From Dog
Facial abscess due to Bacteroides spp-associated bite wound[1]

An abscess is any wound which involves the formation of pus. The majority of abscesses in dogs involve primary or secondary bacterial infections, but some abscesses form as a result of necrotic tissue which has formed due to ischaemia - e.g. neoplasia

Both superficial dermal abscesses (pyoderma) and internal abscesses (e.g. hepatic abscess, pyothorax) occur in dogs, usually involving a number of anaerobic bacteria.

Commonly involved bacteria include:

Treatment of superficial abscesses are relatively straightforward with lancing of fluid-filled swelling, bathing or flushing with antimicrobial solutions such as chlorhexidine.

Parenteral broad-spectrum antimicrobial drugs are usually indicated, with good sensitivity afforded using ceftiofur, enrofloxacin, amoxycillin/clavulanate or amikacin.

Abscess involving internal organs can be more problematic, depending on the organ involved.