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Small Ruminant Research 106 (2012) 6– 10

Contents lists available at SciVerse ScienceDirect

Small Ruminant Research

jou rna l h omepa g e: www.elsev ier .com/ locate /smal l rumres

mportant sheep flock health issues in Scandinavia/northern Europe�

.J. Ulvundorwegian School of Veterinary Science, Section for Small Ruminant Research, Sandnes, Norway

r t i c l e i n f o

rticle history:vailable online 17 May 2012

eywords:

a b s t r a c t

This paper reviews some key aspects of important flock health issues in Scandi-navia/northern Europe. The number of sheep in Scandinavia/northern Europe and the sheeplivestock trend are shortly summarized, and focus is made on sheep disease diagnostics andhealth records, disease and management, approach to flock problems, lamb loss, and some

heepcandinaviaisease managementnimal welfare

specific diseases not being dealt with by others; like toxoplasmosis, trace element deficien-cies, plant poisoning (“alveld”) and radioactivity problems. Although few notifiable sheepdiseases and zoonoses occur in Scandinavia, numerous common diseases are causing wel-fare problems among sheep and economic loss to the farmer, and there is a lot to be gainedby improved diagnostics and preventive work.

. Introduction

The number of sheep in Scandinavia (Norway, Swedennd Denmark) is low with 1,414,000 winter fed sheepWFS) as compared to the largest sheep producing coun-ries in Europe (UK 21,295,000, Spain 18,471,000, Romania,400,000, France 7,402,000 and Germany 1,800,000)Eurostat, 2010). The number is, however, higher thanhe sheep number of the smaller countries in Northernurope (Finland 90,000, Iceland 400,000, The Netherlands,211,000, Poland 213,000, Lithuania 58,000, Latvia 67,000nd Estonia 62,000). Among the Scandinavian countries,orway has 1,054,000 WFS, Sweden 270,000 and Denmark0,000 (Eurostat, 2010). The significance of sheep hus-andry in Scandinavia is much larger than the actualumber of sheep indicates. The sheep have great valuearticularly for landscape preservation and prevention of

vergrowth, local home industries, culture and populationn faraway areas.

� This paper is part of the special section entitled: Animal health chal-enges for Scandinavian and northern European countries, Guest Editedy N.D. Sargison.

E-mail address: martha.ulvund@nvh.no

921-4488/$ – see front matter © 2012 Elsevier B.V. All rights reserved.ttp://dx.doi.org/10.1016/j.smallrumres.2012.04.011

© 2012 Elsevier B.V. All rights reserved.

The number of sheep flocks in Norway is 15,000, inSweden 10,000, in Denmark 9200, and the average flocksize is 67, 30 and 12 WFS, respectively. The sheep livestocktrend in the main producing member states of the EU hasbeen declining during the last ten years (Eurostat, 2008).In Norway, the number of sheep is slightly increasing; thenumber of flocks is decreasing, but the sheep flocks areincreasing in size (Statistics Norway, 2010). In Scandinavia,the main type of farming is categorized as specialist fieldcropping in the whole of Denmark, most of Sweden, as wellas eastern Norway, while northern and western Norwayis defined as specialist grazing livestock (Eurostat, 2011).Sheep husbandry is of large importance here, and the dis-tribution of WFS (1000×) shows that 57% of the sheep arelocalized in western Norway (Statistics Norway, 2010).

2. Notifiable diseases and sheep health situation

The Scandinavian countries have had few outbreaks ofserious notifiable diseases (Fig. 1) (WAHID interface OIE,2011) and zoonoses (Hofshagen et al., 2009), and the healthsituation among the sheep is generally good. Nevertheless,

common sheep diseases occur, and are causing animal wel-fare problems and economic losses to farmers. Diagnosticfacilities are few in Sweden and Denmark, but in Norway,there are six diagnostic laboratories situated from north

M.J. Ulvund / Small Ruminant Research 106 (2012) 6– 10 7

Disease Norway Swede n Denmark

Blue tongue - 200 8 2007

Paratub erculosis(Johne’s dise ase)

Ver y seldo m (goats +) seldo m seldom

Class ical scrapie + (2009) - -+ - -

Scrapi e Nor 98 yearly se ldo m se ldom

Brucella melitensis - 1957 -

Brucella ovi s (ov ine ---(epidid ymi�s)

Contageou s agalac�a ---

Enzoo�c abor�on - 2003 -

Q fever ---

Salmonello sis(S.abortusovis)

-- (?) -

Maedi 2005 + ++ +

terface

Fig. 1. Notifiable diseases, Scandinavia. WAHID in

to south, receiving materials from sheep (Tromsø, Harstad,Trondheim, Bergen, Sandnes and Oslo). In spite of this, offi-cial production animal disease statistics are not easy to find.Official statistics cover notifiable diseases and surveillanceprograms. The last general disease report in Norway was in1975, the number of sheep examined and diagnoses at theveterinary laboratories are not officially or easily available.

Sheep Health Services are available in Norway andSweden. In Norway, this is a joint venture with the Nor-wegian Sheep and Goat Breeders Association, Gilde NorskKjøtt (Co-op for meat production) and the National MeatProducers association. The Sheep Health Records generatesheep disease statistics on a local, regional and nationallevel, and co-ordinates and promotes preventive measures,herd diagnostics, and organized disease supervision. Mem-bership in Sheep Health Records includes 27% of all sheepflocks in Norway, which means that 73% are not members(2010).

The most frequently reported diseases in ewes from 27%of the sheep flocks (Animalia, 2011), and in percentageof total numbers of sheep, include mastitis (2.3), para-sites (1.2), metritis/vaginitis (1), lambing problems (0.6),hypocalcemia (0.3), listeriosis (0.2), vaginal prolapses (0.2),teat injuries (0.2) and uterus prolapse (0.1). The most fre-quently reported diseases in lambs are parasites: coccidia(0.7), joint disease (0.3), entropion (0.1), ectoparasites (0.1),lungs and airways (0.1), myiasis (0.1), hoof disease (0.1)and echtyma-orf (0.1). The most frequent preventive treat-ments include treatment against gastrointestinal parasites,pasteurellosis and clostridial disease, ectoparasites, defi-ciency disease and lice.

3. Disease and management (Norway)

Occurrence of disease among sheep and lambs is very

much related to management, age of the animals, andtime of the year. Norway is a “long” country, the dis-tance between the south and the top of north Norway isthe same as the distance from south Norway to Rome in

OIE – Animal health situation, 2010 – and earlier.

Italy. This reflects differences in climate and management.The sheep are usually kept indoors during winter, and aregrazing outdoors during summer, the indoor season beinglongest in the north, while the outdoor season is longestin the south. Dependent on the location, lambing startsin March–April in south, and a month later in the north.During the indoor season, listeriosis, polioencephalomala-cia (CCN), pneumonia, chronic fasciolosis and footrot occurin both sheep and lambs. Common diseases in pregnantanimals are toxoplasmosis, ketosis, hypocalcemia, metri-tis and mastitis. After outlet, there is a period with grasstetany, metritis and mastitis in the ewes, and infectionsand deficiencies (Escherichia coli, pyogenic infections, coc-cidiosis, helminthiasis, muscular degeneration, echtyma,pulpy kidney, tick borne fever (TBF) and pasteurellosis) inthe lambs. During the summer season, blowfly myiasis iscommon, and in the lambs photosensitization (“alveld”)and cobalt deficiency is common in parts of the country.During the autumn, TBF, parasites (gastrointestinal, lung,liverflukes), echtyma and pasteurellosis are common, aswell as clostridial disease in unvaccinated flocks (pulpykidney, braxy, other). Challenges are cold climate, rainyareas, long indoor feeding periods, breeding policies withincrease of number of lambs per ewe, scarce spring pas-tures, intensive fertilizing, transport to and from summerpastures, mountain pastures, coastal areas deficient in traceelements, use of ram circles and ram circle activities. Sur-vey of management and disease, conditions and challenges,are summarised in Fig. 2.

4. Approach to flock problems

In addition to teaching of veterinary students, The Nor-wegian School of Veterinary Science, Section for SmallRuminant Research in Sandnes, offers examination of sheep

material and gives advice to veterinarians and farmers. Theapproach to flock problems involves uptake of anamnesticinformation from farmer, and local veterinarian, collectionof relevant data (from sheep recording, abattoir, other),

8 M.J. Ulvund / Small Ruminant Research 106 (2012) 6– 10

Condi�on s Challenges Dise ase occ urrenceCold clima te; Housin g : humidity, ven�la �on, Infec�ons , pneumoni a, ma s��s,Cold clima te;long indoo r feedin g perio d

Housing : humidity, ven�la �on,animal density, feeding prac�ces,quality of feeds

Infec�ons , pneumoni a, ma s��s,listeriosis , CCN, deficiencies,hypo calcaemia , be nt leg

N: Breeding policy – in creasenumber of lam bs

Not enough space in the abdomen! Increas e in vaginal/u terus prol apses,abdominal herni as, di aphragmp gruptures. Ketosis . Increas e in ar�ficiallyfed lam bs , gastropathi es, indi ges�ons

Scarce spring pastures.Intensive fer�lizing.

High animal density on springpastures. Intensi ve gras s growth.

Coccidiosis, Nem atod irus, otherparasi tes. Gras s tetany.

Transport to and fromsummer or mountain pa stu res

Stress, co ntac t wit h other flocks Sp rea d of infec�ons

Mountain pa stu res Pred ators, toxic pl ants, inland high Cu Alveld, myias is, deficiencies, toxici�es

C l�t d t t l S d fii t i C C Z D fii iCul� vated pastures, coastal Som e are deficient in Cu, Co, Zn Deficiencies

indeficientareSomePasturesinland Se, I MD, other

Ram circles Live animal infec�onsofSpreadflocksbetweencontacts

Rainy area s moi st pastures Foot hygiene li ver flu kes Footrot fasciolosisRainy area s, moi st pastures Foot hygiene, li ver flu kes Footrot , fasciolosis

Milde r clima te, reducedgrazing stock

Bushes, overgrowing TBF

e condi

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5

5

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Fig. 2. Management and disease, som

eceipt of proper material (blood samples, faecal samples,ive sheep, dead sheep, other), and in some cases farm vis-ts, often together with the local veterinarian, if wanted.he results of the examinations are forwarded to the farmernd the local veterinarian in the form of a short report, ifeeded with suggestions of handling of problems withinhe flock, in cooperation with the local veterinarian. Mate-ials and flocks are used in teaching of veterinary studentscourses during 8th–11th semester).

.1. Clinical pathology

In connection with flock problems, we find great helpn clinical pathology results, and perform analyses foraematology (ADVIA: Wbc, Rbc, Hb, Ht, MCV, MCH, MCHC,lt, differential counting), total serum protein, albumin,lucose, Ca, Mg, P, Fe, Cu, caeruloplasmin, Zn, GLDH,amma-GT, urea, vitamin B12, folate, BHBA, GPx, insulin,nd creatinin. Profiles available for veterinarians includene for lamb ill thrift, one for disease in pregnant sheep, oneor anaemia, faecal egg counting, and PCR for scrapie sus-eptibility (PrP genotyping). Post mortem examinations areffered, with bacteriology, histopathology, immunohisto-hemistry, and parasitology. Prices are kept low, and duringeaching courses, the examinations are free of cost.

. Some selected important diseases causing losses

.1. Abortions

Around 80% of the abortions in sheep in Norway areaused by Toxoplasmosis. Toxoplasma gondii was firstetected from aborting sheep in Norway, by mouse inoc-lation, in 1966 by John Øverås. Waldeland followed up

is work, and found that around 80% of the total lamb

oss was due to toxoplasmosis. He found at least oneeropositive lamb in 48–80% in the flocks, and at least oneositive ewe in 79–90% of the flocks (Waldeland, 1977).

tions and challenges in Scandinavia.

Later examinations of slaughter lambs have shown that44% of Norwegian sheep flocks, and 16.2% of individualswere positive (Skjerve et al., 1998). NVH Sandnes has per-formed diagnostics of abortions ever since, and the numberof abortions due to toxoplasmosis has not gone down.Today, the loss due to toxoplasmosis has been calculatedto at least 50,000 lambs per year, and more than 25 millionNOK. NVH Sandnes has urged for use of available live vac-cine (Toxovax; MSD Animal Health) in the country, but theNorwegian authorities have been reluctant, as they havebeen afraid of introducing unknown contagious agents,or pathogenic toxoplasma variants. Through cooperationand support from the meat industries (Nortura Forus, Fat-land Jæren AS), farmer’s associations (Rogaland Sau ogGeit, Norwegian Sheep and Goat Association), the RegionalCommissioner, Rogaland Agricultural division, and Inter-vet Schering-Plough Animal Health®, NVH Sandnes wasgiven permission to vaccinate against toxoplasmosis in2009. Fifty (became 46) sheep flocks with 5310 sheep wereincluded, and 2575 sheep (48%) were vaccinated (everysecond sheep in each age group in every flock). Altogether23 local veterinarians were involved (Ulvund and Juvik,2011).

The vaccination resulted in significantly more ewes(yearlings and gimmers) giving birth to live lambs,significantly fewer abortions (also among the young),significantly fewer ewes giving birth to one or severalmore stillborn lambs, 13.3% increased lambing percent-age among the lambs and 8.1% among the gimmers. Basedon the results, total lamb production in Norway can beincreased with more than 32,000 lambs, yielding a profitgain of at least 16 million NOK annually. The results alsoconfirmed that the infection was widespread among adultsheep, which were probably already infected and partly

immune. Based on the results, various vaccination alter-natives have been discussed: (i) vaccinate all sheep everysecond year between May and October, and lambs everyyear at 5 months old; (ii) vaccinate the whole flock in the

M.J. Ulvund / Small Ruminant Research 106 (2012) 6– 10 9

Typ e feed, Norway Added, mg/k g Natu ral content inraw materials

Total, mg/kgraw materials,mg/kg

Concentrates forrumin ants before

10 7 17rumin ants, before2006

Concentrates forsheep, a�er 2006

3 7 10p,

Concentrates forca�le /goats , a�er2006

15 7 22

f Cu con

Fig. 3. Copper content in concentrates for sheep in Norway. EU, 2006: “Ithis feed may result in Cu-poisoning in some sheep breeds”.

first year during September and October, and then only vac-cinate lambs every year; (iii) vaccinate only lambs from 5months of age between September and October every year;(iv) vaccinate only lambs from about 2 to 4 weeks of age.All alternatives will result in reduced number of cysts in themeat, with option (iv) achieving the largest effect. Commer-cial vaccination will probably take place during the autumnof 2011. The logistics will be a challenge in Norway.

5.2. Trace element deficiencies

Parts of Norway, and particularly focal areas along thecoast, where most sheep are found, may be deficient incobalt, copper and zinc, while the inland is more deficient inselenium. Earlier examinations have revealed that ill thriftin lambs during late summer and autumn has been due tocobalt deficiency (Ulvund, 1990). Mean live weights (kg) inuntreated lambs with cobalt deficiency and lambs on thesame pastures dosed with cobalt or vitamin B12, may dif-fer with between 8 and 17 kg at 5 months of age. Ill thriftmay also be due to a combined deficiency of Co, Cu andZn as well. Examinations of trace elements in cultivatedpasture grass (Ulvund et al., 1989) as well as wild pasturegrass (Sivertsen et al., 2009), have revealed scattered pock-ets of deficient areas, particularly along the coast. Due toEU rules and regulations, the recommended copper con-tent in concentrates for sheep was changed in 2006. If theCu content is above 10 mg/kg, following declaration is nec-essary: “Cu content in this feed may result in Cu-poisoningin some sheep breeds”. In earlier available Norwegian con-centrates, natural contents of Cu in raw materials wereset to 7 mg/kg, and before 2006, 10 mg/kg Cu was added,resulting in totally 17 mg Cu/kg in the feeds. After 2006,and as the companies do not want to declare danger of Cupoisoning, the added Cu has been reduced to 3 mg Cu/kg,resulting in a total of 10 mg Cu/kg; meaning a reduction of7 mg Cu/kg (Fig. 3). We, therefore, seem to be getting moreCu deficient sheep, and are presently following this up withexaminations of blood analyses and feeds.

The open trade, and availability of very different mineraladditives, salt licks and mineral buckets, also cause confu-

sion among farmers and veterinarians, as the macro- andmicroelement contents vary very much between the prod-ucts. In addition to deficiencies, also poisonings may occur.There is therefore a need for education of farmers and

tent is above 10 mg/kg, following declaration is necessary: Cu content in

veterinarians, as well as a need for research projects withinthe field.

5.3. Alveld

One of the more common causes of lamb loss along thecoast is “alveld”. The disease is a hepatogenous photosen-sitization caused by the Lillie plant Narthesium ossifragum.The disease also occurs in Scotland, and is called “Yel-lowses”, or “Plochteach”. Facial oedema may lead toblindness and ears falling off. There is still uncertainty as towhether the sapogenins in the plant alone are causing theliver damage, or whether other factors, like fungal toxins,are necessary (Flåøyen, 2000).

5.4. Radioactivity

During the Tsjernobyl accident 25 years ago, cesium-137 was spread to Scandinavia and Norway by winds andrainfall, and was taken up by plants and fungi on sheeppastures. This led to accumulation of radioactivity in sheepmeat, and during the period 1986–2010, around 2.2 mil-lion sheep were treated to reduce radioactivity. Even 25years after the accident, there is still need for controllingand effectuating efforts to ensure a radioactive content<600 Bq/kg. The sheep have to be fed two to ten weeks onfeeds free of radioactivity, before they can be slaughtered.In 2010, 20,000 sheep/lambs had to be handled (Gjelsvik,2011).

Conflict of interest

None.

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Eurostat, 2010. Eurostat Website: http://ec.europa.eu/eurostat (accessed12.02.12).

Eurostat, 2011. Farming Structure and Accounts at Regional Level, http://epp.eurostat.ec.europa.eu/statistics explained/index.php/Farming

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