Jo Payne

Diagnosis and implications of botulism

BOTULISM is a neuroparalytic condition affecting birds, mammals and fish, and is caused by exposure to toxins produced by various biotypes of Clostridium botulinum. Until a few years ago, botulism was considered to be a rare disease in farm animals in the UK. However, since 2003, there has been an upsurge in the number of suspected cases reported, particularly in cattle and more recently sheep. The diagnosis of botulism is problematic and relies heavily on clinical signs. Confidence in the diagnosis is improved by identifying the risk factors and suspect sources, and by ruling out the more common differential diagnoses. This article describes the clinical signs of classic and atypical disease, and discusses the implications of a diagnosis of botulism with regard to animal welfare, food safety and public health.

Lead poisoning in cattle and sheep

Lead has no known biological role and is harmful to human and animal health. Over the past three decades, there has been a large reduction in lead in foods, and its use in food-related products such as for solders in food cans and bottle seals has been abolished. The use of lead in paints for domestic and livestock housing has been massively reduced and leaded gasoline has been withdrawn. Despite this, lead poisoning remains the most commonly diagnosed cause of poisoning in cattle and sheep and most incidents are preventable. This article reviews the sources of lead that can cause lead poisoning in cattle and sheep and the implications of this for food safety. It also outlines how the incidence of cases might be reduced.

Diagnosis and investigation of fluorosis in livestock and horses

Fluorosis (fluoride ion poisoning) can affect all mammals and birds. Acute fluorosis is rare in the UK. Mild dental fluorosis is probably quite common but will not affect production. Severe dental fluorosis and skeletal fluorosis (which requires longer-term exposure than dental fluorosis) occur close to fluorine-emitting industries. Fluorosis should be included in the differential diagnosis of dental conditions, lameness and skeletal abnormalities. Background sources of fluorides include soil, feed crops, superphosphate fertilisers and phosphate feed supplements. UK environmental hot spots include natural mineral deposits and areas close to fluorine-emitting industries. Volcanic ash also contains fluorides and small quantities of volcanic ash grounded in the UK following recent eruptions in Iceland, but monitoring in the UK confirmed that fluoride levels in grass remained within the expected background range. This article describes acute and chronic fluorosis, and discusses how to assess and manage the associated risks.

Salinomycin toxicity in dairy calves

SINCE the beginning of October, Animal Health and Veterinary Laboratories Agency (AHVLA) regional laboratories and SAC disease surveillance centres have been investigating unusual incidents of clinical respiratory disease presentations in calves on four farms. All affected calves have received medicated calf starter pellets that included a decoquinate premix. Affected calves, aged two to three months, have typically presented with tachypnoea/dyspnoea for two to eight days before death or euthanasia, and no clinical response was noted following treatment for suspected pneumonia. Pyrexia was a variable feature. However, one …

Plant poisoning in farm animals

Livestock plant poisonings, per se, are relatively uncommon, but feed incidents associated with some plant components of a diet are more frequently observed and some of these can have a significant impact. It is not uncommon for a variety of very different plant by-products to be fed to livestock, most of which can be associated with some level of risk. This paper reviews and discusses the more common plant poisonings that can occur in UK livestock.

Botulism in farmed ducks and pheasants

We recently investigated an outbreak of botulism in a duck ( Anas platyrhynchos ) and pheasant ( Phasianus colchicus ) farm where 30,000 mallard ducks and 35,000 pheasants are reared from one day old for shooting. The farm set up is that ducks are kept on several ponds with the water refreshed using pumps. The pheasants are initially reared in small pens and later in large runs with adjacent cover provided by maize. The birds each receive commercial pelleted feed. From the middle of August increased losses were identified in the ducks on one of the ponds and in the pheasants in one of the runs, which was nearest to the affected pond. Ducks also wandered into this run. The ducks and pheasants were reported to show similar clinical signs: weakness, inability to stand, becoming recumbent on their keels, with wings extended and resting their beaks on the ground. Six dead mallard ducks and two live pheasants were submitted for examination to the APHA Shrewsbury Veterinary Investigation Centre. Five of the ducks had been …

Establishing the plasma copper reference range in Boer goats

IN response to the letter by McKay and others on establishing the plasma copper reference range in Boer goats ([ VR , September 25, 2010, vol 167, p 499][1]), we question the need for adjustments to reference ranges to explain the presumed apparent paradox of swayback in a Boer goat flock of ‘