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Farm and Home Biosecurity
Livestock/Row Crop Producer
Arkansas Farm Biosecurity Plan -
Disease Symptoms – Clinical Signs
Foot-and-Mouth Disease (FMD) •
Anthrax •
Bovine Spongiform Encephalopathy (Mad Cow Disease) •
Scrapie •
Avian Influenza (AI) •
Newcastle •
Spring Viremia of Carp Virus •
West Nile Virus
Foot-and-Mouth Disease (FMD)
Cattle, swine, sheep, goats, bison, deer, antelope, wild swine, llama, elk,
camels, moles, voles, rats and hedgehogs.
- Fever and blister-like lesions and erosions on
the tongue and lips, in the mouth, on the teats and between the hooves.
- Blisters will break and form raw patches or
ulcers.
- Blister and/or sores can develop on the teats
and cause mastitis in dairy cattle
- The incubation period is two to 14 days,
depending on the infecting dose, susceptibility of the host and the strain of
virus.
- The clinical signs are more severe in dairy
cows and intensively reared pigs than in sheep and goats.
- After the incubation period, a fever of up to
106° F develops, the animal is anorectic and salivates and stamps it feet as
vesicles develop on the tongue, dental pad, gums, lips, and on the coronary
band and interdigital cleft of the feet.
- Young calves, lambs, kids and piglets may die
before showing any vesicles because of virus-induced damage to the developing
cells of the myocardium.
- Milk drops dramatically in milking animals, and
all animals show a loss in condition and growth rate that may persist after
recovery.
- Sheep and goats may develop only a few vesicles
on the coronary band of the mouth.
- Vesicles in the mouth, even when severe,
usually heal within 7 days, although recovery of the tongue papillae takes
longer.
- In pigs, the complete horn of the toe may be
lost.
- Cattle and deer may also lose one or both horns
of the foot.
- FMD has frequently been ignored or misdiagnosed
in small ruminates.
- Many animals recover from FMD infection, but
the disease leaves them debilitated. The virus can remain infected and carry
the virus in the pharyngeal region for up to 2.5 years in cattle and 9 months
in sheep.
- There are seven separate types of the FMD
virus, in addition to many subtypes of the virus. Immunity to one type does
not protect an animal against other types.
- FMD can be spread by animals, people or
materials that bring the virus into physical contact with susceptible animals.
- Dogs and cats cannot become infected with FMD.
- There are other diseases that exist in the U.S.
that show similar signs of FMD, such as Vesicular Stomatitis Virus and
Bluetongue Virus.
Anthrax
All warm blooded animals including man
- Most commonly occurs in cattle, horses, sheep
and wild animals. When it occurs in a human, it is usually because a person
has been exposed to infected animals or tissue from infected animals.
- • The incubation period is typically 3 to 7 days
(range 1 to 14 days or more).
- • The peracute form is characterized by sudden
onset and a rapidly fatal course. Staggering, difficult breathing, trembling,
collapse, a few convulsive movements, and death may occur in cattle, sheep or
goats without any previous evidence of illness.
- • In acute anthrax of cattle and sheep, there is
first an abrupt rise in body temperature and a period of excitement followed
by depression, stupor, respiratory or cardiac distress, staggering, convulsion
and death.
- The body temperature may reach 107° F,
rumination ceases, milk production is materially reduced, and pregnant animals
may abort.
- There maybe bloody discharges from the natural
body openings.
- The disease in horses is acute. They may show
fever, chills, severe colic, loss of appetite, extreme depression, muscular
weakness, bloody diarrhea, and swelling in the region of the neck, sternum,
lower abdomen, and external genitalia. Death usually occurs within 2 to 3
days.
- In swine, some animals in a group may die of
acute anthrax without having shown any previous signs of illness. Others may
show rapidly progressive swelling about the throat, which, in some cases,
causes death by suffocation. Some in the group may develop the disease in a
mild chronic form and make a gradual recovery.
- The carcass of an animal dead of anthrax should
not be subjected to necropsy, because the anthrax bacilli form spores when
exposed to free oxygen. The spores are resistant to extremes of temperature,
chemical disinfectants and desiccation.
- The spores may persist for long periods in dry
products such as feed, animal by-products, stored contaminated objects or in
soil.
- Outbreaks of anthrax commonly are associates
with neutral or alkaline, calcareous soils that serve as "incubator areas" for
the organism. Cattle, horses, mules, sheep and goats may readily become
infected when grazing such areas.
- Outbreaks originating from soil-borne infection
primarily occur in warmer seasons when the minimal daily temperature is above
60° F.
- Man may develop localized cutaneous lesions
from contact of broken skin with infected blood or tissues. This lesion
usually begins as an itchy bump that resembles an insect bite. Within a day or
two, the bump develops a vesicle and then a painless ulcer, usually 1 to 3
centimeters in diameter, with a characteristic dying area in the center.
Adjacent lymph glands may swell.
- If a person inhales anthrax spores, the initial
symptoms may resemble a common cold. The cold-like symptoms may progress to
severe breathing problems and shock. Inhalation anthrax is usually fatal.
- The intestinal form of anthrax that can occur
from eating contaminated meat is characterized by inflammation of the
intestinal tract. Initial symptoms, including nausea, loss of appetite,
vomiting followed by abdominal pain, vomiting of blood and severe diarrhea.
- The normal incubation period for anthrax in
humans is three to seven days.
Bovine Spongiform Encephalopathy (Mad Cow Disease)
Cattle and sheep
- The prevailing belief is the agent is a mutated
protein molecule called a prion which causes progressive degeneration of the
nervous system
- Studies have identified the Bovine Spongiform
Encephalopathy (BSE) agent only in the nervous tissue (brain, spinal cord and
eye) of clinically affected cattle and the digestive tract (intestine) of
experimentally infected cattle.
- Spread of the disease was associated with
contaminated feed and meat and bone meal where the disease agent was not
destroyed by the rendering process. The disease does not appear to spread from
animal-to-animal although calves born to cows suffering from the disease show
an increased risk of getting BSE themselves.
- BSE has spread to other species through
contaminated feed (cats and antelope) and through experimental exposure
through injection and/or feed (sheep, goats, pigs and monkeys).
- BSE has spread to other countries by selling
infected cattle and by selling infected meat and bone meal for animal feed.
- Changes in temperament such as nervousness or
aggression.
- Abnormal posture, uncoordinated and difficulty
in rising.
- Decreased milk production and/or loss of body
weight despite appetite.
- Only way to detect is examination of brain
tissue or by the detection of the abnormal form of the prion protein.
Scrapie
Sheep and less often of goats
- It is characterized by loss of wool, intense
itching, altered gait, debility and trembling.
- When trembling is the dominant sign, intense
itching may be absent.
- The disease is rarely seen in animals less than
two years old.
- Affected sheep become more excitable, and fine
tremors of the head and neck may be observed.
- The most characteristic feature is intense
itching, which often begins over the rump, and may extend to other parts. In
some cases, the itching makes it difficult for the animal to feed and rest
normally.
- Nervous signs may be elicited from a quiet but
affected sheep by sudden noise or movement.
- The wool is dry, separable, and brittle,
resulting in loss of fleece over large areas.
- Some areas may be rubbed raw.
- Sheep will nibble at their limbs in an effort
to relieve the itching and are emaciated, weak and uncoordinated in the
hindquarter in the later stages, and are unable to rise.
- When make to trot, there is often a peculiar
high-stepping action of the forelegs, sometimes with galloping movements of
the hind legs.
- Animals live about 1½ to 6 months following the
onset of signs.
- The agent causing Scrapie is carried in and
passed to the young through germplasm. However, infection of the lamb may come
directly from the dam because their close association facilitates oral or
nasal transmission of the infectious agent.
- It is not found in lambs less than 9 months
old.
Avian Influenza (AI)
Domestic and wild birds
- A viral disease characterized by the full range
of responses from almost no signs of disease to very high mortality.
- The incubation period also is highly variable,
and ranges from a few days to a week.
- Respiratory signs are commonest, but disease
signs range from only a slight decrease in egg production or fertility to an
exploding infection.
- In severely affected hosts, greenish diarrhea,
edema of the head, comb, and wattle, bloody discoloration of the shanks and
feet, and bloodstained oral and nasal discharges are common.
- Severe respiratory signs with excessively
watery eyes and sinusitis.
- Sinusitis is not uncommon in ducks, quail and
turkeys.
- Location and severity of gross lesions are also
highly variable and may consist of hemorrhages, oozing a liquid through the
pores and necrosis in the respiratory, digestive and urogenital systems.
Newcastle
Domestic and wild birds
- Caused by an RNA virus
- Highly pathogenic and easily transmitted
- Two types – neurotropic (respiratory and
nervous signs) and viscerotropic (respiratory signs, watery-greenish diarrhea,
swelling of the head and neck)
- Onset is rapid and signs appear simultaneously
throughout the flock 2½ days after exposure.
- Respiratory signs include gasping, coughing,
sneezing and rales
- Nervous signs include drooping wings, dragging
legs, twisting of the head and neck, circling, depression, inappetence, and
complete paralysis
- Motility can occur with either type and can
reach 100%
Spring Viremia of Carp Virus
Cultured fish including cyprinids like common carp, koi, grass carp and
goldfish
- SVC multiplies in fish during the winter and
then kills fish in the spring as the water warms. It is possible for outbreaks
to occur in the fall if temperature patterns are right.
- The most likely temperature range for SVC fish
kills is 10-20° C (60-70° F). Fish kills occurring at temperatures greater
than 70° F are not likely to be SVC.
- Lesions on fish infected with SVCV look a lot
like fish with other bacterial or parasitic diseases and do not serve as
useful indications that the disease is present.
- Typical signs are swollen abdomen, red patches
on the skin and red spots on the swim bladder.
- When temperatures are right, mortality may be
very high.
- The only way to prevent SVCV is to avoid
introducing the virus.
- European SVCV experts believe that the virus
will not survive for long periods in the southern U. S. where summer water
temperatures are high. If this is correct, then virus introduced in the fall
might propagate through the winter and kill fish in the spring, but it is
unlikely to survive through the summer.
West Nile Virus
Domestic and wild birds, horses and man
- The most serous manifestation of West Nile
Virus infection is fatal encephalitis (inflammation of the brain) in humans
and horses, as well as mortality in certain domestic and wild birds.
- Humans can become infected from the bite of
mosquitoes infected with the West Nile Virus.
- Mosquitoes become infected when they feed on
infected birds, which may circulate the virus in their blood for a few days.
Infected mosquitoes can then transmit West Nile Virus to humans and animals
while biting to take blood.
- The virus is located in the mosquito’s salivary
glands. During blood feeding, the virus may be injected into the animal or
human, where it may multiply, possible causing illness.
- The spread of West Nile Virus is tracked by
surveillance of mosquitoes and sentinel birds. Crows have become the primary
sentinel species because they seem to be particularly susceptible to West Nile
Virus-caused fatalities.
- "Mosquito Hygiene" includes source reduction of
mosquito breeding sites and avoidance of biting mosquitoes – both are key to
reducing risk from West Nile Virus.
- Eliminating mosquito-breeding sites is
important to reduce mosquito numbers. Clean out rain gutters, aerate swimming
pools and ponds, empty unused buckets, water trough, etc., keep unused tires
under cover so they do not collect water, drill drainage holes in tires and
other containers used in construction sites, farms, gardens and play areas,
clean bird baths and animal water bowls at least once a week, and avoid
mosquito bites by wearing long clothes and/or by using insect repellent when
out after dusk or in shaded areas (such as woods) during the daytime hours.
- Human symptoms include fever, disorientation,
muscle weakness, neck stiffness, headache, and nausea. Older people and the
immuno-compromised are at greater risk of becoming seriously ill from West
Nile Virus.
- Owners should consider vaccinating horses for
protection.
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