Client Information Sheet:
Methicillin-Resistant Staphylococcus Pseudintermedius (MRSP)
This resource has been developed for our clients who are preparing for their pet's MRSP treatment.
A guide to help you understand MRSP, its diagnosis, and treatment, supporting the safe management of your pet’s infection.
What Is MRSP and How Does It Develop in Pets?
Staphylococcus pseudintermedius is a common bacterium and a normal part of the skin flora, living on the skin and mucosa of most healthy dogs. MRSP strains have genes that make them resistant to certain antibiotics, which can make infections more difficult to treat with standard medications.
You may have heard of a similar bacterium in humans, called methicillin-resistant Staphylococcus aureus (MRSA, sometimes referred to as “golden staph”). The characteristics and implications between MRSP and MRSA infections are very different, therefore, it is important to differentiate between the two.
In pets with pre-existing skin disease (most commonly allergies), these bacteria can multiply and cause an infection. This is often referred to as a ‘secondary infection’, because it wouldn’t have occurred without the primary skin disease starting it.
While MRSP infections can happen at any time, risk factors such as multiple or incomplete courses of antibiotics, other underlying skin diseases, and the pet’s immune status can also contribute to the development of MRSP.
Is MRSP Contagious to Other Pets or People?
A resistant strain can be passed between dogs through direct contact, contact with contaminated surfaces, or on human hands or clothing. In healthy dogs, this is unlikely to cause problems and is usually replaced by their normal strain over time.
Pets with underlying skin disease are more susceptible to developing infection if exposed. To reduce risk, avoid close contact with other dogs, such as at dog parks, while your pet’s MRSP infection is active. Pets with MRSP may also require simple home hygiene measures, such as cleaning bedding, toys, and grooming tools, to help prevent transmission. During veterinary hospital visits, additional infection control measures may be used to reduce the risk of MRSP spreading between patients.
MRSP is adapted to dogs and carries very low risk to healthy people or other pets, such as cats. Transmission to healthy people is uncommon, but individuals who are immunocompromised or have open wounds should take extra hygiene precautions, including thorough hand washing, when handling an affected pet.
How We Identify MRSP Infections?
Symptoms
MRSP infections can occur anywhere on your pet’s skin or ears and often cause:
Inflammation, hair loss, scabbing, or pimple-like spots
Itching or discomfort
Foul odour from the skin in some cases
These symptoms typically don’t resolve with standard antibiotic use, which may prompt further investigation.
Our clinician may first perform cytology, a simple test to examine skin cells and bacteria under a microscope. This helps determine whether an infection is present.
Diagnosis
If MRSP is suspected:
- A culture and sensitivity (C+S) test may be recommended. This confirms the specific bacteria involved and identifies which antibiotics are effective (sensitive, S) and which are not (resistant, R).
This testing allows us to tailor treatment to your pet’s specific infection, improving the likelihood of successful management.
MRSP infections are typically treated using a combination of approaches, tailored to your pet’s specific infection and underlying conditions.
What We Consider When Treating MRSP
Topical Therapy
Gentle antiseptic washes such as chlorhexidine or piroctone olamine shampoos used 1–2 times per week help reduce bacterial load on the skin.
Additional antiseptic solutions (e.g., chlorhexidine diluted to appropriate concentration) may be applied directly to specific affected areas once or twice daily
Topical therapy may be all that is needed for superficial or limited lesions and can reduce the need for systemic antibiotics.
Systemic Antibiotics
Systemic antibiotics are used only when necessary and generally reserved for deep pyoderma, extensive infections, or cases where topical treatment alone is insufficient.
The choice of antibiotic and its duration is guided by culture and sensitivity (C+S) testing, which identifies antibiotics the specific bacterial strain is sensitive to.
Because MRSP is resistant to many commonly used antibiotics, treatment choices need to be made carefully and on a case-by-case basis.
Addressing Underlying Causes
MRSP infections often occur alongside other skin problems (eg. allergies, hormonal issues, or immune‑related conditions), and managing these underlying conditions is essential.
Your dermatologist may suggest other diagnostics or adjust current treatments (e.g. medications that reduce itch and inflammation) while treating MRSP to support healing.
Without addressing underlying causes, infections are more likely to recur or persist.
What Can I Expect for My Pet’s MRSP Treatment and Recovery?
Initial Treatment
The early phase of treatment is often the most intensive. This may involve more frequent use of topical therapies to reduce bacterial load and bring the infection under control.
Investing time and effort at this stage can improve response rates, speed up resolution, and can make ongoing management easier as treatment progresses.
Recovery & Monitoring
Most pets begin to show improvement within 2 to 4 weeks, although this can vary depending on the severity and depth of infection.
Regular follow-up appointments allow our clinicians to monitor response to treatment and make adjustments if needed, helping ensure the best possible outcome.
Long-Term Management
Once the infection has resolved, some pets, particularly those with underlying skin conditions such as allergies, require ongoing dermatological care.
Managing these underlying issues is key to preventing recurrence. With appropriate long-term management, most dogs go on to live normal, comfortable lives.
If you’d like more information on how we approach diagnosis and treatment planning, you can visit our consultations services page.
Still have questions?
We are here to help!
Resource Prepared By
Dr Elisa Dennis
BVSc (Hons) MANZCVS
Dermatology Resident