Page 376 - Problem-Based Feline Medicine

368 PART 7 SICK CAT WITH SPECIFIC SIGNS

● Leukocytes are activated by a multitude of infec- scratches, but can be from other animal bite wounds,
tious agents, neoplasia, tissue necrosis and or foreign bodies such as grass awns.
immune-mediated diseases.
Tissue trauma results in decreased blood flow to the
area, and therefore selects for those bacteria which are
WHERE? facultative or obligate anaerobes.
Fever is defined as systemic elevation of core body Common bacteria isolated from cat abscesses
temperature above 39.2˚C (102.5˚F). are obligate anaerobes (Fusobacterium, anaerobic
cocci, Bacteroides, Eubacterium, Peptococcus and
The most accurate measurement of core body tempera-
Peptostreptococcus) and/or microaerophilic or facul-
ture is obtained rectally.
tative organisms (Pasteurella, Corynebacterium,
Aural temperature is approximately −17.2˚C (0.5˚F) Actinomyces and Micrococcus); abscesses commonly
lower than the rectal temperature. contain more than one isolate.
Abscesses resulting from cat bites are often infected
WHAT? with Pasteurella spp.; L-forms and Mycoplasma spp.
are occasionally involved.
Fever is a general clinical sign that can be associated
with many different diseases. Proliferation of injected organism results in infiltration
of tissue by neutrophils and other phagocytes and even-
The most common disease causing fever in the cat is
tual pus production.
percutaneous cellulites or abscess.
The body generally walls off infection, and purulent
Many viral and bacterial diseases cause fever because
products build up to form a soft, fluccuant swelling,
leukocytes are recruited and activated as part of the
usually associated with hair loss over the area.
general immune response.
The abscess may rupture spontaneously.
Organ inflammation, such as pancreatitis, cholangio-
hepatitis and myocarditis, can be associated with an ele- Persistent cellulitis can be a consequence of long-
vated temperature even when an infectious agent is not standing abscess.
present.
Bone involvement may also occur with long-standing
abscesses. Osteomyelitis should be suspected if the
DISEASES CAUSING AN ELEVATED abscess heals but repeatedly breaks as a draining tract.
TEMPERATURE

Clinical signs
PERCUTANEOUS
CELLULITIS/ABSCESS*** Owners will report that cats are indoor/outdoor or
recently escaped up to a week prior to appearance of
the clinical signs.
Classical signs
● Fever. Pyrexia may occur within 12 hours of a fight. Cats
● Anorexia (partial or complete). may be quite depressed following a fight, even prior to
● Reluctance to move, lethargy and the onset of fever.
depression. Some cats present without systemic signs and only a
● Pain, heat or swelling at site of abscess or mild swelling in the fore- or hindlimbs, neck, face or
cellulitis. head.

If limbs are involved, the only complaint may be pro-
Pathogenesis gressive lameness.
Percutaneous abscesses and cellulitis are caused by Reluctance to move and anorexia may be a conse-
puncture wounds, most typically from cat bites or quence of pain, fever or systemic response to infection.