Results
AFIP Wednesday Slide Conference - No. 27
7 May 1997
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- Conference Moderator: COL Nancy Jaax
Diplomate, ACVP
U. S. Army Medical Research Institute of Infectious Disease
ATTN: MCMR-UIP
Bldg. 1425
Fort Detrick, MD 21702-5011
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Case I - X5893-3 (AFIP 2579514)
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- Signalment: Adult, male, common pintail duck (Anas
acuta acuta).
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- History: This duck was housed in a large outdoor enclosure
with several other male pintails. The bird was noted to have
a drooping left wing and apparent inability to use this wing.
Physical examination revealed severe swelling of the carpal joint
of this wing associated with the presence of yellow caseous material.
The wing was amputated at the distal radius and ulna and submitted
for histopathologic examination.
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- Gross Pathology: There was diffuse swelling (up to
3 times normal) of the soft tissues surrounding the carpal and
carpometacarpal joints. Caseous yellow nodules measuring up to
1 cm diameter were scattered throughout the joints and periarticular
soft tissues.
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- Laboratory Results: See contributor's comments.
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- Contributor's Diagnoses and Comments: Joint (carpus),
arthritis, granulomatous and heterophilic, septic, severe.
- Bone, carpal, osteomyelitis, granulomatous and heterophilic,
septic, moderate.
- Bone marrow, hyperplasia, myeloid, moderate.
- Etiology: Staphylococcus aureus
- Septic arthritis is a relatively common problem in captive
collections of waterfowl. The joints of the feet are most commonly
affected and Staphylococcus aureus is the etiologic agent usually
isolated from these lesions. In our experience at the National
Zoo, birds with chronic infections often die from acute staphylococcal
septicemia. Hepatic, splenic and/or renal amyloidosis are also
common sequelae secondary to chronic inflammation.
- This bird died 2 weeks following the wing amputation. Death
was attributed to a combination of hepatic failure from severe
amyloidosis and terminal bacterial septicemia. At necropsy, pure
cultures of Staphylococcus aureus were isolated from the wing
stump, liver, and heart blood.
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- AFIP Diagnosis: Wing, carpus: Arthritis, osteomyelitis
and tenosynovitis, necrotizing, granulomatous and heterophilic,
multifocal to coalescing, severe, with granulation tissue, periosteal
hyperostosis, and colonies of cocci, pintail duck (Anas acuta
acuta), avian.
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- Conference Note: The incidence of staphylococcosis
among captive Anseriforms is relatively high. In free living
waterfowl, staphylococcosis tends to be sporadic and is not responsible
for large numbers of mortalities. The major pathological findings
include: endocarditis, arthritis, tenosynovitis, osteomyelitis,
peritonitis, hepatitis, splenitis, nephritis, pneumonia, encephalomyelitis,
and enteritis. The most common route of infection in Anseriforms
appears to be through skin wounds, with initial infection of
subcutaneous or muscular tissues, followed by dissemination through
the blood stream to other organs and tissues. A higher frequency
of infection is observed in males especially during the breeding
season and winter; this is probably related to their naturally
aggressive breeding behavior and frequent fighting.
- Amyloidosis is a common finding in Anseriforms and is often
secondary to chronic infections, such as tuberculosis, aspergillosis
or other persistent bacterial infection.
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- Contributor: National Zoological Park, Smithsonian
Institution, Washington, DC 20008.
- References:
1. Dias JLC and Montali RJ: Staphylococcosis in captive exotic
waterfowl. Avian Pathol 23:659-669, 1994.
- 2. Gerlach H: "Bacteria:, In: Ritchie BW, Harrison GJ,
and Harrison LR (eds.), Avian Medicine: Principles and Application,
Wingers Publishing, Inc., Lake Worth, FL, pp. 965-968, 1994.
- 3. Halliwell WH and Graham DL: "Bacterial diseases of
birds of prey", In: Fowler ME (ed): Zoo & Wild Animal
Medicine, Second Edition, WB Saunders Co., Philadelphia, pp.
415-416, 1986.
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- International Veterinary Pathology Slide Bank: None.
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Case II - 96-1515 (AFIP 2551544)
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- Signalment: 4-month-old, female, nude mouse (Nu/JNu).
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- History: This mouse was housed with APOe (deficiency
of apolipoprotein E) mice suspected to have pneumocystosis. A
research technician placed the nude mouse in the colony to act
as a sentinel mouse.
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- Gross Pathology: The perineum was stained with dried
feces and fluid. Well developed pus was present in the left uterine
horn. The gastrointestinal tract was distended with gas.
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- Laboratory Results: Enterobacter spp. cultured from
reproductive tract. An acute multifocal neutrophilic hepatitis
and moderate Pneumocystis pneumonia were present.
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- Contributor's Diagnosis and Comments: Acute to subacute
suppurative and necrotizing placentitis and metritis with fetal
death (coagulation necrosis) and intralesional bacteria.
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- A literature search failed to reveal information on spontaneously
occurring suppurative and necrotizing placentitis in mice induced
by Enterobacter spp. It has been shown that gram-negative bacteria
such as Klebsiella oxytoca, K. pneumonia, Escherichia coli, and
Enterobacter sp. can cause suppurative utero-ovarian infections
in nongravid mice (Rao, 1987). Pasteurella pneumotropica, frequently
found in the upper respiratory tracts of normal mice, has been
demonstrated to cause a necrotizing suppurative metritis and
fetal resorption, similar to the lesions in the case presented
here (Ward, 1978; Casillo, 1972). Mice inoculated experimentally
with Brucella abortusor E. coli endotoxin can develop a necrotizing
placentitis (Tobias, 1993;McKay, 1963). The pathogenesis of the
placentitis shown here is uncertain, but could result from an
ascending vaginal infection from intestinal flora or could be
the result of a septicemia (this mouse also had a mild, acute,
neutrophilic hepatitis). It has been speculated that the local
immune suppression of pregnancy may allow bacteria to proliferate
preferentially in the placenta (Tobias, 1993). The immunodeficiency
in this nude mouse was likely a predisposing factor to infection.
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- AFIP Diagnosis: 1. Uterus, gravid: Metritis and placentitis,
necrotizing, acute, diffuse, severe, with vasculitis and numerous
intracellular and extracellular bacilli, nude mouse (Nu/JNu),
rodent.
2. Fetus: Autolysis, diffuse, moderate.
3. Fetus, lung: Numerous squamous epithelial cells and meconium.
4. Fetus, nasal mucosa, dermis, dental pulp, tongue: Necrosis
and acute inflammation, multifocal, mild.
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- Conference Note: The conference participants agreed
with the contributor's diagnosis and comments. The death of the
fetus was attributed to loss of blood supply due to placental
vasculitis and necrosis. The presence of squamous epithelial
cells and meconium within fetal lungs indicates fetal stress.
Enterobacter sp. are occasionally reported to cause placentitis
in horses and sporadic cases of mastitis and urinary tract infections
in dogs.
- In addition to those listed by the contributor, the following
bacteria have been isolated from the reproductive tracts of female
mice that aborted: Streptococcus sp., Proteus mirabilis, and
Proteus vulgaris.
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- Contributor: The Ohio State University, Department
of Veterinary Biosciences, 1925 Coffey Rd., Columbus, OH 43210.
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- References:
1. Casillo S, Blackmore DK: Uterine infections caused by
bacteria and mycoplasma in mice and rats, J Comp Pathol 82:477-482,
1972.
- 2. McKay DG, Wong TC: The effect of bacterial endotoxin on
the placenta of the rat. Am J Pathol 42(3):357-377, 1963.
- 3. Rao GN, Hickman RL, Seilkop SK, Boorman GA: Utero-ovarian
infection in aged B6C3F1 mice. Lab Anim Sci 37(2):152-158, 1987.
- 4. Tobias L, Cordes DO, Schurig GG: Placental pathology of
the pregnant mouse inoculated with Brucella abortus Strain 2308.
Vet Pathol 30:119-129, 1993.
- 5. Ward GE, Moffatt R, Olfert E: Abortion in mice associated
with Pasteurella pneumotropica. J Clin Microbiol 8(2):177-180,
1978.
- 6. Hong CB, et al: Etiology and pathology of equine placentitis.
J Vet Diag Invest 5(1):56-63, 1993.
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- International Veterinary Pathology Slide Bank: None.
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Case III - H96-1183 G 96-1210 (AFIP 2551540)
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- Signalment: Black-gloved wallaby (Macropus irma).
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- History: The animal was an adult wild wallaby found
blind on a farm. It was euthanized and necropsied.
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- Gross Pathology: Apart from superficial predator damage,
the animal was otherwise normal and well muscled. Blood was submitted
for serology; brain and eye were submitted for virus isolation.
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- Laboratory Results: See below.
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- Contributor's Diagnosis and Comments: Choroiditis,
non-suppurative, moderate, diffuse. Wallal virus infection.
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- The presenting history and clinical signs of this case were
suggestive of "choroid blindness", a disease recently
shown to be due to infection with orbiviruses belonging to the
Wallal and Warrego serogroups. The histological findings of a
diffuse non- suppurative choroiditis and a moderate, diffuse,
non-suppurative encephalitis, also present in this case, were
strongly supportive of this diagnosis. Testing at the Australian
Animal Health Laboratories (AAHL) demonstrated an antibody response
in blood; Wallal virus was isolated from samples of eye and brain
from this case.
- Recent and continuing outbreaks of blindness in various species
of kangaroo across vast areas of central and western Australia
have been attributed to Wallal virus infection. The species commonly
affected include western grey kangaroos (Macropus fuliginosus),
eastern grey kangaroos (Macropus giganteus), red kangaroos (Macropus
rufus) and euros (Macropus robustus). Typically, affected animals
are found blind and stumble into bushes and other objects but
otherwise are generally able to hear, move, feed, and maintain
body condition.
Misadventure, injury and drowning are common causes of death.
As in the present case, blindness is due to severe necrotizing
retinitis, choroiditis, atrophy of optic nerves, and mild non-suppurative
encephalitis.
- Field and laboratory investigations carried out by the various
States' Departments of Conservation and of Agriculture isolated
orbiviruses of the Wallal serogroup from tissues taken from various
affected kangaroos, particularly from eye, brain and blood. AAHL
has identified orbivirus belonging to the Wallal virus serogroup
in whole blood and sera. Polymerase chain reaction (PCR) has
been used to confirm the presence of Wallal serogroup virus in
the eyes and brains of affected cases. PCR has demonstrated the
same virus in Culicoides dycei and C. austropalpalis. Indirect
immunofluorescence testing has been used to demonstrate reactions
to Wallal serogroup in the affected retinas of a number of cases.
Grey kangaroos inoculated with Wallal virus developed clinical
and pathological evidence of the disease after incubation periods
of about 4 to 5 weeks. The lesions in the retinas of their eyes
were confirmed at AAHL as specific to an orbivirus of the Wallal
serogroup by PCR and immunofluorescence.
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- AFIP Diagnosis: Eye: Choroiditis, lymphocytic, diffuse,
severe, with moderate anterior uveitis, retinitis, retinal detachment
and intra-ocular fibrinocellular exudate, black-gloved wallaby
(Macropus irma), marsupial.
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- Conference Note: The conference participants agreed
with the contributor's diagnosis. Differential diagnosis for
this lesion includes viral infection and autoimmune reaction.
The distribution of these lesions is interesting. Many orbiviruses
cause more generalized, often vascular, lesions. Other orbiviruses
of veterinary importance include: bluetongue virus, epizootic
hemorrhagic disease of deer virus, African horse sickness virus,
Palyam virus, Ibaraki virus, and equine encephalosis virus.
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- Contributor: Murdoch University, School of Veterinary
Studies, Murdoch, W.A., 6150, Australia.
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- International Veterinary Pathology Slide Bank: None.
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- References:
1. Blacksell SD, Lunt RA, White JR: A rapid indirect ELISA for
the serogrouping of Australian orbiviruses. Journal of Virological
Methods 49:67-78, 1994.
- 2. Durham PJK, Finnie JW, Lawrence DA, Alexander P: Blindness
in South Australian kangaroos. Australian Veterinary Journal
73:111-112, 1996.
- 3. Hooper P: Blind roo epidemic. Microbiol Australia
17:22, 1996.
- 4. Fenner FJ, et al. (eds): Veterinary Virology, Second edition,
Academic Press, pp. 537-552, 1993.
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Case IV - 96L-107 (AFIP 2552479)
- Signalment: A 7-month-old female marmoset.
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- History: First seen 7-1-96. Initially exhibited partial
closure of left eye, with a pinpoint pupil and excessive lacrimation.
Treated with Baytril. 9-1-96: Left eye still inflamed with development
of a small yellow pustule by left eye. Betsolan added to treatment.
12-1-96: Still jumping about and scratching left eye area. Betsolan
drops stopped; Neobiotic ointment dispensed and Betsolan injection
given. 13-1-96: Condition worse - several skin lesions on left
side of face and head. Trauma from scratching or pathological
process?
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- Gross Pathology: Moist matted fur around the facial
and neck region and dried exudate around the left eyelids. No
other significant findings.
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- Laboratory Results: Sections of cerebrum reacted positively
for herpes simplex virus types I and II when stained with an
HRP-linked antibody against human herpes virus (Dakopatts B114).
- Contributor's Diagnosis and Comments: Necrotizing
meningoencephalitis caused by herpesvirus infection.
AFIP Diagnosis: Brain: Meningoencephalitis, necrotizing,
subacute, multifocal, moderate to severe, with astrocytosis,
multifocal hemorrhage, ventriculitis, vasculitis, and neuronal
and astrocytic eosinophilic intranuclear inclusion bodies, marmoset,
primate.
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- Conference Note: The lesions are consistent with herpes
simplex virus infection. Marmosets are susceptible to both herpes
simplex and herpes T infection. Both viruses cause systemic infection
with similar gross and microscopic lesions. Encephalitis has
not been described in Herpesvirus T infection but this would
not be a reliable criterion on which to base the differentiation
of the two diseases.
Herpes simplex infection is generally acquired from humans, the
natural reservoir. Human to monkey or monkey to monkey transmission
can occur via contact with active lesions. Lesions may be localized
or generalized. The most characteristic gross lesions are discrete
ulcers, necrotic plaques, and erosions or ulcers of the oral
mucous membranes and at the mucocutaneous junction of the lips.
Conjunctivitis is frequently present. Internally, foci of necrosis
can be seen in most organs (i.e., liver, adrenal, spleen, lung,
lymph nodes, and occasionally, kidneys). The brain of affected
animals is usually grossly normal. Important histologic lesions
include oral, lingual, labial, or genital vesicles and ulcers,
conjunctivitis, keratitis, necrotizing meningoencephalitis, and
focal necrosis in visceral organs. Intranuclear inclusion bodies
and multinucleate syncytial cells are characteristic findings.
The most striking feature herpes simplex encephalitis is necrosis
of neurons, particularly of the temporal cerebral cortex and
the thalamus. Intranuclear inclusions may be found in neurons
and astrocytes.
- Marmosets, owl monkeys, tree shrews, lemurs, and tamarins
are susceptible to generalized herpes simplex infection. Chimpanzees
and gibbons can be infected, but lesions usually remain confined
to the skin, oral cavity, external genitalia, and conjunctiva.
Fatal encephalitis is rarely reported in gibbons.
- Herpesvirus simplex was also recently diagnosed in an African
pygmy hedgehog. See 1996/97 Wednesday Slide Conference 9, Case
1 for more details.
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- Contributor: University of Liverpool, P.O. Box 147,
Liverpool L69-2BX, UK.
References:
1. Hunt RD: Herpesvirus simplex Infection. In: Monographs on
the pathology of laboratory animals: Nonhuman primates I, Jones
TC, et al (eds), Springer-Verlag, pp. 82-86, 1993.
- 2. Baskin GB: Pathology of Nonhuman primates. 42nd Annual
Pathology of Laboratory Animals Course, Bethesda MD, 1995.
- International Veterinary Pathology Slide Bank: None.
- Lance Batey
Captain, VC, USA
Registry of Veterinary Pathology*
Department of Veterinary Pathology
Armed Forces Institute of Pathology
(202)782-2615; DSN: 662-2615
Internet: Batey@email.afip.osd.mil
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- * The American Veterinary Medical Association and the American
College of Veterinary Pathologists are co-sponsors of the Registry
of Veterinary Pathology. The C.L. Davis Foundation also provides
substantial support for the Registry.
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