Download Diseases and Parasites of Beef Cattle

Diseases and Parasites
of
Cattle
Vital Signs of Beef Cattle
• Temp. 100.4-102.8 avg. 101.5
• Pulse 60-70 BPM
• Respiration 10-30 breaths per minute
Anthrax
• Caused by bacteria that may remain in the
soil for 40 years or longer
– Bacteria only become active under certain conditions.
• Infection results from grazing infected
pastures.
• Bacteria enter through the mouth, nose or
open wounds.
• Biting insects may spread the disease from
one animal to another
The Anthrax Cycle
Symptoms
• Sudden death-usually within a few
hours of symptoms
• Less acute symptoms
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High fever
Sudden staggering
Hard breathing
Trembling
Collapse
What to Do
• Carcasses should be burned or buried at
least 6’ deep and covered with quicklime
– Take care not to bury the animal near wells
or streams.
Prevention
• Vaccination
• In problem areas vaccination should
occur yearly
• Where it is not common, vaccinate on
the recommendation of a vet.
Anthrax
Bovine Spongiform
Encephalopathy (BSE)
• Chronic, degenerative disease
• Affects the central nervous system
• 1 of several brain disease called Transmissible
Spongiform Encephalopathy's (TSE’s)
• Other TSE’s
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Chronic Wasting Disease in deer and elk
Feline Spongiform Encephalopathy
Transmissible Mink Encephalopathy
Creutzfeldt-Jakob Disease (CJD- ID in the 1920’s)
New variant CJD (nvCJD ID in 1995)
Gertsmann-Straussler-Scheinker Syndrome
Kuru
BSE in the United States and the
World
• Rare
• 3 cases in the United States
• First diagnosed in Great Britain in 1986
– The US has not imported any beef from
Great Britain since 1985
• USDA and the APHIS maintain
constant surveillance and enforce import
restrictions.
Symptoms
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Nervousness or aggression
Muscle twitching
Abnormal posture
Loss of body weight
Decrease in milk production
Difficulty in rising after lying down
Eventual death
Causes of BSE
• Not fully known
• Related to a prion
– Prion- a microscopic protein particle that is
similar to a virus but lacks nucleic acid
• May be contracted by ingesting protein
in feed that came from an animal source
that was contaminated
– Believed to have been caused by feeding
cattle renderings from Scrapie infected
sheep
• 1997 the FDA banned using ANY
mammal derived protein in cattle feed in
the US
Incubation of and Testing for BSE
• Ranges from 2-8 years
• Death occurs within 2 weeks to 6 months after
clinical symptoms appear
• No test to determine if live cattle are infected
• Only a postmortem microscopic examination
of the brain can determine if the animal had
BSE
– Brain tissue in infected animals has a
spongy appearance when examined under a
microscope
• There is no treatment for BSE
BSE
Bovine Virus Diarrhea (BVD)
• Common throughout the United States
• May appear in mild, acute & chronic
forms
• Spreads by contact
Mild BVD
• Often no symptoms
• If they are present:
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Fever
Coughing
Discharge from the nose
Slow gains
Rapid breathing
Mild diarrhea
• Animals that have had the mild form of
the disease are immune to further
infection.
Acute BVD
• Fever
• Difficult breathing
• Discharges from the
nose and mouth
• Possible lameness
• Dehydration
• Weight loss
• Diarrhea after 3-7
days
• Pregnant animals may
abort if contracted with
in the first 2 months of
pregnancy
• Fetus’s may mummify if
contracted from the 90120th day of pregnancy
• Fetus may also suffer
brain damage,
hairlessness and
underdeveloped lungs in
later stages of
pregnancy
Chronic BVD
• All the same symptoms as the acute plus
– Slow gains
– Rough hair coat
– Lameness
Prevention
• Modified live virus vaccine
• Vaccinate calves between 1 day of age and 3 weeks before
weaning
• May be vaccinated upon arrival in the feedlot
– They should not be vaccinated if they were vaccinated
as calves
• Pregnant cattle should not be vaccinated
• Adult cattle should only be vaccinated
– After calving
– At least 3 weeks before breeding
• Replacement heifers should be vaccinated between 9 & 12
months of age but not during the last 3 weeks before
breeding
• No cure
Brucellosis
• Caused by microorganisms
• Results in heavy economic losses
• Less common due to state and federal
eradication programs—all states are
now free of brucellosis in domestic cattle
herds
• Dangerous to humans
Symptoms
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Abortion during the last ½ of pregnancy
Retaining of afterbirth (placenta)
Sterility in cows and bulls
Reduced milk flow
Enlarged testicles
Weak calves (if born from infected cows)
Brucellosis Spreads By…
• Bringing infected cattle into the herd
• Fence line contact with infected animals
• Aborted fetus’s that carry the Brucella
organism being carried to other farms by
dogs and other carnivorous animals
• Calves being infected by their mothers
• Cattle coming in contact with feed or
water where the organism is present
• Sniffing or licking an aborted fetus or
calf from a cow that has the disease
Prevention and Cure
• No cure
• Prevention is accomplished by good herd
management
Blackleg
• Caused by bacteria that grow only in the
absence of oxygen
• When exposed to air the bacteria form a
spore and may live in the soil for many
years
• Spores enter the animal through the
mouth or wounds
• Young animals are more commonly
affected
Symptoms
• First sign is one or more animals
suddenly die
• Before death symptoms are:
– Lameness
– Swollen muscles
– Severe depression
– High fever (in early stages)
– Animal may be unable to stand
Prevention
• Vaccination
• Calves are vaccinated when young
(typically in the spring at branding or
shortly after calving) and again at
weaning (fall)
• Dead animals should be burned or
buried
Treatment
• Massive doses of antibiotics
• Treatment is only effective if diagnosed
early
• Prevention is more effective and less
costly.
Scours
• Disease complex (group of diseases)
• Most common in fall, winter and spring
• Affects young calves
– calves over 2 months of age are seldom
affected
Symptoms
• Acute
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Shock
Nose, ears and legs are cold
Diarrhea
Sudden death
• Chronic
– Symptoms for several days
– Weight loss
– Death after several days if not treated
Prevention
• Sanitation
– Clean barns and buckets for bucket calves
• Calf needs colostrums (first milk)
• Supplement the cows diet with Vitamin
A before calving
• Vaccines (most common types of scours)
– Vaccinate mothers at least 30 days prior to
calving
Treatment
• Antibiotics
• Sulfa drugs
Foot Rot
• Caused by a variety of bacteria, fungi
and other organisms found in feedlots
• Enter the body when the skin of the foot
is broken
• Muddy, manure filled feedlots only
increase the problem
Symptoms
• First noticeable sign is lameness
• Other symptoms
– Loss of appetite
– Fever
– Depression
– Animals may not want to stand or move
around
• Death may eventually result
Prevention
• Sanitation and paved lots work best
• Good drainage and mounds in the
feedlot also help prevent conditions that
encourage the disease.
• Spreading lime and 5% blue vitriol
around water tanks and feed bunks
Treatment
• Penicillin
• Wide spectrum antibiotics
• Sulfa drugs
Lump Jaw
• Chronic
• Rarely causes death
• Results in economic losses because the
affected body part is condemned at slaughter
• Affects the jaw and surrounding bony part of
the head
Symptoms
• Tumors or lumps on the jaw.
• Loose teeth
• Spongy jaw bone resulting in breathing
problems.
• Weight loss due to difficulty eating
Treatments and Prevention
• Surgical treatment may allow the
animal to remain marketable but
complete recovery is usually not
possible.
• To prevent keep sharp objects out of
the feedlot or pasture.
Pinkeye
• Carried by insects
• Affects the eye of the animal
• A viral form of pink eye is associated with
IBR
• White faced cattle and those with pink skin
pigment around the eye are more likely to
be infected
• Pinkeye occurs year round but is most
common during periods of maximum
sunlight.
Mild Pinkeye
• Eyeball develops a pinkish color
• Cornea becomes slightly clouded
Acute Pinkeye
• Flowing of tears
• Cloudiness of cornea
• As the infection progresses the cloudy
condition becomes worse and ulcers may
develop on the eye
• The eye may become so damaged that
blindness results
• The condition may last 3-4 weeks and if not
treated will spread to the whole heard
Spread By
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Insects
Direct Contact with infected animals
Dust
Tail switching
Prevention
• Control flies and insects
• Vacinate
Treatment
• Isolated in a dark place
• Apply Antibiotics and sulfa drugs to the
eye
• A cloth patch can be used on the affected
eye
Shipping Fever (PI3 Pasteurella,
Bovine Respiratory Disease)
• A disease complex that affects the
respiratory tract
• Most common in young cattle at times of
stress
Stresses
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Moving from range to the feedlot
Extremes of heat or cold
Exhaust fumes
Hunger
Fright
Rough handling
Symptoms
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Early on----fever
Depression
Drooping ears
Discharge from the nose
Watery eyes
Loss of appetite
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Diarrhea
Weight loss
Difficult breathing
Coughing
Pneumonia
Possibly death
If the animal recovers it
will be slow to gain
Prevention
• Vaccination after 4 mo. of age
• Best time is 3-4 weeks before
weaning/shipping
• Reducing stress and exposure
• Good feedlot management and careful
handling of new cattle
Treatment
• Antibiotics
• Sulfa drugs
• Treatment must begin as soon as
symptoms are noticed
• Treatment after an animal has
developed pneumonia is of little value.
Trichomoniasis
• A venereal disease caused by a protozoan,
Trichomona fetus
• Infects the genital tract of the bull and is
transmitted to the cow during breeding
• Clean bulls can also be infected by
breeding “dirty” cows
• Can also be transmitted through infected
semen, even when artificial insemination is
used.
Symptoms
Abortion in early gestation
Low fertility
Irregular heat periods
Uterine infection
Cows may have discharge from their genital tract
Bulls may not show any symptoms but still be capable
of transmitting the disease during breeding
• Identified by microscopic examination of material
from an aborted fetus, the prepuital cavity of the bull
or vaginal discharge from the cow
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Trich Prevention
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Semen testing
Testing cows before breeding
Using only clean bulls on clean cows
Selling all open cows
Vibriosis
• Reproductive disease
• Both intestinal and venereal
• Leading cause of infertility and abortion
in the cattle industry
Vibrosis
• Intestinal form has little harmful effect
• Venereal form is more serious
• If the organism infects the uterus there
will be some abortion in the herd
• Number of cows infected is usually small
• Cows do not become sterile and bulls are
not affected.
Symptoms
Infertility
Abortion
Irregular heat periods
In newly affected herds
conception rates may
drop below 40%
• Calving season is longer
• More open cows in the
fall
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• In chronically infected
herds
– Conception rate is lower
than normal-about 6070%
– Heifers or new additions
will require repeat
breeding or will abort
Prevention and Treatment
• Vaccinate animals 30 days prior to breeding
▫ Vaccination must be repeated every year
• Bulls may be treated with antibiotics but the process
is difficult
• Cows may settle easier if treated with antibiotics
• Skipping two heat cycles before attempting to breed
the cow usually improves the conception rate of
infected cows
• Cows with the disease eventually develop immunity
and will breed again
• The use of AI helps in prevention because the semen
used for AI is treated with antibiotics to eliminate
disease organisms.
Ringworm
• A contagious skin disease that can be spread
to other animals and humans
• Symptoms
– Round, scaly patches of skin that lack hair
• The affected area clears up but moves to
another part of the body
• Sanitation
• Isolate infected animals
• Treat with iodine tincture or quaternary
ammonium compounds
Ringworm