Zinc is commonly used to apply a protective weather-proof covering for steel and iron intended to be used outside (a process called galvanising). Items like feeders, drinkers, and chicken wire can be galvanised and must be taken care of when in a chicken run.
How do hens get zinc poisoning?
Chickens are extremely curious and naturally attracted to shiny objects. Any nail or screw dropped on the ground, perhaps after hen coop repairs, will be fair game and may be swallowed if small enough. Tiny snippings of chicken wire discarded during repairs are a similar hazard, so ensure you tidy up thoroughly after any refurbishment work.
When your hen ingests tiny pieces of zinc through swallowing, this can cause zinc toxicity and can make hens extremely poorly; as many hen feeders and drinkers are made of galvanised metal they should also be checked routinely to spot any corrosion or damage.
Signs of zinc poisoning
Symptoms of zinc toxicity are not always clear and can mimic symptoms seen in several other diseases. However, zinc poisoning isn’t common and if your run is well maintained your chickens will be at little risk. The most common symptoms of zinc poising include:
- Loss of balance or difficulty walking. Hens will have a loss of coordination, falling, stumbling, unsteady, tumbling
- Pale face, comb and wattles
- Paresis or paralysis of the legs – hens will walk stiffly, unable or inability to move
- Polyuria – the production of abnormally large volumes of dilute urine
- Polydipsia – excessive or excess drinking
- Weakness – hens will have an inability to stand, may look lame
- Weight loss
Finally, but vitally, all hen keepers must be aware that Apple Cider Vinegar, a natural hen tonic recommended for their well-being, will react with zinc in metal feeders. As such apply cider vinegar should always be used in ceramic or plastic drinkers to prevent the metal corroding and zinc leaching out into the drinking water.