Infectious Disease

We are fortunate in New Zealand not to have many of the viruses and bacteria that are present in poultry populations in other parts of the world. However, there are still some common ones we need to watch out for as well as monitoring our flocks to make sure they haven’t picked up a foreign disease.  In this section, we will walk through the important things to check and what to do if you think you’ve found something suspicious.

Quick Navigation

Endemic Diseases

There are a few endemic diseases (diseases that are chronically present in poultry populations) that occasionally cause problems for backyard poultry flocks in New Zealand.  These include:

  • Marek’s disease
  • Fowl pox
  • Infectious laryngotracheitis (ILT)
  • Infectious bronchitis
  • Fowl cholera (Pastuerella multocida)
  • Avian mycoplasmosis (Mycoplasma gallisepticum)

If your birds are ex-laying hens from a commercial flock, there is a good chance they have already been vaccinated against many of these diseases.  While it is also a good idea to vaccinate backyard poultry, it is not commonly done because the vaccines are only sold in large bottles containing 500 or 1,000 doses that expire within a few hours after being opened.  Most veterinary clinics don’t have enough poultry patients to make it cost-effective for owners.

Marek’s disease is a herpes virus that causes tumours to grow in different parts of the bird’s body including the brain, spinal cord, nerves, and intestines. The most common signs are weakness, paralysis, and weight loss.  Birds are often infected at a young age, but not all will go on to develop clinical signs.  The disease is almost always fatal once birds are showing clinical signs.

The avian pox virus causes scabby masses and bumps that usually appear on the skin around the face. There almost always needs to be some damage to the skin, usually from biting insects, for the virus to cause clinical signs.  The disease is treateble with good supportive care to manage pain and secondary bacterial infections while the immune system fights off the virus.

Infectious laryngotracheitis, infectious bronchitis, and avian mycoplasmosis are all respiratory diseases that can cause signs of swollen eyes, eye discharge, runny nose, coughing, sneezing, and difficulty breathing. It often requires further diagnostic testing to work out which disease is present.  Fowl cholera more commonly causes swollen wattles and lameness in chickens.

If you have multiple birds in the flock that are acting dull and/or are experience a significant drop in egg production, it’s a good idea to call your veterinarian to work out whether you are experiencing an infectious disease outbreak.

Exotic Diseases

There is always a risk of disease like highly-pathogenic avian influenza (HPAI) entering the country through migratory wild birds. 

If you notice any signs of illness in wild birds around your property or if you have concerns about birds in your flock, get in touch with the MPI Exotic Disease and Pest Reporting Hotline on 0800 80 99 66. One of the experienced disease investigators will ask you some further questions to see if these may be signs of an exotic disease and walk you through the next steps to figure out what may wrong. 

While you may worry about being the person who found HPAI, it would be much worse to be remembered as the person who didn’t notice it when it was there.