Feedback
Sheep health and welfare
To maintain the health and wellbeing of your flock, and ensure maximum profits for your business, you must protect your sheep from diseases.
Prevention is always better than cure, so have a robust sheep health plan in effect to quickly spot any signs of disease.
This guide explains how to protect your flock from the major diseases affecting sheep, as well as from parasites such as worms, flies and lice. It also details how to minimise the risk of accidental poisoning, and strategies to maintain the general wellbeing of your flock, including nutrition, shearing, and trimming hooves and horns.
Managing sheep diseases and disorders
You should ensure you take all available precautions to protect your sheep from disease, including vaccination and looking for any signs that their health has changed.
The following are some of the major diseases that can affect sheep. These include diseases classed as category 1 restricted matter and prohibited matter, which you must report.
- Bluetongue (prohibited matter)
- Cheesy gland
- Fluorosis in sheep
- Foot and mouth disease (prohibited matter)
- Humpy back
- Ovine brucellosis
- Johne's disease (OJD) (category 1 restricted matter)
- Lumpy wool
- Pregnancy toxaemia and hypocalcaemia
- Rabies (prohibited matter)
- Scabby mouth
- Screw-worm fly (prohibited matter)
- Suppurative arthritis
- Clostridial diseases (e.g. tetanus, blackleg, malignant oedema, pulpy kidney)
Clostridial diseases
The most common clostridial diseases that affect sheep are tetanus, blackleg, malignant oedema (blood poisoning), and pulpy kidney (which affects lambs). In older animals, clostridial infections are most likely to be contracted as a result of injury and bruising associated with fighting (rams), or through infections from contaminated dips at shearing.
Vaccinating for clostridial diseases
To minimise losses from clostridial diseases, consider vaccinating the flock. Treating with a 6-in-1 vaccine will give total protection—against tetanus, blackleg, malignant oedema, pulpy kidney and black disease, as well as cheesy gland—at a very low cost (currently around 20-30 cents per injection).
Your vaccination program requires 2 initial injections, 4 weeks apart, followed up with a booster injection every year. Replacement rams should be brought onto the program as soon as practical after they arrive.
Reportable diseases and signs
Under Queensland's Biosecurity Act 2014, you must report suspected category 1 restricted matter and prohibited matter to Biosecurity Queensland on 13 25 23 or to the Emergency Disease Hotline 1800 675 888.
Notifiable incidents
You must immediately report the following signs of disease:
- a high percentage of ill or dead animals, including birds and aquatic animals
- rapid spread of disease through a flock
- animals that are lame, drooling or salivating excessively
- animals that have ulcers, erosions or blisters around the feet, muzzle, udder or teats, or in the mouth
- unusual nervous signs
- profuse bloody diarrhoea
- deep smelly, fly struck wounds.
There are no government charges for investigations into suspected category 1 restricted matter and prohibited matter diseases, including negative diagnoses. All reports are treated confidentially.
Prohibited matter
Prohibited matter diseases are not present in Australia, or are present but not established. If these diseases are confirmed as present in Queensland, Biosecurity Queensland will establish a control or eradication program.
Report suspected prohibited matter
If you notice unusual signs of disease, abnormal behaviour or unexpected deaths in your sheep, call the Emergency Animal Disease Hotline on 1800 675 888. This national service operates 24 hours a day, 7 days a week.
Also consider...
- Learn about lambing sickness and milk fever in ewes.
- Find out about prevention and treatment of foot abscess in sheep.
- Learn about AUSVETPLAN, a resource that sets out roles, responsibilities and policies for responding to animal disease emergencies.
- Read about the National Johne's Disease Control Program.
- Find out about the potential economic consequences of a foot and mouth disease outbreak in Australia.
- Read foot-and-mouth disease information for livestock owners.
Managing worms in sheep
Worms in sheep can be severe enough to cause major production losses and deaths. In particular, Barber's pole worm is a serious threat to sheep in Queensland and costs the industry millions of dollars every year.
Managing worms in sheep with WormBoss
WormBoss is an industry tool that helps Australian sheep farmers effectively manage intestinal worms and other parasites in sheep.
WormBoss will help you understand:
- intestinal worm life cycles
- how pasture management can affect the life span of infective larvae
- how drench resistance develops and how to minimise this with WormTest and DrenchTest kits
- best practice for drenching to ensure animals are treated correctly
- why new animals should be quarantined before they are introduced to the flock.
Find out more about WormBoss.
Also consider...
- View a recorded webinar on worm burdens in the pastoral zone on the Leading Sheep website.
- Learn about lambing sickness and milk fever in ewes.
Managing lice in sheep
Lice are external parasites that may cause extensive economic losses to your wool growing business. If sheep have lice they can become irritated, causing them to bite themselves and rub up against anything available. This damages the fleece by matting the fibres together and tearing the tip of the wool fibres.
Managing lice in sheep with LiceBoss
LiceBoss is an industry tool that helps Australian farmers treat and control the spread of lice and parasites in their sheep.
LiceBoss will help you:
- understand the different causes of itchiness and rubbing in sheep
- identify lice and diagnose an infestation
- understand how lice are spread from sheep to sheep (i.e. via close contact)
- assess the risk of new animals introducing lice into the flock
- decide on the most appropriate treatment option.
Find out more about LiceBoss.
Also consider...
- Learn about lambing sickness and milk fever in ewes.
- Find out about prevention and treatment of foot abscess in sheep.
Managing flies in sheep
Blowflies are a constant problem for sheep. Serious losses occur every year in the Australian sheep industry due to this parasite. Problems such as flystrike can arise in a very short space of time when conditions are suited to blowfly activity and sheep are susceptible.
Managing flies in sheep with FlyBoss
FlyBoss is an industry tool that helps Australian farmers understand how flystrike develops, and control the effect of blowflies on their sheep.
FlyBoss will help you understand:
- the life cycle of the blowfly, including how
- to identify adult and maggot flystrike species
- different climatic conditions affect the development of fly populations
- a 'flywave' can occur
- paddock topography may alter the risk of flystrike
- fly population monitoring can assist with minimising strike in the flock
- what conditions make sheep susceptible to flystrike, including
- what traits increase individual sheep susceptibility
- how to breed against these traits to increase flock resistance to flystrike
- what management tools may decrease animal susceptibility, such as
- tail docking
- crutching
- breech modification
- the options for chemical prevention and treatment of flystrike.
Find out more about FlyBoss.
Flyboss tools
You can use FlyBoss tools to identify the best product to use on flystrike by comparing price and effectiveness. You can also learn how to optimise your treatment schedule.
Also consider...
- Learn about lambing sickness and milk fever in ewes.
- Find out about prevention and treatment of foot abscess in sheep.
Avoiding sheep poisoning
Some plants are toxic to sheep. Any period of heavy rainfall or flooding, or a spell of very high temperatures, can increase the abundance of poisonous plants.
To prevent contact with poisonous plants, you should avoid situations where your sheep are forced to graze plants they would not normally favour. For example, avoid introducing hungry stock to lush pastures or pasture recovering from a flood, or allowing them to overgraze.
You should also prevent an excess of fluorine in your flock's diet (through water or pasture contamination), as this is toxic to sheep and can cause fluorosis.
How plant poisoning affects sheep
Some pasture plants such as silk sorghum, and common native couch grass, can accumulate prussic acid. The annual urochloa and button grasses can accumulate nitrites, especially if growing in nitrogen-rich soils (e.g. in fertilised pastures). Both prussic acid and nitrites can poison and kill an animal in under an hour if left untreated.
The crotalaria group of plants, including rattlepods, accumulates pyrrolizidine alkaloids, which cause liver disease and, if severe enough, will kill the animal.
Other plants that can affect sheep health include:
- noogoora burr - will readily germinate to produce highly toxic seedlings in post-flood conditions
- lantana - may be attractive to stock on lush pasture, as it is often drier and provides more bulk. Lantana can cause photosensitisation and neurological symptoms
- castor oil plants - contain poison within the seeds and are often found along streams
- fireweed - germinates in abundance during autumn, including downstream of previous infestations, and causes damage to the liver.
How to detect plant poisoning
The symptoms of poisoning can come on very quickly in sheep. Sick animals may show rapid deep breathing and weak pulse, salivation, muscle twitching or trembling, spasms, staggering, and sometimes a bluish discolouration of the gums or jaundice.
Identifying and eradicating poisonous plants
It's important to become familiar with the plants your stock may come into contact with when grazing. This will help you to spot any unfamiliar species.
Identify new plants as soon as possible so action can be taken if needed. Move your sheep away from the affected area until the plants can be identified as safe or, if poisonous, eradicated.
Fluorosis in sheep
Fluorine in small quantities in the diet of sheep has a beneficial effect on the teeth and bone, but in excess it is toxic.
The main sources of excess fluorine in the diet are:
- water containing dissolved fluorides
- foodstuffs containing high levels of fluorides (e.g. rock phosphate).
Sheep can exhibit 2 types of fluorine toxicity:
- acute toxicity - when sheep ingest large quantities of fluorine rapidly and death occurs
- chronic toxicity - caused by the continuous consumption of toxic concentrations of fluorine. This causes defects in tooth enamel of young animals, softening of the bones, osteoporosis, and damage to other organs, including the kidney and heart.
Acute toxicity is rare in Queensland, as sheep are seldom exposed to high-fluorine phosphorus supplements. In chronic cases, the teeth become chalky white, mottled, pitted, and wear excessively. The bone of the lower jaw thickens and bony outgrowths may develop.
Preventing fluorine poisoning
There is no treatment for fluorosis, so prevention is essential.
You should restrict the opportunity for sheep to consume high levels of fluorine. When using rock phosphate in a diet, use low-fluorine phosphate or defluorinated rock phosphate.
You should also restrict access to high-fluorine water. Where possible, allow sheep to drink from bores or surface storage areas (e.g. dams, tanks or creeks). Low-fluorine water should be given to young sheep first, as animals under 3 years of age are more severely affected than older ones. Older sheep should be rotated so they may have 3 months on high-fluorine water and 3 months on low-fluorine water.
Also consider...
- Learn about lambing sickness and milk fever in ewes.
- Find out about prevention and treatment of foot abscess in sheep.
Avoiding impacts on sheep from grass seeds
Your sheep and their wool can be affected by grass seed contamination, particularly when seasonal conditions favour high seed production. It's important not to underestimate the negative effect that grass seed contamination can have on your flock's productivity.
Effects of grass seed on sheep
Grass seed infestations can have the following effects on sheep:
- lower bodyweight and growth rate, due to irritation and infection
- small, low-quality and low-value carcasses
- reduced skin quality and value, as seeds penetrating the skin leave abscesses and small permanent holes, which enlarge during tanning
- increased risk of bacterial diseases, higher parasite burden and flystrike (as a result of skin-penetrating wounds and forced changes in grazing habits when sheep attempt to avoid grass seeds)
- damage to the mouth, eyes, ears and feet, causing
- reduced feed and water intake
- starvation
- blindness
- lameness and listlessness
- severe pain and distress
- death.
Reducing the effects of grass seed by shearing
Shearing is the only known way to relieve the pain and discomfort that sheep suffer from high levels of grass seed in the skin and carcass.
Signs of grass seed infestation in sheep
In Queensland, grass seed usually affects sheep during summer and autumn. They are listless, with a stiff gait or a reluctance to move. Some may show skin irritation and rubbing, and cotting of the wool.
Check sheep for dehydration from grass seed
You can check if your sheep are dehydrated from grass seed by gently pinching the skin and then letting it go to see how quickly it recoils into place. If this recoil lasts longer than 2 seconds, the animal is clinically dehydrated. Seeds will be seen visually when the fleece is opened along the neck, jowl, and belly wool.
Checking a carcass for grass seed infestation
After death, if the carcass is skinned, you will see the extent of seed penetration on the underside as confirmation of the problem. Seeds will be found penetrating into the flesh and will pull through the skin during skin pull.
Identifying problem grasses
Problem grasses pose the biggest threat when the seed is mature. The main grasses that can cause grass seed problems for sheep health, wool and skins are:
- wire grass, feathertop and white spear
- spear grass and corkscrew grass
- black spear grass.
Pasture management to prevent grass seed contamination
To manage your pasture effectively and reduce the spread of grass seeds to animals you should consider the following strategies:
- Encourage other grasses as competitors - Mitchell grass, blue grass and mulga grasses will outgrow problem grasses in normal to hot, wet summer rainfall years.
- Burning - destroys problem grasses, but can have other effects on species composition and the subsequent growth of vegetation (depending on the season, amount of herbage, the frequency of burning and the intensity of the burn).
- Mechanical treatment - involves slashing tracks through tall seed-bearing plants to, for example, allow animals safe access to water from grazing areas.
- Herbicides - usually only applicable to intensive, high-rainfall areas as cost prohibits their use in other areas.
Animal management to prevent grass seed contamination
You can also alter your animal management practices to reduce the spread of seeds to your sheep:
- Shearing - shearing sheep before grass seed matures will often reduce wool vegetable matter faults and seed damage to skins. When deciding the best time for shearing, you should also consider how it may affect the spread of lice and flies.
- Stocking rate - strategic short-term heavy stocking, including cell grazing and rotational grazing, may reduce infestations of problem grasses.
- Cross-grazing - a change in stock species or ratios can assist the change back towards a summer grass pasture. Cattle are virtually immune to grass seeds, and their feeding habits can help clear access to short feed for sheep. Horses and goats can do a similar job.
- Spelling - pastures infested with problem grasses should be rested for the summer growing period (December, January and February) to provide competition and maintain a stable population of summer pasture grasses.
- Breeding and selection - Merino sheep with little face cover, or open faces, and few body wrinkles are less likely to be affected by grass seed.
- Rugging - strategic rugging at times when grass seed is mature may help to reduce vegetable matter in wool. (This is usually only feasible for intensive or small sheep operations.)
Also consider...
- Learn about lambing sickness and milk fever in ewes.
- Find out more about grazing and pasture management.
- Find out about prevention and treatment of foot abscess in sheep.
Sheep shearing and trimming
As well as taking steps to protect your sheep from diseases, pests, poisoning and grass seed infestations, you should also attend to their general health, wellbeing and welfare. This includes monitoring the nutrition in their diet, regularly shearing, and trimming horns and hooves.
Nutrition
Managing a balanced diet is crucial to keeping your sheep healthy. For detailed information on nutrition and what to feed sheep during their different stages of production, read about supplementary feeding for sheep.
Shearing sheep
You should regularly shear your sheep to reduce problems associated with heat stress, flystrike and lice. Sheep with short wool are also more active and mobile, making them more able to graze.
Shearing rams
You should shear rams twice a year, at roughly 6-month intervals. One shearing should occur about 2-3 months before joining.
Trimming horns
Long horns on rams make handling the animals difficult and time consuming. Rams have no need of them, beyond protection during fighting.
Horn trimming is very stressful for sheep. You must properly restrain the ram to prevent serious injury. When trimming, it is recommended that you cut the horn about midway around the first curl from the head, level with the animal's ear. This will normally result in a small amount of bleeding but will not cut into the 'meat' of the horn.
If horns are cut too short, rams can become susceptible to flystrike.
Trimming hooves
Sheep with overgrown hooves, particularly rams, will have difficulty walking far enough to get the maximum nutritional benefit from available pasture.
You should use hoof trimmers or a good pair of garden secateurs. Regular trimming will prevent any need to cut deeply to get the hoof back to its original size and shape, which can result in some temporary lameness. When trimming hooves you must restrain the animal properly to prevent injury to the sheep and yourself.
Welfare of sheep
You have a duty of care to look after your sheep. Find out about your responsibilities by reading the code of practice for the welfare of sheep.
Also consider...
- Take the Making More From Sheep Quick Quiz to find ways to improve the health and wellbeing of your flock.
- Learn about lambing sickness and milk fever in ewes.
- Find out about prevention and treatment of foot abscess in sheep.
Biosecurity for sheep producers
Biosecurity for sheep involves protecting their health and environment by reducing the risk of disease, chemical residues and pests on your property.
You can improve the profitability of your business and contribute to good biosecurity in your community by assessing biosecurity risks and planning to control them.
Risks to farm biosecurity
- Visitors can bring disease onto your property. Visitors include neighbours, agents, salespeople, advisers, shooters, fishers and vets.
- New animals are the most common way that disease is introduced to a flock. This includes brought-in replacement stock and stray, feral or wild animals.
- Biosecurity matter such as disease-causing agents, weeds and chemicals can be accidentally introduced to your property via carriers such as water or food, or on machinery.
Reducing biosecurity risks from visitors
To reduce biosecurity risks from visitors:
- place a sign at the front gate advising visitors to report to your house or office rather than driving over the farm looking for you
- have an entry point for vehicles and ensure vehicles entering your property are clean
- conduct a risk assessment before allowing a visitor onto the property
- allow visitors access to livestock and property only where necessary
- drive visitors around the farm in your farm vehicle
- keep a record of names and dates of every visitor to your property
- ensure that visitors wash their hands, and have clean clothing and boots
- provide protective clothing, footwear and disinfectant for visitors inspecting your animals.
Reducing biosecurity risks from new animals
To reduce biosecurity risks to your farm when introducing new animals, you should always:
- isolate new sheep on arrival
- purchase new sheep from a known and reliable source
- seek written assurances about the health status of new sheep.
- find out about any diseases at place of purchase that may affect your existing sheep (e.g. Ovine Johne's Disease)
- ensure movement requirements are met
- keep a record of the property of origin of livestock and notify the NLIS database of relevant movements (if applicable)
- inspect and maintain the boundaries of your property to reduce the risk of other animals gaining access.
Reducing biosecurity risks from other outside sources
To reduce biosecurity risks to your farm from other carriers such as food, water and machinery, you should:
- assess water sources for biosecurity matter such as pathogenic agents, chemicals and algal bloom
- assess feedstuffs for contamination with weeds, seeds and chemical residues
- know where hay, straw and grain is coming from and obtain a vendor declaration
- not feed restricted animal matter (animal meal and fish meal) to ruminants (sheep, cattle etc.)
- ensure machinery is cleaned and disinfected with high-pressure water or air to remove soil, faeces and weed seeds before entry onto the property
- avoid sharing equipment between properties - if equipment is borrowed or lent, clean and disinfect it thoroughly.
Farm biosecurity toolkit
For more detailed information about managing the environmental impacts of your farm, use the Farm Biosecurity Toolkit.
Also consider...
© The State of Queensland 1995–2024
- Last reviewed: 08 Sep 2021
- Last updated: 08 Sep 2021