Type
A, type C, type Asia
1,
and type O of virus have been identified in Pakistan. The antigenic
difference among various types and sub types is the main problem in
the control of the disease. So regular typing and sub typing of
virus should be done and field strains should be added into vaccine.
Mostly cattle and exotic breeds are susceptible. Mouth lesions are
more severe in cattle and foot lesions are more severe
in buffalo.
Some
Factors due to Which FMD is not Controlled in Pakistan:
-
In Pakistan numerous natural and socio-economic problems made
the control of FMD very difficult.
-
Occurrence of different serotypes, subtypes and frequent
mutation is one of the major problems in control of FMD. Apart
from 7 serotypes there are several subtypes that are
ontogenetically and immunologically different and do not
provide cross protection. About 80-88 subtypes have been
identified.
-
New antigenic subtypes are constantly emerging. Animals which
are immune against one subtype remain susceptible to the
emerging subtype.
-
Quality of vaccine: in our area trivalent (A, O, Asia 1) vaccine
is given having three serotypes but most of the times FMD
contains newly emerging strains which lead to failure of
vaccine.
-
Lack of comprehensive vaccination program.
-
FMD virus is quite resistant even to commonly used
disinfectants.
-
There is lack of quarantine measures in case of entry and exit
of animal at farm.
-
Nomadic animals move from one geographical area to another area
carrying infection.
-
Some non susceptible animals like birds, dogs, and cats are
potential source of spread. Virus passes unchanged from GIT of birds so birds play
important role in dissemination of virus from one area to
another. Similarly dogs and cats fed on animals died of FMD also
become the source of spread.
-
About 50 % of recovered animals act as FMD carriers. So it is
more beneficial to keep recovered animals separate from healthy
animals.
-
Lack of communication between farmers and veterinarian.
-
Non certification of freedom from disease before introducing
them to the farm.
-
Nosocomial
spread (from hospital, veterinarian and para veterinary staff)
by syringes, crush, thermometer etc.
-
Common grazing and watering and common and not properly
disinfected utensils.
-
Socio economic factor: farmers cannot afford the vaccination
-
Farming with multiple animal species.
-
Lack of effective reporting system.
Etiological Agent:
Picornaviridae, genus Aphthovirus. There are 7 types A, O, E, Asia
l, SAT 1, SAT 2, and SAT 3.
One
of the important characteristic of FMD is that the virus is produced
in large amount in infected animal and present in all secretions and
excretions of animals including urine, feaces, and exhaled air; that
is why it is contagious disease. Virus is also present in the
products from infected animals e.g. meat, milk, hides etc.
Transmission:
-
Direct contact with effected animals
-
Movement of contaminated animal products
-
Through artificial insemination
-
Contaminated feed and water
-
Spread through wind
Clinical Signs:
-
High rise in body temperature that generally do not respond to
antibiotics
-
Heavy stringy salivation
-
Occurrence of vesicles and ulcers in the mouth, on feet and
teats
-
Reduction
in feed intake and milk production
-
Teat infection may lead to mastitis
-
Lameness due to lesions on feet
-
High death rate in young animals
-
Deformities in hooves
-
50 % weight loss
Diagnosis:
Laboratory diagnosis of FMD is made by the demonstration of FMD
viral antigen in samples of tissue or body fluids. Detection of a
specific antibody can also be used for the diagnosis, but this
requires an absence of any history of vaccination, as it is not
always possible to differentiate a serological response to natural
infection from that of vaccination. Diagnosis based on serological
response may also be problematic in endemic areas due to possibility
of previous infection and carriers. At the OIE/FAO World Reference
Laboratory for FMD, preferred procedure for the detection of FMD
viral antigen and identification of viral serotype is ELISA. The
polymerase chain reaction (PCR) can be used in diagnosis of FMD.
Treatment:
-
As it is a viral infection so no specific treatment but purpose
is to shorten the disease.
-
Isolate the sick animal with separate feeding and watering
utensils.
-
Wash the mouth of animal with 2 % alum solution or 1:1000
dilution of potassium per magnate.
-
Ointment for vesicle (Smear on vesicle (mouth) three times a
day):
-
Antibiotics - Tribrissen 20ml intramuscularly for four days in
adult buffalo and cattle
-
Dipyrone (antipyretic) 25 ml (intramuscularly). Cold water
therapy for fever
-
2 % solution of CuSO4, wash feet lesions and then
smear with piodine or tincture iodine
-
Multivitamins 15 ml (intramuscularly)
-
Soft diet (leafy) should be given
-
Protect lesion from flies to avoid maggots because maggots can
produce in lesions
-
Ethnoveterinary practices:
-
Hot bread (roti) with butter is offered which will rupture the
vesicles.
-
Walk on hot sand or floor.
-
Water from tanneries my be applied on vesicles. It will dry
the vesicles.
Vaccination:
Vaccinate animals twice a year.
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