Prevalence and risk factors for heartworm infection in cats from northern Florida

Necropsies were performed on 630 adult cats in northern Florida to determine the prevalence and risk factors for heartworm infection in cats of this region. Heartworms were identified in 4.9% of cats, and serological evidence of heartworm exposure was present in 17% of cats. Not all cats from which heartworms were recovered were seropositive for heartworm antigen or antibody. There was no association between heartworm infection and co-infection with feline leukemia virus (FeLV) or feline immunodeficiency virus (FIV). Male cats were at higher risk of infection with heartworm, FeLV, or FIV than were females. Because even a single heartworm can cause clinical disease or death in cats, the authors conclude that cats in this region should receive heartworm prophylaxis to prevent heartworm infection.     

Haemolytic complement activity,C3 and Factor B consumption in serum from chickens divergently selected for antibody responses to sheep red blood cells

Antibody responses, serum complement haemolytic activity, and complement component C3 and Factor B consumption were studied in chickens divergently selected for high and low antibody responses to sheep red blood cells, and in a randombred control line. Significantly higher total and IgG antibody responses to SRBC were found after intramuscular immunisation in the high antibody responder (H) line versus the low antibody responder (L) line and the control (C) line. Also significantly higher antibody titres were found in the C line as compared to the L line. Ca-dependent (classical) and Ca-independent (alternative) complement haemolytic activity was significantly higher in the H line than in the L line. Also initial complement haemolytic activity and C3 levels prior to immunisation with SRBC were significantly higher in the H than in the L line. The L line, on the other hand, showed numerically higher Factor B levels. Immunisation with SRBC was followed by a different consumption of C3 in serum of the H line than the L line.The results indicated that divergent selection of chickens for specific antibody responses to SRBC affected complement levels and C3 consumption in these chickens. This suggests a genetic linkage between these two immune traits.     

Effects of feeding aspirin and supplemental vitamin E on plasma concentrations of 3-methylindole, 3-methyleneindolenine-adduct concentrations in blood and pulmonary tissues,lung lesions,and growth performance in feedlot cattle

OBJECTIVE: To evaluate the effect of feeding aspirin and supplemental vitamin E on growth performance, lung lesions, plasma concentrations of 3-methylindole (3MI), and 3-methyleneindolenine (3MEIN)-adduct concentrations in blood and pulmonary tissues of feedlot cattle. ANIMALS: 256 crossbred steers; 64 cattle were used in experiment 1 and 192 cattle were used in experiment 2. PROCEDURES: A 2 X 2 factorial design was used for each experiment. Treatment factors were aspirin (0 or 3 g daily) and vitamin E (200 or 1,500 IU daily). Steers were housed in pens (8 steers/pen). Steers were slaughtered on days 59 and 138 for experiments 1 and 2, respectively. Lungs were grossly evaluated. 3MEIN-adduct concentrations were determined, and blood and pulmonary tissues. RESULTS: Treatment was not associated with improvement or adverse effects on weight gain, dry-matter intake, or feed efficiency in experiment 2. In experiment 1, 36 of 63 (57.1%) steers had lung lesions. Lesions were not associated with treatment or concentrations of 3MI and 3MEIN-adduct. Plasma 3MI concentration and concentrations of 3MEIN-adduct in blood and pulmonary tissues were 3.11 microg/mL, 0.51 U/microg of protein, and 0.49 U/microg of protein, respectively. Aspirin was associated with increased blood concentrations of 3MEIN-adduct for diets that did not contain supplemental vitamin E. CONCLUSIONS AND CLINICAL RELEVANCE: Differences n performance of feedlot steers were not associated with treatment diet. It is possible that concurrent exposure of feedlot cattle to other factors typically associated with development of respiratory tract disease would affect these findings.     

Reliable ELISAs showing differences between resistant and susceptible lines in hens orally inoculated with Salmonella Enteritidis

Reliable ELISAs were investigated with the aim to select hen lines resistant to Salmonella Enteritidis and producing high levels of antibodies. In the first experiment, the relation between the humoral response and the bacteriological results was assessed on hens from the Y11 resistant line and the L2 susceptible line, orally inoculated with 10(8) CFU S. Enteritidis per animal. Anti-lipopolysaccharide (LPS) IgG titres were higher but the liver and spleen were less contaminated in hens from the Y11 line than in hens from the L2 line (p = 0.013, 0.031 and 0.026 respectively). In the second experiment, the hens were inoculated orally with 1.7 x 10(8) CFU S. Enteritidis per animal in order to select the ELISA methods showing the more significant differences. ELISAs were based on LPS, flagella, LPS from rough (LPS-R) and smooth strains (LPS-S) and detected IgG and IgM antibodies from sera and yolks. No between-line host response variation was observed in the yolk, with LPS-S and R antigens nor with anti-LPS IgM in the sera. Otherwise, significant differences were encountered between hen lines with the ELISAs performed on the sera detecting anti-LPS IgG, anti-flagella IgG or IgM (p = 0.017, 0.017 and p < 0.001 respectively). When comparing the kinetics of the selected ELISAs, the IgG antibodies against LPS detected between-line variations as early as 1 to 4 weeks pi, whereas with IgG against flagella, the differences were only detected at 1 and 2 weeks pi and with IgM against flagella, the differences were significant at 1, 2, 4 and 8 weeks pi. In conclusion, resistant hen lines producing higher levels of antibodies than the susceptible hen lines may be selected with these ELISAs.     

Clinical utility of serum N-terminal pro-B-type natriuretic peptide concentration for identifying cardiac disease in dogs and assessing disease severity

OBJECTIVE: To determine whether serum N-terminal pro-B-type natriuretic (NT-proBNP) concentration could be used to identify cardiac disease in dogs and to assess disease severity in affected dogs. DESIGN: Cross-sectional study. ANIMALS:119 dogs with mitral valve disease, 18 dogs with dilated cardiomyopathy, and 40 healthy control dogs. PROCEDURES: Serum NT-proBNP concentration was measured with an ELISA validated for use in dogs. Results of physical examination, thoracic radiography, echocardiography, and serum biochemical analyses were recorded for dogs with cardiac disease. RESULTS:Serum NT-proBNP concentration was significantly higher in dogs with cardiac disease than in control dogs, and a serum NT-proBNP concentration > 445 pmol/L could be used to discriminate dogs with cardiac disease from control dogs with a sensitivity of 83.2% and specificity of 90.0%. In dogs with cardiac disease, serum NT-proBNP concentration was correlated with heart rate, respiratory rate, echocardiographic heart size, and renal function. For dogs with cardiac disease, serum NT-proBNP concentration could be used to discriminate dogs with and without radiographic evidence of cardiomegaly and dogs with and without congestive heart failure. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that serum NT-proBNP concentration may be a useful adjunct clinical test for diagnosing cardiac disease in dogs and assessing the severity of disease in dogs with cardiac disease.