Diseases / List of Bacterial Diseases / Disease description:
Yersiniosis (with special reference to Waterfowl, Hedgehogs, Lagomorphs, Bears and notes on Elephants)

INFORMATION AVAILABLE

GENERAL INFORMATION

CLINICAL CHARACTERISTICS & PATHOLOGY

INVESTIGATION & DIAGNOSIS

TREATMENT & CONTROL

SUSCEPTIBILITY & TRANSMISSION

ENVIRONMENT & GEOGRAPHY

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General and References

Disease Summary
BIRDS Bacterial infection which may be seen as a chronic disease with caseous necrotic foci, enteritis or acute septicaemia.
MAMMALS Typically a disease of rodents and lagomorphs, but also seen in other species. (J514.1.w1)

Rodents:

  • Common infection of rodents especially cavies (guinea pigs). (B603.3.w3, B614.8.w8)

Lagomorphs:

  • Yersinia pseudotuberculosis has been reported to cause internal abscesses and septicaemia in hares and rabbits. (B284.10.w10)
  • Rabbits: Yersiniosis is moderately common in wild rabbits but is rare in domestic pet rabbits. (B600.16.w16, B603.3.w3, B614.8.w8)
  • Hares: In Europe wild hares act as an important reservoir of this organism. (B614.8.w8)

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Alternative Names (Synonyms)
  • Pseudotuberculosis

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Disease Type
 Bacterial Infection

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Infectious/Non-Infectious Agent associated with the Disease
  • Yersinia pseudotuberculosis (= Pasteurella pseudotuberculosis) (= Shigella pseudotuberculosis) (B209.19.w19)
  • Yersinia enterocolitica (D48, J1.27.w13)
  • Yersinia pestis is considered a subspecies of Yersinia pseudotuberculosis. (B88)
  • Yersinia pseudotuberculosis is a small, Gram-negative rod. (J514.1.w1)

Pathogenesis of Yersinia pseudotuberculosis in rabbits:

  • This organism multiplies in the intestine and then invades the lymphoid tissue of the gastrointestinal tract. There is then haematogenous spread to the spleen and septicaemia. (B603.3.w3)

Infective "Taxa"

Non-infective agents

 --

Physical agents

 -- Indirect / Secondary

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References

Disease Author

 Debra Bourne MA VetMB PhD MRCVS (V.w5), Nikki Fox BVSc MRCVS (V.w103); Gracia Vila-Garcia DVM, MSc, MRCVS (V.w67)
Click image for main Reference Section

Referees

 William Lewis BVSc CertZooMed MRCVS (V.w129)

Major References / Reviews

Code and Title List

 B10.26.w10, B11.39.w7, B13.46.w1, B14, B15, B16.2.w2, B32.14.w18, B37.x.w1, B47, B209.19.w19
D48
P17.24.w3, P23.1999S.w8

Hedgehogs:
J3.128.w2, J138.61.w1
B22.27.w3, B282.21.w21
P17.24.w3

Elephants:
J267.26.w1

Lagomorphs:
B284.10.w10, B209.19.w19, B600.16.w16, B603.1.w1, B603.2.w2, B603.3.w3, B614.8.w8
J1.9.w6, J514.1.w1

Other References

Code and Title List

 Bears:
J1.25.w8, J1.25.w9, J1.27.w13, J4.181.w4
P9.2004.w6

Lagomorphs:
J1.39.w8, J9.172.w1, J319.9.w1, P17.24.w3

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Clinical Characteristics and Pathology

Detailed Clinical and Pathological Characteristics

General
  • Acute, subacute or chronic disease (D48, B209.19.w19)
  • Generally a mild to severe gastroenteritis, possibly with mesenteric lymphadenopathy, and in the most severe cases progressing to septicaemia. (B209.19.w19)
  • Signs are non-specific. (B282.21.w21)
WATERFOWL Usually chronic wasting disease, occasionally acute septicaemia (B15).
HEDGEHOGS Reported associated with severe diarrhoea and dysentery. (J3.128.w2)
LAGOMORPHS
  • Yersinia pseudotuberculosis has been reported to cause internal abscesses and septicaemia in hares and rabbits. (B284.10.w10)
  • A septicaemic disease is more likely to be seen in rabbits with yersiniosis rather than the gastrointestinal disease that is seen in other animals with this disease. (B601.8.w8)
Clinical characteristics Mammals
  • General: 
    • Non-specific signs may include lethargy/listlessness, anorexia, emaciation. (B16.2.w2, B209.19.w19)
    • Fever, usually biphasic 2-3 and five days post infection in rodents and lagomorphs. (B16.2.w2)
  • Gastro-intestinal signs: Diarrhoea. (B16.2.w2, B209.19.w19)
  • Respiratory: Respiratory distress. (B209.19.w19)
  • Locomotor: Incoordination. (B209.19.w19)
In chronic disease:
  • Marked weight loss, emaciation.
  • Dehydration.
  • May be 30% decrease in bodyweight in rodents and lagomorphs

(B16.2.w2)

Birds

  • May present as acute or chronic disease.
  • Non-specific signs. 
  • Birds may be seen fluffed up and lethargic.
  • Acute death or diarrhoea and general signs of acute septicaemia. 
  • In chronic cases weight loss, dyspnoea, diarrhoea, Inappetance, reduced mobility, lameness.

(D48, B11.39.w7, B14, B32.14.w18, B37.x.w1)

HEDGEHOG
  • Illness, sometimes fatal, with dysentery and severe diarrhoea. (J3.128.w2)
  • Chronic weight loss and hind leg weakness. (B22.27.w3)
LAGOMORPHS Clinical Findings in Rabbits: 
  • Wasting disease (B284.10.w10, B600.16.w16, B603.1.w1)
  • Dull coat (B284.10.w10, B600.16.w16)
  • Lethargy (B603.3.w3)
  • Occasional diarrhoea (B284.10.w10, B600.16.w16, B603.1.w1)
  • Jaundice if there is hepatic involvement. (B603.1.w1)
  • Nodular swelling of the liver. (B600.16.w16, B603.2.w2)

Lepus europaeus - Brown hare:

  • Acute to chronic disease. (J514.1.w1)
  • Dyspnoea. (J514.1.w1)
  • Diarrhoea. (J514.1.w1)
  • Death. (J514.1.w1)
  • Subcutaneous submandibular Yersinia enterocolitica abscesses were found in a wild hare in Belgium; the hare also had purulent conjunctivitis associated with a Pasteurella sp. infection (Pasteurellosis in Lagomorphs). (J1.27.w13)

Incubation

 WATERFOWL May be three to six days for acute infection, two week or more for chronic forms (general avian) (B32.14.w18).
HEDGEHOG --
LAGOMORPHS --
Mortality/ Morbidity

 

 Usually seen as a sporadic disease, but sometimes epidemics occur. (J514.1.w1)

In birds generally:

  • Sporadic mortality in wild birds, may be seen causing localised mortality incidents of garden birds (D48)
WATERFOWL --
HEDGEHOG
  • Fatalities reported. (J3.128.w2, B22.27.w3)
LAGOMORPHS
  • Important lethal disease of Lepus europaeus - Brown hare; up to 50% mortality in affected populations. (J514.1.w1)
  • The most important bacterial cause of death in some hare populations. Isolated from up to 60% in hares in some areas in France and Germany. (J1.9.w6)

Pathology

 Mammals

Gross pathology

  • Liver: granulomatous nodules, yeloow to grey, 1 - 3 cm diameter.
  • Spleen: sometimes enlarged; granulomatous nodules, yeloow to grey, 1 - 3 cm diameter.
  • Lungs: serofibrinous pneumonia. Sometimes granulomatous nodules, yeloow to grey, 1 - 3 cm diameter.
  • Mesenteric lymph nodes: granulomatous nodules, yeloow to grey, 1 - 3 cm diameter.
  • GIT: often necrotic lesions.

(B209.19.w19)

Histopathology

  • Granulomatous nodules: centrally caseous to liquified, and usually with bacterial colonies present, surrounded by lymphocytes and macrophages, without giant cells or encapsulation. (B209.19.w19)

Rodents and lagomorphs:

Gross pathology:

  • Liver: may be multifocal necrosis. 
    • Nodules may reach several centimetres in diameter. 
    • Larger nodules may have a caseous centre.
  • Spleen: may be multifocal necrosis.
    • Nodules may reach several centimetres in diameter. 
    • Larger nodules may have a caseous centre.

Histopathology:

  • Liver: Focal necrosis or microgranuloma with central liquefaction.
  • Spleen: Focal necrosis or microgranuloma with central liquefaction.

(B16.2.w2)

Birds

  • General - May be emaciated (with chronic disease) or normal body condition (acute disease)
  • Gastro-intestinal tract - inflammation (enteritis)
  • Liver - may be focal necrosis and granuloma formation.
  • Spleen - may be focal necrosis and granuloma formation.
  • Lungs - may be focal necrosis and granuloma formation.

(D48)
WATERFOWL Acute:
  • Liver and spleen enlarged, enteritis (catarrhal to haemorrhagic); with a slightly longer course the liver and lungs may contain grey-white miliary foci.

Chronic:

  • Granulomatous lesions (caseous yellow necrotic foci) in various organs (e.g. liver, lungs, spleen) and in musculature; also enteritis.

(B10.26.w10, B11.39.w7, B14, B15, B32.14.w18, B37.x.w1)
HEDGEHOG Gross Pathology:
  • Lesions typical of yersiniosis (pseudotuberculosis). (J3.128.w2); characteristic caseous-necrotic lesions. (J138.61.w1)
  • Hepatic: Caseous foci in the liver. (B22.27.w3)
  • Spleen: Caseous foci. (B22.27.w3)
  • Lymph nodes: "altered". (B22.27.w3)
LAGOMORPHS
  • Liver, spleen, intestine, mesenteric lymph nodes: multifocal caseous necrosis. (J514.1.w1)
  • Spleen: caseous necrotic lesions. (B600.16.w16)
  • Gastrointestinal tract: caseous necrotic foci of Peyer's patches at ileocaecal ampulla and also of other intestinal lymphoid aggregates. (B600.16.w16, B603.2.w2, B614.8.w8)
  • Liver: Nodular swelling and caseous necrosis. (B600.16.w16, B603.2.w2, B614.8.w8)
  • Mesenteric Lymph nodes: Caseous necrosis in advanced cases. (B600.16.w16, B603.3.w3, B614.8.w8)
  • General: other organs, including the kidneys and lungs, may also be involved. (B614.8.w8)

Lepus europaeus - Brown hare:

  • Subcutaneous submandibular Yersinia enterocolitica abscesses were found in a wild hare in Belgium; the hare also had purulent conjunctivitis associated with a Pasteurella sp. infection (Pasteurellosis in Lagomorphs). (J1.27.w13)

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Human Health Considerations
Can cause disease in humans (D48, J514.1.w1). Minimal importance as a zoonosis, but does occur as a rare human infection which can be severe or even fatal. (B10.26.w10, B15, B37.x.w1, B47, B209.19.w19)
  • Yersinia enterocolitica is more likely to cause disease in humans than is Yersinia pseudotuberculosis. (B209.19.w19, P23.1999S.w8)
  • Infection is by the faeco-oral route; transmission is more likely with poor hygiene. (P24.334.w4)
  • Disease has been reported after consumption of water which has been contaminated with faeces from wild animals. (B209.19.w19)
  • Consumption of wild hares in winter has been associated with yersiniosis in humans in Belgium. (B209.19.w19)
  • The incubation period in humans is 7 to 21 days. (B12.22.w13)
  • Disease syndromes include acute mesenteric lymphadenitis (presenting as pseudoappendicitis), erythema nodosum or enteritis. Septicaemia is rare, but when it occurs can lead to 50% mortality. (B12.22.w13, P24.334.w4) Polyarthritis can also occur. (P24.334.w4)

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Susceptibility / Transmission

General information on Susceptibility / Transmission
Mammals

Susceptible:

  • Wide range of mammals, particularly rodents and lagomorphs (B16.2.w2).
  • Infection is often latent and may become manifest under stress including e.g. poor food availability or inclement weather/exposure.  (P17.24.w3)

Transmission:

  • Transmission is most likely to be faeco-oral. (P23.1999S.w8)
  • Organism is excreted in the faeces of infected animals (B16.2.w2).
  • Transmission may occur through faecal contamination of food and/or water sources. (B209.19.w19)
  • In carnivores transmission also may occur through ingestion of infected prey. (B209.19.w19)
  • Ubiquitous in the environment. (J514.1.w1)

Birds

Susceptibility:

  • A range of bird species (D48).
  • Probably variation in susceptibility between species (D48).

Transmission:

  • Faecal contamination of food by infected animals including apparently healthy birds and rodents (B603.3.w3, D48)
  • Infection by ingestion of contaminated food (B603.3.w3, D48).
WATERFOWL Susceptible:
  • All species of waterfowl may be susceptible (B10.26.w10, B14).
  • Yersiniosis appears to be rare in waterfowl. Clinical disease may be linked to stressors such as food deprivation or bad weather (B11.39.w7, B15).
  • Very young birds may be more susceptible (B32.14.w18).

Transmission:

  • Infected animals may excrete the organism and contaminate food, soil and water (B32.14.w18). 
  • Infection by ingestion in contaminated food, or through a break in skin or mucous membranes (B10.26.w10, B11.39.w7, B14, B15, B32.14.w18, B37.x.w1).
LAGOMORPHS

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Disease has been reported in either the wild or in captivity in:

Hedgehogs:

Elephants:

  • One (0.3%) of 330 Loxodonta africana - African Elephant sera samples obtained from a culling operation in August to September 1975 in Wankie National Park, Zimbabwe (Rhodesia), showed antibodies against Yersinia pestis by the indirect haemagglutinating test. (J267.26.w1)

Bears:

  • Antibodies to Yersinia pestis were detected by ELISA in 19/125 sera (15%) from Ursus americanus - American black bear from California, USA. [1982](J4.181.w4)
  • Twenty-five (36%) of 69 Ursus americanus - American black bears serum samples obtained from 1983 to 1985 in Redwood National Park, California, showed antibodies against Yersinia pestis by the passive haemagglutination test. (J1.25.w9)
  • Yersinia enterolitica serogroup O5A and untyped strains were isolated from faeces of Ursus arctos - Brown bear from the Tokyo Tama Zoo in Japan in December 1985. The isolates were non-pathogenic (J1.25.w8)
  • Yersinia enterocoltica was isolated from an Ursus americanus - American black bear at a zoo in California during a survey after death of a bird from Yersinia pseudotuberculosis infection. (P9.2004.w6)

Lagomorphs:

  • Yersiniosis is moderately common in wild rabbits but is rare in domestic pet rabbits. (B600.16.w16, B603.3.w3, B614.8.w8)
  • Hares: In Europe, frequent isolation of Yersinia pseudotuberculosis from faeces or caecal contents from wild hares indicate these animals are an important reservoir of this organism. [1968] (B614.8.w8)

Further information on Host species has only been incorporated for species groups for which a full Wildpro "Health and Management" module has been completed (i.e. for which a comprehensive literature review has been undertaken). Host species with further information available are listed below:

Host Species List

 BIRDS:

MAMMALS:

(List does not contain all other species groups affected by this disease)

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Disease has been specifically reported in Free-ranging populations of:

Hedgehogs:

Elephants:

  • One (0.3%) of 330 Loxodonta africana - African Elephant sera samples obtained from a culling operation in August to September 1975 in Wankie National Park, Zimbabwe (Rhodesia), showed antibodies against Yersinia pestis by the indirect haemagglutinating test. (J267.26.w1)

Bears:

  • Twenty-five (36%) of  69 Ursus americanus - American black bears serum samples obtained from 1983 to 1985 in Redwood National Park, California, showed antibodies against Yersinia pestis by the passive haemagglutination test. (J1.25.w9)

Lagomorphs:

  • Yersiniosis is moderately common in wild rabbits but is rare in domestic pet rabbits. (B600.16.w16, B603.3.w3, B614.8.w8)
  • Hares: 
    • In 1968 in Europe, it was reported that Yersinia pseudotuberculosis was frequently isolated from the faeces or caecal contents from wild hares indicating these animals are an important reservoir of this organism. However, in Japan, similar attempts to isolate this organism from hares have reportedly [1984] been mostly unsuccessful, which suggests that a different species harbours Yersinia in that country. (B614.8.w8)

Further information on Host species has only been incorporated for species groups for which a full Wildpro "Health and Management" module has been completed (i.e. for which a comprehensive literature review has been undertaken). Host species with further information available are listed below:

Host Species List

 BIRDS:

MAMMALS:

(List does not contain all other species groups affected by this disease)

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Environment/Geography

General Information on Environmental Factors/Events and Seasonality
  • Seen in garden birds more commonly in winter. (D48)
  • Contaminated environment, including feed contaminated by faeces, is the source of infection. (B11.39.w7, B13.46.w1, B15)
  • Bad weather and severe winters may act as stressors and trigger clinical disease. (B13.46.w1, B15, B32.14.w18)
  • Seen most commonly in the winter months when exposure to cold and starvation are likely, particularly in free-living animals. (P17.24.w3)
  • Particularly a disease of winter, but year-round in wet areas. (J514.1.w1)

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Regions / Countries where the Infectious Agent or Disease has been recorded

  • Widespread, probably worldwide. (B16.2.w2, B32.14.w18)
  • In hares, important in some parts of Europe including France and Germany; also seen in the UK. (J1.9.w6)

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Regions / Countries where the Infectious Agent or Disease has been recorded in Free-ranging populations

  • Reported in a variety of free-living mammals and birds in the UK and on continental Europe. (P17.24.w3)
  • In hares, important in some parts of Europe including France and Germany; also seen in the UK. (J1.9.w6)

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General Investigation / Diagnosis

General Information on Investigation / Diagnosis
Mammals
  • Culture of the organism, from faeces or tissues, is required for definitive diagnosis. (B209.19.w19)

Rodents and lagomorphs:

  • Post mortem examination findings may be suggestive.
  • Culture of the organism (from blood or faeces, or from tissues at post mortem examination) is required for definitive diagnosis.
  • (B16.2.w2)

Birds

  • Post mortem examination findings (pale areas in liver and spleen) is suggestive.
  • Bacterial isolation from lesions and identification required for definitive diagnosis.

(D48).
WATERFOWL Post mortem examination findings of miliary foci or larger granulomas. Bacterial isolation and identification (N.B. bacterial growth and isolation may take two weeks) (B10.26.w10, B11.39.w7, B15, B37.x.w1).
LAGOMORPHS
  • Reaching a definitive diagnosis is difficult in the live rabbit.
    • Haematology: there may be changes in leucocyte morphology and numbers that is suggestive of a bacterial infection. (B603.3.w3)
    • Abdominal palpation: large spleen or nodular liver. (B603.3.w3) 
  • Post mortem examination: see pathology in the section above.
  • Isolation of the organism: from faeces or caecal contents. (B600.16.w16)
Related Techniques
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Similar Diseases (Differential Diagnosis)
Mammals (general)
  • Clostridial enterotoxaemias, gastro-intestional salmonellosis, and other bacterial septicaemias (e.g. pasteurellosis, plague, septicaemic salmonellosis and tularemia). (B209.19.w19)
  • Serological cross-reactions may occur between:
    • Salmonella groups B and D, some Escherichia coli strains, Enterobacter cloacae and Yersinia pseudotuberculosis serogroups II, IV, IVA, VI. (B209.19.w19)
    • Some Brucella spp. and Yersinia enterocolitica serogroup O:9. (B209.19.w19)
    • Salmonella factor O:47 and Yersinia enterocolitica serogroup O:12 (B209.19.w19)
    • Vibrio cholerae and Yersinia enterocolitica. (B209.19.w19)

Rodents and lagomorphs:

  • Tularaemia.
  • Sylvatic plague (enzootic in many populations of New World rodents).
  • (B16.2.w2)
WATERFOWL Avian tuberculosis (granulomas) (acid-fast organisms with Ziehl-Neelsen staining) (Avian Tuberculosis), aspergillosis (granulomas) (Aspergillosis), avian cholera (pasteurellosis) (Avian Cholera), colibacillosis (can also produce miliary lesions) (Colibacillosis); and other causes of septicaemia (B11.39.w7, B14, B15, B37.x.w1).

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Treatment and Control

Specific Medical Treatment
Mammals

Rodents and lagomorphs:

  • Broad-spectrum antibiotics (B16.2.w2).
Birds
  • Antibiotic therapy may be effective if started sufficiently early.(D48).
WATERFOWL
  • Antibiotics are rarely curative for chronic cases (B11.39.w7).
LAGOMORPHS
  • This disease can be very difficult, if not impossible, to eradicate. The zoonotic potential has to be taken into account when decisions are being made on treatment options. (B603.2.w2)
  • Prolonged courses (several weeks) of antibiotics are administered to the affected and contact animals. (B603.3.w3)
Related Techniques
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General Nursing and Surgical Techniques
WATERFOWL --
Related Techniques
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Preventative Measures
Vaccination WATERFOWL --
Prophylactic Treatment

WATERFOWL
  • Antibiotic treatment (based on culture and sensitivity) of a group of birds in which an affected individual has been diagnosed (B11.39.w7).
Related Techniques
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Environmental and Population Control Measures
General Environment Changes, Cleaning and Disinfection In birds generally:
  • Improve general hygiene.
  • For wild birds such as "garden birds".
    • Move feeding stations regularly, avoid feeding at the same site continuously.
    • Avoid using suspended feeders with sills on which food particles and droppings may collect
    • Clean up discarded feed and droppings from under suspended feeders and bird tables regularly e.g. by sweeping, and dispose of hygienically (incineration is ideal).
    • Brush bird tables or other surfaces used for feeding daily.
    • Thoroughly clean bird feeders/tables regularly (as appropriate for speed of build up of droppings) and daily during a disease outbreak.
    • Wash or soak feeders/tables using a 5% sodium hypochlorite solution or a safe disinfectant (e.g. Tamodine-E, Vetark), followed by thorough rinsing.
    • Use fresh, good-quality foods, dispose of uneaten food hygienically
    • Store foods carefully in rodent-proof  containers.
  • (D48)
General Environment Changes, Cleaning and Disinfection

WATERFOWL
  • Improve sanitation. Exclude rodents and wild birds (reservoirs of infection) from food storage areas and also where possible from bird pens (B10.26.w10, B11.39.w7).
LAGOMORPHS
  • Exclude wild birds and rodents from the food stores and housing. (B600.16.w16, B603.3.w3)
  • Wash all fresh vegetables before feeding. (B603.3.w3)
Population Control Measures In birds generally:
  • Reduce stocking densities at wild bird feeding stations by e.g. reducing food quantity supplied. (D48)
WATERFOWL --
LAGOMORPHS
  • In colony situations there may be a need for culling and restocking. (B603.2.w2)
Isolation, Quarantine and Screening WATERFOWL --
Related Techniques
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