Alpacas and rye grass staggers

By Nic Cooper, Southern Alpacas Stud, Christchurch

Rye grass is a basic component of New Zealand pasture, especially in the middle and lower latitudes. Perennial rye grasses will last a long while, whereas Italian and hybrid rye grasses last only a few seasons before re-sowing.

Rye grasses suffer from attack by insects which curtail their productive life. As a result commercial perennial varieties have been developed that include endophyte(s). The endophyte gains nutrition from the grass, and also releases toxins that protect the grass from insects - but can also cause neurological effects in animals that consume it (called staggers).

Recognising Perennial Rye Grass from Pasture and Forage Plants for NZ
- Drs Alan Stewart and Deric Charlton.

Do alpacas get staggers?

Yes. Alpacas can be more susceptible than other animals to ryegrass staggers. Some alpacas (the younger and lighter colour animals) seem more susceptible than others. Research in sheep indicates that there is a strong genetic susceptibility to staggers.

What does staggers look like?

It is hard to notice the early stages of staggers. It begins with a slight tremor of the head that is most noticeable when stressed. It can worsen quickly and a noticeable shake may soon appear. The animal may be walking strangely. In bad cases it will stagger violently, stumble and fall down. The damage can, if left untreated, quickly become permanent.

The symptoms become exaggerated when the alpaca is under any form of stress, including management, treatment, or movement.

Rye grasses only create staggers in certain conditions. This is from late spring through to late autumn. It is more prevalent during drought, and particularly in the flush of growth following drought. Staggers, therefore, tends to be minimal in the lower South Island where moister, cooler summers are the norm, but more prevalent further north.

Staggers affects alpacas grazing the seed heads and the base of the stem, which means staggers is more likely in pastures that are heavily grazed, or not topped.

Staggers can be mitigated by pasture and animal management, and treatment during the initial stages. It cannot be cured once it has got established. So the keywords for this disorder are: management, observation, and rapid response.

Rye grass is not the only grass to create "staggers-type" symptoms. In sheep, staggers symptoms have been noted on phalaris grass pastures, and some fescues. Similar symptoms can be seen in animals with magnesium deficiency.

Prevention and management

Prevention is the best way of managing staggers, and starts with pasture management. Ensure your soils and pasture carry the correct mix and quantity of trace minerals. A healthy alpaca is less susceptible.

Do not have endophyte rye grasses in your pastures, or have some paddocks free of rye grass to keep your most susceptible animals on at high-risk times. Most paddocks are primarily rye grass, so that can mean spraying out and re-sowing paddocks.

There are many grass types available that alpacas seem to prefer to eat - prairie grasses, bromes, coxfoot, fescue, and herbal mixes and rye grass does not need to be used. There are nil-endophyte rye grasses available, but from our experience the incidence of re- or cross- infection is high.

If you have rye grass paddocks, regularly top these paddocks to avoid seed heads. Avoid paddocks if they are well eaten down during drought, and especially after rain or irrigation.

Alpaca in non rye grass pastures with
herbs and legumes

If your alpaca develops staggers, it is important to remove them immediately and entirely from the rye grass. Move onto a specially sown paddock, or feed non-rye grass hay. If necessary, move them to a grass-free yard and provide supplements to eat. Take a companion animal along to minimise the stress of isolation from the herd.

Treat the alpacas with:
1) Cocktail Vitamin B (e.g. Duoject B1+B12) injections.
2) Equiguard toxin remover sprinkled over supplemental feed, or mixed to a paste and drenched down the alpaca throat.

Do not sit and await developments. We have found nothing to cure staggers once it has truly set in. Quick and decisive action in the first 48 hours of symptoms occurring can turn the event into a minor short term management effort.

Prevention is truly better than cure.

About the Author

Nic Cooper has been breeding alpacas for over 20 years at Southern Alpacas Stud in Christchurch. He was involved in some of the initial research into rye grass staggers in alpacas in Canterbury. Nutritional research led to development of a recommended pasture mix for alpacas which is now used widely by alpaca breeders.