Fever of unknown origin: interesting feline cases (Proceedings)
Cats with fevers (103° F-106° F) are a common occurrence in everyday practice. Most cases respond to antibiotic therapy or are self-limiting (abscesses, viral infections, post-surgical fevers). However, the most frustrating case is one in which a routine course of antibiotics does not improve the clinical condition of the cat, routine diagnostics do not identify the cause and the fever is ongoing. This is the fever of unknown origin (FUO) case that requires a methodical approach to discover the exact cause of the fever so that proper therapy can be instituted. Your approach may vary based on the clinical presentation of each cat, as well as the patient's geographic location/travel history. You must also consider the cost/benefit of the diagnostic testing as well as the invasiveness of the tests performed. Tests may need to be repeated as the case progresses.
• Obtain a complete history, including travel, vaccination, drug/supplements.
Follow any leads noted on history, physical examination or localizing signs.
Lameness – Joint fluid for cytology, cultures (aerobic, anaerobic, Mycoplasma), joint radiographs
While performing the hunt, don't forget to treat the patient.
• Therapeutic drug trials – Weigh risks versus benefits.
The fever should break within 3 days if the drug therapy is going to work for that case...
Maintain hydration – fluid therapy as needed.
Encourage appetite. Appetite will typically return once the fever breaks.