Goats, TB, and other concerns - Veterinary Practice
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InFocus

Goats, TB, and other concerns

Richard Gard reports on the latest meeting of the Goat Veterinary Society

ULTRASOUND is the way ahead
for diagnosis, according to Dr Phil
Scott, a reader at the Royal (Dick)
school, speaking at the spring
meeting of the Goat Veterinary
Society last month.

A practical point, he said, is that it is
important to be able to see the
scale of the image in order to
interpret the size of lesions.

The sounds from respiratory
wheezes and crackles of
unknown source, from air bubbling
through and causing vibrations, are not
a confirming diagnosis.

Sounds are heard over a larger area
than the lesion. There is very little air
movement in chronic lung lesions and
it is necessary to scan to determine the
pathology within the lung.

A few specific observations included:
with endocarditis fewer than 30%
of lesions result in audible sounds;
ultrasound images with fatty liver
syndrome are a waste of time for
diagnosis; penicillin is the antibiotic of
choice for fibrinous pleurisy.

Greenstick fractures in neonatal
lambs are often overlooked and he
indicated that this could be the same
situation with kids. Growth plate infections in young sheep have been
found to respond well to antibiotics.
Ligament rupture in sheep is found
quite commonly. Rams are expensive
animals and diagnostic exploration
prior to successful treatment is
worthwhile commercially.

In a second presentation, Dr Scott
discussed the use of therapy and
noted that the Goat Veterinary Society
literature on goat disbudding is used
with veterinary students as a source of practical information. The advice
is to assume that all lameness in lambs
before six weeks old is infectious.

Mildly lame lambs should be treated
and non-treatment leads to increased
lameness with age. Examples were
given of four-day-old lambs with
Streptococcus dysgalactiae infection being
treated with dexamethasone short-
acting plus penicillin, with recovery six
hours later.

Polyarthritis is treated on
presentation with corticosteroid
and penicillin, initially intravenously by the vet and then
intramuscularly by the
farmer. Meningitis cases
receive a high dose of
dexamethasone.

Corticosteroids
have a role in first
opinion practice and
Dr Scott advises using
NSAIDs before surgery.
Intravenous NSAID
followed by a low
extradural injection of
lignocaine plus xylazine show an
immediate improvement. Mention was
made of the benefits of medetomidine
but this product is not licensed for
small ruminants.

Feeding small herds

Practical aspects of feeding the small
herd of goats was discussed by Sue
Smith from Castle Cary, Somerset.
Pet goats are normally too fat and
should be offered good quality hay and
nothing more, she said.

A goat measured over the sternum,
lumbar region and ribs should be body
condition score 3. For the commercial
herd, a maintenance ration of 80g of
coarse mix twice daily, or a similar
amount of sugar beet, plus hay, is
targeted. Early grass is preferred to hay
and with grazed goats there should be
access to housing at all times utilising a
summer barn.

There are many different ways of
feeding the small pedigree herd, she
said. Grazing improves the well-
being of the animal but makes little
difference to the dietary content. With
milking goats there are no standards to
indicate how much feed is required to
yield a litre of milk and maintain body
condition.

Various points of detail were raised
by other goat keepers present and
detailed experiences of herd situations
were highlighted and discussed.

TB in goats

Alastair George of the AHVLA,
London, is a member of the TB
policy team and he summarised the
official recognition of TB in goats.
A consultation is due on TB in
non-bovine farmed and companion animals and from the information shared
at this meeting it is
clear that an accurate
assessment of the wider
aspects of the disease is
overdue.

Included in the
records for 2012 are
confirmed TB in two
goats, 22 cats, 36 alpaca
and 19 sheep. It is
believed that the most common route of infection in goats is
by inhalation. The official position is
that TB in goats is a minor problem.

The skin test is not validated for use
in goats. TB lesions at slaughter are
notifiable and movement restrictions
can be enforced on suspicion of TB.
Suspect animals that are slaughtered
can be compensated but the co-
operation of the owner is required.

AHVLA consent is required for
private testing if formal action is to be
taken when positives are found.

Voluntary surveillance

Alastair Hayton of the Synergy vet
group in Somerset discussed diagnostic
options and voluntary surveillance
with TB in goats. There have been
two major outbreaks of TB in milking
goats in the past year and the incidence
with one of the herds – 500 milking
goats and 300 followers, with 200
animals purchased – was discussed.

Clinical cases were found and 150
reactors were identified with 70%
showing lesions on slaughter. Follow-
up tests showed that the cell-mediated
immunity skin test found 14 positives
with four having lesions, but an antigen
test indicated 339 positive for TB
antibodies.

Trials with the Enterplex TB test
have been carried out with blood
samples but ongoing studies with
milk indicate that there is a good
correlation between blood and milk.
Antibodies may be produced early on
in the disease and the identification
of specific antigens (from 1 to 7) aids
diagnosis and positive action.

There are concerns about the
transfer of infection internally to
milking staff and externally with unpasteurised goat
milk products. The
trials have indicated
that there are no false
positives and the same
samples can be used for
other laboratory tests if
required.

Camelid owners are
taking part in voluntary
screening and testing
a statistically derived
proportion of the herd rather than the whole herd. DEFRA
recommends that animals are primed
with an intradermal antigen and
the antigen test approach is being
scrutinised prior to validation as an
approved test.

If the tests are negative no action
is required but positive tests results
indicate a review of the herd history
and existing biosecurity.

This presentation generated
considerable discussion and
speculation. The antigen test approach
has clear advantages over the skin test in time and cost and the aspect
of early warning of disease with true
indications, by identifying specific
antigens, jumps the control of TB into
another league.

Sheep scab

Chris Lewis gave an entertaining
review of sheep scab (Psoroptes ovis)
from first identification in 1530, when
the wool trade collapsed, to the present
day.

The first commercial dips were
introduced in 1893 and scabby sheep
were regularly imported from the USA
and Ireland. Scab was eliminated in the
1940s and the country remained free
until 1973 when more imports started
years of disease.

Chris said that scab should be
notifiable, with restricted movement
from infected premises; correct
treatment should be supervised with financial penalties for inaction. The
Stamp Out Scab campaign requires veterinary and farmer
support.

Lentivirus

Dr Lynn Batty of the SRUC
summarised the disease of
caprine arthritis encephalitis
(CAE) and indicated that
there is no vaccine against
the lentivirus, no therapy
and the animal is infected
for life. The birth of small
sickly kids and arthritis in adults are clinical signs
with a fall in milk yield and there may not be signs of lameness.
Often over 50% of a herd can become
infected.

The disease is difficult to manage
with the need for separate equipment
for “dirty” and “clean” goats. Older
thinner goats should be tested before
any clinical awareness together with
bought-in stock. Infected goats are
more susceptible to other infections.
Sheep on the same farm are a potential
source of infection.

Top tips

The day concluded with a top tips
section led by Kat Bazeley. Among
the gems were that pet goats should
have no access to wet ground in winter
and there should be two entrances to a shed to overcome guarding by
dominant goats. Goats are affected by warmth and cold with the need for
fan ventilation and insulated buildings.
Kids will climb into troughs and
contaminate feed. Hay racks need lids.

New chairman

The AGM of the society held
during the day concluded with Dr
Tony Andrews handing over the
chairmanship to David Harwood after
15 years of, it was hinted, blood, sweat
and tears. In commemoration he was
presented with a bronze casting of a
British Saanen male and he joins John
Matthews and Rob Ankorn as stalwarts
of the society.

  • The autumn meeting of the Goat
    Veterinary Society is planned for 24th
    October. Useful information about
    goats is available at www.goatvetsoc.co.uk.

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