Lesions
Thymic atrophy (shrinkage) in
puppies
Hyperkeratosis
(hardening) of
nose and footpads
Secondary
Infections:
Bronchopneumonia
Interstitial pneumonia
Skin pustules
Necrosis of lymphatic tissue
6.Enteritis
(inflammation of the gut)
7. Skin Pustules
8.
Bronchopneumonia
Histological
or Microscopic
Examination(1)
Cytoplasmic/Intranuclear inclusion
bodies in:
Respiratory
Urinary
GIT (gastrointestinal) system
Neurological:
gliosis
demyelination
perivascular cuffing
nonsuppurative leptomeningitis
Increased CSF (cerebral spinal
fluid) protein
9:
Distemper viral body inclusions
present
in erythrocytes (red
blood cells)
and
10.
Lung
lesions in an African wild dog with canine distemper. leukocytes (white
blood
cells).
Hematoxylin and eosin staining.
A. Bronchiole
occluded by
inflammatory cells and cell debris.
B. Detail of A, showing multiple
eosinophilic intracytoplasmic viral inclusions (arrows) in bronchiolar
epithelium.
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Diagnosis
Distemper
should be considered as a
diagnosis for any
febrile (feverish) puppy with multisystemic disease, with
associated
neurological involvement (1).
Diagnosis must be made
on the basis of
vaccination history and clinical signs
and laboratory tests (2).
The
diagnosis may be confirmed by the following:
Histological
lesions:
The
presence of intracellular inclusion bodies in leukocytes, conjunctival
or
vaginal imprints, bronchial cells, urine sediments, or CSF is
sought
(1,6). Note, a
negative
result does not rule out CDV infection
(2).
Immunofluorescent
assay:
Viral antigens (proteins) may be detected in certain tissues including:
conjunctival or
vaginal imprints, tracheal
cells and epithelia (1). In this assay,
special proteins labeled with a
fluorescent chemical are used to detect and bind viral antigens present
in various tissue samples. As with histology, a
negative
result does not rule out the possibility of CDV infection (2). Virus
isolation
is not available at most veterinary diagnostic laboratories (6).
Serology:
The serological presence of a viral
specific IgM (antibodies) or an increased ratio of CSF to serum viral
specific IgG
(antibodies) will
indicate the presence of CDV infection (1).
The IgM
antibody persists in dogs with distemper
for 5 weeks to 3 months, depending on virus strain and host response,
and may
be evaluated using an ELISA test (6).
Serology itself is not considered
diagnostic for CDV as dogs may die without significant antibody
production, and
chronically infected dogs may have antibody levels comparable to
vaccinated
dogs (6).
PCR
Polymerase chain reaction (PCR) is a
technique that helps
identify viral nucleic acid. It is usually more sensitive than either
histological
examination for viral inclusion bodies or immunofluorescence (2,6).
Spinal
Tap:
Cerebrospinal
fluid (CSF) may be examined for
viral specific antibodies, interferon, elevated
levels of particular proteins and mononuclear cells
that
indicate the presence of the virus (2,6).
Hematology:
Blood work is often non specific and
non helpful in the
diagnosis of CDV. In some cases, early infection may produce a
lymphopenia (low
white blood cell count). Leukocytosis (high
white blood cell count) may occur as the
infection progresses (2).
Thrombocytopenia (low platelet count) and
monocytosis (high monocyte count) may be found (6).
Imaging:
Radiography (X-rays), Ultrasound and
CT Scans
may be used to
nonspecifically diagnose pneumonia associated with CDV(2).
Differential diagnoses include
(1,2):
11.
Coccidiosis
12.
Neosporosis
13. Leptospirosis
14.
Toxoplamosis
15. Organophosphate
Poisoning
16. Rocky Mtn.
Spotted Fever
Gastroenteritis: Giardiasis, Parvovirus, Coronavirus,
Toxin Ingestion
Epilepsy
Infectious Canine Hepatitis (Adenovirus)
Kennel Cough
