Health Status of Bulls Used For Natural Breeding on Farms in South West Scotland

One hundred and nine breeding bulls were examined during the period November 1992 to June 1993 on farms in south west Scotland for evidence of infectious diseases associated with breeding. Preputial washings were collected to screen for Campylobacter fetus venerialis, together with serial blood samples to assess their seroprevalence to Bovine Virus Diarrhoca virus (BVDv), Bovine Herpes Virus-1 (BHV-1), Leptospira hardjo and Bovine Herpes Virus-4 (BHV-4). The possible impact of natural mating on the epidemiology of these diseases is described. Evidence of infections with Campylobacter fetus and BVH-4 were not found in this sample. The overall seroprevalence to BVDv was 78%, for BHV-1 49%, and L. bardjo 27% at titres of ≥ 1/400. This study shows that bulls may be responsible for the introduction and dissemination of these diseases when moved from farm to farm as part of normal cattle breeding in this area. Young unproven bulls may be particularly susceptible to endemic diseases associated with lowered reproductive performance.     

Characterisation of adult green lacewing (Chrysoperla carnea) digestive physiology: impact of a cysteine protease inhibitor and a synthetic pyrethroid

BACKGROUND: In spite of concern regarding potential non‐target effects of GM crops, few studies have compared GM pest control with conventional methods. The impacts of cypermethrin and oilseed rape expressing oryzacystatin‐1 (OC‐1) were compared in this study on the predator Chrysoperla carnea (Stephens). RESULTS: Adults fed purified rOC‐1 showed a subtle shift in digestive protease profile, with an increasing reliance on serine proteases (chymotrypsin), increase in aspartic proteases and a slight reduction in elastase activity. Although there were no effects on mortality, onset of oviposition was delayed; however, once egg production commenced, egg laying and hatching success rates were comparable with those of controls. Oryzacystatin‐1 expressed in pollen showed no detrimental effects. Cypermethrin had no effect on mortality owing to high levels of non‐specific esterase activity resulting in partial breakdown of the insecticide. In spite of this, there was a significant delay in onset of oviposition and a significant reduction in egg production and viability. CONCLUSION: This study demonstrates the potential for pest management to impact on predators, but importantly it highlights the ability of the predator to detoxify/respond to treatments with different modes of action. In this case, exposure to an insecticide carried a greater fitness cost than exposure to a protease inhibitor expressed in transgenic crops. Copyright © 2009 Society of Chemical Industry     

Efficacy of trilostane for the treatment of equine Cushing's syndrome

REASONS FOR PERFORMING STUDY: Trilostane, a competitive 3-beta hydroxysteroid dehydrogenase inhibitor, has been used successfully to control clinical signs and cortisol excess in canine pituitary dependent hyperadrenocorticism. OBJECTIVES: Trilostane was evaluated for its efficacy in resolving clinical and clinicopathological abnormalities of equine Cushing's syndrome (ECS) and to assess its safety. METHODS: Twenty horses (mean age 21 years) diagnosed with ECS were followed for 1 or 2 years. Affected horses received 0.4-1 mg/kg (mean 0.5 mg/kg) trilostane once daily. RESULTS: Clinical signs assessed over 1 or 2 years, showed a reduction in lethargy in all horses post treatment. Polyuria and/or polydipsia, present in 11 horses, was reduced in all after treatment. Recurrent or chronic laminitis, present in 16 horses, improved in 13/16 (81%) of cases. There were no side effects reported. Combined dexamethasone suppression and thyrotropin releasing hormone (TRH) stimulation tests were significantly different before and 30 days following therapy. There was a significant reduction (P = 0.01) of cortisol following TRH administration before (160 +/- 53.0 nmol/l) and after (130 +/- 46.1 nmol/l) trilostane. CONCLUSIONS: Trilostane caused improvement in clinical signs in horses, without side effects, and a corresponding decrease in cortisol response to TRH administration. POTENTIAL RELEVANCE: Trilostane may be a useful therapy for the treatment of ECS. Further work comparing the effects of trilostane and pergolide is warranted.     

Unusual pathophysiological mechanisms of ptyalism in two horses

This report outlines two cases of ptyalism that were not associated with oral conditions or primary dysphagia. The first, a 9-year-old Thoroughbred gelding, was associated with left-sided peripheral vestibular disease and bone modelling around the left tympanic bulla. The second, a 7-year-old Dutch Warmblood mare, was associated with progressive bilateral laryngeal paralysis and a mediastinal T-cell lymphoma. In Case 1, a neurological pathophysiology was proposed involving altered autonomic innervation of the salivary glands; whilst in Case 2, the mechanism remains unclear but may have involved mechanical compression of the intrathoracic oesophagus or stimulation of afferents within the vagus nerve. This case series highlights rare causes of ptyalism that have not been previously reported in the literature.