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Salmonellosis in Cattle
Randall
J. Berrier, DVM
Staff Veterinarian
Technical Service
GENERAL INFORMATION AND SYMPTOMS
Salmonellosis is a bacterial disease with a rising prevalence
in the cattle industry. It is most common in dairy calves one
to ten weeks of age, but can also be seen in adult dairy cows
and beef cattle. Salmonellosis has a serious economic impact
on the cattle industry worldwide. Livestock mortality,
treatment costs, abortion, reduced production, discarded milk
and reduced consumer confidence all contribute to the cost of
salmonella to cattle industries.
Fecal contamination of feed and water from shedding cattle to
naïve cattle is the most common source and route of
infection. Contaminated milk, contaminated processed feeds,
and improperly cleaned calf-feeding equipment can also serve
as sources of infection. Ravens, opossums, pigeons, rats and
mice can also serve as carriers or vectors.
The top two most common isolates from cattle at the National
Veterinary Services Laboratories are: 1) Salmonella
typhimurium and 2) Salmonella dublin. Once
ingested, salmonellae colonize and multiply in the intestine
resulting in acute infection. Typical clinical signs of acute
salmonella enteritis include fever and severe watery diarrhea
with subsequent rapid onset of dehydration. The diarrhea is
usually putrid and may contain blood and mucus. Salmonellae
produce toxins that can contribute to gut damage and have
systemic effects. If sufficient damage occurs to the
intestinal lining, the bacteria may enter the bloodstream,
resulting in septicemia, and the bacteria can spread to the
brain, lungs, joints, uterus (causing abortion in pregnant
cows) and other organs.
Cattle can be chronically infected and serve as carriers
within the herd without exhibiting clinical signs. It has been
reported that one carrier cow can shed one billion salmonellae
a day in the feces.
Salmonellosis is also a significant public health concern.
Humans and other animals can become infected from consumption
of contaminated drinking water, raw dairy and milk products,
and undercooked meat products.
TREATMENT
Successful treatment by your Veterinarian for bacteremia
caused by Salmonella includes:
-
Fluids and
electrolytes,
-
Antimicrobial drugs
and
-
Non-steroidal
anti-inflammatory drugs.
The use of antibiotics for
salmonella enteritis without septicemia (bacteremia) is
controversial. The population of normal intestinal bacterial
microflora may be altered as well as the possible development
of antibiotic resistance by salmonella organisms.
CONTROL AND PREVENTION
Prevention should involve two avenues, the first being
decreasing the chances of exposure to the organism and the
second being increasing resistance in cattle.
Critical control points to decrease exposure risks in dairy
cattle are:
-
Have herd serotested
and cull carrier cows.
-
Quarantine and
serotest replacement stock.
-
Isolate sick cows. Use
only antimicrobials approved by your veterinarian.
-
Avoid wet areas,
provide dry loafing areas, clean and disinfect calf pens
and maternity area between calves.
-
Use clean flush water.
Use only water from milking parlor.
-
Check feed commodities
for salmonella. Store and handle feed properly.
-
Control infected
rodents and birds.
-
Do not allow rendering
trucks access to feed or animal areas. Do not use
front-end loaders for manure or to haul dead animals and
then haul feed with them.
-
Avoid prophylactic use
of antibiotics.
Increasing resistance in
the young calf can be accomplished in two ways. One method is
to vaccinate pregnant cows in late gestation with a salmonella
bacterin. The pregnant cow will respond by producing increased
antibodies to salmonella that will be passed on to the calf
through the colostrums. Salmonella bacterins are also helpful
in building immunity when salmonellosis is a problem in adult
beef and dairy cows. Some less common and exotic salmonella
serotypes may not respond to vaccination with the Salmonella
dublin – typhimurium bacterin and may require an
autogenous bacterin to be made specifically for your herd. The
second method to increase resistance is to supplement the
antibodies by administering an antibody solution containing
additional antibodies to salmonella. BOVI-SERA contains
antibodies to Salmonella and will supplement the protection
the calf received when it consumed colostrum from the cow
early in life. BOVI-SERA can also be given later in life when
the calves’ own immune system isn’t fully developed.
It is recommended that
producers consult with a veterinarian before instituting a
treatment, prevention or control program.
Colorado Serum Company
proudly produces SALMONELLA DUBLIN-TYPHIMURIUM BACTERIN and
BOVI-SERA to assist producers and veterinarians with
Salmonella control and prevention in cattle.
Reference: Bradford P. Smith, DVM, ACVIM;
and John K. House, BVMS, ACVIM; University of California,
Davis.
Salmonellosis is a
bacterial disease with a rising prevalence in the cattle
industry. It is most common in dairy calves one to ten weeks
of age, but can also be seen in adult dairy cows and beef
cattle. Salmonellosis has a serious economic impact on the
cattle industry worldwide. Livestock mortality, treatment
costs, abortion, reduced production, discarded milk and
reduced consumer confidence all contribute to the cost of
salmonella to cattle industries.
Fecal contamination of feed and water from shedding cattle to
naïve cattle is the most common source and route of
infection. Contaminated milk, contaminated processed feeds,
and improperly cleaned calf-feeding equipment can also serve
as sources of infection. Ravens, opossums, pigeons, rats and
mice can also serve as carriers or vectors.
The top two most common isolates from cattle at the National
Veterinary Services Laboratories are: 1) Salmonella
typhimurium and 2) Salmonella dublin. Once
ingested, salmonellae colonize and multiply in the intestine
resulting in acute infection. Typical clinical signs of acute
salmonella enteritis include fever and severe watery diarrhea
with subsequent rapid onset of dehydration. The diarrhea is
usually putrid and may contain blood and mucus. Salmonellae
produce toxins that can contribute to gut damage and have
systemic effects. If sufficient damage occurs to the
intestinal lining, the bacteria may enter the bloodstream,
resulting in septicemia, and the bacteria can spread to the
brain, lungs, joints, uterus (causing abortion in pregnant
cows) and other organs.
Cattle can be chronically infected and serve as carriers
within the herd without exhibiting clinical signs. It has been
reported that one carrier cow can shed one billion salmonellae
a day in the feces.
Salmonellosis is also a significant public health concern.
Humans and other animals can become infected from consumption
of contaminated drinking water, raw dairy and milk products,
and undercooked meat products.
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