127. Salmonella diseases of swine. Flashcards
Swine typhoid Occurence ethiology and epidemiology?
SWINE TYPHOID
OCCURRENCE, ETIOLOGY AND EPIDEMIOLOGY
- Occurrence
- Formerly common, nowadays rare, exceptional
- Ethiology
- Causes by S. typhisuis,
- only swine are susceptible,
- antigen is identical with S. choleraesuis
- Epidemiology
- Introduction with infected asymptomatic animals and fecal contamination
- Obligate pathogen,
- long presence in the farm/herd
- Slow spreading, chronic disease
- Mainly in growing-finishing pigs (above 5-6 weeks of age)
- Good management
- losses can be reduced
Pathogenesis of swine typhoid?
PATHOGENESIS
- Oral infection,
- get into large intestine
- replicate in lymphoid patches
- inflammation,
- necrosis of the mucous membrane and ulcers get into the gut wall and to the mesenterial lymph nodes
- Blood stream(Bacteraemia)
- Parenchymal organs
- Focal inflammation and necrosis ʹ typhoma in lungs, spleen, liver, kidney etc.
- Carriers and shedders for a long time,
- Practically life long
Clinical signs and pathology of swine typhoid?
CLINICAL SIGNS
- Chronic and slow, weight loss,
- anorexia, diarrhea (watery, yellow, stinking),
- abdominal pain, increasing cough,
- retardation in growth (underdeveloped)
- Pathology
- Large intestine have enlarged lymphoid patches, ulcers (crater-like),
- fibrin between bowels,
- sometimes
- the bowels are attached to each other
- Lungs have grey and congested areas,
- focal inflammation and necrosis on organs and tonsils
Diagnosis and differential diagnosis of swine typhoid?
DIAGNOSIS
- Epidemiology, clinical signs and pathology ʹ quite typical! Can get diagnosis on the spot
- Detection of agent
- Bacterium isolation from parenchymal organs
- Identification serotyping!
- Antigenic structure is identical to S. cholerasuis
- Differentiation from S. choleraesuis
- Detection of antibodies ʹ cannot be used because of the antigenic structure Æ S. choleraesuis!
- Differentials
- Paratyphoid, coli diarrhea (suckling piglets),
- proliferative enteropathies,
- swine dysentery (lesions are different ʹ extended necrosis, most typical in adult animals)
o Viral infections:
- PMWS
- TGE (younger animals)
- epidemic diarrhea (younger animals)
Treatment and prevention of swine typhoid?
TREATMENT AND PREVENTION
- Movement restriction
- movement only to slaughter house
- not keeping animals to breeding or selling
- Antibiotic treatment
- Stamping out the herd is recommended
Swine paratyphoid occurence ethiology and epidemiology?
SWINE PARATYPHOID
OCCURRENCE, ETIOLOGY AND EPIDEMIOLOGY
Occurrence
- Worldwide occurrence,
- relatively frequent,
- getting less common due to eradication programs
Ethiology
- S. choleraesuis (from swine),
- S. typhimurium,
- S. derby and other serovars (from environment)
- Facultative pathogens
Epidemiology
- Acute, generalized disease
- agent is present in the herd,
- most frequently occur in 2-5 month old animals
- Predisposing factors ʹ overcrowding, cold, mixing, transportation, feed, viral infections
- Shedding in large numbers,
- limited to one flock
Pathogenesis, clinical signs and pathology of swine paratyphoid?
PATHOGENESIS, CLINICAL SIGNS AND PATHOLOGY
- Per os infection
- small intestine, cause inflammation
- blood => septicemia
- parenchymal organs
- Incubation period of 2-3 days
- C.S.
- fever (42°C),
- anorexia, depression, cyanosis,
- Diarrhea (yellow, creamy, watery)
- If animal survives acute phase
- chronic ʹ pneumonia, cough, arthritis, tenosynovitis (lameness)
- Pathology
o Acute ʹ cyanosis, hemorrhages, hyperplastic spleen, enlarged lymph nodes, gastroenteritis (small Int.)
Liver ʹ focal inflammation and necrosis (histology)
Chronic ʹ necrosis of mucous membranes of the gut (small int.), ulcer of lymphoid patches, sometimes
ulcers in large intestine
Diagnosis of Swine paratyphoid?
DIAGNOSIS
- Epidemiology, clinical signs and pathology
- Detection of agent ʹ bacterium isolation ʹ
intermittent shedding; dead animals Æ
parenchymal organs
- Detection of antibodies ʹ Agglutination and ELISA
- Differentials
- Generalized diseases with fever
- CSF
- ASF
- Aujezky-disease
- erysipeloid
- A. pleuropneumonia
- Cyanosis
- PDNS
- PRRS
- Diarrhea coli diarrhea
- proliferative enteropathy
- swine dysentery
Treatment and prevention of swine paratyphoid?
TREATMENT AND PREVENTION
- Antibiotic treatment ʹ tetracyclines, fluoroquinolones, wide spectrum antibiotics
- Diseased animals ʹ parenteral treatment, Herd ʹ medicated water
- Carriage of bacteria
- Prevention of predisposing factors, general epidemiological measures ʹ all-in-all-out
- Hygiene ʹ removing dung, slurry, disinfection
- Vaccines ʹ vaccination around weaning, inactivated, attenuated, reduce the risk and financial losses, but cannot
- completely prevent the disease
- Eradication ʹ difficult, but important
Typhocolitis of swine Occurence ethiology and epidemiology?
TYPHOCOLITIS OF SWINE
OCCURRENCE, ETIOLOGY AND EPIDEMIOLOGY
OCCURRENCE
- More frequent
Ethiology
- Caused by S. typhimurium and other salmonella serotypes
- Mainly in growers and finishing pigs,
Epidemiology
- Morbidity 100%,
- mortality 4-5%,
- after treatment Æ carriage
Pathogenesis , clinical signs treatment and prevention of typhocolitis of swine?
PATHOGENESIS
- P.O. infection
- Æ intestine Æ inflammation
Clinical signs:
- Yellow, watery diarrhea,
- bloody diarrhea,
- sometimes mucoid feces
Pathology
- large intestine: necrotic enterocolitis, typhlitis
TREATMENT AND PREVENTION
- P.O. antibiotics (resistance)
- No vaccines, elimination of predisposing factors
- isolation from birds and rodent control
Asymptomatic carriage of salmonella by swine Ethiology and pathogenesis?
ASYMPTOMATIC CARRIAGE OF SALMONELLA BY SWINE
ETIOLOGY
- S. typhimurium and S. Derby,
- other salmonella serotypes
Pathogenesis
- Infection from environment (other animals, feces from other animals, soil etc.)
- Limited to the gut, stress (transportation)
- Bacterium can get into blood and muscles
- Shedding, contamination can happen at slaughter
Clinical signs treatment and prevention of salmonella of swine?
CLINICAL SIGNS, TREATMENT AND PREVENTION
- Exceptional clinical signs ?
Treatment
- Antibiotic treatment does not eliminate salmonella
- probiotics to restore the gut flora
Prevention
- General epidemiological measures,
- Hygiene, probiotics & prebiotics to restore gut flora
- Vaccines ʹ can reduce the carriage and shedding rate of the agent
Eradication of salmonella species?
ERADICATION
- Aim ʹ reducing infection below 1% and reach free state
- Control of eradication
- Bacteriological examination of ileocecal lymphoid tissue, bacteriological examination of slaughtered pigs
- examination of antibodies in meat juice
- Free ʹ examination of the feces of each animal,
- Two bacteriological negative results with interval of 1 month
- Eradication, reduction in Denmark
- Surveillance of blood, feces and meat juice, hygiene alone is not enough, nutrition (pellet, barley, dry/wet feed)
- Introduction of animals only from negative herds,
- Eradication can be reached with depopulation
