If you have farmyard chickens then sure as eggs are eggs you will have to deal with sick birds sooner or later.  There are many minor problems that you can deal with yourself, so it’s important to know what signs to look for and to have an understanding of the range of potential poultry health problems that can occur and what you can do about them. 

Having dealt with the most common diseases in the last two articles, this final article focuses on how to administer medications to chickens and the importance of good hygiene.

Remember that you should consult a veterinarian if any birds become seriously unwell and particularly if the disease seems to be spreading.  If it’s a significant disease, it’s false economy to battle along on your own, and there is a real risk of delaying effective treatment or simply causing more problems on top of those you’ve already got.


Medication for birds with internal problems is usually given in feed or water or by injection. 

In individual birds, medications are generally given over a short period of time, usually by mouth or by injection. 

  • It is important to follow your veterinarian’s or adviser’s instructions and/or to read the manufacturer’s instructions carefully. 
  • The dose of medication is usually related to the body weight of the bird, so make sure you calculate the correct dose by weighing the bird first. 
  • Under-dosing or dilution of the medicine may not produce the results required. 
  • Overdoses of some medicines can be poisonous.
  • Long-term overuse of antibiotics can lead to some bacteria developing resistance to them.
  • It’s important to observe the with-holding period, ie the time that must pass before meat or eggs from the treated birds can be sold.

In groups of birds, medication to prevent certain diseases (like coccidiosis) can be given in small daily doses over a longer period, usually in the feed or water.  This type of treatment can be useful to allow progressive exposure of birds (point-of-lay pullets or lay hens that are moulted on arrival) from cage systems to free-range, where there is bound to be a risk of protozoal and worm parasites.  Gradually increasing exposure to these parasites over a period of about 3 weeks allows natural immunity to develop.

Treatment for birds with skin problems can usually be applied directly to the skin.  For example, to treat external parasites like lice, insecticide powders can be dusted into the base of the feathers.  Treatment is repeated after 2 to 3 weeks.  For skin wounds, antiseptic cream or iodine wash can be applied.  Sometimes skin treatment is best given by a veterinarian in the form of an injection, for example, antibiotics in the case of bacterial infections.  Sometimes treatment is given by mouth, eg an anthelmintic called ivermectin for some types of mange.


In many backyard flocks, there is a very low risk of viral disease so vaccination is not necessary.

However, in some flocks, it can be wise to buy chicks that have been vaccinated in the hatchery against serious diseases such as Marek’s disease.  In some places, birds should be vaccinated against avian encephalitis and infectious bronchitis and fowl pox. 

Because of different disease risks in different countries and regions, it isn’t possible to give general advice on which vaccinations are appropriate.  You should consult a poultry veterinarian or local poultry expert.

Environment disinfection

When an area has been destocked, nest boxes, percheries, and pathways should be cleaned and disinfected, particularly if any infectious diseases have occurred during the life of the previous flock.

  • Thorough cleaning and removal of all waste is the first important criterion, then disinfection.
  • Sunlight is a good natural way to clean areas.
  • Earth floors can be disinfected using a phenolic solution preferably diluted in oil and there are oo-cides (to kill coccidial eggs) that can be used.
  • Fumigation uses antimicrobial and/or insecticidal fumigants.

The last word:

It’s useful to know how to prevent disease in your backyard flock.  When a health problem does occur, you should know how to recognise it, perhaps even diagnose it (ie to determine the cause), and how to control and treat it.  Hopefully, this series of articles has helped you understand these issues … and made you a better poultry farmer as a result.