Backyard Poultry Navigation
Keeping backyard poultry can bring a lot of positive benefits to our lives. However, there are some additional risks of illness and/or injuries that we need to manage to keep ourselves and our families safe in the process.
In this section, we will cover the three main categories of risk and how to manage them: (i) infections diseases that can pass between poultry and people, (ii) toxins and contaminants in poultry eggs and meat, and (iii) physical injuries from pecking or scratching.
There are several infectious diseases that can spread from poultry to people and people to poultry. These are called zoonotic diseases.
One of the more serious zoonotic diseases is avian influenza virus. While we don’t currently have any of the highly pathogenic strains in New Zealand, it is important keep a close eye on your flock as well as other local wildlife for signs of a possible outbreak. Check out the HPAI website from MPI for more information.
If you have flu-like symptoms, have someone else take over the chores for your flock so you don’t accidentally make your birds sick too.
The most common bacteria you can find on the surface of eggs in New Zealand are Campylobacter jejuni and E. coli – remember that eggs come through the same opening as all the other waste that chickens produce and may be laid into environments that are already contaminated with droppings. Salmonella is a big problem in other countries, but fortunately not very common in New Zealand flocks.
When an egg leaves a chicken, it will be at the same body temperature of around 41°C. As the egg cools to the same temperature as the environment, bacteria can be pulled through pores in the shell as well as entering through small cracks. Eating raw eggs can put you at risk of picking up these bacteria, which can cause all kinds of unpleasant symptoms like diarrhoea, vomiting, abdominal cramps, nausea, and fever.
There are several things you can do to help reduce the risk:
Set-up your nest boxes so that birds are only tempted to be in them when laying and clean out any droppings or soiled bedding everyday to prevent a build-up of bacteria. For more tips on setting up nest boxes, check out our Nest Boxes page in the Preventive Care section.
Pick up eggs at least once a day, preferably two or three times, to minimise the amount of contact they have with the nest bedding and faecal material. Any eggs with broken or cracked shells should be immediately discarded and be careful cooking with eggs that have been picked up off the ground.
Eggs have a natural protective layer on the outside called the cuticle that seals the pores in the shell and helps prevent bacteria from entering. Cleaning eggs with water and/or soaps can remove this layer making it more likely for the eggs to become contaminated. If the eggs are covered in faeces, first check your birds for signs of diarrhoea by examining their droppings and their vent as this could be a sign they are getting sick. Otherwise, there are two main options for cleaning:
Raw eggs can be refrigerated and consumed for about 3 to 5 weeks, but their quality will start to decrease over time. This is mainly due to the egg yolk absorbing water from the white and the egg white losing moisture from evaporation through the shell. This causes the egg white to become thinner and runnier while the egg yolk becomes larger and more fragile.
Anything substance that passes through your chicken’s beak has the potential to collect in the eggs or stick around in the muscle tissue, which can be a risk to you if your backyard birds are also a source of eggs or meat for your household.
When chickens are treated with dewormers and other medications, the drugs can stick around in their system for a much longer time.
Most products will come with withholding times, which is the number of days after the animal receives its last dose of medication you have to wait before eating any eggs or meat from it. If the withholding time is 0 days or nil, it means that it’s safe to eat even when the animal is being treated. Always consult the label of the product or check with your veterinarian if you are concerned.
Many of the drugs we give to chickens are used off-label meaning that the pharmaceutical companies have not done specific safety and efficacy studies of the drugs in chickens because it is expensive for them to do so. The Ministry for Primary Industries (MPI) has guidelines on withholding times for common poultry medications published here. If there is no available information about the product you are using, MPI suggests a minimum of 63 days for meat and 10 days for eggs.
Chickens can pick up a lot more than just insects and shrubs when they are foraging in your garden.
A 2019 study by Cowie and Gartrell found that more than half of eggs sampled from 30 backyard poultry flocks in Auckland contained lead levels that were high enough to be concerning for human health if they were consumed. Levels were higher in eggs produced on properties with homes built before 1941 and homes that were constructed from weatherboard, which was most likely related to chickens eating chips of lead paint coming off the building.
Chickens have sharp beaks and nails which they are not afraid of using if they feel threatened. It’s very easy for children to get scratched even when they are being careful about handling. Roosters can be particularly aggressive. It’s important to teach children how to pick up birds correctly and children under 10 years of age should not be left unsupervised with your flock. Always have children wash their hands after handling birds.
