MRSP in dogs: methicillin-resistant Staphylococcus pseudintermedius
4-year-old Belgian Shepherd with recurrent generalised superficial pyoderma. Culture isolates methicillin-resistant Staphylococcus pseudintermedius (MRSP), also resistant to fluoroquinolones, clindamycin and trimethoprim-sulphonamide; susceptible to amikacin, rifampicin and chloramphenicol.
Which statement about the management of this case is correct?
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A. A long-acting cephalosporin (cefovecin) is a good option because it improves compliance
Methicillin resistance means resistance to all beta-lactams, including cephalosporins of every generation and amoxicillin-clavulanate.
B. Oral rifampicin should be started immediately, as it is the only effective drug
Rifampicin is hepatotoxic, quickly selects resistance and is a key drug in human medicine. It is reserved for when topical therapy fails and there is no alternative, always guided by susceptibility testing.
C. Intensive topical therapy (chlorhexidine shampoo 2–3 times a week plus daily sprays or wipes on localised lesions) and control of the primary cause
Correct. Antibiotic resistance does not protect the bacterium against antiseptics: chlorhexidine and benzoyl peroxide are effective against MRSP. In superficial pyoderma, topical therapy alone is often enough and avoids using reserve antimicrobials.
D. MRSP is more virulent than susceptible strains and must be treated like deep pyoderma
MRSP is not more virulent: it causes the same lesions as susceptible strains. What changes is the treatment options, not the severity.
lightbulb Key takeaway
MRSP is a problem of treatment options, not virulence. Prioritise topical antiseptics, avoid beta-lactams and reserve drugs such as rifampicin or amikacin. Advise hand hygiene at home: transmission to people is uncommon but possible.
References: ISCAID: Guidelines for the diagnosis and antimicrobial therapy of canine superficial bacterial folliculitis (Hillier et al., 2014)
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Updated: October 31, 2026 · Educational content for veterinary professionals. It does not replace current clinical guidelines or the judgement of the attending veterinarian.