Analysis of national serological surveys for the documentation of freedom from porcine reproductive and respiratory syndrome in Switzerland

Results of national serological surveys for porcine reproductive and respiratory syndrome (PRRS) conducted in Switzerland in 2001 and 2004 were analyzed. In 2001, 41,124 breeding sows from 2,540 herds out of 6,406 were sampled, and in 2004, 7,498 animals were sampled from 1,074 herds out of 5,320. All serum samples were tested for PRRS using an ELISA developed at the Institute of Virology and Immunoprophylaxis (IVI), Switzerland with a sensitivity (Se) and specificity (Sp) of 94 and 97%, respectively. Positive samples were re-tested with a commercial ELISA (IDEXX) with Se of 100% and Sp of 99%. Samples positive in the second test were confirmed with the fluorescent antibody test (FAT). A stochastic model using data from the main survey conducted in 2001 was done to verify whether the sampling scheme used could detect at least one infected herd with 99% confidence level if the herd designed prevalence was at 0.1 or 0.2%. Additionally, a Bayesian approach was conducted to calculate the post-survey probability of freedom from PRRS using data from the 2001 and 2004 surveys. A Monte Carlo simulation with 5000 iteration was run for each model. Eleven samples in 2001 and six in 2004, all from different farms, could not be conclusively confirmed as negative by the FAT. All other samples were negative. Truly infected animals and herds were not predicted by a stochastic model at the 99% confidence level and 0.1% herd prevalence using data from the 2001 survey. However, it was demonstrated that the prior probability of freedom from PRRS increased from 89.3 to 99.2% after the 2001 survey. Upon completion of the 2004 survey, the probability of freedom from PRRS reached a value of 99.7%. Based on our results, we could conclude that the pig industry in Switzerland is free of PRRS virus with this level of confidence. Restricted import activities over the last decades are a possible explanation for the continuing absence of PRRS-infection in the Swiss swine population. Import requirements defined by the pig industry minimize the risk of introduction of PRRS-infected animals in the future.     

Genetic variant BDNF (Val66Met) polymorphism alters anxiety-related behavior

A common single-nucleotide polymorphism in the brain-derived neurotrophic factor (BDNF) gene, a methionine (Met) substitution for valine (Val) at codon 66 (Val66Met), is associated with alterations in brain anatomy and memory, but its relevance to clinical disorders is unclear. We generated a variant BDNF mouse (BDNF(Met/Met)) that reproduces the phenotypic hallmarks in humans with the variant allele. BDNF(Met) was expressed in brain at normal levels, but its secretion from neurons was defective. When placed in stressful settings, BDNF(Met/Met) mice exhibited increased anxiety-related behaviors that were not normalized by the antidepressant, fluoxetine. A variant BDNF may thus play a key role in genetic predispositions to anxiety and depressive disorders.     

Pharmacokinetics of pentoxifylline and its 5-hydroxyhexyl metabolite after oral and intravenous administration of pentoxifylline to healthy adult horses

OBJECTIVE: To determine serum pharmacokinetics of pentoxifylline and its 5-hydroxyhexyl metabolite in horses after administration of a single IV dose and after single and multiple oral doses. ANIMALS: 8 healthy adult horses. PROCEDURES: A crossover study design was used with a washout period of 6 days between treatments. Treatments were IV administration of a single dose of pentoxifylline (8.5 mg/kg) and oral administration of generic sustained-release pentoxifylline (10 mg/kg, q 12 h, for 8 days). Blood samples were collected 0, 1, 3, 6, 12, 20, 30, and 45 minutes and 1, 2, 4, 6, 8, and 12 hours after IV administration. For oral administration, blood samples were collected 0, 0.25, 0.5, 0.75, 1, 2, 4, 8, and 12 hours after the first dose and 0, 0.25, 0.5, 0.75, 1, 2, 4, 8, 12, and 24 hours after the last dose. RESULTS: Elimination of pentoxifylline was rapid after IV administration. After oral administration, pentoxifylline was rapidly absorbed and variably eliminated. Higher serum concentrations of pentoxifylline and apparent bioavailability were observed after oral administration of the first dose, compared with values after administration of the last dose on day 8 of treatment. CONCLUSIONS AND CLINICAL RELEVANCE: In horses, oral administration of 10 mg of pentoxifylline/kg results in serum concentrations equivalent to those observed for therapeutic doses of pentoxifylline in humans. Twice daily administration appears to be appropriate. However, serum concentrations of pentoxifylline appear to decrease with repeated dosing; thus, practitioners may consider increasing the dosage if clinical response diminishes with repeated administration.     

Effects of caloric restriction and a moderate or intense physiotherapy program for treatment of lameness in overweight dogs with osteoarthritis

OBJECTIVE: To evaluate the effects of a weight reduction program combined with a basic or more complex physical therapy program including transcutaneous electric nerve stimulation on lameness in overweight dogs with osteoarthritis. DESIGN: Nonblinded prospective randomized clinical trial. Animals-29 adult overweight or obese dogs with a body condition score of 4/5 or 5/5 and clinical and radiographic signs of osteoarthritis. PROCEDURES: A weight-loss program was initiated for all dogs. One group received caloric restriction and a home-based physical therapy program. The other group received the identical dietetic protocol and an intensive physical therapy program including transcutaneous electrical nerve stimulation. Lameness was assessed clinically and by kinetic gait analysis on a treadmill with 4 force plates to measure symmetry of ground reaction forces (GRFs) of the affected and contralateral limbs in bimonthly intervals for 6 months. RESULTS: Significant weight loss was achieved in both groups; however, greater weight reduction was attained by dogs treated with caloric restriction and intensive physiotherapy. Mobility and symmetry indices of GRFs were improved after 6 months; the best outcome was detected in the group receiving energy restriction combined with intensive physical therapy. CONCLUSIONS AND CLINICAL RELEVANCE: Caloric restriction combined with intensive physical therapy improved mobility and facilitated weight loss in overweight dogs. The combination of dietetic and physical therapy may help to improve the health status more efficiently than dietetic treatment alone.     

Bacterial cholangiohepatitis in a dog

A 9-year-old female Yorkshire terrier was presented for vomiting and diarrhea. Blood chemistry tests revealed hepatic dysfunction, cholestasis, and inflammation. Liver ultrasonography and liver biopsy were consistent with cholangiohepatitis. Fine-needle aspiration of the gallbladder revealed the presence of bacteria later identified as Clostridium spp. The cholangiohepatitis was successfully treated.     

Comparative spatiotemporal analysis of the intrathecal immune response in natural listeric rhombencephalitis of cattle and small ruminants

This study examined the spatiotemporal immune response in listeric rhombencephalitis of ruminants in situ. Our data support the view that astrocytes facilitate the containment of infectious lesions. Results on the natural disease recapitulate observations in experimental rodent models and suggest that the mounted adaptive lymphocytic response of ruminants is effective in eliminating Listeria monocytogenes (LM). However, our data indicate earlier participation of the adaptive immune response, a stronger B lymphocyte contribution and a more protracted macrophage infiltration in the natural disease than it has been deduced from experimental models. Therefore, such models should be complemented by studies in natural host systems. Various macrophage and microglia subsets are involved in listeric rhombencephalitis and their differential contribution may account for species differences in clinical course and outcome of infection as might species differences in the B-cell response. Future functional ex vivo and in vitro studies are necessary to further investigate the findings obtained in the present study.     

Ganjam virus/Nairobi sheep disease virus induces a pro-inflammatory response in infected sheep

Partly due to climate change, and partly due to changes of human habitat occupation, the impact of tick-borne viruses is increasing. Nairobi sheep disease virus (NSDV) and Ganjam virus (GV) are two names for the same virus, which causes disease in sheep and goats and is currently known to be circulating in India and East Africa. The virus is transmitted by ixodid ticks and causes a severe hemorrhagic disease. We have developed a real-time PCR assay for the virus genome and validated it in a pilot study of the pathogenicity induced by two different isolates of NSDV/GV. One isolate was highly adapted to tissue culture, grew in most cell lines tested, and was essentially apathogenic in sheep. The second isolate appeared to be poorly adapted to cell culture and retained pathogenicity in sheep. The real-time PCR assay for virus easily detected 4 copies or less of the viral genome, and allowed a quantitative measure of the virus in whole blood. Measurement of the changes in cytokine mRNAs showed similar changes to those observed in humans infected by the closely related virus Crimean Congo hemorrhagic fever virus.