Ryegrass Staggers



Tremors/ Staggers Syndrome - A number of grasses may cause a condition in which the head and neck and even body and legs may be involved in tremors and shaking and incoordination (ataxia)...

Rye Grass Staggers-

A clinical disease from eating rye grass infected with mycotoxins which are produced by endophyte fungus.- characterized as follows:

Moderate signs include stiffness when walking or trying to run, swaying, incoordination, falling and a high stepping gait when forced to run. Severely affected animals may stand in a saw horse stance and sway back and forth.

Phalaris Staggers:

In the early stages of this syndrome the clinical manifestations are similar to Rye grass staggers, including tremors, head nodding, staggering, a high stepping gait and falling when excited. Has been diagnosed in Alpacas in Australia.

Grass Staggers or Tetany

The signs exhibited may include difficult breathing, incoordination, excitability, salivation, grinding of teeth, muscle twitching, convulsions.......similar to Stagger/tremor syndrome but animal is usually aggressive or belligerent.

Perennial Ryegrass produces excellent feed of up to nine months of the year in many areas and is one of the most valuable pasture species available. One disadvantage of perennial Ryegrass is the incidence of Ryegrass Staggers. This is caused by a fungus -- Acemonium iolii -- which grows in the leaves and stems of the plant. This fungus is known as an "endophyte". Ryegrass Staggers is a problem in late spring and summer when the plant is in the reproductive phase.

There are two strategies which can be used to reduce the incidence of Ryegrass Staggers:

1. Grazing management - If you have a number of paddocks with different types of pasture, you may be able to put your animals into a paddock where there is no Ryegrass during the danger period. It is also possible to reduce the amount of endophyte present by grazing the pasture heavily and reducing the amount of stem and seedhead.

2. Use low-endophyte varieties - Plant breeders have persisted with varieties which have high levels of endophyte (i.e. greater than 50% of plants infected) because the advantages seem to outweigh the disadvantages. High endophyte lines are generally more persistent and productive than low endophyte lines. This pasture productivity in most cases outweighs the reduced animal performance resulting from ingestion of the toxin. There are many low-endophyte varieties available which will be suitable for all areas. Ask your local seed supplier for information.

From the Summer 1996 Alpacas magazine, Pg 57, "Grasses - The Dark Side", by Murray Fowler

According to "Merck" 5th ed. pp.1046-7, Perennial Ryegrass can cause staggers in sheep, cattle and horses in NA, Europe and Australia. Generally occurring in dry seasons a few days after rainfall. Move them to a nontoxic pasture and most will recover. Annual Ryegrass staggers occurs in Australia.


If you notice staggering in llamas, also consider heat stress or Meningeal Worm.

Return To Medical & Care Index


Return To Llama Management

Return To Home Page