizzard at

opening to proventriculus; nodules also may be present.

 

Treatment : None

 

Descriptions

Gapeworms : Red, ¼ to 1½ inches* long, worms that infect the inner

lining of the trachea . Two species involved.

 

Large Roundworms : Grey, white worms 1½ to 4 inches* long infecting

the lumen ** of the duodenal loop through the small intestines .

Several species of roundworms involved.

 

Cecal Worms : White, ¼- to ½-inch* long worms infecting the lumen** of

the cecal pouches . Several species of roundworms involved.

 

Eye Worms : White, ¼- to ½-inch* long worms infecting the eye, beneath

the nictitating membrane. One species of roundworms involved.

 

Gizzard Worms : Red, ½ to 1 inch* long, worms that infect the

musculature of the gizzard .

 

* Length varies with age and species.

 

** Lumen is the space inside the specific organ wall occupied by feed

that is being digested and/or absorbed.

 

Footnotes

1. This document is PS18, one of a series of the Animal Science

Department, Florida Cooperative Extension Service, Institute of Food

and Agricultural Sciences, University of Florida. Original publication

date June 1, 1997. Reviewed June 1, 2003. Visit the EDIS Web Site at

http://edis.ifas.ufl.edu.

 

2. R.D. Jacobs, multi-county poultry extension agent, J.A. Hogsette,

USDA-ARS, Gainesville, and G.D. Butcher, professor with Veterinary

Medicine, Cooperative Extension Service, Institute of Food and

Agricultural Sciences, University of Florida, Gainesville, 32611.

 

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information on obtaining other extension publications, contact your

county Cooperative Extension service.

 

U.S. Department of Agriculture, Cooperative Extension Service,

University of Florida, IFAS, Florida A. & M. University Cooperative

Extension Program, and Boards of County Commissioners Cooperating.

Larry Arrington, Dean.