A census of the prevalence of vaginal prolapse in sheep flocks in the Borders region of Scotland

A postal census of vaginal prolapse in sheep flocks in the Borders region of Scotland yielded 540 replies from 963 owners (56 per cent). There were 262,250 ewes in 976 flocks and 2573 vaginal prolapses were reported. Analysis of the data revealed that 390 (40 per cent) of the flocks had no vaginal prolapses and in 237 (24.3 per cent) the reported prevalence was between 0.1 per cent and 1.0 per cent. Only 63 (6.5 per cent) of flocks had a greater than 5 per cent prevalence of vaginal prolapses. The greatest number of prolapses occurred in an upland flock of greyface ewes mated with Suffolk tups with 50 cases among 700 ewes (7.1 per cent) and the highest prevalence was in an upland Scottish blackface flock of ewes bred with Suffolk tups with 15.2 per cent (35 cases among 230 ewes). There were marked breed differences; very few hill breeds were affected and most cases occurred in greyface ewes mated with Suffolk tups.     

Nutritional factors associated with vaginal prolapse in ewes

Serum calcium, magnesium and phosphate values of ewes recently affected by vaginal prolapse were compared with unaffected ewes in four flocks. Subclinical hypocalcaemia was demonstrated in some affected and unaffected ewes in three flocks. Magnesium and phosphate values were normal. In two flocks the body condition of ewes recently affected by vaginal prolapse was variable and reflected the variation in condition found in the flock. In a third flock affected ewes had significantly lower body condition scores than unaffected ewes (P less than 0.001). Analysis of the fourth flock was not possible. Oestrogenic mycotoxins were not detected in any of the feed samples taken from these flocks. The following year the management, nutrition and energy, and the protein and calcium status of ewes in 12 flocks of greyface/mule ewes with a history of a regular high (greater than 3 per cent) or low (less than 1 per cent) prevalence of vaginal prolapse were compared. A high prevalence was not associated with any particular feedstuff. A high or intermediate (1 to 3 per cent) prevalence of vaginal prolapse was found in three of the four flocks managed as a single group and these three flocks were fed on an unrestricted basis. Body condition scoring and beta-hydroxybutyrate estimation confirmed that ewes in these flocks were overfed. The prevalence of vaginal prolapse in the flocks was not related to the serum albumin, calcium or urea of the ewes. Therefore subclinical hypocalcaemia was probably a consequence of vaginal prolapse rather than a cause.     

Incidence of indurative lymphocytic mastitis in a flock of sheep infected with maedi-visna virus

Sheep in a flock in which 88 per cent of the ewes had antibodies to maedi-visna virus were clinically examined for udder induration during lactation and after drying off. On both occasions about half of the ewes had indurated udders. Histological examination revealed lymphocytic mastitis associated with maedi-visna virus infection, in the udders of six of 25 hoggs (24 per cent), 21 of 39 shearlings (53.8 per cent) and 42 of 67 ewes (62.7 per cent). Distinct lung lesions were found in 8 per cent of the hoggs, 12.5 per cent of the shearlings and 10 per cent of the ewes. The results of a clinical examination of dry udders were correlated with the histological findings.     

The cost of Border disease infection in a commercial flock

The performance of a flock of 203 crossbred ewes on a lowland farm was examined. Before lambing the ewes were run in two groups (A and B). Group A (124 ewes) produced significantly fewer marketable lambs as a consequence of neonatal and later losses. The associated clinical features were consistent with Border disease infection and the presence of the virus was demonstrated. These features were not evident in the progeny of group B (79 ewes). The market sale returns of both groups of sheep were compared and the flock performance was contrasted with that of the two previous years. The outbreak of Border disease resulted in a potential reduction of income in excess of 20 per cent. Such a loss supports the necessity for an effective control strategy for Border disease.     

Hypocalcaemia in 23 ataxic/recumbent ewes: clinical signs and likelihood ratios.

Twenty-three ewes in a flock of 2000 were identified as having acute onset ataxia and/or having become recumbent in late pregnancy and early lactation. The presence or absence of 15 clinical signs were recorded. Thirteen of the ewes (57 per cent) were hypocalcaemic and 10 (43 per cent) were normocalcaemic. In the hypocalcaemic group, loss of anal reflex, constipation, tachycardia, hyposensitivity, ruminal stasis, ruminal tympany, salivation and tachypnoea were recorded in 50 per cent or more of the cases. In the normocalcaemic group, tachycardia, tachypnoea and ataxia were recorded in 50 per cent or more of the cases. Constipation, ruminal stasis, salivation and hyposensitivity had likelihood ratios of 3 and above for being associated with hypocalcaemia. Ruminal stasis and hyposensitivity had the likelihood ratios of 0.10 and 0.11 respectively for not being associated with hypocalcaemia.     

A study of a restricted programme of strategic dosing against Fasciola hepatica with triclabendazole

A restricted programme of strategic dosing with triclabendazole was used to treat a sheep flock with severe clinical fascioliasis. After five years the percentage of ewes passing fluke eggs was reduced from 49 per cent to less than 1 per cent, without the reappearance of clinical fascioliasis. It is suggested that this programme offers an efficient and practical means of controlling fascioliasis.     

Field trial of the efficacy of dicyclanil for the prevention of wohlfahrtiosis of sheep

Two groups of 40 ewes from each of two flocks were used in a field trial of the efficacy of dicyclanil to protect them against a natural infestation by Wohlfahrtia magnifica larvae, when administered topically as a spray-on formulation. The animals of one group in each flock were treated with dicyclanil and those of the other group were left untreated as controls. The trial lasted 31 weeks and the animals were inspected daily for wohlfahrtiosis. The incidences of wohlfahrtiosis ranged from 17.5 per cent to 20 per cent in the control groups and from 2.5 per cent to 5 per cent in the treated groups, and 77.8 per cent of the infestations were in the genitalia. When compared with the control groups, dicyclanil achieved a 100 per cent reduction of infestation in the treated groups of both flocks for at least 24 weeks, and an 80 per cent reduction for 31 weeks.     

Pestiviral infections in sheep and pigs in Northern Ireland

Serological surveys were carried out to determine the prevalence of pestiviral infections in sheep and pigs in Northern Ireland. Sera from 918 ewes in 92 flocks from 10 regions were tested by ELISA for antibodies to border disease virus and positive results were obtained from 49 ewes (5.3 per cent) in 28 flocks (30.4 per cent). There were highly significant geographical variations in its flock prevalence ranging from 0 per cent in the Enniskillen region to 70 per cent in the Coleraine region. There was no significant association between the proportion of seropositive flocks and the presence of cattle on the farm (P = 0.583). In the positive flocks, the average rate of seroprevalence was 17.5 per cent, and the highest was 40 per cent. Comparative neutralisation studies on 14 positive sera with bovine viral diarrhoea virus type I (BVDV I) and border disease virus revealed higher titres (> or = four-fold) to BVDV I in all cases. Only one positive result was obtained when fluids from 186 aborted ovine fetuses were tested for border disease virus by ELISA. Serum samples from 680 pigs in 46 herds were tested for virus neutralising antibodies to border disease virus. Twenty sera (2.9 per cent) were cytotoxic, and only one of the remaining 660 sera gave a positive result. This sample tested negative for classical swine fever by ELISA, and comparative neutralisation studies showed that it had a four-fold higher titre to BVDV I than to border disease virus.     

Cryptosporidium parvum infection in orphan lambs on a farm open to the public

A longitudinal survey was undertaken on an open farm to investigate the occurrence of Cryptosporidium species infection in orphan lambs obtained from three local flocks. During an initial pilot study, Cryptosporidium oocysts were detected by a fluorescent antibody test (fat) in the faeces of two of 21 lambs aged between one and three weeks derived from one flock (flock A). Pooled pen samples of faeces were collected weekly from lambs derived from each flock; oocysts were detected by fat in 24 (49.0 per cent) of 49 samples from lambs from flock A, 18 (30.5 per cent) of 59 samples from lambs from flock B and 14 (29.8 per cent) of 47 samples from lambs from flock C. Oocyst counts of 1 x 10(3) to more than 2 x 10(6) per gram of faeces were detected in lambs up to 12 weeks old, with the peak counts occurring at six weeks of age in the lambs from flocks A and B and at four weeks of age in those from flock C. The oocysts were confirmed by molecular analysis as Cryptosporidium parvum. Virtually all the infections were subclinical.     

Assessment of pregnancy in sheep by analysis of plasma progesterone using an amplified enzyme immunoassay technique

An amplified enzyme immunoassay kit for progesterone analysis was used to diagnose pregnancy in a flock of 130 mule ewes. An accuracy of 100 per cent was obtained after the analysis of progesterone in plasma samples taken 15 to 16 days after mating. In mule ewes a plasma progesterone level greater than 5.9 nmol/litre was indicative of pregnancy. In the validation of the technique, duplicate ewe plasma samples and progesterone standards were compared with a radio immunoassay technique; the regression coefficient between the two techniques was r = 0.82.     

Pulmonary adenomatosis (jaagsiekte) of sheep in Canada

Sheep pulmonary adenomatosis has recently been reported in Canada. The literature is briefly reviewed and an account of the present status of the disease in Canada is described.

Sheep pulmonary adenomatosis was first diagnosed in Canada in December 1979 in a first generation descendent of sheep imported from Great Britain. In March 1980 two further cases of sheep pulmonary adenomatosis were diagnosed in a second flock. A total of 43 sheep involving eight flocks from five provinces have been observed from December, 1979 to May, 1981. The clinical signs and laboratory findings were similar to those described in sheep from other countries. It is estimated that 30% of Canadian flocks may contain sheep imported from Great Britain during the 1970's.

     

A field study of watery mouth: clinical, epidemiological, biochemical, haematological and bacteriological observations

More than 500 cases of watery mouth in newborn lambs were recorded in 11 flocks and a detailed examination was performed in more than 200 cases. The condition occurred predominantly in lambs aged 24 to 48 hours. The incidence in a flock varied from 1 per cent to 24 per cent and the mortality in affected lambs varied from 7 per cent to 83 per cent. A bacteraemia was found in 38 per cent of the affected lambs. There were no consistent abnormalities of clinical biochemistry or haematology. Watery mouth was more common in twins and especially in triplets than in single lambs. In twins the highest incidence of watery mouth was recorded in lambs born to ewes in poor body condition. Antibiotic given orally within 15 minutes of birth greatly reduced the incidence of watery mouth.     

Spread of Coxiella burnetii infection in a flock of sheep after an episode of Q fever

In October 1998, two abortions associated with Coxiella burnetii occurred in a group of 34 pregnant ewes in the sheep flock belonging to INRA Tours-Nouzilly. The flock was kept in groups of approximately 40 ewes, which were housed together in the same accommodation. The prevalence of C burnetii infection in the groups was investigated by using ELISA and PCR tests, which revealed a high prevalence of C burnetii. The ewes were treated with oxytetracycline to reduce the shedding of C burnetii and to prevent further abortions. Nevertheless, five abortions attributed to C burnetii occurred in January and March 1999 in three groups of ewes, and 24 of the ewes still shed the bacteria into their vaginal tracts. In addition, a serological study was carried out during the first year of life of the female lambs born in 1999 and 2000; 12 per cent of 113 lambs born in 1999 were seropositive for C burnetii by ELISA, and half of the ELISA-positive lambs were born either to serologically positive ewes or to dams that excreted the pathogen into their vaginal tracts. However, all the 150 lambs born in 2000 were ELISA-negative, suggesting that the preventive measures undertaken had suppressed both the abortions and the shedding of C burnetii, and reduced the transmission of the agent.     

Descriptive epidemiology of scrapie in Great Britain: results of a postal survey

In 1998, a questionnaire was sent to 11,554 British sheep farmers to determine how many believed that scrapie cases had occurred in their flock; 61.4 per cent of them responded anonymously. The results indicated that 14.9 per cent of farmers with more than 30 breeding ewes thought that they had ever experienced scrapie in their flock and 2.7 per cent thought that they had had cases in the past 12 months. A comparison of these results with the number of farmers reporting suspect scrapie cases to MAFF, in accordance with the statutory requirement, suggests that only 13 per cent of farmers who suspect that they may have cases of scrapie are currently reporting them. Scrapie occurred in all regions of the country but there was an apparent regional variation. Larger farms and those with purebred sheep appeared to be at greater risk of having cases. Other differences between affected and unaffected farms included lambing practices and sheep purchasing policy. On the majority of farms the first case occurred in a purchased animal. The survey also revealed a need for the provision of further information about scrapie to farmers.     

Border disease without nervous signs or fleece changes

A natural infection with border disease virus occurred in a flock on low ground in Argyll in the spring of 1984. The outbreak was unusual in that the typical clinical signs of border disease, ie, tremor and, or, fleece changes were not present; manifestations of disease were restricted to abortion and the birth of small weak lambs. The disease was shown to have been introduced to the flock by four healthy ewes persistently infected with border disease virus among a group of 39 purchased in October 1983. Further investigations in late August 1984 detected viraemia in six of seven ill-thriven lambs and four of 24 apparently healthy lambs. Attempted 'natural vaccination' of susceptible sheep by mixing them at grass for three months with groups of ewes and lambs known to contain virus excretors was largely unsuccessful as only four of 22 'sentinel' sheep seroconverted. In October 1984 the persistently infected purchased animals and all that year's lamb crop were removed from the farm. No disease occurred in 1985 when the lambing percentage was 129 per cent compared with 100 per cent in 1984. Two of the four persistently infected purchased ewes were mated at Moredun Research Institute in December 1984 and both produced healthy but persistently infected lambs.     

Abomasal dilatation and emptying defect in a flock of Suffolk ewes

Abomasal dilatation and emptying defect was identified in 14 of 130 Suffolk sheep from a single flock in northern California. Abomasal dilatation and emptying defect was diagnosed in 13 of the sheep between November 1986 and April 1987. All affected sheep were ewes and in all, the condition developed during the lambing season. Clinical signs consisted of chronic anorexia and weight loss. Laboratory data from affected ewes reflected concurrent disease and was not helpful in diagnosis of the disease. Necropsy of 13 affected ewes revealed a distended, ingesta-filled abomasum in all of them. The brain stem of 6 ewes was examined, and lesions suggestive of scrapie were not observed. Pedigree analysis determined that in this flock, abomasal dilatation and emptying defect development was independent of sire. A relationship between the age of affected ewes and the disease was not found. Treatment was unsuccessful in 13 ewes, but 1 recovered after treatment with metoclopramide.     

An investigation into dystocia in a south country Cheviot flock.

An abnormally high incidence of dystocia was encountered in the south country Cheviot flock at the Hill Farming Research Organisation's research station at Sourhope, Yetholm, Roxburghshire over the past four years, 1970 to 1973. Lambing records were only available for 1972 and 1973 for Sourhope ewes and gimmers of all breeds and showed the following: (see article) This meant that in terms of attention and vigilance, a high shepherding input was necessary with the South Country Cheviot flock. Intensive observation and measurements of some relevant parameters were therefore made in the gimmer age group of this flock, numbering 126, during the lambing season of 1974; 39-7 per cent required assitance. This paper describes the behavioural pattern in lambing and demonstrates differences between those animals which were assisted and those which were not. The features of the dystocias and their possible cause are discussed.     

Studies in epidemiology of maedi/visna in sheep.

Lambs born to ewes from flocks with a high incidence of maedi/visna were separated from their dams at birth (group 1), or after 10 h (group 2), six weeks (group 3) or one year (group 4) and were observed for periods of up to eight years. Group 1 lambs remained free of infection while 28 per cent, 76 per cent and 81 per cent respectively of lambs in the other groups developed clinical, serological or histopathological evidence of infection during the observation period. It is therefore concluded that vertical transmission, if it occurs at all, is of little significance in the epidemiology of the disease. The number of serologically, virologically and histopathologically maedi/visna positive sheep, the time of onset of disease and the severity of lesions were related to the duration of exposure to the parent flock. In a separate trial no evidence was obtained for the transmission of maedi/visna by Muellerius capillaris larvae.     

Three-step procedure for isolation of epithelial cells from the lungs of sheep with jaagsiekte

An efficient and reproducible technique is described for the isolation of transformed sheep pulmonary adenomatosis cells. It includes three basic steps: prolonged trypsinisation to kill fibroblasts, magnetic removal of macrophages and adherence to remove the rapidly adherent cells. The resultant preparations of lung cells were enriched to 96.6 per cent type 2 pneumocytes.     

Some factors affecting pregnancy rate in ewes following laparoscopic artificial insemination

The fertility of 646 ewes and gimmers bred by laparoscopic artificial insemination (LAI) in the autumn of 2006 was investigated using a questionnaire and individual ewe breeding records kept for 13 commercial sheep flocks that used LAI routinely. Overall, the pregnancy rate was 66 per cent, but it was highest in ewes bred for the fourth time. Technical aspects of LAI influenced fertility: pregnancy rates were 70 per cent for ewes bred using frozen semen compared with 58 per cent when fresh semen was used (P≤0.01), and 74 per cent of ewes that travelled to an artificial insemination centre for mating conceived, compared with 62 per cent that remained on their own farm (P<0.01). Higher doses of equine chorionic gonadotrophin (>400 iu) used for oestrus synchronisation reduced pregnancy rates to only 49 per cent (P<0.001). However, the largest effect was associated with shepherds gathering, handling and treating breeding ewes four to six weeks before mating; pregnancy rates were 54 per cent among ewes where this was carried out, compared with 74 per cent for ewes not treated in this way (P<0.01).