Lung Parasites 3: Equine, Swine and Poultry

The parasite is Dictyocaulus arnfieldi what is the host, where does it live and how it gets there, and is in the feces

• host: donkey → horse

• where it lives: brochi

• How it get there: Grazes L3; donkeys are the reservoir

• In feces: L1 (donkeys)

The parasite is Parascaris larvae what is the host, where does it live and how it gets there, and is in the feces

• host: foal

• where does it live: Liver → lungs → trachea

• how does it get there: Swallowed egg; larvae migrate

• in feces: none

The parasite is Metastrongylus spp. what is the host, where does it live and how it gets there, and is in the feces

• host: Pig

• where does it live: Bronchi, caudal lobes

• how does it get there: Eats an earthworm (intermediate host)

• in feces: Larvated egg

The parasite is Syngamus trachea. what is the host, where does it live and how it gets there, and is in the feces

• host: gamebirds, chickens, and turkey

• where does it live: Trachea

• how does it get there: Egg or L3 — often in an earthworm

• in feces: Egg, plug at each end

Does Dictyocaulus arnfieldi have a direct or indirect lifecycle and is there an intermediate host

Direct life cycle — no intermediate host

Dictyocaulus arnfieldi live where in the donkey

Adults live in the bronchi — mainly of donkeys

When do the eggs of the Dictyocaulus arnfieldi hatch

Eggs hatch soon after passing → L1 in the feces

L1 develop to the infective L3 on

pasture; Pilobolus may help spread them

Horses and donkeys are infected by what When

grazing the L3

When is the Prepatent period about for Dictyocaulus arnfieldi

2–3 months in donkeys

First step of Dictyocaulus arnfieldi — life cycle

Adults in the bronchi of a donkey

second step of Dictyocaulus arnfieldi — life cycle

Larvae coughed up, swallowed → L1 in feces

third step of Dictyocaulus arnfieldi — life cycle

L3 on pasture

fourth step of Dictyocaulus arnfieldi — life cycle

Horse or donkey grazes the L3

fifth step of Dictyocaulus arnfieldi — life cycle

Larvae reach the lungs and mature

D. arnfieldi is a lungworm that is found what animal

The lungworm of equids — donkeys, horses, zebras

Which animal is the reservior for D. arnfieldi

Donkeys = the reservoir

• patent for life

• she L1

• few or no signs

Which animal is not patent for D. arnfieldi

Horses: usually not patent — yet the worms still cause disease

What are the risks for equids that can get affected by D. arnfieldi

Risk: horses grazing with donkeys on contaminated pasture

In horses what do we look for in lungworm causes

In horses: parasitic bronchitis — persistent cough, nasal discharge, faster breathing, no fever

In horses with showing : parasitic bronchitis — persistent cough, nasal discharge, faster breathing, no fever can be mistaken for

Easily mistaken for equine asthma

When a horse coughs, look at the

donkey, or check if the pasture was grazed previously by donkey!

What diagnosis tool we use for D. arnfieldi

§ Baermann on the donkeys' feces — motile L1 readily found

§ L1: granular gut, a small spike at the tail tip

§ The horse's feces are often negative — infection not patent

How do we treat and control D. arnfieldi —

§ Ivermectin 0.2 mg/kg PO — labeled for lungworms; treats horses and donkeys

§ Some benzimidazoles (fenbendazole, mebendazole) also reported

§ Treat the whole group — above all the donkeys, not just the coughing horse

§ Don't graze horses with untreated donkeys

§ New donkeys: quarantine, Baermann, treat before turnout

§ Pick up manure, rest or rotate pasture, and keep testing the donkeys

What is Parascaris

A gut worm whose larvae cross the lungs

How are Foals and yearlings affected

sticky eggs cling to the mare's udder

What is the Lung phase for Parascaris how long is it there for

Lung phase, first ~4 weeks: cough, grey nasal discharge — foal stays bright and alert

Is there eggs in the feces

No eggs in the feces yet — the worms are not adults

Metastrongylus - swine lungworm is it direct or indirect

Indirect

What is the intermediate host for Metastrongylus — the swine lungworm

the earthworm is the intermediate host

Where are the adults found in Metastrongylus — the swine lungworm

Adults in the bronchi; larvated eggs in the feces

Inside the earthworm the larva reaches

L3 in about 10 days

Pig roots up the earthworm; prepatent how many days/weeks/months

about 4 weeks

L3 live as long as the

earthworm — up to 7 years

What is the treatment for Metastrongylus

fenbendazole, levamisole, ivermectin, doramectin

How do you control Metastrongylus

house the pigs, keep them off soil, cultivate the pasture

if there is a Light infections in Metastrongylus what do we see

no signs, especially older pigs

if there is a Heavy, young pigs in Metastrongylus what do we see

cough, dyspnea, nasal discharge, slow growth

What kind of test we can use for Metastrongylus

Flotation in a dense solution (Sheather's sugar or MgSO4): heavy, rough-shelled, larvated egg

Syngamus trachea — the gapeworm has a intermediate host or not? and is it direct or indirect

Direct — no intermediate host is needed

In Syngamus trachea L3 develops where

inside the egg in the soil

How does the L3 get into the bird

Bird eats the egg or L3 — or an earthworm carrying it

In Syngamus trachea who is the transport host

Earthworm = transport (paratenic) host — holds L3 for years

• L3 → lungs → trachea; worms pair by day 7

What is the Prepatent for Syngamus trachea — the gapeworm

16–20 days; eggs survive 9 months in soil

what are the clinical signs for Syngamus

§ "Gapes": gasping, beak open, neck stretched, head shaking

§ Heavy: worms block the trachea → suffocation

§ Chicks under 2–3 months; turkeys of any age — adults carry it

What is the diagnosis for Syngamus

flotation: egg with a plug at each end; necropsy: red Y-shaped worms

What is the treatment for Syngamus

benzimidazoles in feed for several days (approved, or extra-label with FARAD)

How do we control Syngamus

young birds off soil and away from adults; dry runs; keep wild birds out