Page 388 - Problem-Based Feline Medicine

380 PART 7 SICK CAT WITH SPECIFIC SIGNS

Complete blood count findings are non-specific and Diagnosis
may include leukopenia or leuko-cytosis, eosinophilia
Myocarditis/diaphragmitis is a diagnosis of exclusion.
and anemia.
Biochemistry and complete blood counts are unre-
MYOCARDITIS/DIAPHRAGMITIS** markable, except for a mild to moderate increase in CK
in less than 50% of experimentally infected cats.
Classical signs Definitive diagnosis can only be made at necropsy.
● Uniphasic or biphasic fever. Histopathology shows a neutrophilic infiltrate with a
● Depression. foci of myonecrosis in myocardium and diaphragm.
● Lethargy.
● Mild generalized lymphadenopathy. Differential diagnosis
● +/- Signs of cardiac failure.
Any other causes of fever should be ruled out includ-
ing infectious, inflammatory, immune-mediated, drugs,
Pathogenesis neoplasia and metabolic.

Several different infectious agents have been impli- Other causes of cardiac failure that should be ruled
cated in cats: out include congenital deformities, hypertrophic car-
● Viral, e.g., FIP has been shown to cause cardiac diomyopathy, restrictive cardiomyopathy and dilatative
infection. cardiomyopathy.
● Trypanosoma cruzi, which causes Chagas’ disease
in humans. Treatment
● Streptococcus and Borrelia (Lyme’s disease) in cer-
Supportive therapy is indicated if dehydration or
tain geographic areas.
cardiac disease are present.
No single agent has been identified, and the disease
Broad-spectrum antibiotics are indicated if complete
may be multifactorial.
blood count supports an infectious cause.
Clinical signs
Prognosis
Fever is biphasic in 50% of the cats; if biphasic:
Fever and depression resolve spontaneously in the
● First fever occurs approximately 10 days after
majority of cats.
exposure, lasts 1–3 days and peaks at 39.3–40.7˚C
(102.7–105.2˚F). Prognosis is poor if peracute cardiac failure is present
● Second fever occurs 1–2 weeks after the first fever with systemic signs of fever and depression.
(at 3–4 weeks post-exposure), lasts 5 days and
peaks at 39.9–40.9˚C (103.8–105.6˚F). Prevention
Depression and lethargy lasts 5–10 days. Although an infectious agent is suspected, no single
etiologic agent has been identified, making recommen-
Appetite is mildly decreased in some cats, but most
dations for prevention difficult.
continue to eat and drink.
Some animals exhibit mild generalized lymph-
TRAUMA**
adenopathy.
Irritable disposition and hyperesthesia may occur, Classical signs
and are most likely due to fever and malaise.
● Cardiovascular or respiratory compromise.
In a few case reports, cats have died from peracute ● External signs of injury.
cardiac failure, but this outcome is not common.