23 Dec 2021
David Harwood BVetMed, FRCVS summarises talks from the Goat Veterinary Society’s autumn meeting, which was held in person at Taunton Racecourse
David Harwood
Job Title
Figure 1. Aiden Foster, of the University of Bristol, speaking to delegates.
After many months of Zoom meetings and webinars, the Goat Veterinary Society (GVS) held its autumn meeting in a face-to-face format – providing a chance to renew friendships and generally catch up with each other.
The society welcomes both vets and owners/keepers to its meetings – ensuring that in addition to some excellent CPD and great speakers (Figure 1), useful discussion always spills over into lunch (Figure 2).
The society was pleased to welcome BVA senior vice‑president James Russell to the meeting.
He started by discussing the evolving Animal Health and Welfare Pathway. This initiative involves farmers, supported by their vets, other specialists and Defra colleagues, working together. It was evident at the outset that the farmers’ own vet needed to be at the heart of delivery, and veterinary input has been key to taking the first steps.
The programme is set to start in spring 2022 with a vet visit, paid for by the Government. The visit will involve undertaking a health and welfare review of the farm, including diagnostic/monitoring testing, to set the foundations for the perceived onward journey along the pathway.
The initial focus will be on improving disease prevention and controlling or eradicating an industry‑agreed list of diseases in each species.
Relevant to this meeting was the fact goats do not currently feature in the initiative – posing the question as to where they do fit.
While analogies exist between the dairy goat and dairy cow sectors, this “fit” would not be applicable across the wide range of current goat‑keeping activities.
Delegates were keen that all goats be eligible for future inclusion, from commercial to hobby keepers.
The second speaker was Jude Capper of Harper Adams University. She made the point that no definitive sustainable protein system exists to aspire to – but that every system can be sustainable.
Sustainability comprises three pillars under the umbrella of One Health – animal health, human health and ecosystem health – underpinned by economics, environmental concerns and social conscience.
We can have only a limited impact on the social conscience – such as the increasing move to vegetarianism and veganism – spurred on by social media, often with celebrity endorsement.
The carbon footprint of the foods we eat vary considerably – and global averages often quoted are misleading, particularly when food production is local/regional.
A chart showing the carbon footprint of small ruminant milk and meat production (Figure 3) showed the wide variation around the world, with inevitable variation within each region.
When considering the greenhouse gas emissions (GHG) for dairy goats, approximately 30% comes from the goats themselves and 30% from their manure, with the remainder spilt between crop and other feed production systems.
Improving animal productivity, by improving key performance indicators, undoubtedly reduces the environmental impact of meat and milk, with fewer animals in production.
A 2019 survey by the Department of Energy and Climate Change found total UK meat and dairy production accounts for about 6.9% of total GHG emissions. Even if every person in the UK went meat and dairy free for one day each week, the national carbon footprint would decrease by less than 1%.
Dr Capper predicted that sustainability indices would be increasingly added to meat labels in supermarkets in future.
The first of two presentations on Johne’s disease came from Bryony Kendall of Tynedale Vets. She described a joint GVS/Milking Goat Association initiative to develop a Johne’s control plan for the Red Tractor scheme.
She began by describing Johne’s disease as it presents in goats – showing many similarities with disease in cattle, particularly with reference to testing, but also displaying many subtle differences in its clinical presentation.
Diarrhoea, for example, is not displayed by goats until the later stages of disease and the gut changes at postmortem examination (PME) are far more subtle.
Phase one will see the development of a sector‑agreed fact sheet outlining risks, aims and objectives. In phase two, the plan will be launched, and will try to categorise milking units into one of three categories:
Testing will be based around the currently available ELISA blood test and faecal PCR test, although discussions have also taken place with the suppliers of the Actiphage test as another possible tool.
The most labour-intensive category is undoubtedly eradication – in which kid snatching, washing, and towel drying were suggested as a routine management requirement.
The second presentation came from Alison Braddock of Scotland’s Rural College (SRUC), who ran through some of the rules for the college’s Premium Sheep and Goat Health Scheme for Johne’s disease, in which members progress from entry level 5 to level 1, achieved following three successive clear herd tests. Information is freely available on the SRUC website.
In the next joint presentation, GVS secretary Ben Dustan, of Tarn Farm Vets, and APHA colleagues described the investigation into a suspect herd TB outbreak (Figure 4).
The herd in question was a newly established dairy goat herd in Cumbria, based in a known local TB hotspot with more stringent control measures in place since 2015. The herd health background was described, which included several deaths from enterotoxaemia when the herd was first set up.
It was the increasing suspicion of Johne’s in the herd, however, that prompted the submission of a typical case to the APHA laboratory at Penrith. Of significance was the fact this goat had tested positive to the Johne’s blood ELISA test, but negative to a faecal PCR.
PME revealed multiple lung abscesses with thick, creamy pus, with local areas of lung cavitation. Similar lesions were also identified in the spleen, mesenteric lymph nodes and, somewhat unusually, in the submucosal tissue of the distal jejunum.
The overall pattern was not typical of Johne’s disease, but considered more suggestive of TB, so the local APHA field team was notified while further laboratory tests continued.
Statutory Mycobacterium cultures confirmed the isolation of a Mycobacterium species, but not Mycobacterium bovis. The culture was identified as Mycobacterium avium subspecies hominissuis (MAH; as distinct from M avium subspecies paratuberculosis; MAP, the causative organism of Johne’s disease). MAH is an opportunistic pathogen that can cause infection in both animals and humans worldwide, and is an unusual isolate in the UK.
While the culture results were awaited, the herd was placed under TB restrictions and visited by APHA staff.
Goat-keepers and vets have a legal obligation to report a suspicion of TB to the APHA when suspect lesions are identified at PME (or if a clinical suspicion exists of disease in live goats). Once TB had been eliminated as the cause, restrictions were lifted.
The final speaker of the day was Aiden Foster of the University of Bristol, who returned for the third time following previous presentations in 2010 and 2015 – because skin problems can be very perplexing in goats.
Beginning with ectoparasites, the speaker described chorioptic mange (foot mange; Figure 5) as the most common presentation, with sarcoptic mange becoming more rarely identified. Environmental mites, such as harvest and forage mites, with Culicoides midges may all contribute to allergic skin responses.
A common practice to rule out these ectoparasites is to use a macrocyclic lactone. Currently only eprinomectin is licensed for use in goats in the UK, although others are used.
It seems appropriate to recommend that, when not using licensed eprinomectin, double doses are used when deploying doramectin, ivermectin or moxidectin (this would usually be 0.4mg/kg, by mouth or SC injection).
The speaker also advised it was unlikely a single dose would have much impact on an established ectoparasite burden; therefore, given that the life cycle is usually three weeks, he recommended giving a second dose two to three weeks later.
It is important that an ongoing awareness of the possibility of promoting endoparasite resistance is made when using these products, and of the need to follow statutory meat and milk withdrawal periods using the product under cascade principles.
The speaker then discussed a case of the pygmy goat keratinisation disorder often referred to as “pygmy goat syndrome”, recognised by those present as difficult to treat or manage.
The typical early age of onset is about five months, and the distribution of scaling lesions (with some alopecia and occasionally crusting) involving the head (Figure 6), limbs and ventral body extending up to the tail are typical features.
Glucocorticoids are likely to help in part because they are keratoplastic and slow down epidermal turnover. Shampoos designed for the pet market that are indicated for the control of greasy/scaly skin may also be helpful.
Soaking for 10 minutes twice‑weekly over several weeks may show some benefit.
Given the timescale for epidermal turnover to impact on lesion formation, the speaker said it is likely that clinical improvement with most therapeutic interventions would take several weeks – so warn owners.
