Comparison of invasive and oscillometric blood pressure measurement techniques in anesthetized sheep,goats, and cattle

ObjectiveTo determine the level of agreement between an oscillometric (O-NIBP) and an invasive method (IBP) of monitoring arterial blood pressure (ABP) in anesthetized sheep, goats, and cattle.Study designProspective clinical study.AnimalsTwenty sheep and goats, 20 cattle weighing <150 kg body weight, and 20 cattle weighing >150 kg body weight.MethodsAnimals were anesthetized and systolic ABP (SABP), mean ABP (MABP), and diastolic ABP (DABP) were measured using IBP and O-NIBP. Differences between IBP and O-NIBP, and 95% limits of agreement (LOA) between SABP, MABP, and DABP values were assessed by the Bland–Altman method.ResultsMean difference ± standard deviation (range) between SABP, DABP, and MABP measurements in sheep and goats was 0 ± 16 (-57 to 38) mmHg, 13 ± 16 (-37 to 70) mmHg, and 8 ± 13 (-34 to 54) mmHg, respectively. Mean difference between SABP, DABP, and MABP measurements in small cattle was 0 ± 19 (-37 to 37) mmHg, 6 ± 18 (-77 to 48) mmHg, and 4 ± 16 (-73 to 48) mmHg, respectively. Mean difference between SABP, DABP, and MABP measurements in large cattle was -18 ± 32 (-107 to 71) mmHg, 7 ± 29 (-112 to 63) mmHg, and -5 ± 28 (-110 to 60) mmHg, respectively. The 95% LOAs for SABP, DABP, and MABP were -31 to +31, -19 to +44, and -19 to +34 mmHg, respectively in sheep and goats; were -37 to +37, -19 to +44, and -19 to +34 mmHg, respectively in small cattle; and were -81 to +45, -50 to +63, and -59 to +50 mmHg, respectively in large cattle.ConclusionsAgreement was poor between O-NIBP and IBP monitoring techniques.Clinical relevanceArterial BP should be monitored in anesthetized sheep, goats, and cattle using IBP.     

The use of a geographic information system in an epidemiological study of pseudorabies (Aujeszky''s disease) in Minnesota swine herds

A geographic information system (GIS) is being developed to study the spread of pseudorabies virus (PRV) among swine herds in the state of Minnesota. This GIS features an interface with a database management system that stores and manages pertinent data. These data include herd size, type of production system, degree of confinement, topographical features surrounding the farm, density of swine herds and distance to the closest quarantined herd. A pilot study was conducted in one Minnesota county with 280 swine herds, of which the PRV status was known in 115. Cox regression analysis was used to determine factors associated with herd PRV status. Relative risks (RR) and 95% confidence intervals (CI) were calculated. No association was detected between the PRV status of the herd and distance to the nearest county road, highway or quarantined herd. However, the following factors were significant: located within 1 km of a river or lake (RR, 0.524; CI, 0.328–0.828); farrow to finish (RR, 2.120; CI, 1.194–3.791); complete confinement (RR, 3.423; CI, 1.639–7.139); density of swine herds within a 5 km radius (RR, 1.036 per herd; CI, 0.996–1.064).     

Retrospective study of 60 cases of feline lymphosarcoma

Objective To characterise epidemiological and clinical findings, and diagnostic procedures undertaken, in cats with lymphosarcoma at a veterinary teaching hospital.
Design Retrospective case study.
Procedure Hospital records were reviewed for 7159 cats, sick or healthy, examined during a 10-year period (1984 to 1994). Sixty cats with lymphosarcoma were identified and classified by anatomical location of the tumour. Data on breed, age, sex, clinical signs and diagnostic procedures were collated.
Results The prevalence of feline lymphosarcoma in the hospital population was 0.84%. Siamese cats appeared predisposed to lymphosarcoma but other purebreds were not. Males were somewhat overrepresented amongst affected cats. Similar numbers of cases (12 to 18) were seen in each of the four anatomic categories (multicentric, mediastinal, alimentary and extranodal). Cats with mediastinal lymphosarcoma were mostly young and Siamese. Clinical signs in affected cats were varied, usually multiple and often nonspecific. Two of 22 cases tested positive for feline leukaemia virus antigen in blood and 6 of 13 were positive for feline immunodeficiency virus antibody.
Conclusions Extranodal lymphosarcoma seemed more prevalent in this study than reported elsewhere. Siamese cats in the study population may have had a genetic predisposition to lymphosarcoma. Limited evidence suggested feline leukaemia virus may be less important, and feline immunodeficiency virus more important, in the local population than indicated in overseas reports. Additional studies are needed to investigate breed predisposition and feline leukaemia virus and feline immunodeficiency virus status in Australian cats with lymphosarcoma.     

Poliomyelitis in Monkeys: Decreased Susceptibility after Avoidance Stress

Eleven monkeys were subjected to avoidance stress for 24 hours followed immediately by intravenous inoculation with type I poliovirus. Twelve control monkeys not so stressed were similarly inoculated. Seven of 11 stressed animals survived the infection while only one of the controls lived and their average incubation period was significantly longer than the average for controls. The number of circulating lymphocytes decreased significantly in experimental animals during and immediately after exposure to stress.