Michael Millar

Clinical features of psoroptic mange in cattle in England and Wales

The clinical signs, treatments used and spread of psoroptic mange in cattle from October 2007 until March 2011 are described. The disease was first diagnosed in South West Wales, having not been reported in Great Britain since the 1980s. The likely source was identified as a farm that had imported two animals from mainland Europe in the summer of 2006. Since that time, disease has been diagnosed on a further 22 premises, the majority in South West Wales but also in South East and Mid Wales and on one farm in England. Bought in animals harbouring the Psoroptes species mite but not showing clinical signs were considered the greatest risk of introducing the infestation into a herd. This, together with the difficulties of treatment to eliminate the parasite, means that it is unlikely that this outbreak has been controlled. There is also a continuing threat of importing the disease from abroad. The disease is not notifiable in the UK.

Embolic pneumonia in adult dairy cattle associated with udder cleft dermatitis

WE wish to report a number of cases of pneumonia in adult dairy cows that were associated with embolic spread from abscessation cranial to the udder, in turn preceded by udder cleft dermatitis (UCD) – also known as udder intertrigo and ulcerative mammary dermatitis.nnUCD is a moist dermatitis mostly seen between the anterior of the udder and the abdomen, but also between the front quarters (Bouma and others 2016). It can present with a pungent odour, take many weeks to resolve and is more common in older cows (Warnick and others 2002). High-yielding cows which have calved at least three times are more likely to develop UCD (Waller and others 2014), and cows with a deep udder and a small angle between the udder and abdominal wall are more likely to be affected (Olde Riekerink and others 2014). It has been proposed that the treponemes associated with digital dermatitis (DD) are also involved in the pathogenesis of UCD. However, the aetiology of UCD is likely to be more polymicrobial than DD (Evans and others 2010) and the exact cause of this condition has not been determined.nnEmbolic pneumonia results from haematogenous spread from an infected focus elsewhere in the body, with the most common source …

Rumen fluke in South American camelids in Great Britain

Rumen fluke infections have been increasingly diagnosed in cattle and sheep in Great Britain in recent years (Foster and others 2008), primarily through the detection of rumen fluke eggs in faecal samples, with a peak in total diagnoses in 2013 after the wet summer and autumn of 2012 (APHA 2015).nnAlpacas and llamas are herbivorous but not true ruminants, and have three stomachs or compartments – C1, C2 and C3 (C1 is similar to the rumen, C2 to the reticulum and C3 to the abomasum). nnRumen fluke eggs in faeces, or adult rumen fluke seen at postmortem examination, have been detected and coded only seven times in South American camelids since 2010 on the VIDA database across Great Britain. In contrast, 100 diagnoses of liver fluke have been recorded since 2010 on VIDA (eggs in faeces and at postmortem examination) in camelids. Rumen and liver fluke eggs are detected using the same faecal examination techniques.nnClinical disease due to immature rumen fluke infestation (adult …

Transient agalactia in ewes

WE wish to alert practitioners to a syndrome of transient agalactia in sheep, because we are developing a survey to investigate the risk factors for this condition.nnEach year, we hear of a few flocks in Great Britain and Northern Ireland with partial or complete agalactia with variable prevalence (in some cases up to 80 to 100 per cent of the flock). The affected ewes develop a hard udder at the time of, or soon after, lambing, and little or no colostrum/milk is produced. There is no associated mastitis, and milk production/let-down usually gradually returns over three to seven days, although some ewes do not achieve full production. During the period of agalactia, lambs have to be bottle fed, with all the accompanying cost …

Two cases of embolic pneumonia associated with udder cleft dermatitis in dairy cattle from the same farm

Two Holstein cows from the same farm were presented within eight months of each other with malaise, milk drop and dyspnoea. Both cows had active or historic udder cleft dermatitis (UCD) lesions. Clinical examination and diagnostic tests led to an initial diagnosis of chronic suppurative pneumonia in both cows. The cases were poorly responsive to antibiotic treatment and died or were euthanased, 18 and 16 days respectively, after presentation. Postmortem examination of each case resulted in the diagnosis of embolic pneumonia associated with UCD. In both cases, UCD lesions, which were considered insignificant by the farmer and the veterinarian, are thought to have been the initiating source of infection. It is important that both farmers and vets are made aware of the possible severe consequences of udder cleft lesions and that early detection strategies for UCD and udder cleft lesions are adopted and implemented on-farm.

Bleeding disorders in calves

WE wish to highlight the occurrence of a bleeding disorder in calves clinically and histopathologically indistinguishable from bovine neonatal pancytopenia (BNP), where there is no possibility of ingestion of colostrum derived from PregSure-vaccinated cattle.nnBNP was first recognised as a clinicopathological entity in Europe in 2007 (Bastian and others 2011) and in the UK in 2009 (Penny and others 2009), defined as a haemorrhagic disease occurring in calves less than 28 days of age and involving bone marrow lesions of trilineage hypoplasia (severe depletion of all three main haematopoietic cell lineages) (Lambton and others 2012). It has been diagnosed in calves of many breeds between one and four weeks of age, and a strong association has been demonstrated with vaccination of the dam with the bovine viral diarrhoea virus (BVDV) vaccine PregSure (Lambton and others 2012, Sauter-Louis and others 2012). Field and experimental data strongly suggest the pathogenesis involves colostral alloantibody-mediated destruction of haematopoietic progenitor cells in bone marrow. This results in cytopenias, including thrombocytopenia, and hence bleeding.nnBNP is still being diagnosed despite the withdrawal of the PregSure vaccine in 2010, both in calves born to PregSure-vaccinated cows that have previously had affected calves, but also in calves born to cows that previously raised …

Drenching gun injuries in cattle

DRENCHING gun injuries are well recognised in sheep and have been clearly shown to pose a threat to the health and welfare of sheep in the UK (Harwood and Hepple 2011). In cattle, liver fluke infection is associated with the widespread use of anthelmintic products to reduce the impact of infection on production, particularly in dairy cattle (Howell and others 2015). We wish to report on three cases of dosing gun injury, with fatal outcome, for three dairy farms where cattle were treated for liver fluke.nnOn the first farm, three cows in a 130-cow dairy herd had died in a week, with the first two to die showing reduced milk yield and some coughing. One of these was examined at the knackers yard and had a large amount of blood in its ‘stomach’. Coughed up blood had been noted on …

‘Kangaroo gait’ in ewes

SIR, — We wish to report histologically confirmed cases of ‘kangaroo gait’ in three unrelated flocks in different parts of England in 2006. The Veterinary Laboratories Agency (vla) is also aware of several anecdotal reports of the condition this year from veterinary surgeons in general