Pests & Diseases

Chronic wasting disease

Chronic wasting disease

This disease is NOT in New Zealand.

Report any suspected cases to the hotline, ph 0800 809 966.

General Information

For New Zealand to be able to export deer products, we rely on our ability to prove to the rest of the world that we do not have chronic wasting disease (CWD), a serious disease of deer and elk, and that we would be able to detect it if it occurred here.

Early detection of CWD, if it occurred in New Zealand, would be essential for eradication to be successful.

CWD was first observed in the 1960s but until 1997 appeared to be restricted to a rather limited area in the western United States. However, it has subsequently been found in free-ranging and/or farmed cervids in Nebraska, Wisconsin, Montana, South Dakota, Oklahoma, Kansas, New Mexico and the Canadian provinces of Saskatchewan and Alberta. CWD has also been detected in South Korea in an elk imported from Canada.

Farmers and veterinarians are usually the first people to notice when an animal becomes sick and they play an essential role in New Zealand's exotic animal disease surveillance.

It is vitally important to be aware of the signs of CWD and immediately report any suspected case to the Ministry of Agriculture and Forestry's Exotic Disease and Pests Diseases Hotline on 0800 80 99 66.

What to look for

CWD is one of a group of brain wasting diseases called transmissible spongiform encephalopathies (TSEs).

Unlike BSE (bovine spongiform encephalopathy or "mad cow disease"), CWD can be transmitted from animal to animal and can spread through a herd. There is also a risk of spreading TSEs through feeding ruminant protein to ruminants. This practice is banned in New Zealand and many other countries.

CWD is characterised by a loss of body condition and changes in behaviour in affected deer or elk.

Animals may become anti-social and difficult to handle. They may show repetitive behaviours such as pacing, sleepiness or depression, or may carry their head and ears lowered.

In later stages many animals drink and urinate excessively, lose their coordination, drool and slobber profusely and have difficulty swallowing. Death is inevitable.

However, sometimes signs are not so obvious and it is not uncommon to see cases of older animals in excellent condition losing weight quite suddenly, not responding to treatment, and dying from pneumonia caused by inhaling food or cud.

Most cases of CWD are in animals three to seven years old, although the disease has been seen in animals as young as 17 months and as old as 15 years. The length of time the animals are sick may vary from a few days to a year, with most surviving for only a few months. Occasionally sudden death may occur.

Diagnosis of CWD

A definite diagnosis can only be obtained from samples sent to a veterinary diagnostic laboratory. There is no reliable blood test, and diagnosis requires samples of brain, which can only be taken from a dead animal.

If a veterinarian is unable to confirm that signs are due to another cause, then the animal should be euthanased and brain samples taken to ensure that the disease is not CWD. MAF pays for laboratory testing in these cases.

Remember

All TSEs are notifiable under the Biosecurity Act 1993. Any person suspecting a TSE in an animal in New Zealand must notify MAF. The Biosecurity Act 1993 provides for very heavy penalties (up to $200,000 and up to 5 years prison) for failure to notify.
The possibility of CWD should be considered in deer of any species or elk that show signs of wasting, nervous disease or acute pneumonia.
If you suspect CWD, contact the MAF exotic pest and disease hotline 0800 80 9966 immediately.
Feeding of ruminant protein, such as meat and bone meal, to ruminants (including deer) is banned. There are heavy penalties for non-compliance.