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Sheep are popular on lifestyle farms because they are small and relatively easy to handle and the barriers to entry are small.

Grass Staggers

Grass Staggers occurs when the intake of magnesium is exceeded by its output. It is common in spring due to an increased requirement of magnesium for lactation and the decreased magnesium content of lush green pasture. Grass staggers is not just restricted to the first few days of lactation. As with all metabolic conditions, it is important to act fast. Contact North Canterbury Vets immediately if you notice the following symptoms:

  • Hyper-excitability and restlessness
  • Unsteadiness and lack of coordination
  • Over-alert appearance

Grass staggers can occur in cattle, and ewes in late pregnancy due to poor nutrition.

Pregnancy Toxaemia

Pregnancy toxaemia (also known as twin-lamb disease, sleepy sickness, lambing sickness and pregnancy disease) is a disease mainly seen in twin bearing ewes in late pregnancy. The condition arises when pregnant ewes do not receive enough nutrition in the latter stages of gestation. If the signs are not picked up early and treatment is delayed, the chances of a successful outcome will rapidly decrease

If you notice any of the early signs of pregnancy toxaemia you can begin a daily treatment with oral energy drenches such as Ketol. Contact North Canterbury Vets if you notice any of the following:

  • Separation
  • Depression
  • Loss of appetite
  • Wool pull-where the wool is easily plucked

Without treatment, they will progressively worsen with apparent blindness, aimless wandering, staggering, frothing at the mouth and champing of the jaws. If left untreated the animals will eventually become comatose before dying.

Flystrike Prevention

Fly is a disease caused by blowflies laying eggs on the skin which hatch as maggots and eat into the skin causing sores. There are several species of blowfly throughout New Zealand, the most aggressive being the Australian green blowfly. We recommend Extinosad for the effective killing of maggots and lice.

Treatment with oral energy drenches are only effective for mild cases if caught in the early stages. North Canterbury Vets will provide you with the best chance for a successful outcome. We can give IV dextrose solution, steroids and fluid therapy for more serious cases.

Barbers Pole (Haemonchus contortus)

Is a potentially harmful roundworm , blood sucking parasite that thrives in moist humid conditions. Anemia is the basic feature of infection due to blood loss. Deaths can occur suddenly while the sheep still appear to be in good health. North Canterbury Vets recommend incorporating long-acting drenches that prevent the buildup of the parasite. Two actives that work well are Closantel and Moxidectin.

Lamb Scours

Lamb scours can be divided into two groups: nutritional and infectious. Nutritional scours is often caused by poor quality milk or sudden changes to milk formulas. Milk that is too hot or too cold can also lead to diarrhea or bloat. Nutritional scourers is identified by white or yellow sticky runny faeces.

Infectious scours are more common in young lambs. Faeces can be watery and brown or yellow. Lambs will become very dehydrated which can lead to sunken eyes. Severely affected animals are weak and lethargic.

Scouring animals can die from dehydration so it is important to act fast. Keep sick animals isolated, dry and warm. Administer quality electrolyte feeds such as Diarrest or Revive.

Colostrum is the biggest preventative measure. Lambs should ideally receive colostrum from their mother. Alternatively, freeze-dried colostrum powder can be used.


A bearing is the prolapsing of the vagina. They can happen in both pregnant and non-pregnant ewes, but are most common in the month leading up to lambing. Bearings tend to occur in ewes in good condition, or those carrying more than one lamb. They can also be seen when there has been sudden access to lush feed in late pregnancy.   

Affected ewes will separate themselves from the flock and strain to urinate. The longer the bearing is out the poorer the prognosis for the ewe as the tissue starts to dry out and become infected.

Bearings are a genetic condition and a ewe that has had a bearing in the past has an increased risk of repeating this next season. Likewise, a lamb born from a ewe that has had a bearing is much more predisposed to having a bearing in the future.

If you notice a bearing in one of your ewes, give us a call and we will get a vet out to you as soon as possible.

Milk Fever

Milk fever (Hypocalcaemia) occurs when the ewe does not have enough calcium in her diet to sustain her demands and those of the foetus.  It most commonly occurs in older sheep, late in pregnancy, but occasionally happens after lambing.

Affected ewes may be wobbly and hyperactive initially, but quickly lie down and become comatose. Bearings may also occur. Treatment with calcium leads to a rapid response and the ewe will often get up within 15-30 mins of administration. If animals not treated rapidly they can die within 24 hours.

Prevention of milk fever lies in avoiding stressful conditions for ewes in late pregnancy/early lactation. Avoid any unnecessary time off feed or sudden changes in feed during this period.

If you think your ewe is affected by milk fever, give us a call and one of our veterinarians can speak to you.

Pregnancy Toxaemia

Pregnancy toxaemia (sleepy sickness, ketosis, twin lamb disease, lambing sickness) is a disease of ewes in late pregnancy. It occurs when the ewe does not have enough glucose to continue the growth of the ewe and the lamb in the final stages of parturition.

Affected ewes will look dull and depressed, will stop eating, lie down and may show neurological signs. They may separate themselves from the flock.  

Feeding the ewe is key. If she is still eating then the prognosis is much better. Once the ewe is down and inappetant it can be very difficult to reverse the effects and death can occur.

Energy given in the form of oral Ketol and injectable Glucalphos can help in the early/moderate stages.

Prevention is key to dealing with sleepy sickness. Keep ewes on a rising plane of nutrition, the requirements are greatest in the last 6 weeks of pregnancy where 70% of the foetal growth occurs. Supplemental hay/baleage may need to be provided. Preferentially feed lighter ewes or those carrying more than one lamb (if you know). Minimise stressful events/time off feed leading up to lambing. 

If you think your ewe has sleepy sickness, give us a call and one of our veterinarians can speak to you.

Parts of this are reproduced with permission thanks to Franklin Vets, Papakura

Our Clinics

North Canterbury Veterinary Clinics operates four clinics throughout the Hurunui region.