Clinical experience of disease outbreaks - Veterinary Practice
Your browser is out-of-date!

Update your browser to view this website correctly. Update my browser now

×

InFocus

Clinical experience of disease outbreaks

RICHARD GARD reports on the latest meeting of Goat Veterinary Society and the wide-ranging discussions

THE latest meeting of the Goat Veterinary Society revealed clinical issues with goats that are equally relevant to other stock.

For some time members of the society have been involved in developing “correct procedures” for the disbudding of kids and a DVD was compiled last year to demonstrate good practice. However, there continue to be concerns and contact with members from veterinary surgeons who are unsure about current practice, so a buddy system has been launched.

Anyone who wishes to can contact the society and be linked to a veterinary buddy with experience of disbudding to advise on the best practical way forward.

The technical programme included clinical experience of particular outbreaks, control of disease and latest research, goat milk cheesemaking and the developments with TB in camelids and cattle.

Lucy Gill, when working in practice at Sturminster Newton, investigated an outbreak of abortion in a herd of 45 goats purchased over a three-month period in 2011. Foetal tissue sent to the VLA failed to reveal a diagnosis.

More abortions followed and a positive PCR for BVD indicated that although the does were past the 100 days in kid point, where resistance to BVD is expected, the disease can still cause abortion.

A shed used by a herd of 70 suckler beef cattle was cleaned at turnout and the goats used the shed. The cattle were a “flying herd” purchased from various sources and identification of PIs in the cattle, although advised, was not done. Breeding cows and the bull were vaccinated. It is not known if the vaccine would be effective for goats. It is thought that the virus has been transferred to the goats on boots and in dung and the advice is to control the disease in cattle and thereby reduce the risk to goats and sheep.

David Harwood presented a review and update of the latest situation with Schmallenberg virus.

The infection is established in the UK midge population with 1,753 holdings known to have infection. Clinical cases have been confirmed in calves and lambs but not in goats or alpacas.

A four-year-old goat was found positive on serology but had two healthy kids and a kid born with a deformed foot was serology positive (colostrum derived) but no virus detected on PCR. Anecdotal information indicates that goat kids have been born with abnormalities. The pygmy goat website is reporting that the disease has been found in Lancashire.

So far this year very few cases of deformed calves or kids have been submitted to the VLA. There is an on-line survey being conducted with sheep farmers. A South Wales practice survey indicated that 21 of 23 flocks encountered SBV-like abnormalities in sheep and 13 of 23 herds had abnormalities in calves. There was a low level of laboratory diagnosis due to the cost.

The launch of the MSD Bovilis SBV vaccine is welcomed and more information needs to be gathered about the threat from the virus and successful control.

Telephone advice on lameness

Lameness control by a telephone advisory approach, in collaboration with the client’s practice, was outlined by Jen Hall from the St David’s Farm Practice in Exeter. Adult female milking goats in a Cornish herd of 15 animals, with a few sheep, suffered serious lameness.

The goats were kept in at night and out by day. When brought in they were a bit lame but by the morning were “hopping lame”.

Antibiotics administered to an older goat had provided some relief but the lameness returned and the animal was euthanased. An infectious origin was suspected and a copper and zinc hoof paste administered.

The goats lick the paste off the feet but a beneficial effect was achieved and only a mild scald seen, which cleared up quickly. The farm had very muddy gateways with the goats standing around in the mud.

The advice was to reduce standing in mud, reduce the stocking density, maintain better hoof cleanliness and to treat any cases of lameness as early as possible.

Lameness studies at Bristol University have led to a request for information. Practitioners who are aware of a herd of goats being fed ad lib concentrates, with no lameness, are asked to contact margit.groenevelt@bristol.ac.uk.

Kathy Anzuino explained that two herds of milking goats are suffering 40% (400 goat herd) and 67% (600 goat herd) lameness. Only adults are afflicted and not youngstock and there is routine foot trimming.

Some of the cases are serious with welfare concerns. Interdigital swabs have shown that the condition is not foot-rot and although treponemes have been found the lesions are atypical. A few animals have coronary band lesions. The indications are that small lesions are providing entry for secondary infections including treponemes.

The goats are on an 18% ad lib ration with little active nutritional management and poor quality forage. More information is being collected from radiographs of legs and poor horn quality is suspected. There could be an underlying acidosis and enterotoxaemia.

Nick Clayton (hon. secretary of the GVS) updated delegates on the initiative to detect Johne’s diseasefree herds. Individual goat samples are mixed at the SAC laboratory and the procedure provides a “good GVS meeting – from previous page certainty” of indicating that the herd is Johne’s free. A major aim of the trial is to overcome the effects on the PCR test of an inhibitory substance found in goat faeces. A total of 500 bulked samples are being sought for the trial. For more information contact nickclayton2@mac.com.

Sarah Hampton of Brock Hall Farm Dairy in Bridgnorth is a goat cheese enthusiast with an upmarket retail business from a 100 goat pure Saanen herd.

Emphasis is placed on the management of the goats with synchronised breeding, scanning, observation of mating twice a day and males kept away from the main herd to remove physical and olfactory influence. Diet and exercise are considered highly important with happy goats, sunshine and play reinforcing the pecking order.

Raw milk cheese, both hard and soft, is hand-made. Soft cheese is more profitable but has a short shelf life of 21 days. Hard cheese spends more time in the press with a lower yield and requires more labour but cheesemongers find it attractive as it is seen as a “safe” product.

Concerns about listeriosis are widespread. With marketing directly to restaurants there is immediate feedback and the idea of fresh-fromthe-farm is respected.

Wholesalers and large delis collect from the farm but there is no control over how the brand is portrayed to consumers. Capra Nouveau sweet and creamy cheese was voted one of the top 50 foods in Britain with a maximum three star rating.

TB in camelids

A TB Forum evoked considerable enquiry and worthwhile discussion. Alistair Hayton of Crewkerne in Somerset reviewed the detection of TB in camelids. With some animals valued at many thousands of pounds, TB is a major concern and an alternative to the skin test is sought.

Trials with antibody tests have shown a good detection rate with a low risk of false positives. Traditionally, testing for antibodies has not been accepted but new work has shown that different antibodies are produced at different stages of infection.

Comparisons have been made between products containing 2, 5 and 7 antibodies with the multiple product showing detection from soon after infection up to late clinical stages with the disease. A full copy of his paper will be in the Goat Veterinary Society Journal.

Richard Gard outlined the value of local herd assessment with the involvement of veterinary practices. An example of 11 herds with neighbouring land showed 6,000 individual cow tests each year for three years from 1,300 cattle.

Collation of the ages and types of the cattle (dairy, beef, youngstock), their precise location and date of testing, yields very valuable information and can direct control activity.

Within a local area, veterinary practices may need to co-operate with colleagues to bring together the test findings, leading to an initial full assessment and ongoing monitoring. Emphasis on the local situation is seen as important and this aspect is lost with the larger areas for control that are currently proposed.

Alistair Hayton expressed concern that problems with skin testing of cattle are well known. There are 120 close related species of Mycobacterium and the test is effective as a herd test but can yield false positives. The longer the duration of infection, the poorer the immune response, which raises difficulties of detection with endemic herds.

The possibility of using a single blood sample for cattle was discussed, with benefits to farmers and veterinary surgeons from one collection of animals and one visit.

It may be valuable for veterinary surgeons to consider the new information and the likely social, practical, economic and diagnostic improvements.

Have you heard about our
IVP Membership?

A wide range of veterinary CPD and resources by leading veterinary professionals.

Stress-free CPD tracking and certification, you’ll wonder how you coped without it.

Discover more