Kikuyu poisoning in livestock

Page last updated: Monday, 14 January 2019 - 9:58am

Kikuyu (Pennisetum clandestimun) is a subtropical perennial grass with spring to autumn growth. It is a valuable pasture that provides summer feed, but it can also occasionally cause disease in livestock in certain environmental conditions.

Kikuyu poisoning can resemble emergency diseases

Certain emergency animal diseases not present in Western Australia have similar signs to kikuyu poisoning. If any of these diseases became established in WA, market access for animals and animal products could be severely impacted. Early diagnosis of an emergency animal disease is vital to allow rapid eradication of the disease and re-establishment of market access.

If you see any unusual signs of disease, abnormal behaviour or unexpected deaths in stock, including signs that look like kikuyu poisoning, call your private vet, a Department of Primary Industries and Regional Development (DPIRD) veterinary officer or the Emergency Animal Disease hotline on 1800 675 888.

What is kikuyu poisoning?

Kikuyu poisoning can occur in livestock when they are placed onto heavy kikuyu pasture during certain environmental conditions. It can cause signs of neurological disease and death. Noticing signs of kikuyu poisoning early is important to prevent production losses.

Which animals can be affected?

Cattle are most affected by kikuyu poisoning, however sheep and goats are also susceptible. Animals of any age and condition can be affected.

Causes and risk factors

The definite cause and toxin involved in kikuyu poisoning are currently unknown. The endophyte Fusarium torulosum is suspected but unproven. F. torulosum is known to produce the toxin wortmannin that has been shown to damage the gut and heart in rats.

In the past, outbreaks have occurred in summer or autumn after a period of drought followed by summer rain that causes the kikuyu grass to grow rapidly. Stock placed onto these pastures two to three weeks after rainfall are at greatest risk of poisoning. Paddocks left ungrazed for long periods may provide the biggest risk to livestock.

Other factors such as plant stress (e.g. locust or army worm infestations) may also play a role in disease.

Signs of kikuyu poisoning

Livestock usually show signs of poisoning 1-8 days after moving onto the affected paddock. After removal from the paddock, animals may continue to show signs for up to eight days.

Signs of kikuyu poisoning include:

  • drooling
  • sham drinking, tongue paralysis, dehydration
  • unusual vocalisation
  • abdominal pain, distended rumen, smelly green diarrhoea
  • lack of coordination, staggering, high stepping gait, aimless wandering
  • lying down, reluctance to move
  • death.

How is kikuyu poisoning diagnosed?

A vet can diagnose kikuyu poisoning by clinical or post-mortem examination.

Other diseases may also resemble kikuyu poisoning and a thorough disease investigation by a private vet or department vet may help ensure kikuyu poisoning is the true cause of disease.

Other diseases that look similar to kikuyu poisoning include:

  • infectious diseases such as listeriosis and Histophilus meningoencephalitis
  • milk fever, grass tetany and other metabolic conditions
  • other poisonings including lead, salt and nitrate poisoning
  • reportable animal diseases such as foot-and-mouth disease.

Treatment

There is no specific treatment for kikuyu poisoning, but many animals will recover if removed from the affected paddock and given supportive care. This includes managing them to minimise stress and supplying them with good quality hay, water and shelter.

It is not known how long the pasture remains toxic so it is advisable to keep the affected paddock free from stock for as long as practically possible. This will vary depending on individual properties and the amount of other feed on offer (FOO).

Prevention

Monitoring livestock closely after moving animals onto kikuyu-dominant paddocks after summer rain events is important.

What to do if you suspect kikuyu poisoning

If producers notice any unusual signs in their stock, they are encouraged to contact a DPIRD vet or private vet to determine the cause and limit production losses. Investigating the cause of the disease also provides evidence of freedom from significant diseases that can affect access to markets.

Subsidised disease investigations are available through the department’s Significant Disease Investigation Program. Contact your DPIRD vet or private vet for more information.

For more information about DPIRD's livestock health surveillance program, watch this short video:
Animal Health Surveillance in Western Australia.