Pharmacokinetics of lidocaine in serum and milk of mature Holstein cows

The purpose of this study was to evaluate the pharmacokinetics of lidocaine in mature Holstein cows following an inverted L and caudal epidural nerve block. Plasma and milk concentrations were determined using high-performance liquid chromatography assay. Pharmacokinetic parameters were estimated using a noncompartmental method. Following administration via inverted L nerve block, serum T_max was 0.521 ± 0.226 h and serum C_max was 572 ± 207 ng/mL. Serum AUC was 1348 ± 335 ng·h/mL. Apparent serum t_½β was 4.19 ± 1.69 h and MRT was 5.13 ± 2.33 h with clearance uncorrected for the extent of absorption of 2.75 ± 0.68 L/kg/h. The last measurable time of lidocaine detection in serum was 8.5 ± 1.4 h with a mean concentration of 51 ± 30 ng/mL. Milk T_max was detected at 1.75 ± 0.46 h with C_max of 300 ± 139 ng/mL. Milk AUC till the last time was 1869 ± 450 ng·h/mL with the mean AUC milk to AUC serum ratio of 1.439 ± 0.374. The last measurable time of lidocaine detection in milk was 32.5 ± 16.2 h with a mean concentration of 46 ± 30 ng/mL. There was no detectable lidocaine concentration in any samples following caudal epidural administration.     

Effect of colostrum treated by heat on immunological parameters in newborn lambs

Seventeen newborn lambs were fed with untreated colostrum (group A) and 18 lambs were fed with colostrum treated by heat (56 °C, 30 min) (group B). Blood samples were obtained at seven time points from day 0 to 38 of life. Clinical status and body weight were recorded and serum protein fractions and IgG levels were determined in blood. Phagocytosis of neutrophils from the lambs and opsonic capacity of their serum were examined using a flow cytometry method. As an indicator of in vivo cellular immunity, reactions to intradermal injection of phytohemagglutinin (PHA) were examined at 8 and 16 days of age. There were no clinical signs of disease and no significant differences in body weight between groups. Lambs from group B had lower total protein initially and lower γ-globulin and IgG levels until day 32 compared to lambs from group A (P < 0.01). Heat treatment of colostrum had no significant effect on serum opsonic capacity or phagocytosis by neutrophils and these functions increased with age. However, responses to PHA in lambs from group B were lower (P < 0.01) than group A at day 8 of life, but not at day 16, suggesting that cellular immunity was affected by the treatment of colostrum. These results showed that colostrum treated by heat impaired cellular and IgG levels in lambs, but not phagocytic function. However, these changes did not affect the health or performance of the lambs.     

Effects of feed intake on in situ rumen microbial contamination and degradation of feeds

An in situ study was conducted using four rumen cannulated wethers and five feeds (corn grain (CG), soybean meal (SBM), sunflower meal (SFM), vetch–oat hay (VH), and lentil straw (LS)) to determine (using ¹⁵N infusion techniques) the effects of two intake levels (40 and 80 g DM/kg W^0.75) on the microbial contamination and rumen degradation of DM or CP. Degradation studies were also performed for neutral and acid detergent fibres (NDF and ADF, respectively) of VH. In most cases, the evolution with time of the microbial DM adhered to particles fitted well to exponential curves, which diverged between both levels of intake due to the lower values attained at high intake. However, as a consequence of the large and progressive increase of the variability of microbial contamination, statistical evidence is only partial. This behaviour was less evident for CP contamination, especially in forages. The lack of these corrections underestimated (P < 0.001) the effective degradability (ED) of all tested fractions, with important differences between feeds. The intake level had not relevant effects on the distribution of soluble, insoluble available and unavailable fractions of DM or CP (or fibres in VH), but determined some changes in their degradation rates (k_d). Direct relations between these last values and rumen outflow rates (k_p) were shown in some feeds for the degradation of CP and also of DM in concentrates, whereas negative relations were shown for the degradation rates of DM in forages (or NDF and ADF of VH). All ED estimates decreased with the intake rise, but for CP this effect (P < 0.05) was only detected in SBM and VH. These decreases represent 40.8 (CG), 80.8 (SBM), 62.1 (SFM), 66.8 (VH), and 19.5% (LS) than those estimated considering only k_p changes, which shows the interest to consider conjointly the variations of both rates to study the effect of diet changes on ED.     

First report of thelaziosis (Thelazia anolabiata) in an Andean Cock of the Rock (Rupicola peruviana) from Peru

Thelazia anolabiata is a spirurid nematode living in the orbits of birds which can cause lacrimation, keratitis, conjunctivitis, and corneal ulcers. This species is reported for the first time from an Andean Cock of the Rock, Rupicola peruviana (Passeriformes: Cotingidae), from a zoo in Lima, Peru. Clinical signs of keratoconjunctivitis were resolved with the treatment of ivermectin, ciprofloxacin, and an epithelium regenerator, and the host is presently in good health. The nematodes were identified using the primary characteristics used to differentiate the species of this genus as lengths of spicules and other morphologic characteristics.     

Review of diagnostic laboratory submissions of adult cattle 'found dead' in England and Wales in 2004

A total of 253 submissions from adult cattle 'found dead' in England and Wales were referred to the Veterinary Laboratories Agency in 2004. Carcases accounted for 54 per cent of the submissions and were of more diagnostic value than other types of sample. Whether the animals were beef or dairy, their distance from the laboratory and the number of deaths in the incident affected the likelihood of samples being submitted. The probability of reaching a diagnosis was influenced by the type of sample, the level of testing and the interval from sampling to receipt in the laboratory. Systemic disease was the most frequent cause of death in both dairy and beef cattle with hypomagnesaemia being the most frequent diagnosis (52 per cent) in beef cattle. In dairy cattle, 34 per cent of the diagnoses were for sporadic events, including haemorrhage and torsions of the digestive and reproductive tracts.     

Immunolocalization and pathological alterations following Strongyloides venezuelensis infection in the lungs and the intestine of MHC class I or II deficient mice

The present study, investigated the mechanisms involved in the immune responses of Major Histocompatibility Complex class I or class II knockout mice, following Strongyloides venezuelensis infection. Wild-type C57BL/6 (WT), MHC II(-/-) and MHC I(-/-) mice were individually inoculated with 3000 larvae (L3) of S. venezuelensis and sacrificed on days 1, 3, 5, 8, 13 and 21 post-infection (p.i.). Samples of blood, lungs and small intestines were collected. The tissue samples were stained with hematoxylin-eosin for the pathological analysis. The presence of the parasite was demonstrated by immunoperoxidase analysis. MHC II(-/-) mice presented a significantly higher number of adult worms recovered from the small intestine on day 5p.i. and presented elevated numbers of eggs in the feces. The infection by S. venezuelensis was completely eliminated 13 days after infection in WT as well as in MHC I(-/-) mice. In MHC II(-/-) mice, eggs and adult worms were still found on day 21 p.i., however, there was a significant reduction in their numbers. In the lung, the parasite was observed in MHC I(-/-) on day 1 p.i. and in MHC II(-/-) mice on days 1 and 5 p.i. In the small intestine of WT mice, a larger number of parasites were observed on day 8 p.i. and their absence was observed after day 13 p.i. Through immunohistochemistry analysis, the parasite was detected in the duodenum of WT on days 5 and 8 p.i., and in knockout mice on days 5, 8 and 13 p.i.; as well as in posterior portions of the small intestine in MHC I(-/-) and MHC II(-/-) on day 13 p.i., a finding which was not observed in WT mice. We concluded that immunohistochemistry analysis contributed to a more adequate understanding of the parasite localization in immunodeficient hosts and that the findings aid in the interpretation of immunopathogenesis in Strongyloides infection.