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COUNTRY LIFE IN BC • JANUARY 2020


Fatal sheep diseases are largely preventable Producers can help reduce mortality by deworming, condition scoring


by BARBARA JOHNSTONE GRIMMER ABBOTSFORD – Sick sheep often die untimely


deaths, producers attending the BC Sheep Federation conference in Abbotsford in October heard. “The top causes of death in sheep that we see – haemonchosis, enterotoxaemia, starvation and septicaemia – are mostly preventable,” BC Ministry of Agriculture veterinary pathologist Glenna McGregor said as she presented mortality data to producers. Based at the province’s Animal Health Centre in Abbotsford, McGregor performs cause-of- death investigations on a wide range of species. The centre is one of two accredited veterinary diagnostic labs in BC, and the leading one in Western Canada. She is also well-known to the sheep community through ministry workshops on keeping flocks healthy. Parasitic deaths due to Haemonchus contortus


or “barber pole worm” are becoming more common, mostly due to the development of resistance to common dewormers such as Ivomec. “It is easily diagnosed on the farm, killing sheep rapidly. A classic sign is severe anemia, bottle jaw, and a lack of diarrhea,” says McGregor. “A post-mortem examination can reveal the classic red and white worms in the abomasum.” Enterotoxaemia, also known as overeating or


pulpy kidney, is caused by Clostridium perfringens type D. Young animals are the most susceptible, due to excessive consumption of milk or feed with high concentrations of grains. “You can vaccinate mothers to protect lambs, and


add grain to the diet slowly so that the rumen bacteria can adapt,” says McGregor. “And make sure


Besides starvation, nutritional causes of death include white muscle disease from selenium or V itamin E deficiency, urinary calculi or water belly, copper toxicity, copper deficiency, impaction, dicoumarol toxicity and goitre from iodine deficiency or goitrogenic crops like white clover and brassicas. Coccidiosis is caused by a single-cell


protozoan, causing diarrhea, dehydration and death if untreated. The symptoms are often confused with worms. Abortions result in economic losses but can also be a public health issue. The top three infectious causes of abortion in sheep can cause life-threatening disease in pregnant women, such as toxoplasmosis or listeriosis, resulting in fetal death or malformation.


“Half of the cases [in sheep] have unknown FILE PHOTO


stored grain is inaccessible to animals.” Starvation is commonly seen as a cause of death,


resulting from insufficient feed, poor quality feed, restricted access due to inadequate bunk space or dominant animals, teeth problems, disease and parasites. “Condition scoring is the best management tool


for improving production,” says McGregor. “Your sheep should be evaluated at least three times a year. Some people new to sheep do not know how to feel the sheep for fat cover. The wool can be deceiving.”


causes. Producers can submit placentas and freeze them in case you get more cases,” says McGregor. An abortion storm can result from ewes sharing their lambing pens so good hygiene is important. The available data has limitations since what is seen in the lab is not entirely representative of what happens on all BC sheep farms. “Causes of death that are readily diagnosed on the farms are underrepresented, such as predation and barber pole worm,” explains McGregor. “There is a bias towards well-managed farms with veterinary support and farms in the Fraser Valley, which are overrepresented. Sporadic deaths are less likely to be submitted and there is a small sample size, so data is presented in a simplified format.” McGregor encourages producers to send samples or animals to the lab if they have concerns. There is no need for a vet’s referral.


An effective health and safety plan involves everyone.


The planning decisions you make today can affect the health and safety of workers tomorrow.


Find resources to prevent injuries at worksafebc.com/agriculture


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