Why summer can be a time of toxicity

THE DANGER LIST - toxic to poultry

Copper

How: eating copper-coated seeds (protection from fungi), fruit tree sprays. Signs: convulsions, paralysis, green-blue diarrhoea.

Creosote

How: pecking treated wood

Signs: uneven growth, waddling gait caused by fluid in the abdomen, enlarged liver, more susceptible to disease, including coccidiosis.

Fertiliser (superphosphate, RPR rock)

How: eating granules spread on pasture or in the garden.

Signs: can cause an upset of the calcium-phosphorous balance, may affect egg production and eggshell strength.

Insecticides (organophosphates)

How: birds eating insects that have died from insecticide spray.

Signs: respiratory distress, often misdiagnosed as a respiratory illness.

Lead

How: eating soil, insects, and worms. An NZ study found higher lead levels in chickens living outside houses:

• clad with weatherboards;

• built before 1950.

Lead is also found in soil close to formerly busy roadsides (due to lead in petrol pre-1980), and in gardens and orchards where lead-based pesticides were used (eg former orchards).

Signs: usually no symptoms – you need to do blood tests, test the eggs and/or the soil. Fatal to hens, and residue affects humans who eat the meat or eggs.

Mycotoxins

How: eating moulds, often found in old/ stale/rancid feeds or grains, especially in feed that has been damp.

Signs: may be vague, including failure to grow, poor production, scouring.

Rodenticides (brodifacoum, bromadiolone)

How: eating bait and/or bodies of poisoned rats and mice.

Signs: internal bleeding, death.

Salt

How: birds may eat salt-based weed-killing products, brine/salt discarded from home curing of bacon and ham, or scraps of meat and bone with high levels of salt.

Signs: extreme thirst, difficulty breathing, twisted necks, turkeys more easily affected than chickens, can be fatal.

Zinc oxide

How: birds may eat granules or other products added to water or pasture used to prevent facial eczema in livestock. Signs: induced moulting.

Other toxins

• cat or dog flea treatments, often toxic to poultry, eg Frontline (fipronil) – never use on poultry.

• slug and snail baits in excessive quantities.

• plants sprayed with weed killer or fungicides;

• naturally-occurring fungal and bacterial toxins, especially in water;

• disinfectants not rinsed off after

• sanitising equipment such as drinkers.