Dynamics of Moraxella bovis infection and humoral immune response to bovine herpes virus type 1 during a natural outbreak of infectious bovine keratoconjunctivitis in beef calves

Infectious bovine keratoconjunctivitis (IBK) is an acute disease caused by Moraxella bovis (Mb). Several factors may predispose animals to an IBK outbreak; one commonly observed is infection with bovine herpes virus type 1 (BHV-1). The aim of this study was to investigate the dynamics of BHV-1 virus infection and its relation with clinical cases of IBK in weaned calves from a beef herd with a high prevalence of lesions caused by Mb. Sampling was carried out in six stages and included conjunctival swabs for isolating Mb as well as blood samples for identifying antibodies specific for BHV-1. A score for IBK lesions after observing each eye was determined. The findings of this study showed a high prevalence of BHV-1 virus infection (100% of animals were infected at the end of the trial); 67% of animals were culture-positive for Mb, but low rates of clinical IBK (19% of calves affected) were detected at the end of the trial. These results suggest that infection with BHV-1 did not predispose these animals to IBK, and that Mb infection produced clinical and subclinical disease in the absence of BHV-1 co-infection.     

Chronic hypertrophic pyloric gastropathy in 14 dogs

SUMMARY Ten mate and 4 female dogs with chronic hypertrophic pyloric gastropathy were seen at the Sydney University Veterinary Teaching Hospital in the period 1982–88. The most commonly affected breeds were the Shihtzu and Maltese. The mean age was 8.2 yr and the mean body weight 6.5 kg. The most common clinical signs were vomiting, weight loss, polydipsia and depression. Hypokalaemia was present in 11 of 12 dogs examined and hypochloraemia in 10 of 11 dogs examined. Five of the six dogs that had blood gases measured were found to have a metabolic alkalosis. Surgery was performed on 13 dogs; pyloromyotomy 7, pyloroplasty 4, gastroduodenostomy 2. There was a recurrence of symptoms in one pyloromyotomy dog, and fatal ulceration and perforation of the cardia occurred in one pyloroplasty case. The remaining 11 dogs had a mean known symptom-free survival time of 20 mo. This study confirms the preponderance of affected males, identifies electrolyte and blood gas disturbances as significant complications of chronic hypertrophic pyloric gastropathy, and suggests that relatively minor surgery (pyloromyotomy) may have a place in the treatment of a selected subgroup of cases.     

Pre-parturition staphylococcal mastitis in primiparous replacement goats: persistence over lactation and sources of infection

This investigation reported for the first time the occurrence of intramammary infections caused by Staphylococcus in primiparous replacement goats before parturition and the persistence of clinical Staphylococcus aureus infection during the lactation period. Subclinical infections, mainly caused by coagulase negative staphylococci (CoNS), did not persist during lactation. Genotyping analysis indicated that environment seems to play a moderate role as source of intramammary infections to goats before parturition, but causative agents of mastitis in lactating animals are not genotypically related to environmental staphylococci. The occurrence and persistence of intramammary infections in replacement goats demonstrate the need to consider those animals as potential sources of infections in dairy goat herds.