An echocardiographic study of healthy Border Collies with normal reference ranges for the breed

ObjectivesThe objectives of this study were to obtain standard echocardiographic measurements from healthy Border Collies and to compare these measurements to those previously reported for a general population of dogs.AnimalsStandard echocardiographic data were obtained from twenty apparently healthy Border Collie dogs. These data (n = 20) were compared to data obtained from a general population of healthy dogs (n = 69).MethodsBorder Collies were deemed healthy based on normal history, physical examination, complete blood count, serum biochemical profile, electrocardiogram, and blood pressure, with no evidence of congenital or acquired heart disease on echocardiographic examination. Standard two dimensional, M-mode, and Doppler echocardiographic measurements were obtained and normal ranges determined. The data were compared to data previously obtained at our hospital from a general population of normal dogs.ResultsTwo dimensional, M-mode, and Doppler reference ranges for healthy Border Collies are presented in tabular form. Comparison of the weight adjusted M-mode echocardiographic means from Border Collies to those from the general population of dogs showed Border Collies to have larger left ventricular systolic and diastolic dimensions, smaller interventricular septal thickness, and lower fractional shortening.ConclusionsThere are differences in some echocardiographic parameters between healthy Border Collies and the general dog population, and the echocardiographic reference ranges provided in this study should be used as breed specific reference values for Border Collies.     

Serological surveillance and factors associated with influenza A virus in backyard pigs in Southern Brazil

Backyard pig populations are not monitored for influenza A virus (IAV) in Brazil and there are limited data about seroprevalence and risk factors in these populations. Our goal was to assess possible factors associated with IAV seroprevalence in backyard pig populations using an indirect ELISA protocol based on a recombinant nucleoprotein. Following the IAV screening using NP‐ELISA, subtype‐specific serology based on hemagglutination inhibition (HI) assay of the ELISA‐positive pigs was conducted. The survey comprised a total of 1,667 sera samples collected in 2012 and 2014 in 479 holdings and the estimated seroprevalence was 5.3% (3.84%–7.33%) and 2.3% (1.34%–3.71%) in the respective years. In both years, H1N1pdm09 was the most prevalent subtype. The multivariable analysis showed main factors such as “age,” “sex,” “number of suckling pigs” and “neighbours raising pigs” that presented the greatest effect on IAV seroprevalence in these pig populations. These factors may be associated with the low biosecurity measures and management of backyard holdings. In addition, the low IAV seroprevalences found in these backyard pig populations could be related to a low number of animals in each pig holding and low animal movement/replacement that do not favour IAV transmission dynamics. This low frequency of H1N1pdm09 seropositive pigs could also be due to sporadic human‐to‐pig transmission of what is now a human seasonal influenza A virus; however, these factors should be explored in future studies. Herein, these results highlight the importance of IAV continued surveillance in backyard pig holdings, since it is poorly known which IAVs are circulating in these populations and the risk they could pose to public health and virus transmission to commercial farms.     

UTILIZATION OF INSTANTANEOUS EJECTION VOLUME IMAGES TO PRODUCE VENTRICULAR VOLUME CURVES FROM AN EQUILIBRIUM RADIONUCLIDE VENTRICULOGRAM

Equilibrium radionuclide ventriculograms were performed in 6 normal dogs during resting and isoproterenol challenged states. A new method of analysis of the equilibrium radionuclide ventriculograms using a simple digital subtraction technique was compared to traditional methods of analysis and echocardiography. There was no significant difference between ejection fraction values from the three methods tested. The equilibrium radionuclide ventriculograms ejection fraction was significantly increased following isoproterenol administration using both the new and traditional methods of analysis but the pre versus post-isoproterenol increase ejection fraction derived from echocardiographic measurements of ejection fractions was not significantly different. The new digital subtraction method consistently produced reproducible, high quality ventricular volume curves for the left and right ventricle. Left and right ventricular maximum and average emptying and filing rates were determined from the slopes of the volume curve and the results were similar to those previously published for man and dog. The emptying and filling rates of both ventricles were significantly increased following isoproterenol administration. The time to peak emptying significantly decreased following isoproterenol. Time to peak filing decreased following isoproterenol but the difference was not significant.     

Monoclonal antibodies to lymphocyte surface antigens for cetacean homologues to CD2, CD19 and CD21.

CD2 is a pan-T cell marker, while CD19 and CD21 are important molecules in signal transduction of B lymphocytes. CD19 and CD21 are both present on mature B cells, while CD19 is also present in developing B cells and plasma cells. Monoclonal antibodies (mAbs) against cetacean lymphocyte putative homologues to CD2 (two different antibodies), CD19 and CD21 were characterized. The proteins immunoprecipitated were as follows: F21.I (putative anti-CD2), 43 and 59kDa; F21.B (putative anti-CD19), 83 and 127kDa; F21.F (putative anti-CD21), 144kDa. The second putative anti-CD2 (F21.C) selectively inhibited the binding of F21.I. Both the putative anti-CD2 (T cell markers) stained T-cell zones on lymph node sections, while both the B cell markers (putative CD19 and CD21) stained B-cell zones. F21.B and F21.F were absent from thymus single cell suspension but labeled 63 and 65% mesenteric lymph node lymphocytes, respectively, while both F21.C and F21.F were present on 100% thymocytes and fewer lymph node lymphocytes. B and T cell markers were mutually exclusive on double labeling using flow cytometry. These mAbs are foreseen as possible valuable diagnostic and research tools to assess immune functions of captive and wild cetaceans.     

Resistance of domestic cats to a US sheep scrapie agent by intracerebral route.

Feline spongiform encephalopathy (FSE) is thought to have resulted from consumption of food contaminated with bovine spongiform encephalopathy and the latter is believed to result from the consumption of food contaminated with scrapie. However, no direct experimental documentation exists to indicate that the scrapie agent is capable of amplifying in cats, and, therefore, crossing the species barrier. During 1979, 6 cats ranging in age from 3.5 to 18 months were intracerebrally inoculated with sheep scrapie (inoculum G-639-PP) and were observed for an extended period. Inoculated cats did not develop neurologic disease, and microscopic lesions of spongiform encephalopathy were not evident. Immunohistochemistry and Western blot techniques failed to detect the abnormal form of prion protein (PrP(res)). These results indicate that the sheep scrapie agent (G-639-PP) used in this study was not capable of amplifying in cats and therefore was unable to cross the species barrier to produce FSE.     

Neuronal vacuolation in an adult ferret

The brain of a ferret showing abnormal neurologic signs was evaluated by histopathologic, histochemical, immunohistochemical, and ultrastructural examinations. Extensive neuronal vacuolation was observed. Since the brain was negative for protease-resistant protein prion (PrP'"), it was concluded that this was not a case of transmissible spongiform encephalopathy.     

Effect of temperature on the starch content of potato callus tissue

Starch content was determined in Lemhi Russet callus grown on MS medium for 2 and 4 weeks at 25, 15, and 5°C with 50 μM 2,4-D or 10 μM picloram as the only plant growth regulator. A treatment of 5°C for 4 weeks followed by 25°C for 2 and 4 weeks was included to simulate reconditioning. Callus starch content ranged from 0.01 to 0.08% on a wet weight basis and 0.5 to 4.0% on a dry weight basis. Starch content was highest after 2 weeks at 25 and 15°C and decreased with time in a similar manner at both 25 and 15°C. Starch content decreased at 5°C, then increased significantly during simulated reconditioning at 25°C. Starch content was higher in callus grown with 50 μM 2,4-D than in callus grown with 10 μM picloram. After staining the callus with I₂-KI solution, starch granule formation was observed in the callus grown with 50 μM 2,4-D, while little granule formation was observed in the callus grown with 10 μM picloram.