Chicken Health

Health Issues and Combs

Parasites – looks like black mould (scaly leg mite).  Smother comb with petroleum jelly to suffocate mites.  Reapply over several days.

Fowl cholera – Purple comb, along with swollen wattle, temperature, coughing, ruffled feathers, lameness.

Favus – fungal condition.  Also known as white comb or avian ringworm.  Grey white patches on the comb may look like it has been dusted with flour.  Can thicken up to form a wrinkled crust that smells mouldy.

Coccidiosis – Parasite that infects the intestine of chicks and pullets (4-16 weeks old) or new birds coming into the flock.  Comb will be pale, blood in droppings, sitting fluffed up, dropping wings, death.

Avian Flu

Not in NZ but worth keeping an eye out for.

Swollen blue comb and wattles

dark red and white spots on comb and legs

sudden and unexplained death

rapid spread through flock

drop in egg production


loss of appetite

coughing, sneezing


Can kill a large flock in just a few days

Report and suspicion to MPI 0800 80 99 66


Fowl Pox (Avian Pox)

Is most prevalent during October-February

Virus is carried by mosquitos and other biting insects.  More common in free range birds.  Not thought to be transmitted to other species (e.g game birds)


Dry pox:

Most common

Shows on unfeathered parts of the bird (face and comb)  Wart like growths that form black scabs.  Can be in a cluster or spread around the face

Wet pox – yellow or white pustules inside mouth and throat that can affect breathing and swallowing.  More likely to be mortal or cause blindness than dry pox.

Other symptoms  depression, lack of appetite poor growth, drop in egg production.

No cure


Vaccine available More prevalent in warmer tempertures (north of Taupo) so vaccine is more common in those areas.

Eliminate mosquito breeding areas

ensure clean, fresh water and containers

prevent puddles and muddy areas in warmer months

Avoid getting birds from northern regions where the disease is more common

quarantine new birds for 2 weeks.  Ensure clean footwar and wash hands when moving from new flock to old.

Marek’s Disease

Also know as new pullet disease, range paralysis, grey eye

Typically affects young birds 10-25 weeks old.  Most susceptable for the first month of life of contracting it.

25% mortality rate.

Viral disease fromt he Herpes family

Named after Hungarian vet József Marek.

Vaccine has been available since 1970.  However only for large commercial flocks as it comes in a minium 1000 dose.  This is because the vaccine needs to be stored in liquid nitrogen, one mixed it must be used within 2 hours, it must be on one day old chicks.  It takes 2 weeks for immunity to develope so chicks must be isolated from main flock and possible contamination

“If you chicken breathes it has been exposed to Marek’s” – the disease is more common than you think.

Not transmitted via the egg but rather via shed skin particles and feather cells.  THe disease suppresses the immunity increasing susceptability to other diseases.

Can incubate for up to 3 months

No cure available.  Birds who survive the disease will be immune.

Some breeds such as silkies and white leghorns are more susceptable.  Also more susceptable if there is contamination in the environment or they have had a previous immune lowering condition.


Note:  Symptoms could be a sign of other disease.

Mortality may occure with no symptoms present.

Immuce suppression means the birds are more prone to secondary infection such as coccidiosis or blackhead

Nerves are affected to the birds head may appear bent and twisted to one side.

Iris of the eye may appear grey and pupil distorted.

Paralysis noteabley one leg forward and one leg back.  May drag one wing.

Rescue Birds

Are more vulnerable to infections as they lack immunity.


External pests:  Red mite, Scaly Leg Mite, Poultry Lice, Pultry r Cat Fleas, Ticks

Internal Parasites:  Round Worm, Gape Worm, Tape worm, Caecal worm

Protozoan Infections – Coccidiosis Blackhead

Mammals – Rats, Mice, Stoats

Other Insects – Lesser Meal Worm Beetle, Ants, Spiders, Mosquitoes, Flies

Mites and Lice

Redmites live in the coop and can be difficult to get rid of.  Spread by wild birds

Mite eggs can survive up to two years int he environment

Ripcord is effective as is Neem Oil – spray the coop, nests, perches.

Scaly Leg Mite

Burrow under the Leg scales

Suffocate with petroleum jelly spread over the legs.  Use an old toothbrush to get into crevices.  Repeat every day or two for over a week.

Apple Cider Vinegar

Improves gut health but there is not scientific evidence that it is a cure for worms.  Add 5ml to 5 litres of water a couple of days each month.  No more than this as vinegar will kill off good bacteria as well as bad.

Garlic Juice Spray – for Mites

Peel and crush cloves, juice and filter through a coffee filter.  10 ml juice to 100ml water.  Spray on birds skin once a week.  THis will reduce but not exterminate mites.

Diatomaceous Earth (DE)

Causes desiccation of the outer layer of an insects body.  Not effective on internal parasites however applied to the skin or surfaces of the coop are effective.