J. A. García de Jalón

Enzootic nasal tumour of goats: demonstration of a type D-related retrovirus in nasal fluids and tumours.

Nasal exudate and tumour tissue from goats with enzootic nasal tumours were shown to contain a reverse transcriptase activity associated with a particle of buoyant density typical of retroviruses. The same particle contained a 25,000 Mr protein that cross-reacted with the p27 of Mason-Pfizer monkey virus (MPMV) and with p25 of sheep pulmonary adenomatosis retrovirus. It also contained a low Mr protein related to p10-12 of MPMV.

Pathology of Enzootic Intranasal Tumor in Thirty-eight Goats

Intranasal tumors were studied in 38 goats ranging from 7 months to 8 years of age of both Murciana-Granadina and crossed breeds. Tumors were diagnosed in eight herds. Clinically, the affected goats showed a copious seromucous nasal discharge, ocular protusion, and skull deformations. The tumors originated from the ethmoid region. They involved one or both nasal cavities, although most were bilateral (26/38). The tumors were generally accompanied by inflammatory polyps. The histologic patterns were very similar in all cases, and the tumors were classified as low grade adenocarcinomas of the nasal glands. Histochemical, immunohistochemical, and ultrastructural studies suggested that the serous glands of nasal mucosa were the probable origin of the neoplastic cells. Budding and extracellular retrovirus-like particles were observed ultra-structurally in 6/8 tumors. The similarities between these caprine tumors and nasal tumors in sheep and the etiologic role of the retrovirus are discussed.

Experimental Transmission of Enzootic Intranasal Tumors of Goats

The successful experimental transmission of enzootic intranasal tumor (EIT) from goat to goat is described. Ten kids, less than 48 hours old, from a flock free of the disease and seronegative for ruminant lentiviruses were inoculated intranasally or intrasinusally with either nasal fluid from goats with naturally occurring EIT or EIT retrovirus concentrated from such fluids. EIT was induced in three kids after 12-24 months. The EIT retrovirus was demonstrated in tumor material from each of the three kids by western blotting and electron microscopy. All kids were seronegative for ruminant lentiviruses.

Biochemical Changes in Apparently Normal Sheep from Flocks Affected by Polioencephalomalacia

Blood samples were obtained for determination of the activities of lactate, pyruvate and erythrocyte transketolase, and faeces as samples for estimation of thiaminase, from 190 apparently healthy sheep from 19 flocks in which at least one animal had been diagnosed with polioencephalomalacia (PEM), from 59 control animals and from 7 affected by PEM. Feed and pasture grass samples were collected for thiaminase analysis and thiaminase was assayed in ryegrass and fescue. Decreased erythrocyte transketolase activity, accompanied by a corresponding rise in the thiamin pyrophosphate effect, and estimation of the thiaminase content in faeces, may be useful diagnostic procedures by which to identify periods of greater risk, during which animals could develop PEM. The changes in the diet probably acted as a primary factor for microbial production of thiaminases in replacement ewes. In these, the prevalence was higher in the spring months.

Possible adverse reactions in sheep after vaccination with inactivated BTV vaccines.

PREVENTION programmes against bluetongue virus (BTV) infection have been conducted in numerous countries throughout Europe. In spite of some variations, depending on the expected serotypes of BTV and country-specific conditions, generally, inactivated vaccines have been selected. In the period from

The distribution of immune cells in the lungs of classical and atypical ovine pulmonary adenocarcinoma

Ovine pulmonary adenocarcinoma (OPA) is a contagious tumour caused by infection of sheep with Jaagsiekte sheep retrovirus. Two forms of OPA have been identified, classical and atypical, which can be distinguished clinically and pathologically. Most notably classical OPA is progressive until death, while atypical OPA remains subclinical. In the present study the local immune responses in the lungs of cases of atypical OPA were compared with those from classical cases by immunohistochemistry using a panel of mouse anti-sheep mAbs. Distinct differences in the distribution of immune cell subsets in the two forms of OPA were observed. In particular there was an intratumoural influx of T cell subsets and MHC Class II expression on the tumour cells in atypical OPA, neither of which was seen in classical OPA. It is possible that these differences may contribute, at least in part, to determining the progressive course of classical OPA compared with the subclinical nature of atypical OPA.

A case of ovine female XY sex reversal syndrome not related to anomalies in the sex-determining region Y (SRY).

The human XY gonadal sex reversal is a rare disease. Primary amenorrhea, lack of secondary sexual characteristics and the possible existence of streak gonads are the most common signs of this syndrome. Five cases of this syndrome have been described in the last 42 years in bovines. However, to the knowledge of the authors, no similar descriptions are available in sheep. In the present report, we are presenting the case of a 4 year old ewe 2n = 54,XY showing primary sterility and total absence of masculinization signs. The promoter and the complete coding segment of the sex determining region Y (SRY) were sequenced and found to be absolutely normal. The presence of the testis-specific protein gene (TSPY) was also verified by means of PCR. Necropsy findings include short vagina, lack of uterus and complete absence of masculine remains. Streak gonads concordant with previous descriptions in humans were also found.

Coexistence of pituitary adenocarcinoma and intraocular melanoma in a sheep.

PITUITARY adenocarcinomas and intraocular melanomas are very rare tumours in sheep. This short communication describes the coexistence of both these tumour types in a sheep that also showed lesions of ovine pulmonary adenocarcinoma, another more frequently diagnosed neoplasia. A 14-year-old Rasa Aragonesa ewe was presented to the Veterinary Faculty Hospital, University of Zaragoza, Spain, with a history of neurological signs. Its rectal body temperature was 38·5°C, heart rate 102 bpm and respiratory rate 16 breaths/minute. Examination of the cardiovascular, respiratory and digestive systems detected no abnormalities. The animal was very depressed, with reduced conscious proprioception and slow spinal reflexes, and showed a tendency to head press against the walls of the cage. Pupillary light reflexes were reduced on the left side and absent on the right side. Ocular examination of the left eye was within normal limits, but ocular disorders, including microphthalmos and severe enophthalmos with the eyelid detached from the ocular globe, were observed in the right eye. A deeper ocular examination of this eye by ultrasound (HDI 3500 system; Advanced Technology Laboratories) with a high frequency probe, showed an internal mass invading the posterior chamber, and several calcification foci were also evident (Fig 1a). The animal was euthanased due to its advanced age and ongoing deterioration. At postmortem examination, a large neoplastic mass (4·0 mm x 2·5 mm x 3·0 mm) replaced the normal pituitary gland, and compressed the adjacent brain structures (Fig 2). Histopathologically, the mass was composed of neoplastic cells polyhedral in shape, very pleomorphic with a lightly eosinophilic cytoplasm. The shape of the nuclei was very variable, but the majority were large and vesiculated. Multinucleated cells were occasionally observed and mitotic figures were very common, as were haemosiderin -laden macrophages (Fig 3a). Internally, the mass had large areas of necrosis, with many haemorrhages and calcified foci evident. The tumour had destroyed the pars distalis of the pituitary gland, and infiltrated the neurohypophysis and adjacent brain structures. These findings were histopathological features strongly suggestive of malignancy (Capen 2002) and the tumour was diagnosed as a pituitary chromophobe adenocarcinoma. Macroscopically, the right ocular globe was atrophied. Calcified foci were found in the posterior chamber and a large, deeply pigmented mass filled this chamber producing lens dislocation and a rupture into the anterior chamber (Fig 1b). Histologically, the tumour appeared to originate from the iris and ciliary body and extended into the retina producing degeneration and detachment. The tissue consisted of spindle-shaped cells with abundant intracytoplasmic melanin granules that obscured the nuclear morphology (Fig 3b). Intraocular melanoma was diagnosed. Another lesion was found in the right lung. A small grey nodule was located on the surface of the diaphragmatic lobe in a ventral position. Histologically, this nodule was consistent with a preclinical lesion of classical ovine pulmonary adenocarcinoma (OPA), a lung neoplasia associated aetiologically with a Jaagsiekte sheep retrovirus (JSRV) infection (De las Heras and others 1992, 1995, Garcia-Goti and others 2000). The presence of this virus was confirmed by JSRVspecific PCR (Palmarini and others 1996). Metastases of these three tumours were not observed and the only other lesions detected were grossly visible sarcocysts in the oesophagus. The most common pituitary tumours in domestic animals are found in the dog and horse, and reports in ruminants are very rare, especially in sheep. The majority of the ovine descriptions are adenomas (Olson and others 1981, Gonzalez and others 1994, Oda and others 1997), but more recently an adenocarcinoma was documented (Zanolari and others 2004). In the sheep in this report, the malignant histological features of the pituitary tumour favoured its diagnosis as an adenocarcinoma, even though metastases were not detected. However, other primary tumours were found in this animal. To the authors’ knowledge, this is the first evidence for the coexistence of a pituitary chromophobe adenocarcinoma, an intraocular melanoma and an OPA nodule within the same sheep. Pigmented ocular tumours are also extremely rare in sheep, and reports are limited to an intraocular malignant melanoma (Saunders and Barron 1958) and a melanotic tumour of the eye (Head 1990). In contrast, OPA is an ovine lung cancer that has been recorded on many occasions in many countries (Sharp and DeMartini 2003). The advanced age of this animal could have contributed to the emergence of the multiple tumours, increasing the opportunity for the development of several primary tumours. Reported cases of pituitary tumours to date have Veterinary Record (2006) 159, 718-719

Ultrasonographic diagnosis of an adrenocortical carcinoma in a dog

The ultrasonographic findings in a nine-year-old female Drahthaar with an adrenocortical carcinoma of the left adrenal gland are described. Examination of the abdomen revealed a large, hypoechoic mass cranial to the left kidney. Areas of calcification inside the mass and the lateral displacement of the caudal vena cava were assessed. The right adrenal gland was thinner and smaller than normal. Several targetlike lesions were present in the hepatic parenchyma. A moderate amount of haemorrhagic abdominal fluid was also present. The ultrasonographic findings were consistent with this type of adrenal neoplasia which produces atrophy of the contralateral gland and frequently metastasises to the liver. The ultrasonographic diagnosis of adrenocortical carcinoma was confirmed by histopathological examination.

Laryngeal hemiplegia in a ram associated with Sarcocystis species infection.

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