S. E. Long

ABATTOIR SURVEY OF CONGENITAL REPRODUCTIVE ABNORMALITIES IN EWES

A survey of abnormalities of the reproductive tract of female sheep was undertaken at two abattoirs in the south west of England over a period of 12 months. During the survey, 9970 reproductive tracts from cull ewes and 23,536 tracts from nulliparous sheep (prime lambs and hoggets) were examined. A total of 655 (6.57 per cent) ewes and 459 (1.95 per cent) nulliparous sheep had abnormalities of the reproductive tract. Of these, congenital abnormalities of the paramesonephric ducts accounted for 2.4 per cent of the ewes and 7.4 per cent of the nulliparous sheep, congenital abnormalities of the ovaries accounted for 2.6 per cent of the ewes and 7.4 per cent of the nulliparous sheep and cystic structures that were considered to have been of congenital origin accounted for 27.2 per cent of the ewes and 52.7 per cent of the nulliparous sheep. The most common lesion was paraovarian cysts (26.6 per cent of ewes and 39.0 per cent of nulliparous sheep), but few of these appeared to have affected the sheeps reproductive function. Several specific conditions were recorded, including some described for the first time in sheep. Uterus unicornis occurred in 20 sheep and other forms of segmental aplasia of parts of the paramesonephric ducts occurred in a further 13 animals. Uterus didelphys occurred in six sheep, and 11 animals were intersex. Intersex sheep had vestigial structures that were derived from the paramesonephric ducts, hypoplastic or masculinised gonads and some had masculinised external genitalia. Ovarian hypoplasia occurred in 34 sheep, and in a further 12 mainly nulliparous animals, the ovaries were fused. Sixty nulliparous animals and two ewes had hydatids of Morgagni.

Morphological, histological and histochemical studies of the gonads of ovine freemartins

Freemartins are XX/XY chimaeras that develop as a result of the fusion of the placental circulation of at least one male and one female fetus. Of 19 freemartin ewes, 13 had testis-like structures, seven of them in an abdominal position and six in an inguinal position. Histologically, their gonads had structures resembling seminiferous tubules and interstitial cells, and grossly, most had structures derived from the mesonephric ducts (vasa deferentia, epididymides and vesicular glands). The other six freemartin ewes had small, undifferentiated gonads that lacked either follicles or seminiferous tubule-like structures. They also lacked any structures derived from the mesonephric ducts. No derivatives of the paramesonephric ducts were detectable in any of the freemartin ewes. The gonads of the male-type freemartins stained immunocytochemically for 3β-hydroxysteroid dehydrogenase (3β-HSD) and histochemically for alkaline phosphatase (AP) in a similar way to, but more extensively and intensely than, the gonads of normal rams, and the staining was confined to interstitial cell-like structures. The staining in the undifferentiated-type freemartins was weak, but both 3β-HSD and AP were present in unidentified cell types.

Abattoir survey of acquired reproductive abnormalities in ewes

Abnormalities of the reproductive tract of female sheep were studied by examining 9970 reproductive tracts from cull ewes and 23,536 tracts from nulliparous sheep (prime lambs) over a period of 12 months in abattoirs in south-west England. Overall, 3.37 per cent of the tracts were pregnant (8.11 per cent of cull ewes, and 1.36 per cent of nulliparous sheep), with a peak incidence between September and December. A total of 655 ewes (6.57 per cent) and 459 nulliparous sheep (1.95 per cent) had acquired abnormalities of the reproductive tract. Within these totals, abnormalities of the ovaries accounted for 3.51 per cent (for the ewes) and 10.68 per cent (for the nulliparous sheep) of all the abnormalities, and abnormalities of the ovarian bursa and uterine tube accounted for 42.1 per cent (for the ewes) and 5.23 per cent (for the nulliparous sheep). In addition, uterine lesions (hydrometra and metritis) accounted for 9.92 per cent (for the ewes) and 13.51 per cent (for the nulliparous sheep); lesions of the cervix and vagina (total of 1.44 per cent) and Cysticercus tenuicollis cysts associated with the reproductive tract (total of 3.05 per cent) were less common. Among the ewes the most common ovarian lesions were ovulation tags, and follicular cysts were the most common in nulliparous animals. Lesions such as bursitis, parametritis and abscesses of the reproductive tract were much more common in cull ewes than in nulliparous sheep, probably having arisen from peripartum infections. Hydrosalpinx and hydrometra, in which the intraluminal fluid was clear, were present at relatively high incidence in nulliparous animals, but not in cull ewes. The proportion of tracts containing macerated fetal remnants (2.14 per cent of all abnormalities in cull ewes) was lower than expected. It was considered that the functional significance of many of the lesions, such as ovulation tags and C tenuicollis cysts, was likely to be low, although in some cases of the latter calcification of the cyst had occluded the uterine tubes. Other lesions, notably hydrosalpinx, bursitis and metritis were likely to have made the affected animals sterile. The acquired abnormalities were therefore more significant in terms of individual animal infertility than as a major cause of infertility in flocks.

Anatomical, cytogenetic and behavioural studies of freemartin ewes.

The external phenotype and reproductive behaviour of 21 freemartin sheep and two male pseudohermaphrodite sheep were recorded with the aim of identifying any characteristics which might be used to predict a failure to breed. The size and shape of the vulva and clitoris, the length of the vagina, the size of the teats, the presence or absence of inguinal gonads, and the ultrasonographic characteristics of the inguinal gonads were recorded. A subjective assessment of the masculinity of each animals body form was also made, and its behavioural responses to a virile ram and to an oestrus ewe were recorded. A number of physical and behavioural abnormalities were detected but the only consistent finding in all 23 animals was a short vagina which varied in length from 3.1 to 7.0 cm, compared with 10 to 14 cm in normal animals.

Inheritance of multifocal retinal dysplasia in the golden retriever in the UK

ers 1977, Wiedosari and others 1991, Radostits and Blood 1994). The findings reported in this study clearly demonstrate that an oral infective dose of 1000 metacercariae of Fgigantica produced a dinically severe disease in buffalos with 36-8 per cent establishment of the infective dose. The main objective of this experimental study, however, was to generate baseline data on the effect ofthe disease on the growth ofthe host and to determine the stage of infection at which treatment might most usefully be undertaken in order to reduce the effect of the parasite on the host. The fact that the animals dosed with 1000 metacercariae of Fgigantica gained significantly less bodyweight than the controls was due mainly to their lower intake of dry matter (Fig 1). Calves infected with Fgigantica were equally as efficient as the healthy controls in digesting and assimilating nutrients as there were no significant differences in the intake of digestible nutrients, per cent digestibility or balance ofnutrients between the groups. The significant decline in feed conversion efficiency seen in the infected animals may have been due to inappetence. This inappetence was most pronounced between sixth and 10th weeks after infection and again during the week preceding death ofthe host. These findings are in broad agreement with earlier reports on fascioliasis caused by F hepatica in cattle and sheep (Boray 1969, Berry and Dargie 1976, Hope Cawdery and others 1977). The onset of inappetence during the sixth week after infection coincides with the end of the migration stage ofthe flukes and their establishment in the biliary system, and hence inappetence could be a sequel to the traumatic lesions caused during this process and to the hepatotoxic effects of metabolites released by the developing F gigantica juveniles in the liver. As a consequence of this inappetence, infected animals show a marked reduction in bodyweight gain. Therefore, treatment should be undertaken as early as possible, during the prepatent period, before Fgigantica eggs appear in faeces of the host, in order to minimise losses and improve the performance of buffalos. References AOAC (1990) Official Methods of Analysis. 15th edn. Washington DC, Association of Official Analytical Chemists BERRY, C. I. & DARGIE, J. D. (1976) The role of host nutrition in the pathogenesis of ovine fasciolosis. Veterinary Parasitology 2, 317-332 BORAY, J. C. (1969) Experimental fascioliasis in Australia. In Advances in Parasitology. Vol 7. Ed B. Dawes. London, Academic Press. pp 95-210 DHAR, D. N. & SHARMA, R. L. (1986) Laboratory studies on the life cycle of Lymnaea auricularia sensu stricto. Indian Veterinary Journal 63, 621-623 HOPE CAWDERY, M. J. & CONWAY, A. (1971) Production effects of the liver fluke Fasciola hepatica on beef cattle. Veterinary Record 89, 641-643 HOPE CAWDERY, M. J., STRICKLAND, K. L., CONWAY, A. & CROWE, P. J. (1977) Production effects of the liver fluke in cattle. 1. The effects of infection on liveweight gain, feed intake and food conversion efficiency in beef cattle. British Veterinary Journal 133, 145-159 KEARL, L. C. (1982) Nutrient Requirements of Ruminants in Developing Countries. Logan, Utah, International Feedstuffs Institute, Utah State University. p 82 RADOSTITS, 0. M. & BLOOD, D. C. (1994) Veterinary Medicine. 8th edn. London, ELBS. p 1230 ROSS, J. G. (1970) The economics of Fasciola hepatica infections in cattle. British Veterinary Journal 126, 13-15 SHARMA, R. L., DHAR, D. N. & RAINA, 0. K. (1989) Studies on the prevalence and laboratory transmission of fasciolosis in animals in the Kashmir Valley. British Veterinary Journal 145, 57-61 STEEL, R. G. D. & TORRIE, J. H. (1980) Principles and Procedures of Statistics. A Biometrical Approach. 2nd edn. New Delhi, India, McGraw-Hill International Book Company TALAPATRA, S. K., ROY, S. C. & SEN, K. C. (1940) Estimation of phosphorus, chlorine, calcium, magnesium, sodium and potassium in food stuffs. Indian Journal of Veterinary Science andAnimal Husbandry 10, 243-258 URQUHART, G. M., ARMOUR, J., DUNCAN, J. L., DUNN, A. M. & JENNING, F. W. (1987) Veterinary Parasitology. London, ELBS, Longman. p 100 VAN SOEST, P. J., ROBERTSON, J. B. & LEWIS, B. A. (1991) Methods for dietary fibre, neutral detergent fibre and non-starch polysaccharides in relation to animal nutrition. Journal ofDairy Science 74, 3583-3597 WIEDOSARI, E., GRAYDON, R. & COPEMAN, D. B. (1991) Comparative pathological studies of hepatic changes induced by Fasciola gigantica and Gygantocotyle explanatum in Japanese thin-tailed sheep. Journal of Comparative Pathology 105, 147-155

Male tortoiseshell cats in the United Kingdom

A questionnaire concerning the coat colour and sex of cats being vaccinated or neutered was sent to 2585 veterinary practices; 393 (15.2 per cent) were returned and information was obtained about 9816 cats. Of 4598 males, 20 were recorded as tortoiseshell (0.43 per cent). The frequency of the orange gene was 19.7 per cent, assuming that male tortoiseshell cats had two X chromosomes. The chromosome complement and/or gonadal histology of 14 male tortoiseshell cats is described. Cytogenetic analysis of 11 animals revealed six with a 38,XX/38,XY complement, two with 39,XXY, two with 38,XX, and one with a 38,XY complement.

Congenital abnormalities of the ovineparamesonephric ducts

Summary A 15 month survey of ovine reproductive tracts was undertaken in slaughterhouses in southwest England. A total of 33506 tracts were examined; 23536 from lambs and 9970 from adults. In total, 3.4% of tracts were pregnant and 3.3% exhibited abnormalities. Twenty cases of uterus unicornis, six of uterus didelphys and 11 of segmental aplasia were encountered, such that partial aplasia of the paramesonephric ducts accounted for 3.3% of all abnormalities. Although developmental abnormalities of the ovine female genital system are relatively uncommon, a substantial proportion of these can be accounted for by development defects of the paramesonephric ducts.

Ovarian hypoplasia in Lleyn ewes

Anti-inflammatory drugs and bovine alveolar macrophages ANTI-INFLAMMATORY drugs have been advocated as adjuncts to antimicrobials for the treatment of bovine respiratory tract dis- ease. The aim is to reduce pulmonary tissue damage associated with the host response. In an in vitro study bovine alveolar macrophages were pretreated for 30, 60 or 120 mins with an anti- inflammatory compound (dexamethasone, flunixin meglumin or phenylbutazone) at several concentrations (0, 1, 10 and 100). The macrophages were then exposed to lipopolysaccharide (Escher- ichia coli 055:B5) in the presence and absence of fetal bovine serum for four hours. None of the drugs modified procoagulant activity expression as measured by a chromogenic assay. If in vivo events mimic the model, it seems unlikely that anti-inflam- matory drugs will reduce the procoagulant activity of bovine alve- olar macrophages and the associated pulmonary fibrosis. OLCHOWY, T. W., DEAN, D. F. & BOCHSLER, P. N. (1996) American Journal of Veterinary Research 57, 659 Use of doramectin to control lungworm in calves A PADDOCK in County Clare with a history of lungworm was divided into two halves each of which was grazed by 12 calves set- stocked for the grazing season. One group was treated at tumout in early May and 54 days later with doramectin subcutaneously at 200 pg/kg, and the other group remained untreated until the signs of parasitic bronchitis appeared towards the end of July; one of them died on July 24 and three others which were slaughtered on the same day were heavily infected. The remaining animals were treated with fenbendazole, and had to be retreated on September 3. The calves treated with doramectin remained healthy until they were housed in late September, when they had gained on average 10.5 kg more weight than the remaining control calves. TALTY, P. J., McSWEENEY, C. & SIMON, A. J. (1966) Irish Veterinary Journal 49, 66f 101

38,XX/38,XY CHROMOSOME CHIMAERISM IN THREE FELINE SIBLINGS

SEX chromosome chimaerism is not an uncommon finding in male tortoiseshell cats (Moran and others 1984, Leaman and others 1999), but it has only previously been reported in other cats in a case of true hermaphroditism (McEntee 1990). This may reflect the fact that cats are rarely examined chromosomally except where an anomaly is signalled by the coat colour and sex of the animal. In this study, the litter mates and dam of the proband, a male tortoiseshell cat, were known and their owners were willing to have the animals examined to establish their genetic sex. In the authors experience, it is unusual for relatives of male tortoiseshell cats to be available for examination and this presented a rare opportunity to try to elucidate the aetiology of any chromosome anomaly. Examinations were first carried out on an 11-month-old tortoiseshell cat (case 1). A blood sample was referred for cytogenetic analysis because it was known that such animals normally have chromosome anomalies. Subsequent cytogenetic analyses were made of two sibs of the male tortoiseshell cat. One was a tabby male (case 2) and the other a tabby and white female (case 3). The dam of these animals (case 4) which was tabby and white was also examined. The sire of the litter was unknown. Heparinised blood samples from peripheral blood were sent by post to the laboratory. Short-term cultures of whole blood were established using RPMI 1640 (Gibco) supplemented with 20 per cent fetal calf serum, 1 per cent L-glutamine, 1 per

Morphological, histological and histochemical studies of the pituitary glands of ovine freemartins

Freemartins are XX/XY chimaeras that develop as a result of the fusion of the placental circulation of at least one male and one female fetus. The pituitary glands of eight normal ewes at various stages of the oestrous cycle and three rams were compared with those of two male-type and three undifferentiated-type freemartins. The pituitaries were heaviest in the male-type freemartins, and their pattern of gonadotrophs, assessed by differential staining, was more intense than in the normal males. The pituitaries of the undifferentiated-type freemartins weighed less than those of the normal ewes but had more stained gonadotrophs than the normal ewes or rams. In both types of freemartins the pattern of cells resembled that of a castrated male.