Ear temperatures in the horse during recovery from anesthesia

Ear temperatures were measured during and after halothane anesthesia in 16 horses and ponies. Aural hypothermia developed during recovery and persisted for more than one hour following standing. The decreased ear temperature was attributed to decreased peripheral perfusion and was considered to be related to other cardio-pulmonary and neuro-endocrine derangements that occur during recovery.     

Influence of maternal antibody on efficacy of embryo vaccination with cell-associated and cell-free Marek's disease vaccine

Vaccination with turkey herpesvirus (HVT) of 18-day-old chicken embryos from a commercial source or from a cross (15 X 7) of two inbred lines induced better protection against early post-hatch challenge with virulent Marek's disease virus (MDV) than vaccination at hatch, despite the presence in embryos of maternally derived antibodies to HVT or to HVT and MDV. However, 50%-protective-dose (PD50) assays revealed that maternal antibodies in embryos reduced vaccine efficacy. The PD50 assays were conducted by vaccinating 15 X 7 embryos with serial dilutions of HVT at the 18th day of incubation. Embryonally vaccinated and unvaccinated chicks were challenged with MDV on the day of hatch. In the absence of maternal antibodies, the PD50 values in plaque-forming units for cell-associated and cell-free HVT were 57 and 328, respectively. In the presence of maternal antibodies, PD50 values for cell-associated and cell-free HVT were 105 and greater than 4,000, respectively.     

Effects of dexamethasone on pancreatic tissue and on serum amylase and lipase activities in dogs

The effects of dexamethasone on the pancreas and on pancreatic amylase and lipase activities were determined in clinically normal dogs and in dogs with neurologic disease. Dexamethasone increased serum lipase activity without any histologic damage to the pancreas in either group of dogs. It decreased serum amylase activity in the normal dogs and had a variable effect in dogs with neurologic disease, with or without confirmed pancreatitis. It was suggested that high serum lipase activity in dexamethasone-treated dogs may not be attributable to pancreatitis and that the reasons are still unknown. It was concluded that high serum lipase activity is an unreliable basis for diagnosis of pancreatitis in dogs treated with dexamethasone. The data allowed no conclusion about an additive effect of dexamethasone and neurologic disease causing pancreatitis.     

Effect of Fusarium roseum corn culture containing zearalenone on early pregnancy in swine

A corn culture of Fusarium roseum was added to a standard corn-soybean swine gestation ration. Low, middle, and high dosage mixed feeds contained 7, 38, and 64 mg of zearalenone/kg of feed (7, 38, and 64 ppm) and 0.5, 2.5, and 4.5 mg of deoxynivalenol/kg, respectively. Control feed was the standard ration without added F roseum corn culture. Mature gilts were bred by natural service and fed control or F roseum molded feed from 3 to 34 days after breeding. The main effect of the molded feed was an inhibition of fetal development, with decreased numbers of fetuses present in treated animals at slaughter (38 to 43 days after breeding). Normal litters were present in 7 of 8 control animals, in 2 of 4 gilts given the low-dosage feed, in 1 of 4 gilts given the medium dosage, and in 0 of 4 given the high-dosage feed. Corpora lutea were maintained in all treated animals, as evidenced by serum progesterone concentrations. Serum estradiol concentrations were decreased in gilts in the middle- and high-dosage groups. The genital system of the gilts fed low- and middle-dosage feeds had a gross and microscopic appearance similar to that of the pregnant controls and reflected prolonged progesterone stimulation. Morphologic changes in the genital system of the high-dosage group were intermediate between changes induced by progesterone and those induced by estrogen. Clinical signs of hyperestrogenism and partial feed refusal were noticed in only some of the high-dosage group animals.     

Passive immunisation of neonatal lambs via colostrum and milk of ewes previously immunised with live attenuated Salmonella typhimurium protects neonatal lambs from experimental salmonellosis

Lambs sucking non-immunised ewes or ewes immunised 4-5 weeks before lambing with live attenuated, aromatic-dependent (aroA) Salmonella typhimurium (strain CS 332) were challenged orally at either 2, 4 or 7 days of age with virulent S. typhimurium (strain CS 94) at doses ranging from 10⁹ to 10¹³ colony forming units. No lambs displayed signs of clinical salmonellosis and all survived challenge but those sucking immunised ewes had organisms of the challenge strain in their faeces for much shorter periods of time than lambs of the control ewes. High titres of specific antibodies were measured in colostrum and milk of immunised ewes in comparison with very low titres measured in samples from control ewes; these differences were reflected by the titres of antibodies in the sera of corresponding lambs. At 2 days after lambing, the major antibody isotype in the colostrum of immunised ewes and sera of their lambs was IgM whereas at 7 days IgG1 was the predominant isotype. While it was clear that vaccination of pregnant ewes with the live attenuated vaccination conferred protection against experimentally-induced salmonellosis in their lambs, considerable protection was observed in control lambs in spite of there being very low titres of antibodies in the mammary secretion of their dams. The latter observation could be related to the presence of contain non-antibody potent bactericidal factors previously described in colostrum and milk.

Résumé

Des agneaux qui tètent des brebis non immunisées, ou bien immunisées, 4 à 5 semaines avant la mise bas avec un vaccin atténué constitué d'une souche de Salmonelle typhimurium dépendente pour sa croissance de la presence de composés aromatiques (souche aro A CS 332) ont reçu, à l'âge de 2, 4 ou 7 jours, par voie orale, des doses allant de 10⁹ à 10¹³ Salmonella (souche virulente CS 94). Aucun agneau n'a présenté de signes cliniques et tous ont survécu à cette administration, mais les agneaux des brebis immunisées ont excrété la souche d'épreuve dans leur fécès pendent moins longtemps que les agneaux des brebis non vaccinées. Des titres plus élevés d'anticorps sont détectés dans le colostrum et le lait des brebis vaccinées et comparés aux brebis témoins. Cette différence est également notée pour les titres d'anticorps présents dans le sérum des agneaux issus de brebis vaccinées ou non. Deux jours après la mise bas, la classe des anticorps majoritaires, tant au niveau du colostrum des brebis vaccinées que du sérum de leurs agneaux, est la classe des IgM, alors qu'après 7 jours, les IgG1 prédominent. Bien qu'il soit clair que des brebis pleines vaccinées à l'aide d'un vaccin vivant atténué, apportent à leurs agneaux une protection vis à vis d'une Salmonella expérimentale, une réelle protection est également observée chez les agneaux témoins, malgré les titres faibles d'anticorps présente dans les sécrétions mammaires de leur mères. Cette dernière observation peut être mise en rapport avec la présence d'agents bactériodes ne contenant pas d'anticorps, déjà décrits dans le colostrum et le lait.