Local tissue reaction to the administration of an inactivated Brucella ovis saline-in-oil vaccine by the intraperitoneal route

An inactivated Brucella ovis saline-in-oil vaccine was administered to 14 adult ewes using both the intraperitoneal route and the subcutaneous route. Pairs of animals were necropsied at intervals between 24 hours and ten weeks after injection. The nature of the local inflammatory reaction to the administration of the vaccine was similar at all sites. The lesion consisted of granulomatous inflammation arranged around droplets of oily vaccine. Diffuse peritonitis was seen at necropsy in 12 of the 14 animals. A local extraperitoneal inflammatory response at the injection site was present in four animals despite careful attempts to deposit the vaccine within the abdominal cavity. A second study of 30 rams vaccinated by the intraperitoneal technique confirmed that extraperitoneal deposition of vaccine commonly occurred and that approximately 20% of animals vaccinated by the intraperitoneal method still had peritonitis six months later.     

Epidemiology and management of Leptosphaeria maculans (phoma stem canker) on oilseed rape in Australia, Canada and Europe

Phoma stem canker (blackleg), caused by Leptosphaeria maculans , is an important disease on oilseed rape (canola, rapeseed, Brassica napus , Brassica juncea , Brassica rapa ) causing seedling death, lodging or early senescence in Australia, Canada and Europe, but not in China. The two forms of L. maculans (A group and B group) that occur on oilseed rape are now considered to be separate species. The epidemiology and severity of phoma stem canker differs between continents due to differences in the pathogen population structure, oilseed rape species and cultivars grown, climate and agricultural practices. Epidemics are most severe in Australia, where only the A group occurs, and can be damaging in Canada and western Europe, where both A and B groups occur, although their proportions vary within regions and throughout the year. Epidemics are slight in China, where the A group has not been found. Dry climates (Australia, western Canada) lengthen the persistence of infected debris and may synchronize the release of airborne ascospores (after rain) with seedling emergence. L. maculans spreads from cotyledon and leaf infections down petioles to reach the stem, with infections on cotyledons and leaves early in the season producing the most damaging stem cankers at the stem base (crown). Development of both crown cankers and phoma stem lesions higher up stems is most rapid in regions with high temperatures from flowering to harvest, such as Australia and Canada. Breeding for resistance (genetic, disease escape or tolerance), stubble management, crop rotation and fungicide seed treatments are important strategies for control of phoma stem canker in all areas. Fungicide spray treatments are justified only in regions such as western Europe where high yields are obtained, and accurate forecasts of epidemic severity are needed to optimize their use.     

Hereditary chondrodysplasia ("spider syndrome") in a New Zealand Suffolk lamb of American origin

The first case of hereditary chondrodysplasia ("spider syndrome") in a New Zealand Suffolk lamb of American origin is described. An imported Suffolk ram of American origin was test mated to 27 of his daughters. In one of the resulting progeny, found dead at birth, a diagnosis of hereditary chondrodysplasia was made based on the typical radiographical abnormalities of multiple centres of ossification in the anconeal process of the ulna, vertebrae, sternebrae and pelvic bones. These changes were confirmed histopathologically.     

Observations on the efficacy of mass treatment by subconjunctival penicillin injection for the control of an outbreak of infectious bovine keratoconjunctivitis

Infectious bovine keratoconjunctivitis was diagnosed on a Manawatu beef cattle farm, with inflammation of 85% of eyes in a group of 150 6-month-old-calves. Comeal inflammation was recorded in 23% of eyes. All active lesions healed over a 3-week period following whole group subconjunctival penicillin injection. Morarellu bovis was cultured from two of seven conjunctival swabs at the time oftreatment and from four of six conjunctival swabs 9 days after treatment. Concurrently, pink-eye was noted in older cattle, with inflammation in 50% of eyes. For practical handling reasons, these older cattle were not treated. Despite nontreatment, their clinical signs regressed over a 3-week period. The rationale of whole group treatment for the control of infectious bovine keratoconjunctivitis is discussed.     

Inefficacy of moxidectin and doramectin against ivermectin-resistant Cooperia spp. of cattle in New Zealand

Two cases are described in which strains of Cooperia spp. of cattle were found to be resistant to either the oral or the injectable formulations of ivermectin. Injectable moxidectin was not effective against the latter strain and doramectin was not effective against either of the ivermectin-resistant Cooperia isolates. In both cases, the anthelmintic efficacy of oral levamisole was 100%.     

Observations on the eradication of Brucella ovis infection from a ram flock

The measures taken to eradicate Brucella ovis infection from a naturally infected flock of 64 rams are described. Lesions of epididymitis were detected in 18 rams, all of which gave either positive or suspicious reactions in the complement fixation test. A further 20 rams gave serological reactions in the complement fixation test. Subsequently, semen was collected from 14 of these 20 rams and B. ovis was cultured from the semen of all 14 rams. Serum samples from two rams failed to react in the complement fixation test. However, they were identified as infected with the aid of an enzyme-linked immunosorbent assay and the subsequent culture of semen samples. It is suggested that, when eradicating B. ovis infection from ram flocks, the enzyme-linked immunosorbent assay be used in addition to both the complement fixation test and the physical examination. Using a combination of tests as described can increase the likehood of an earlier eradication of B. ovis infection.