A case-control study to identify risk factors for acute salmonellosis in New Zealand dairy herds, 2011-2012.

In late 2011 the New Zealand Ministry for Primary Industries reported an increase in confirmed laboratory diagnoses of salmonellosis in dairy herds. To identify risk factors for herd-level outbreaks of salmonellosis we conducted a case-control study of New Zealand dairy herds in 2011-2012. In a multivariable analysis, use of continuous feed troughs [adjusted odds ratio (aOR) 6·2, 95% confidence interval (CI) 2·0-20], use of pelletized magnesium supplements (aOR 10, 95% CI 3·3-33) and use of palm kernel meal as a supplementary feed (aOR 8·7, 95% CI 2·5-30) were positively associated with a herd-level outbreak of salmonellosis between 1 July 2011 and 31 January 2012. We conclude that supplementary feeds used on dairy farms (regardless of type) need to be stored and handled appropriately to reduce the likelihood of bacterial contamination, particularly from birds and rodents. Magnesium supplementation in the pelletized form played a role in triggering outbreaks of acute salmonellosis in New Zealand dairy herds in 2011-2012.

Cerebral infarction and meningoencephalitis following hot-iron disbudding of goat kids.

CASE HISTORY: Twelve of 150 goat kids, 4-10 days old, died 3 days after disbudding with a hot iron. Another 18 kids had been ill the previous day but survived following antibiotic therapy. Five of the dead kids were necropsied. PATHOLOGICAL FINDINGS: There was necrosis and haemorrhage of the skin, subcutaneous tissues and frontal bone at disbudding sites in all five kids examined post mortem. Beneath disbudding sites in 4/5 kids there were bilateral, dark red, often cavitated areas of necrosis extending deep into the frontal cortex of the brain. Histologically, these areas consisted of coagulation necrosis, haemorrhage, vascular thrombosis and suppurative inflammation. Numerous bacteria, predominantly large Gram positive rods, were present in the necrotic brain tissue. In the remaining kid, bilateral areas of yellow discolouration and flattening of gyri in frontal lobes corresponded histologically to extensive polioencephalomalacia. A mixed growth of aerobes and anaerobes was cultured from the brain of one kid with suppurative lesions. CLINICAL RELEVANCE: Thermal disbudding of neonatal kids is widely practised in dairy goat herds and is considered the method of choice for disbudding in New Zealand. However, the skull of goat kids is much thinner than that of calves and the safety margin for thermal injury to the brain is markedly reduced. This report highlights the risks associated with the technique and its potential as a welfare issue.

Concurrent gastro-oesophageal intussusception, trichobezoar and hiatal hernia in a cat.

CASE HISTORY: An adult male Birman cat was evaluated for recurrent, intermittent vomiting or regurgitation, occasionally associated with abdominal discomfort. CLINICAL FINDINGS AND DIAGNOSIS: Radiographs, including an oesophogram, indicated an oesophageal obstruction. Prior to treatment, the cat's condition deteriorated and it was euthanised at the owner's request. Post-mortem examination revealed a gastro-oesophageal intussusception, a trichobezoar impacted into the intussusceptum, and a dilated oesophageal hiatus consistent with a chronic hiatal hernia. CLINICAL RELEVANCE: Gastro-oesophageal intussusception is a rare condition in cats. Its aetiology in relation to a pre-existing hiatal hernia and a trichobezoar is discussed.