Detailed Clinical and Pathological Characteristics
aureus is commonly found on the skin, nose and oropharynx of healthy
animals. It may also be see causing:
- Skin infections.
- Mastitis in cattle, also in sheep, goats, mates, sows, cats and
- Tick pyaemia in lambs.
- Purulent synovitis in poultry.
- Necrotising endometritis in pigs.
- Botryomycosis in horses following castration, with infection of the
stump of the spermatic cord and sometimes fatal generalised infection.
and subcutaneous abscesses
||Localized skin, foot or
joint infection to generalized septicaemic disease. Acute
suppurative to chronic
granulomatous lesions, particularly involving the joints, heart, liver, spleen and lungs,
also the brain.
- Skin disease,
alone or secondary to/in conjunction with other diseases such as fungal
infection or mite infection. (J15.21.w1,
Staphylococcosis can cause suppurative inflammation of any organ in
rabbits but it is most commonly seen in the skin and subcutaneous tissues. (B614.8.w8,
- Fatal septicaemia may occur. (B614.8.w8)
- Pneumonia, lung abscesses or heart abscesses may occur with
disseminated disease. (B602.17.w17)
- Staphylococcal conjunctivitis
is seen (J4.189.w15,
See: Conjunctivitis in Lagomorphs
||Depends on site of
infection. The following are presentations that have been recorded:
- Acute, generalized severe infection: high temperature, ruffled
feathers, wing droop, sometimes lameness and reluctance to walk, later depression,
- Chronic joint infections (septic arthritis): lameness and swollen
- Bumblefoot: lameness, foot lesions (swelling, epithelial
damage) (See also Bumblefoot).
- Yolk sacculitis: - navel area damp, reddened (See also Omphalitis / Yolk Sacculitis)
- Subacute septicaemias are characterised by:
Clinical pathology: A left shift would be expected in the
count. (B16.9.w9, B64.26.w5)
General: Listlessness and emaciation may be seen in affected animals,
lameness if the tendons or joints are involved. In internal disease,
clinical signs include lymphadenopathy and splenomegaly. (B209.28.w28k)
- Infected areas of skin are often encrusted with exudate. (B209.28.w28k)
- Young rabbits (up to ten days in age): moist lesions on
the medial aspect of the hind limbs and the ventral abdomen.
- "Exudative dermatitis with small superficial
pustules" in hairless kits. (J3.114.w9)
- Older rabbits (two to four weeks of age): several small
abscesses over the body and there may also be a purulent
- The infection can then progress to a fatal septicaemia with the
liver and other organs becoming abscessated.
- In contact lactating does: a suppurative mastitis (Bacterial Mastitis in Rabbits)
develop and suckling rabbits can then die due to their dam
- Subcutaneous abscesses; may be widespread in disseminated
- The abscesses may be seen externally as swellings and some of
them may have draining tracts (crusting of the hair may be
- Interdigital abscesses and localised abscesses of the mammary gland
have also been reported. (B614.8.w8)
- Multiple subcutaneous abscesses of varying sizes in Lepus europaeus - Brown hare.(J514.1.w1)
- Superficial mastitis with exudation and suppurative inflammation
around the teats. (J3.114.w9)
- Disseminated, gangrenous mastitis.
- Septic Arthritis in Lagomorphs (Bacterial Disease Summary)Arthritis.
- Disseminated disease due to staphylococcosis has been reported
in both adult and young rabbits:
- Subcutaneous abscesses, visceral abscesses, and also
rhinitis, fibrinous pneumonia, and conjunctivitis were
reported in adult rabbits with disseminated disease. (B614.8.w8)
- Otitis media has also been reported. (B614.8.w8)
- Milk from a doe with mastitis can
transmit Staphylococcus aureus to the nurslings resulting in
septicaemia and death. (B614.8.w8)
- Disseminated disease has been reported in three to five day
old rabbits. Widespread subcutaneous abscesses as well as
abscesses in the heart and lungs. (B614.8.w8)
- Death. (J514.1.w1)
- A pustular dermatitis of young rabbits can occur due to Staphylococcus
aureus. The condition is usually associated with poor
- Clinical signs:
||Short in acute disease:
48-72 hours from experimental intravenous inoculation in chickens to disease.
Mortality / Morbidity
- Usually low (B32.11.w27).
Staphylococcosis was diagnosed in 6.26% of 642 waterfowl necropsied
at the Kortright
Waterfowl Park (J14.29.w1)
and 1.7% of 2450 waterfowl at the National Zoological Park, Washington D.C. (J6.23.w3).
- Infection or carriage of Staphylococcus aureus
appears to be common, including in healthy animals without skin
- Staphylococcosis is commonly seen in rabbits. (B614.8.w8)
- Staphylococcosis is a significant disease of rabbits (Oryctolagus
sp. and Sylvilagus
spp.) and Lepus
spp., that can result in severe and sometimes fatal, disease.
infection: heart, spleen, liver, kidneys, brain, lungs may be affected most
often. necrosis and vascular congestion are commonly seen. Acute necrosis and vascular
congestion to chronic granulomas with giant cells. Gram-positive cocci may be seen in
association with lesions. In joint involvement, arthritis, synovitis and periarthritis may
- Heart - pale areas may be visible in the myocardium, vegetative growths on
valves, particularly left atrio-ventricular valve, occasionally pericarditis
(serofibrinous to suppurative) with effusion and haemorrhages.
- Liver - enlarged, mottled, friable; sometimes necrotic,
- Spleen - enlarged, globular, congested; may be pale foci.
- Kidneys - usually no gross changes; may be enlarged, pale and firm due to
- Lungs - congested,
oedematous, rarely visible
- Gastro-intestinal tract - mild to necro-purulent or granulomatous
- Yolk sacculitis - navel area damp, reddened. Yolk sac enlarged and contents
abnormal in colour and consistency. Sometimes associated peritonitis (see: Yolk
- Joints/skeletal - Particularly toe and hock joints. Thickened joint, reduced
range of movement, swollen tendon sheaths, yellowish purulent to caseous
exudate in joint,
sometimes fibrosis around the joint. Sometimes obvious bone lesions - osteomyelitis, with
yellow caseous foci or lytic areas.
- Bumblefoot - plantar surface epithelial damage, and abscessation.
Muscle - occasionally pale friable areas, most frequently in pectoral muscles.
- Skin - plantar abscess (See also Bumblefoot). Dark moist areas and
crepitation if gangrenous dermatitis.
- Heart - mild septic to granulomatous or necrotic myocarditis,
endocarditis to vegetative valvular thrombo-endocarditis, serofibrinous to suppurative
- Liver - congestion, hepatocellular degeneration and necrosis, Kupffer cell
hyperplasia. Colonies of gram-positive
cocci may be visible within granulomatous or
suppurative areas of tissue.
- Spleen - congestion, lymphoid depletion, plasmacytosis, presence of Mott cells;
multiple necrotic lesions of the parenchyma with severe involvement; sometimes
with giant cells and colonies of cocci.
- Kidneys - congestion, embolic nephritis, interstitial infiltrate of lymphocytes
and plasma cells, acute perivasculitis, septic glomerulonephritis, granulomatous foci with
giant cells; sometimes intravascular colonies of cocci.
- Lungs - mild infiltration with heterophils (acute inflammation) to severe
suppuration or granulomas, frequently with microthrombi, sometimes with colonies of
- Air sacs - occasionally mild subacute airsacculitis.
- Gastro-intestinal tract - mild non-suppurative to necro-purulent enteritis; may
be multiple septic thrombi containing cocci.
- Central nervous system - mild perivascular to severe suppurative or granulomatous
encephalitis, sometimes with associated meningitis.
- Muscle - mild to extensive suppurative to granulomatous myocarditis; infarcts
with bacteria growing around the margins; lesions occur most frequently in pectoral
- Joints/skeletal - Necrosis, with colonies of gram-positive cocci and heterophils.
May be microscopic osteomyelitis (bone involvement) even if no gross bone lesions.
- Bumblefoot - Chronic proliferative necrotic inflammation with heterophil and
macrophage infiltration, perivascular lymphocytic cuffing and gram-positive cocci. (See
Amyloidosis may also be
seen secondary to chronic infection (B39.w1).
J6.23.w3, B9.6.w1, B15, B18, B32.11.w27).
||In a nine-year-old
free-living male Ursus americanus - American black bear
from Labrador, Canada: (J1.36.w8)
- General: good body condition - normal muscle mass and
- Abdominal cavity: about one litre of blood was present.
- GIT: little ingesta present
- Increased size of the left perirenal area (three times that of
the right) due to retroperitoneal haemorrhage.
- Attached to the kidney capsule, clotted blood.
- Within the renal parenchyma (left kidney), haemorrhage.
- Right kidney, cranial pole haemorrhagic.
- On the left and right semilunar valves, small (1.0 - 1.5 by
1.5-3.0 cm) irregular friable masses, consistent with fibrin
deposits, attached to their free edges.
- Beneath the dorsal valvula, a small roughened area of
- Cardiac: On the aortic valve, abundant fibrin. Near the edges
of the semilunar valve, the normal architecture was destroyed. In the
fibrin, inflammatory cells, mainly neutrophils, degenerate and
necrotic, together with many small colonies of Gram-positive cocci. In
the underlying tissue and adjacent endocardium, infiltration with
moderate numbers of neutrophils and macrophages.
- Renal: Areas of infarction, locally extensive, in which were
large colonies of Gram-positive
cocci with surrounding neutrophils in
a thick zone. In many glomeruli, infiltration of the uriniferous
spaces by neutrophils in large numbers , and occlusion of glomerular
tufts by multiple fibrin thrombi. At the corticomedullary junction,
partial occlusion of some vessels by fibrin thrombi, and partial to
complete fibrinoid necrosis of the vessel walls.
- CNS: In perivascular spaces
around small blood vessels, and
scattered through the neuropil of the brain, small aggregates of
neutrophils and macrophages. In a few of the vessels, fibrin thrombi.
- Adrenals: In the cortex, large colonies of Gram-positive
cocci but no associated inflammatory reaction (indicating they
resulted from terminal septicaemia).
||Suppurative inflammation is
characteristic of staphylococcosis (but is also seen in infections caused
by other pyogenic bacteria, including Pasteurella multocida). The
most common areas affected are:
- mammary gland
- respiratory system.
However, suppurative inflammation may be seen in any internal organ if
septicaemia has occurred. (B614.8.w8)
- In acute lesions: diffuse infiltrate of neutrophils along
with oedema, haemorrhage, and fibrin deposition. (B614.8.w8)
Lesions that may be seen include:
- Splenomegaly without abscesses
- Valvular endocarditis
- In subacute or chronic lesions: the inflammation is more
localised resulting in the development of abscesses. These abscesses
contain a creamy and viscous exudate that is mainly made up of
neutrophils and necrotic cell debris. In chronic cases there may be a
fibrous capsule surrounding the abscess. (B614.8.w8)
- Visceral organs that may be affected by abscessation include the
heart, lungs, liver, kidneys, spleen and muscle. (B209.28.w28k)
- There may be enlargement of superficial lymph nodes (cervical,
mandibular, axillary, and inguinal) that contain caseous or
purulent exudate. (B209.28.w28k)
- In botryomycosis: foci of granulomatous or
pyogranulomatous inflammation in the dermis or at other sites; giant
cells may be visible. (B209.28.w28k)
Disease has been reported in either the wild or in captivity
- Bewick's swan Cygnus columbianus bewickii and Coscoroba swan Coscoroba
- Wild mute swan Cygnus olor in Scotland, UK with bumblefoot (J36.41.w1).
- Wild Tundra swan Cygnus columbianus with lead poisoning (J1.11.w4).
- Wild mallard Anas platyrhynchos in winter in Canada, in
association with poor nutritional status and vitamin A deficiency (J1.28.w2).
- Domestic ducks with bumblefoot
- Captive blue-winged teal Anas discors in the UK (J3.70.w1).
- Captive, wild-trapped canvasback ducks Aythya valisineria
associated with stress and malnutrition (J1.12.w5).
- Domestic ducks with arthritis (J6.10.w3).
- Domestic ducks with salpingitis (J6.24.w1).
- Waterfowl at Kortright Waterfowl Park, Ontario, Canada (J14.29.w1).
- American green-winged (common) teal Anas crecca carolinensis,
Bahama (white-cheeked) pintail Anas bahamensis bahamensis, brown pintail Anas
georgica spinicauda, black swan Cygnus atratus, blue-winged teal Anas
discors, common (Northern) pintail Anas acuta, common shelduck Tadorna
tadorna, common (northern) shoveler Anas clypeata, canvasback Aythya
valisineria, chestnut teal Anas castanea, Eurasian wigeon Anas penelope,
Indian spot-billed duck Anas poecilorhyncha poecilorhyncha, mandarin duck Aix
galericulata, mallard Anas platyrhynchos, Moluccan radjah shelduck Tadorna
radjah radjah, mute swan Cygnus olor, North American black duck Anas
rubripes, North American ruddy duck Oxyura jamaicensis jamaicensis,
red-breasted goose Branta ruficollis, redhead Aythya americana, ringed teal Callonetta
leucophrys, rosybill Netta peposaca, South African yellow-billed duck Anas
undulata undulata, white-winged wood duck Cairina scutulata at the National
Zoological Park, Washington D.C., USA (J6.23.w3).
- 23/58 (40%) hedgehogs (Erinaceus europaeus - West European Hedgehog)
in New Zealand, from nasal swabs. (J42.76.w1)
- Coagulase positive Staphylococci were isolated from the paws
of 63% of 35 Erinaceus europaeus - West European Hedgehog)
in New Zealand and from the ventral skin of 71%. Almost pure cultures
and heavy growth were obtained from areas with Trichophyton
mentagrophytes var. erinacei dermatophyte infection. Many
cultures were penicillin-resistant. (J9.201.w1)
- Coagulase positive Staphylococci were isolated from 23/58
(40%) of nasal swabs, 38/56 (68%) of skin swabs, 36/37 (63%) of paws
and 6/11 (55) of anal swabs. Infection was equally common in
"young (less than 500g body weight) and "old" (greater
than 500g bodyweight) animals and was found in 12/12 "very
scabby" animals, 11/14 "slightly scabby" animals and
10/17 "normal" animals. Erinaceus europaeus - West European Hedgehog)
in New Zealand. 86.3% of 107 strains tested were found to be
- Staphylococcus pyogenes infection together
with Caparinia sp. (? tripilis) mites in a hedgehog Erinaceus
europaeus from a collection in the UK, with "mange-like
lesions and skin ulceration." (J46.173.w1)
one strains of novobiocin-resistant coagulase-negative strains of Staphylococcus
were isolated from the skins of hedgehogs, 13 were considered to
resemble Staphylococcus xylosus and 10 to resemble Staphylococcus
sciuri; the remaining eight did not resemble previously-described
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
(List does not contain all other species groups affected by this