Twelve years experience in Switzerland: Quo vadis BSE?

When the first BSE case in Switzerland became public in 1990, it precipitated a chain of events with many diverse consequences. During this time, we continued to gain knowledge, implement new measures, and make practical recommendations in order to attempt to control the disease. This was made possible by the establishment of a huge data base containing information on all cases of BSE that had been diagnosed in Switzerland, as well as by the use of information from experiences in other countries. Analysis of these data allowed the sequence of events to be described temporally and spatially and an epidemiological evaluation to be made. These data also allow predictions to be made regarding the future of BSE in Switzerland, although these predictions must be interpreted cautiously.     

Economically Important Leatherjackets of Grassland and Cereals: Biology, Impact and Control

Despite the large number of cranefly species only two have been convincingly associated with crop damage. The larvae of Tipula paludosa are commonly found as pests in both grassland and spring cereals whereas those of T. oleracea are only established as pests of winter cereals following crops of oilseed rape in the rotation. The latter, however, is probably the species involved in opportunistic situations involving various minor crops. These epidemiological contrasts are attributable to differences in the morphology and behaviour of the adults of the two species in relation to crop rotations. Larvae are sufficiently similar as to cause confusion in identification and this has hampered development of a clear picture of the ecology of the two species. Little is known about the distribution of T. oleracea larvae but T. paludosa larvae are largely regulated by climatic factors, especially rainfall, although the operation of these varies across the distribution range. Many natural enemies have been identified but a commercially viable control method using them has not yet been developed for either species. Control of T. paludosa is relatively easy using broad-spectrum insecticides but inconsistent kills have been observed with winter pesticide applications against T. oleracea. Determination of those fields requiring applications in advance of the damage remains the major problem, especially in grassland and winter cereals, to be resolved for the management of leatherjacket pests.     

Integrated Pest Management of Pest Mole Crickets with Emphasis on the Southeastern USA

There are at least 70 species of mole crickets (Orthoptera: Gryllotalpidae). Some are rare, others are innocuous, and a few are important pests. These soil-dwelling pests damage underground parts of a long list of cultivated plants. Although tillage and flooding are used successfully in some situations to bring these pests to the soil surface and expose them to vertebrate and other predators, chemical pesticides are widely used against them. Knowledge of their life history is used to time application of chemical treatments to save money, but is not used as widely as it might be. Classical biological control has been used against immigrant mole crickets in Hawaii, Puerto Rico, and the southern USA. In Florida, three Scapteriscus species from South America cause major damage to pastures and turf and are targets of a classical biological control program. Population levels of two of the pest species have been reduced substantially in Florida by establishment of a tachinid fly (Ormia depleta) and a steinernematid nematode (Steinernema scapterisci) from South America. The nematode also functions as a biopesticide. Managers of pastures and turf in Florida have thus far derived benefit from these classical biological control agents without understanding their function: use of chemicals is reduced when mole cricket populations are lower due to action of these organisms. Future enhancement of the action of O. depleta and of a sphecid wasp (Larra bicolor, which also was introduced from South America) probably will demand deliberate planting of nectar sources for adults of these biological control agents, and the advantage will be to managers who adopt such a strategy. Chemical pesticide use is strongly promoted by a large chemical industry, whereas biopesticidal use has thus far been little promoted and sales have been few. Even managers who do not change their simple strategy of pesticide use in response to damage by mole crickets, and have no knowledge of the differing life cycles of the three Scapteriscus species or of the presence and action of the classical biological control agents, will derive benefit as these biological control agents (and a predatory beetle which has not yet been released) increase their distribution.     

An Intermediate-Technology Pattern Matching Model of Veterinary Diagnosis

An intermediate-technology pattern matching model and decision support system for veterinary diagnosis is described. Six diseases of cattle occurring in the tropics are used to illustrate the model. The pattern matching model is composed of a series of transparent overlays and a template. Each transparent overlay represents a sign state and contains sign frequency information for the diseases on the template. By superimposing multiple transparent overlays upon the disease template, a ranked list of differential diagnoses can be obtained. Ranking is by summation of disease sign frequencies. Modifications to accommodate observational uncertainty are presented. Disease prevalences can be represented in the model.     

Reduced anchoring fibril formation and collagen VII immunoreactivity in feline dystrophic epidermolysis bullosa

Dystrophic epidermolysis bullosa was diagnosed in a cat with juvenile-onset epithelial sloughing of the oral mucosa, footpads, and haired skin. Dermoepidermal separation occurred in the absence of inflammation or cytolysis of basal epidermal cells. Collagen IV-specific immunostaining corroborated the fact that clefting took place below the epidermal basement membrane. Ultrastructural examination revealed that the proband's anchoring fibrils exhibited a filamentous morphology and were decreased in number compared with those in a normal cat. Finally, the attenuated immunoreactivity for collagen VII in our patient led us to suspect that its encoding gene, COL7A1, could be mutated in this case of feline dystrophic epidermolysis bullosa.     

Radiological measurements from the feet of normal horses with relevance to laminitis.

Lateromedial radiographic projections were made from the feet of 25 normal horses and 3 angles and 3 distances were measured. From these, normal ranges of calculated variables were obtained. The width and length of each foot and the height of the horse at the withers was also measured. In view of its possible importance in clinical laminitis, particular attention was paid to 'founder' distance (D). This is the vertical distance between the proximal limit of the dorsal hoof wall and the proximal limit of the extensor process of the distal phalanx. There were significant differences between breeds in D (P<0.05) and in wall thickness (P<0.01). Further studies investigated the effects of time, differing radiographic projections and different operators on D. D did not alter significantly (P>0.05) over a 6 week study period. It was concluded that errors due to radiographic beam obliquity were not of practical importance. Errors in measuring D between operators can be minimised by use of a standard radiographic technique. Although there was some variation in the value of D measured over time and with different operators, which could make the interpretation of early or subtle changes difficult, measurement variation was not considered to interfere with the assessment of large changes associated with severe laminitis.