Page 375 - Problem-Based Feline Medicine

19 – THE PYREXIC CAT 367

● Cryptococcus neoformans (cryptococcosis)** (p 379)
Low-grade fever, malaise, anorexia and weight loss are typical. Most common form presents with
chronic mucopurulent or hemorrhagic nasal discharge, sneezing, stertorous respiration, distortion
over bridge of nose (Roman nose) or polyp-like mass in nasal opening.

● Histoplasma capsulatum (histoplasmosis)** (p 371)
Signs are often non-specific with fever, depression, and weight loss. Dyspnea, lymphadenopathy,
pale mucous membranes, gastrointestinal signs or ocular signs may be present.
Non-infectious:
● Pancreatitis** (p 377)
Signs are often vague and non-specific with anorexia and depression predominating. Fever is
inconsistent and may be accompanied by abdominal pain, vomiting and dehydration.

● Cholangiohepatitis** (p 378)
Typically anorexia and depression are present together with icterus or increased liver enzymes.
Vomiting may be evident and fever is present in about 1/3 of cats.

● Non-suppurative meningoencephalitis** (p 379)
Signs are chronic, of 1–4 weeks duration and include fever in some cats and variable CNS signs,
especially seizures and focal or multifocal neurologic signs.
● Myocarditis/diaphragmitis** (p 380)
Uniphasic or biphasic fever together with depression and lethargy are typical. Mild generalized
lymphadenopathy may be present and in a few cats overt cardiac failure occurred.
● Immune-mediated disease
Primary immune-mediated disease, such as systemic lupus erythematosus, is extremely rare in cats.
Secondary immune-mediated disease can occur due to primary infection, vaccination or neoplasia.
Anorexia, weight loss, fever and signs specific for the disease occur, such as bleeding, pale mucous
membranes, skin lesion or lameness.

Toxins/drugs:
● Drug-induced fever* (p 381)
Tetracyclines, amphotericin B and other drugs may cause a fever. The severity of fever is out of
proportion with the mild clinical signs. There is a history of antibiotic or antifungal therapy.
Trauma:
● Trauma** (p 380)
Mild fever associated with pain and inflammation often occurs 10–14 h after injury. There is evidence of
external or internal trauma. Sterile surgical trauma causes fever in some cats for 24 hours post-surgery.

INTRODUCTION
True fever results from activation of leukocytes that
MECHANISM? release factors (pyrogens) such as interleukin-1 and
tumor necrosis factor.
True fever must be differentiated from hyperthermia,
● These factors cross the blood–brain barrier and
which can be caused by increased muscle activity,
increase the thermoregulatory set point in the
increased environmental temperature and stress.
hypothalamus.