Risk assessment and surveillance for bovine spongiform encephalopathy (BSE) in Argentina

An assessment was made of the risks of bovine spongiform encephalopathy (BSE) occurring in Argentina. Most of the factors associated with the origin and development of the BSE epidemic in the UK are essentially absent. For example, Argentina's large sheep and cattle industries are based on low-cost production systems using grass. Concentrated feeds are not used for sheep, rarely for beef cattle and to a comparatively modest extent for dairy cows. Particularly important are the facts that scrapie (and BSE) has never been reported in Argentina—very small amounts of waste tissues from sheep are rendered to produce meat and bone meal (MBM)—and MBM is not used in concentrated feeds for cattle. We conclude that Argentina has an exceptionally low risk of BSE due to scrapie. There is a very small risk of BSE having been introduced via live animals imported from countries with BSE, but this could only give rise to isolated cases because MBM is not fed to cattle.

A surveillance programme has been carried out based largely on a histological examination of brains from three categories of old dairy cows: animals reported on the suspicion of having neurological disease; animals in poor condition at slaughter; healthy animals randomly selected in the abattoir. No evidence of transmissible spongiform encephalopathy was seen in several sections from each of a total of 1019 brains. We conclude that, for most practical purposes, Argentina may be considered to be free from BSE.     

Myasthenia Gravis in the Cat

Myasthenia gravis (MG) was diagnosed in four cats--one had an apparently congenital form and three had the acquired autoimmune form. All four cats were examined because of episodes of weakness including gait abnormalities, voice change, neck ventroflexion, and regurgitation. Palpebral reflexes were absent in all cats. Administration of edrophonium chloride resulted in transient resolution of clinical signs in all four cats. Three cats were tested for the presence of serum autoantibodies against acetylcholine receptor (AChR) by radioimmunoassay. Two cats with acquired MG had anti-AChR antibody titers of 10.5 and 96.8 nmol/l (normal, less than or equal to 0.03 nmol/l). Antibodies were not detected in the cat with presumptive congenital MG. All four cats were treated with pyridostigmine bromide. Two cats with acquired MG were euthanatized because of clinical deterioration. The third cat with acquired MG has been asymptomatic since 2 months after diagnosis. The cat with presumed congenital MG is alive 3 years after diagnosis.     

Effect of photoperiod manipulation on daily rhythms of melatonin and reproductive hormones in caged European sea bass (Dicentrarchus labrax)

There are few studies regarding the daily changes in reproductive hormone profiles in teleosts. The aim of the present research was to investigate the effects of photoperiod manipulation on daily rhythms of melatonin and reproductive hormones (pituitary and plasma LH, testosterone [T] and 11-ketotestosterone [11KT]) in juvenile sea bass, kept in net cages under farming conditions in winter. Our results provide the first evidence for the presence of daily variations in pituitary and plasma LH and plasma T in sea bass. Artificial lights suppressed circulating plasma melatonin levels and significantly affected the daily rhythm of LH storage and release.     

Radiographic,ultrasonographic, and computed tomographic characteristics of an accessory liver lobe in a cat

A 5‐year‐old male Norwegian Forest cat presented with increased hepatic serum biochemical parameters. Abdominal radiography showed an oval cranioventral mass and ultrasound revealed a mobile mass attached to one hepatic lobe. Computed tomography (CT) confirmed that the mass was attached to the right medial liver lobe. Differential diagnoses were an accessory liver lobe, benign neoplasia, and focal nodular hyperplasia. The mass was removed and histopathology confirmed the mass to be normal liver tissue. Accessory liver lobe should be included in the differential diagnosis of a mobile cranial abdominal mass with a similar ultrasonographic or CT appearance to the liver.     

Testing the effect of routine fungicide application on ectomycorrhiza formation on Pinus halepensis seedlings in a nursery

The fungicides benomyl, captan, hymexazol, iprodione, propamocarb hydrochloride and thiram were applied in a combined schedule to Pinus halepensis seedlings grown under nursery conditions to study their effect on mycorrhiza formation and plant growth. The inoculated fungi Pisolithus tinctorius (strains 3SR and Mx) and Lactarius deliciosus formed mycorrhizas when fungicides were applied. However, fungicide application led to a significant decrease of mycorrhizal plants with Pisolithus tinctorius strain 3SR (from 62% without fungicides to 35% with fungicides). This effect could be attributed to a direct effect of fungicides on mycelial growth. The morphometric and nutritional parameters were very similar in plants treated with or without fungicides, and no differences on sanitary status of plants were noted. The use of preventive fungicide treatments in plant production, which may have a harmful effect on the environment, is therefore questioned.     

Disposition of orally administered cefpodoxime proxetil in foals and adult horses and minimum inhibitory concentration of the drug against common bacterial pathogens of horses

OBJECTIVES: To determine the disposition of orally administered cefpodoxime proxetil in foals and adult horses and measure the minimum inhibitory concentrations (MICs) of the drug against common bacterial pathogens of horses. ANIMALS: 6 healthy adult horses and 6 healthy foals at 7 to 14 days of age and again at 3 to 4 months of age. PROCEDURE: A single dose of cefpodoxime proxetil oral suspension was administered (10 mg/kg) to each horse by use of a nasogastric tube. In 7- to 14-day-old foals, 5 additional doses were administered intragastrically at 12-hour intervals. The MIC of cefpodoxime for each of 173 bacterial isolates was determined by use of a commercially available test. RESULTS: In 7- to 14-day-old foals, mean +/- SD time to peak serum concentration (Tmax) was 1.7 +/- 0.7 hours, maximum serum concentration (Cmax) was 0.81 +/- 0.22 microg/mL, and elimination half-life (harmonic mean) was 7.2 hours. Disposition of cefpodoxime in 3- to 4-month-old foals was not significantly different from that of neonates. Adult horses had significantly higher Cmax and significantly lower Tmax, compared with values for foals. The MIC of cefpodoxime required to inhibit growth of 90% of isolates for Salmonella enterica, Escherichia coli, Pasteurella spp, Klebsiella spp, and beta-hemolytic streptococci was 0.38, 1.00, 0.16, 0.19, and 0.09 microg/mL, respectively. CONCLUSIONS AND CLINICAL RELEVANCE: Oral administration at a dosage of 10 mg/kg every 6 to 12 hours would appear appropriate for the treatment of equine neonates with bacterial infections.