Page 352 - Problem-Based Feline Medicine

344 PART 6 CAT WITH WEIGHT LOSS OR CHRONIC ILLNESS

Pharmacological appetite stimulation may be consid- Hyperthermia describes a core body temperature
ered but objective evidence of their efficacy is not avail- above that considered normal in the cat. In fever, the
able. set point of the thermoregulatory center is
increased.
In cats which are unable or unwilling to eat, enteral or
parenteral feeding may be considered. Fever may be caused by exogenous pyrogens such as
● Enteral nutrition should be used wherever possi- infectious agents, immune complexes and tissue
ble, as this prevents intestinal mucosal atrophy inflammation or necrosis.
– Nasoesophageal, esophageal, gastrostomy and ● Exogenous pyrogens principally act by causing the
jejunostomy tubes may be used host to release endogenous pyrogens.
– Esophagostomy and gastrostomy tubes are ● Endogenous pyrogens act on the thermoregulatory
preferable in cats requiring more long-term center, alter the set point and induce a febrile response.
nutrition.
Weight loss frequently occurs in cats with prolonged
● Parenteral feeding is more technically complex and
fever because:
expensive, and should only be used when feeding
● Febrile cats are frequently inappetent.
via the gastrointestinal tract is impossible.
● A febrile cat is in a hypermetabolic state.
● Weight loss may be associated with the fever per se,
or more often with the disease causing the fever.
Prognosis
The differential diagnosis list for causes of fever is
The prognosis for each individual case will be depend-
extensive but may be broadly categorized:
ent on the nature of the neoplasm and the response to
● Localized infection.
therapy.
– Including urinary tract infection, pyometra,
Cachexia and hypoalbuminemia tend to be poor prog- pyothorax, peritonitis, abscess, bronchopneumo-
nostic indicators. nia, endocarditis, suppurative cholangitis/ cholan-
giohepatitis, dental disease, retrobulbar or
pulmonary abscess and osteomyelitis.
Prevention ● Systemic infection.
– Including FeLV, FIV, feline infectious peritoni-
Cats with neoplastic lesions should be monitored
tis (FIP), feline panleukopenia, respiratory tract
closely for evidence of malnutrition.
virus infection, bacteremias, toxoplasmosis,
mycobacterial infection and systemic mycoses.
● Immune-mediated disorders.
SEPTIC FOCUS/PERSISTENT FEVER**
– Including primary immunodeficiencies, sys-
temic lupus erythematosus, polyarteritis nodosa,
Classical signs
chronic progressive polyarthritis, immune-
● Fluctuating pyrexia and associated mediated hemolytic anemia and immune-medi-
inappetence. ated thrombocytpenia.
● Weight loss. ● Neoplasia.
● Clinical signs associated with the etiology – Including lympho- and myeloproliferative dis-
of the fever. eases and large neoplastic lesions with central
necrosis.
See main references on page 364 for details (The ● Miscellaneous conditions.
Pyrexic Cat). – Including drug reactions.

Pathogenesis Clinical signs

The thermoregulatory center is located in the preoptic Principal clinical signs will be fever, weight loss and
region of the anterior hypothalamus. inappetence.