Yersiniosis
Yersiniosis occurs in a variety of domestic animals. Disease is usually associated with Yersinia pseudotuberculosis or Yersinia enterocolitica. However, Y intermedia, Y kristenseni and Y frederickseni occasionally cause disease. Yersiniosis can be manifest as one or more of the following conditions:
- Enterocolitis and diarrhoea
- Systemic abscesses and mortality
- Placentitis, abortion and perinatal mortality
- Pneumonia
- Mastitis
- Epididymo-orchitis
In addition, specific entities have been associated with Y pestis in domestic carnivores (plague) and Y ruckeri in fish (enteric redmouth).
Syndromes associated with yersiniosis (Y pseudotuberculosis and Y enterocolitica) in domestic animals:
Cattle
Y pseudotuberculosis
- Enterocolitis, diarrhoea, "flood mud scours", mortality
- Placentitis, abortion, perinatal mortality
- Pneumonia
- Mastitis
Y enterocolitica
- Abortion
Sheep
Y pseudotuberculosis
- Enterocolitis, diarrhoea, ill thrift, mortality
- Systemic abscessation, "pyaemic hepatitis"
- Placentitis, abortion, perinatal mortality
- Epididymo orchitis
Y enterocolitica
- Enterocolitis, diarrhoea, ill thrift
Goats
Y pseudotuberculosis
- Enterocolitis, mortality
- Placentitis, abortion, perinatal mortality, endometritis, infertility
- Systemic abscessation
- Mastitis
Y enterocolitica
- Enterocolitis, mesenteric lymphadenitis, diarrhoea, ill thrift, mortality
Deer
Y pseudotuberculosis and Y enterocolitica
- Enterocolitis, diarrhoea, mortality
- Systemic abscessation
Pigs
Y pseudotuberculosis
- Mild enterocolitis, mild diarrhoea
- Mild systemic abscessation
Y enterocolitica
- Mild enterocolitis, mild diarrhoea
Poultry (domestic fowl, turkeys, ducks, geese)
Y enterocolitica
- Acute septicaemia, enteritis, splenomegaly, diarrhoea, mortality
- Chronic systemic abscessation, chronic enteritis, diarrhoea, ill thrift
- Systemic myositis (turkeys)
Diagnosis
Clinical signs, bacteriology, histopathology.
Recovery of Yersinia spp from the alimentary tract and internal organs using routine and selective media.
NB. Many Yersinia spp inhabit the intestinal tract of clinically healthy animals and a diagnosis of enteric yersiniosis is confirmed by finding typical histological lesions in sections of the intestine and internal tissues.
Recovery of Y pestis is important in view of the zoonotic potential of this bacterium.
Y ruckeri is of regulatory importance in fish.
Specimens required
- Samples of faeces, intestinal contents (particularly ileal contents) and fresh tissue submitted chilled for bacteriology.
- Portions of tissue fixed in neutral buffered formalin for histopathology. Samples of fixed internal organs with lesions should be taken if systemic disease is suspected. Segments from all levels of the intestinal tract, particularly ileum and caecum, as well as mesenteric lymph nodes should be taken in cases of enterocolitis.
- Samples suitable for diagnosis of other causes of diarrhoea, pyaemia, abortion, pneumonia, mastitis and epididymo-orchitis should be collected as appropriate to the syndrome under investigation.