Page 379 - Problem-Based Feline Medicine

19 – THE PYREXIC CAT 371

Initial signs are rapidly followed by sneezing, which
HISTOPLASMA CAPSULATUM
are not paroxysmal and are less prominent than in
(HISTOPLASMOSIS)*–***
herpesvirus.
Nasal discharge is primarily serous to mucoid and Classical signs
rarely progresses to purulent.
● Fever.
Oral ulcerations are common, especially on the ● Weight loss.
tongue, and may be associated with drooling or hyper- ● Anorexia.
salivation. Ulcers may also occur at the mucocutaneous ● Pale mucous membranes.
junction, hard palate and nose. ● Dyspnea.
● Lymphadenopathy.
Fever generally spikes initially after infection prior
to onset of signs, and returns with onset of clinical
See main reference on page 755 for details (The Cat
signs.
With Signs of Chronic Small Bowel Diarrhea).
Viral pneumonia occurs occasionally with certain
strains, and may produce significant mortality. Death is
often sudden and preceded by laboured respiration.
Clinical signs
A rare variant strain (FCV-Ari) reported from the
Clinical signs are often non-specific and include
United States, produces a high fever, facial and paw
fever, anorexia and weight loss.
edema (50% of cats), ocular and nasal discharge, con-
junctivitis and ulcerative stomatitis (50% of cats), hem- Dyspnea and harsh lung sounds without coughing is
orrhage from the nose, GIT, etc. (30–40% of cats), common.
icterus (20% of cats) and rapid death. Mortality is high
Peripheral and visceral lymphadenopathies are fre-
(30–50%).
quently present.
Pale mucous membranes, icterus, hepatomegaly or
splenomegaly may be evident.
Diagnosis
Ocular signs are uncommon, but can occur.
Presumptive diagnosis can be made on basis of history
and clinical signs because treatment for feline herpes Gastrointestinal signs are uncommon in cats com-
virus-1 and calicivirus are similar. pared to dogs, and include chronic diarrhea, mesenteric
lymphadenopathy and anorexia.
Oral ulcerations or clinical signs of pneumonia are
more suggestive of calicivirus. Osseous lesions produce soft tissue swelling and
lameness.
Definitive diagnosis is by viral isolation or reverse
transcriptase polymerase chain reaction assays from
swabs taken from the oropharynx, ideally in the first
week of illness.
Diagnosis
Demonstration of increasing serum antibody titers to
Diagnosis is by demonstration of the organism in
feline calicivirus in paired samples is also useful,
lymph nodes, draining tracts, bone lesions or vitreous
whereas measurement of a single titer is not useful
humor.
because many cats have titers from vaccination.
The organism has a thin capsule and is intracellular
Identification of FCV-Ari is based on the clinical
within macrophages.
syndrome, pathology and culture of virus from blood,
nasal or ocular discharge, spleen or lungs. No reliable serologic test available.