What is Lumpy-skin disease (Lsd)?
What is Lumpy-skin disease (Lsd)?
’ It is a viral disease of cattle and is typically characterised
by nodules or lumps on the skin.
’ All cattle breeds in South Africa can be affected.
’ It usually occurs during the wet summer and autumn months, when
flies are in abundance.
’ The disease
occurs throughout Africa.
Why is Lumpy-skin disease so important?
’ It is a notifiable disease,which means the state veterinarian
must be informed because there are specific control schemes for this disease.
’ Up to 45% of your herd can get infected and the mortality
(death) rate may reach 10%.
’ The disease causes emaciation (loss of body condition because of
unwillingness to eat); temporary or permanent loss of milk production, lowered
or complete loss of fertility in bulls and cows, abortion as well as permanent
damage to hides (skin).
’ There is a loss in income because
of lower production (deaths, milk and meat, abortions, lowered breeding
potential, and damage to valuable hides), and the costs of drugs to treat sick
animals.
What type of animals can be affected?
’ Cattle of all ages can be
infected.
’ Cattle which are vaccinated annually are protected and therefore
less likely to be infected.
’ Cattle which have had the disease and survived cannot be
infected again (also immune).
’ Calves under 6 months of age are protected against the disease
if their mothers were vaccinated or had the disease previously.
how do cattle become infected?
’ Biting flies play the most important role in spreading the
virus. Infections increase during the wet summer and autumn months when there
are more flies.
’ Calves can be infected by drinking milk from a cow
which has the disease.
The disease can also spread
through the saliva of infected animals when they use the same drinking trough.
What are
the signs of Lumpy-skin disease in cattle?
Any one or more of the following:
’ Skin nodules and ulcers:
– can vary from a few to
hundreds
– the size ranges from 0,5–5
cm
– they occur anywhere on the skin,
including the nose, udder and vulva in cows, the scrotum in bulls, as well as
in the mouth (the gums)
’ Legs which become swollen and
develop sores
’ Enlarged lymph nodes
’ Pneumonia/coughing—as a result of
infection of the respiratory tract
(the
windpipe) and lungs
’ Nasal discharge—thick, watery to
pussy fluid from the nose
’ Infertile bulls—due to orchitis
(infection of the testes)
’ Infertile cows
’ Mastitis—this lowers milk
production
’ Lachrymation, infection of the eye
or even blindness
’ Fever
’ Emaciation
’ Salivation.
how can Lsd be diagnosed?
’ A basic diagnosis can
be made by the presence of the typical lesions on the skin and in the mouth. In
longhaired animals you should feel for the nodules on the skin, or you can wet
the hair so that you can see the nodules more easily.
’ A definite diagnosis
can only be confirmed by a veterinarian by taking samples of the skin to a
laboratory where they can identify the virus (this has to be done because there
are other diseases which cause similar signs in cattle and therefore require different methods of control and treatment).
’ If you suspect LSD in your herd, you must inform the state
veterinarian so that the disease can be confirmed and he/she will help you to
control the disease.
how is Lsd treated?
There is NO TREATMENT for lumpy-skin disease.
Nonspecific treatment (antibiotics, anti-inflammatory drugs and
vitamin injections) is usually directed at treating the secondary bacterial
infections, inflammation and fever,
and improving the appetite of the animal.
how can you prevent
Lumpy-skin disease in your herd?
Prevention is the cheapest and best method of control of the
disease. If your animals are protected, you will not suffer any production or financial losses as a result of the ill effects of the disease.
vaccination (the best)
The
attenuated Neethling strain vaccine is a product that contains
a weakened LSD virus. When this vaccine is administered the animal will develop protective
antibodies
(made by white blood cells). These antibodies
then resist the actual virus that is transmitted by biting flies or milk and saliva
of infected animals.
The animal is therefore protected or immune.
The Onderstepoort Veterinary
Institute or the local veterinarian can supply vaccines.
All cattle should be vaccinated annually (once a year), and preferably
before the summer rains to ensure good protection.
Animals that had the disease and recovered, are immune and
therefore do not have to be vaccinated.
Calves
which are under 6 months old and were born to cows which have been
vaccinated or had the disease, do not need to be vaccinated. However, as soon as they are 6 months old, they have to be vaccinated
annually.
There may be a swelling at the site where the vaccine is given,
and a temporary drop in milk production, but the swelling will disappear after
a few weeks with a return to normal milk production.
it is important to read
the instructions for use on the vaccine labels. if you have any questions or
need assistance with vaccination, contact your state veterinarian or animal
health technician for help.
fly control
It is unpractical and almost impossible to control all the flies
in your herd. It is better to prevent flies from biting your animals.
Cattle should be dipped in a product that contains an
insecticide. Make sure that the dip includes insecticides effective against flies. Read and follow
the instructions on the labels of the products.
Fly repellents can be sprayed on
cattle.
Note that fly control will not prevent all cattle from being
infected by LSD. The only way to ensure that all cattle are protected is by
vaccination alone.
