Page 1514 - Small Animal Internal Medicine, 6th Edition

1486 PART XIV Infectious Diseases

TABLE 96.1
VetBooks.ir Clinical Manifestations of CDV Infection

In utero infection
Stillbirth
Abortion
Fading puppy syndrome in the
neonatal period
CNS signs at birth
Gastrointestinal tract Vomiting
disease Small-bowel diarrhea
Respiratory tract Mucoid to mucopurulent nasal
disease discharge
Sneezing
Coughing with increased
bronchovesicular sounds or
crackles on auscultation
Dyspnea
Ocular disease Retinochoroiditis, medallion lesions
(see Fig. 96.1), optic neuritis
Keratoconjunctivitis sicca
Mucopurulent ocular discharge
Neurologic Disease
Spinal cord disease Paresis and ataxia FIG 96.1
Central vestibular Head tilt, nystagmus, other cranial Medallion lesions resulting from canine distemper virus
disease nerve and conscious infection. (Courtesy Dr. Cynthia Powell, Colorado State
proprioception deficits University, Fort Collins.)
Cerebellar disease Ataxia, head bobbing,
hypermetria
Cerebral disease Generalized or partial seizures Hyperkeratosis of the nose and footpads and pustular der-
(“chewing gum fits”) matitis are the most common dermatologic abnormalities.
Depression Puppies infected transplacentally can be stillborn, aborted,
Unilateral or bilateral blindness or born with CNS disease.
Chorea myoclonus Rhythmic jerking of single muscles
or muscle groups Diagnosis
Miscellaneous Fever The combination of clinical findings and routine clinico-
Anorexia pathologic and radiographic evaluation usually leads to a
Tonsillar enlargement presumptive diagnosis of CDV infection. Lymphopenia
Dehydration
Pustular dermatosis and mild thrombocytopenia are consistent hematologic
Hyperkeratosis of the nose and abnormalities. Interstitial and alveolar pulmonary infiltrates
footpads are common radiographic findings in dogs with respira-
Enamel hypoplasia in surviving tory disease. Although some dogs with CNS infection
puppies have normal cerebrospinal fluid (CSF) analyses, most have
mononuclear cell pleocytosis and increased protein concen-
CDV, Canine distemper virus; CNS, central nervous system. trations. The ratio of serum/CSF immunoglobulin G (IgG)
and albumin is commonly high in dogs with encephalitis,
but this only documents inflammation of the CNS, not CDV
Ocular abnormalities associated with CDV infection infection.
include anterior uveitis, optic neuritis with resultant blind- Measurement of serum or CSF antibody titers can aid in
ness and dilated pupils, and retinochoroiditis. The combina- the diagnosis of CDV infection. Documentation of a four-
tion of retinochoroiditis and encephalitis is detected in fold increase in the serum IgG titer over a 2- to 3-week
approximately 40% of affected dogs. Keratoconjunctivitis period or detection of IgM antibodies in serum is consistent
sicca and hyperreflective retinal scars called medallion lesions with recent infection or recent vaccination but does not
occur in some dogs with chronic infection (Fig. 96.1). prove clinical disease. CSF antibody titers to CDV are
Other less common syndromes have been attributed increased in some dogs with encephalitis. False-positive
to CDV infection. Dogs infected before the development results can occur in CSF samples contaminated with blood.
of permanent dentition usually have enamel hypoplasia. If CSF antibody titers are greater than those in serum, the