Sheep – health

Information about disease prevention and signs of illness in sheep.

Administering treatments

Approved activities Category
water 2
topical — udder 3
topical — backline 3
topical —spray 3
topical —dip 3
topical — jetting 3
oral — drench 3
oral — capsules 3
injection — subcutaneous* 3
injection — intramuscular 3
injection — intramammary 3
implant — vaginal 3
implant — subcutaneous 3

* exception Johne’s Disease vaccination (see below Vaccinations)

Image: Oral drenches are a tool for controlling internals parasites.

Sheep need to be protected against internal and external parasites and pathogenic and metabolic diseases. The risks will vary depending on the stock type, geographic location, stocking rates, frequency of stock movement and seasonal weather conditions. Treatments and vaccines should be administrated in accordance with directions and records should be kept.

Effective parasite and disease protection involves the development and documentation of routine control measures, including:

  • Worming: Worm counts can easily build up in small flocks especially if paddock rotation is limited. The entire mob should be regularly treated. A worming program should be designed with the help of a veterinarian and should include faecal worm tests, rotation of drenches, rotation of grazing and documentation of strategies and results.
  • Vaccinations: Veterinarians can provide advice on vaccination regimes that are appropriate to the age and class of sheep. The 5 in 1 vaccine is a popular core vaccine used for sheep. The vaccination program for sheep should commence at marking time, a booster given four weeks later and then annually. While the administration of subcutaneous vaccinations are a category 3 activity the exception is for vaccination to prevent Ovine Johne’s Disease (OJD). Students must not administer the Gudair vaccine as it is harmful if it is accidentally injected to humans and great care must be taken to ensure the correct administration site on the animal. It must be administered subcutaneously, high on the neck, below the base of the ear. Further information is available at OJD fact sheet and Zoetis Australia – Gudair vaccine.
  • Crutching and shearing: Sheep with over 12 months wool growth are more susceptible to flystrike, lice infestation and vision impairment. Sheep should be shorn annually, with the exception of carpet wool breeds that require shearing twice a year. Shearing must be done by an experienced shearer and backline lice treatment applied. After shearing, sheep will need shelter to protect them from wind, rain and cold. Most sheep will require crutching (removing wool from the breech area), in between annual shearing. Crutching aids in preventing flystrike. Spray on preventative treatments can also be used in the treatment and prevention of flystrike. Regular worming also aids in reducing flystrike by reducing the incidence of scouring. It is important to note that sheep with any length of wool can be struck by flies. Wet weather followed by warm temperatures favour the fly life cycle. During these periods, close monitoring of the flock is advisable, as flies will move into a flock quickly, creating additional work and reduced profitability of the flock. It is a good practice to jet, dip or backline sheep off shears with a product designed to repel flies.
Image: Crutching aids in preventing flystrike.
Image: Sheep should be shorn annually by an experienced shearer. The only exception is carpet wool breeds that require shearing twice a year.
  • Footrot prevention: Footrot is defined as either benign or virulent. Virulent footrot is a notifiable disease in New South Wales and outbreaks will generally result in the slaughter of entire flocks. Quarantining new animals from unknown destinations is extremely important. Control of benign footrot and abscess is best achieved by inspection and isolation of incoming stock and foot maintenance including paring and bathing hooves to eliminate bacteria. Affected individuals can also be treated with antibiotics. See Footrot in Sheep and Goats and Footrot Ute Guide for more information.
  • Control of flystrike: It is preferable in a school farm situation to have plain bodied sheep. This reduces the risk of flystrike as there are less skin folds in which flies can lay their eggs. Management practices such as shearing, crutching, tail docking, worm control and strategic chemical use (jetting and backline treatments) are all parts of an integrated pest management program.
Image: Vaccination and oral drenching can be carried out while sheep are standing in the race.

Some health issues and diseases are exacerbated by particular environmental conditions, e.g. liver fluke, pulpy kidney. Hence management of the environment is equally as important in controlling these diseases as is the use of chemicals.

Advice needs to be sought from a reliable and scientific source, e.g. livestock officer, veterinarian. General advice is available through the following:

Parasite and disease control

An annual parasite and disease control program should be developed and documented. All sheep should be vaccinated and treated for parasites prior to moving them to the school farm or introducing them to the school stock.

Whenever chemicals are used including drenches, vaccines and back-line treatments, care must be taken about the following:

  • Reading all labels
  • Maintaining appropriate storage
  • Adhering to withholding periods
  • Determining the weight of the animals to be treated
  • Determining the correct dose rate
  • Using protective clothing if required
  • Using the correct equipment for application
  • Disposal of chemical containers
  • Documenting the dose, chemical name, batch number, expiry date, withholding period, identity of animal(s) administered to and date of administration.

Husbandry activities demonstrates correct techniques for carrying out many of these activities.

Image: Vaccination is important to maintain healthy sheep.

Signs of illness

Flock health should be monitored at least daily. Young lambs require more frequent monitoring as they can dehydrate quickly.

A sick sheep may display signs of:

  • Disorientation
  • Lethargy
  • Changed feeding habits
  • Scouring
  • Nervousness
  • Discharging
  • Separation from or lagging behind the main body of the flock
  • Lameness
  • Ill-thrift or wasting
  • Abnormal gait or reluctance to rise
  • Rise in body temperature.

Sheep failing to thrive or grow is also a sign of illness. Common ailments include mastitis, bloat, internal parasites, footrot, flystrike and lice infestation.

If unable to identify the problem and begin suitable treatment, assistance should be sought from a veterinarian who has experience with sheep. Any illness identified and treatments given must be recorded appropriately.


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