Generalized aspergillosis in dairy sheep.

Two cases of systemic aspergillosis are described in dairy sheep from a flock in which fungal mastitis appeared subsequent to the antibiotic treatment of animals before parturition. Lesions characterized by necrosis and a pyogranulomatous exudate were observed in the mammary glands, supramammary and mediastinal lymph nodes, kidneys, lung, liver, heart, forestomachs and brain. The intense vasculitis with thrombosis observed in various organs, but especially in the mammary glands, suggested a haematogenous dissemination of the infection from this organ. The aetiological diagnosis was accomplished by the immunohistochemical staining of the fungal structures seen in the histological sections by the specific Aspergillus monoclonal antibody Mab-WF-AF-1 together with the isolation of Aspergillus fumigatus in pure culture from affected tissues.

Mammary and systemic aspergillosis in dairy sheep.

Mammary aspergillosis was diagnosed in four flocks of dairy sheep, comprising a total of 1,750 ewes. These animals had been treated prophylactically by intramammary infusion with cloxacillin 5 months prior to lambing. Mammary aspergillosis with concomitant spread to the regional lymph nodes was present in these flocks in a percentage ranging from 2% to 36.4% of treated sheep. Pathologic, bacteriologic, and mycologic studies were performed in seven of the affected ewes. Some of them also had lung, kidney, and liver involvement. The pathologic reaction within lesions ranged from the acute to subacute type, dominated by necrosis and vasculitis with thrombosis, to the chronic granulomatous type, with macrophages and giant cells. The distribution of lesions and the presence of a remarkable vasculitis with fungal thrombi in the mammary gland suggested a hematogenous dissemination of the infection from this organ. Immunologic staining with monoclonal antibody MAb-WF-AF-1, which reacts specifically with Aspergillus hyphae, identified the causative agent in histologic sections of the different affected tissues. The etiologic diagnosis was further supported by the isolation of Aspergillus fumigatus in pure culture from affected tissues and from eight samples of mammary secretions.

Caprine arthritis-encephalitis in an indigenous Spanish breed of dairy goat.

The presence of caprine arthritis and encephalitis (CAE) in Spain has never been officially acknowledged but it is suspected. Goats have been imported from other European countries with a high prevalence of the disease, mainly France, and they might have introduced the disease into the indigenous goat population. A serological survey of caprine arthritis and encephalitis virus antibodies was carried out in 22 volunteer dairy Murciano-Granadina goat herds; 2513 lactating goats were tested with an agar gel immunodiffusion test, and 12.1 per cent were found to be positive. Five of the herds were free of infection, six had a low prevalence of the disease, five had a medium prevalence and six had a high prevalence. Five seropositive goats with clinical signs of CAE were studied. Macroscopic and microscopic lesions similar to those described for CAE were detected in all five goats and a cytopathic effect typical of CAE virus was observed in primary explant cultures from four of them.

Lack of mycobactin dependence of mycobacteria isolated on Middlebrook 7H11 from clinical cases of ovine paratuberculosis.

Mycobacterium avium subsp. paratuberculosis is distinguished from other mycobacterial species by its dependence on the iron-chelator factor mycobactin and its prolonged incubation period when grown in vitro. Traditionally, a very low rate of isolation has been considered characteristic of sheep strains of this mycobacterium species. In the present study, a comparison was made of the performance of two media, Löwenstein-Jensen and Middlebrook 7H11/OADC both with and without mycobactin, on the isolation of M. a. paratuberculosis from ovine cases of the disease. A high isolation rate in both media was observed. Moreover, our results indicated that mycobactin dependence of sheep strains of M. a. paratuberculosis is medium related, being dependent on Löwenstein-Jensen and independent on Middlebrook 7H11/OADC.

Comparison of different media for the isolation of small ruminant strains of Mycobacterium paratuberculosis.

Two different egg based media, with and without the incorporation of sodium pyruvate, were used to isolate M. paratuberculosis from sheep, goat and cattle samples obtained at our laboratory for two years. Both media were adequate for bovine material, with a slightly improved isolation rate for Herrold's egg yolk medium incorporating sodium pyruvate; however, most of the small ruminant strains grew only on Löwenstein-Jensen medium without sodium pyruvate. Those results point out the need to use different media when working with small ruminant samples and provide further evidence for the existence of different varieties of M. paratuberculosis causing paratuberculosis in cattle and in small ruminants.