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MRSP Infection in Dogs: Causes and Symptoms

MRSP Infection in Dogs: Causes and Symptoms

Infection

14 min read

MRSP infection in dogs is a drug-resistant bacterial infection causing skin issues and wounds. Learn its causes, symptoms, and the best treatment options

By 

Sustainable Vet Group

Updated on

March 11, 2025

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What is MRSP Infection in Dogs?

Methicillin-Resistant Staphylococcus pseudintermedius (MRSP) is a type of bacteria that causes infections in dogs and is resistant to many common antibiotics, including methicillin and other beta-lactam antibiotics.

MRSP is a strain of Staphylococcus pseudintermedius, a bacterium naturally found on a dog’s skin and mucous membranes. While regular S. pseudintermedius infections can be treated with standard antibiotics, MRSP infections are much harder to manage due to their resistance to multiple drugs.

Unlike typical bacterial infections, MRSP does not respond to first-line antibiotics, making treatment more complex and prolonged. This resistance develops when bacteria are repeatedly exposed to antibiotics, leading to mutations that allow them to survive even in the presence of these medications.

MRSP is a major concern for veterinarians and dog owners because it can cause persistent skin infections, surgical site infections, and deep tissue infections. These infections are often recurrent and challenging to eradicate.

TL;DR

  • MRSP spreads through direct contact, contaminated surfaces, and repeated antibiotic use, making multi-dog environments high-risk.
  • Antibiotic resistance makes standard treatments ineffective, leading to persistent and recurrent infections.
  • Infected dogs often develop skin lesions, swelling, non-healing wounds, and, in severe cases, fever and lethargy.
  • Topical antiseptics and targeted antibiotics may help, but MRSP-related surgical infections remain difficult to manage.
  • Simini Protect Lavage is the only effective non-antibiotic solution for MRSP surgical cases, preventing bacterial biofilm formation and reinfection.

How Common is MRSP in Dogs?

MRSP infections are becoming increasingly common in veterinary medicine, with rising cases reported worldwide. While Staphylococcus pseudintermedius is a normal part of a dog’s skin flora, the methicillin-resistant strain (MRSP) has been identified more frequently in veterinary clinics, kennels, and households with multiple pets.

Studies indicate that MRSP prevalence varies by region, but infection rates have increased due to widespread antibiotic use in veterinary medicine. Some research suggests that up to 40% of S. pseudintermedius isolates in certain veterinary hospitals show methicillin resistance.

Where MRSP is Commonly Found

MRSP is often detected in dogs with chronic skin conditions, post-surgical wounds, ear infections, and deep tissue abscesses. It is frequently seen in:

  • Dogs with recurrent pyoderma or allergic skin disease
  • Postoperative surgical site infections
  • Dogs undergoing long-term antibiotic treatment
  • Pets in shelters, kennels, or multi-dog households

Why Antibiotic Resistance is Increasing

The overuse and misuse of antibiotics are the primary drivers of MRSP resistance. Repeated exposure to antibiotics, particularly in cases where treatment is stopped early or used unnecessarily, allows bacteria to develop resistance.

Additionally, MRSP can spread between dogs through direct contact or contaminated surfaces, making infection control crucial in veterinary settings.

How Do Dogs Get MRSP?

MRSP is a highly resilient bacterium that spreads easily in veterinary settings and among dogs in close contact. Unlike typical bacterial infections that respond to standard antibiotics, MRSP thrives in environments with frequent antibiotic use, causing treatment-resistant infections.

Ways Dogs Can Contract MRSP

  • Direct Contact with Infected Animals - Dogs can contract MRSP by coming into contact with another infected pet. This is especially common in multi-dog households, kennels, and veterinary clinics where animals interact closely.
  • Exposure to Contaminated Surfaces - MRSP can survive on objects such as bedding, grooming tools, medical equipment, and kennel surfaces. Dogs that frequently visit grooming facilities, boarding kennels, or veterinary clinics may be exposed to these contaminated environments.
  • Repeated Antibiotic Treatments - Overuse or misuse of antibiotics contributes to MRSP infections. When a dog is given antibiotics repeatedly—especially if treatments are stopped early—the bacteria can develop resistance, making future infections harder to treat.
  • Weakened Immune System - Dogs with compromised immune systems, whether due to chronic illnesses, endocrine disorders, or stress, are more susceptible to MRSP. Their bodies struggle to fight off infections, increasing the likelihood of colonization by resistant bacteria.

Risk Factors for MRSP Infection

  • Dogs with Allergies or Endocrine Disorders - Conditions like atopic dermatitis, hypothyroidism, or Cushing’s disease weaken the skin barrier and immune response, making dogs more vulnerable to MRSP infections.
  • Frequent or Prolonged Antibiotic Use - Long-term antibiotic exposure alters bacterial populations, increasing the risk of antibiotic-resistant strains like MRSP.
  • Extended Hospital Stays or Frequent Veterinary Visits - Dogs that require hospitalization, surgery, or repeated treatments are at higher risk due to increased exposure to MRSP-contaminated environments.

By understanding these transmission routes and risk factors, veterinarians and pet owners can take preventive measures to reduce the spread of MRSP and protect canine health.

Signs and Symptoms of MRSP in Dogs

MRSP infections primarily affect the skin but can also lead to deeper tissue infections. Since MRSP is resistant to many antibiotics, symptoms often persist despite initial treatments. Recognizing the signs early can help in timely diagnosis and management.

Hair Loss and Excessive Itching

Dogs with MRSP infections may develop patchy hair loss (alopecia) due to chronic skin irritation. Constant itching, licking, or chewing of the infected area can lead to further skin damage and secondary infections.

Swelling, Pain, or Discomfort

Affected areas may become swollen and tender to the touch. If the infection spreads deeper, pain and localized warmth may be noticeable.

General Signs of Illness

If the infection becomes more severe, dogs may show systemic symptoms, such as:

  • Fever
  • Lethargy or weakness
  • Loss of appetite

Since MRSP infections can mimic other skin conditions, a proper veterinary diagnosis is crucial for effective treatment.

Diagnosis: How Vets Confirm MRSP in Dogs

Diagnosing MRSP requires laboratory testing because it cannot be identified through visual examination alone. Since MRSP is resistant to many antibiotics, early and accurate diagnosis is essential for selecting the right treatment.

Culture and Sensitivity Testing

The most reliable way to confirm MRSP is through bacterial culture and antibiotic sensitivity testing. A veterinarian will collect a sample from an infected area—such as a skin lesion, wound, or ear discharge—using a sterile swab.

This sample is then sent to a laboratory, where technicians grow the bacteria and test its response to various antibiotics. If the bacteria show resistance to methicillin and other common drugs, MRSP is confirmed.

Why MRSP Requires Lab Testing

MRSP infections look similar to other bacterial skin infections, making it impossible to diagnose based on appearance alone. Without lab testing, standard antibiotic treatments may fail, leading to prolonged or worsening infections.

Importance of Early Diagnosis

Timely identification of MRSP allows veterinarians to prescribe the appropriate antibiotic or alternative treatments, reducing the risk of complications. Early diagnosis also helps prevent the spread of MRSP to other pets, especially in multi-dog households, veterinary clinics, and kennels.

How is MRSP Different from Other Staph Infections?

MRSP (Methicillin-Resistant Staphylococcus pseudintermedius) differs from typical Staphylococcus pseudintermedius infections in one key way: antibiotic resistance.

While both types of bacteria can cause skin infections, wounds, and post-surgical complications in dogs, MRSP is resistant to methicillin and many other commonly used antibiotics.

This makes it much harder to treat than regular S. pseudintermedius infections, which typically respond to first-line antibiotics like cephalexin or amoxicillin-clavulanate.

MRSP vs. MRSA: What’s the Difference?

MRSP is often compared to Methicillin-Resistant Staphylococcus aureus (MRSA), another drug-resistant staph infection. However, MRSP primarily affects dogs, while MRSA is more common in humans. Although MRSP can occasionally spread to humans, the risk of transmission is lower compared to MRSA.

Why MRSP is Harder to Treat

  • Limited antibiotic options – Many standard antibiotics fail against MRSP, requiring veterinarians to use second-line or specialized treatments.
  • Recurrent infections – MRSP infections often return after treatment, requiring long-term management.
  • Environmental persistence – MRSP can survive on surfaces like bedding, kennels, and grooming tools, increasing the risk of reinfection.

Because of its resistance and persistence, MRSP requires careful antibiotic selection and strict infection control to prevent outbreaks in veterinary clinics and multi-pet households.

Are Certain Dog Breeds More Prone to MRSP?

Some dog breeds are more susceptible to MRSP due to genetic factors and breed-specific skin conditions. Breeds prone to allergies, skin folds, or chronic dermatitis have a higher risk of developing bacterial infections, which can lead to MRSP if antibiotics are overused.

Breeds at Higher Risk

  • Bulldogs, Pugs, and Shar-Peis – Skin folds trap moisture, creating a breeding ground for bacteria.
  • Labrador Retrievers and Golden Retrievers – Prone to allergic dermatitis and chronic ear infections.
  • German Shepherds – More likely to develop deep pyoderma, a severe skin infection.

Proper skin care and infection prevention are key for these breeds.

Is MRSP Contagious to Other Dogs?

Yes, MRSP can spread between dogs, especially in multi-pet households, kennels, and veterinary clinics. It spreads through direct contact with infected dogs, contaminated surfaces (bedding, food bowls, grooming tools), and shared environments.

Risk Factors for Transmission

  • Dogs in kennels, shelters, or veterinary hospitals
  • Shared items like toys, blankets, or grooming tools
  • Open wounds or skin infections that allow bacteria to enter

Can Asymptomatic Carriers Spread MRSP?

Yes, some dogs carry MRSP without showing symptoms but can spread it to others, making infection control crucial. Regular hygiene and isolation of infected dogs help prevent outbreaks.

Treatment Options for MRSP in Dogs

MRSP infections require a multifaceted treatment approach due to their resistance to common antibiotics. Treatment typically includes culture-guided antibiotic therapy, topical antiseptics, and infection management strategies to prevent recurrence.

Medical Treatments

  • Antibiotic Therapy - Since MRSP does not respond to many first-line antibiotics, culture and sensitivity testing is essential to identify effective options. Some MRSP strains remain susceptible to chloramphenicol, doxycycline, rifampin, or amikacin, but each case requires individualized treatment.
  • Why Some Antibiotics Don’t Work - MRSP carries resistance genes that make it immune to methicillin and other beta-lactam antibiotics, such as cephalexin and amoxicillin-clavulanate. Using ineffective antibiotics can worsen resistance, leading to chronic or recurrent infections.

Topical Treatments

  • Antibacterial Shampoos and Solutions - Regular bathing with chlorhexidine or miconazole-based shampoos helps reduce bacterial load and prevent reinfection.
  • Medicated Wipes and Ointments - For localized infections, antiseptic wipes, gels, or ointments (containing chlorhexidine or mupirocin) help control bacterial spread and promote healing.

The Role of Simini in Surgical MRSP Cases

For MRSP-related post-surgical infections, Simini Protect Lavage is a critical non-antibiotic solution. MRSP increases the risk of surgical site infections (SSIs), which can be difficult to treat with standard antibiotics.

Simini Protect Lavage effectively removes bacteria, disrupts biofilms, and lowers infection risks without contributing to antibiotic resistance. It is particularly beneficial for orthopedic surgeries, wound management, and post-operative care, where MRSP contamination poses a significant challenge.

For non-surgical MRSP infections, a combination of targeted antibiotics, antiseptic treatments, and strict hygiene measures is necessary to prevent recurrence and transmission.

Managing MRSP at Home: Infection Control and Prevention

MRSP can spread easily in multi-pet households, making strict hygiene and infection control measures essential. Since MRSP is resistant to many antibiotics, preventing transmission is just as important as treating the infected dog.

Strict Hygiene Measures

  • Wash hands thoroughly after handling an infected dog, especially before touching other pets or household items.
  • Use disposable gloves when applying topical treatments to avoid spreading bacteria.
  • Limit direct contact, such as cuddling or allowing the dog to sleep on furniture, to prevent contamination.

Cleaning and Disinfecting

  • Wash bedding, toys, collars, and bowls frequently using hot water and pet-safe disinfectants.
  • Clean surfaces like floors and furniture with antibacterial solutions to eliminate lingering bacteria.
  • Use separate grooming tools and feeding dishes for the infected dog to prevent cross-contamination.

Minimizing Spread to Other Pets and Humans

  • Keep the infected dog in a separate space until the infection resolves.
  • Regularly bathe pets with antibacterial shampoos if they share a home with an infected dog.
  • Although MRSP is rarely transmitted to humans, immunocompromised individuals should take extra precautions when handling an infected pet.

Consistent infection control measures help prevent MRSP from spreading and reduce the risk of reinfection.

How to Prevent MRSP in Dogs

Preventing MRSP infections requires a proactive approach that focuses on responsible antibiotic use, regular veterinary care, and maintaining a strong immune system.

Since MRSP thrives in environments where antibiotics are overused or misused, reducing unnecessary antibiotic exposure is key to controlling its spread.

Responsible Antibiotic Use to Prevent Resistance

One of the biggest contributors to MRSP infections is antibiotic resistance, which develops when antibiotics are used improperly. To prevent this:

  • Always complete prescribed antibiotic courses, even if symptoms improve before finishing the medication.
  • Avoid using antibiotics without veterinary guidance, as incorrect treatment can promote resistant bacteria.
  • If your dog has a history of bacterial infections, ask your vet about alternative treatments, such as antibacterial shampoos or topical antiseptics, instead of relying on systemic antibiotics.

Regular Vet Check-Ups to Detect Early Signs

Routine veterinary visits help catch skin infections, wounds, or other risk factors before they become severe. Early intervention reduces the chance of an infection becoming resistant to treatment.

Dogs with allergies, endocrine disorders, or chronic skin issues should have frequent skin assessments to monitor for signs of bacterial infections.

Strengthening the Immune System Through Diet and Hygiene

A strong immune system helps dogs fight off bacterial infections naturally. To improve immunity:

  • Feed a balanced diet with high-quality proteins, essential fatty acids, and vitamins. Omega-3 and Omega-6 fatty acids support skin health, reducing infection risk.
  • Maintain good hygiene by regularly bathing dogs with veterinary-approved shampoos to remove bacteria from the skin.
  • Keep bedding, grooming tools, and food bowls clean to prevent bacterial buildup.

Prognosis: Can Dogs Recover from MRSP?

How Long It Takes to Treat MRSP

The duration of MRSP treatment depends on the severity of the infection and the effectiveness of treatment.

  • Mild skin infections may resolve within 4-6 weeks with proper antibiotic and topical therapy.
  • Deep or recurrent infections can take several months to fully heal, requiring a combination of antibiotics, antiseptic treatments, and strict hygiene measures.
  • Post-surgical MRSP infections require specialized wound management, and in severe cases, additional procedures may be needed to remove infected tissue.

Chances of Recurrence and Long-Term Management

MRSP has a high recurrence rate, especially in dogs with underlying conditions like allergies, hypothyroidism, or chronic skin disease. Preventing reinfection requires:

  • Monitoring for early signs of reinfection, such as skin redness, pustules, or excessive itching.
  • Following hygiene protocols to minimize bacterial spread in the home.
  • Using non-antibiotic alternatives like antiseptic washes and medicated shampoos to reduce bacterial load without contributing to antibiotic resistance.

When to Seek Veterinary Care for Persistent Infections

If a dog’s MRSP infection does not improve with treatment, spreads to deeper tissues, or recurs frequently, veterinary intervention is crucial. Seek immediate care if:

  • Lesions worsen or new infections appear despite antibiotic therapy.
  • The dog develops fever, lethargy, or loss of appetite, which may indicate a systemic infection.
  • A post-surgical wound shows signs of MRSP, as these infections require specialized management to prevent complications.

With early detection, responsible treatment, and infection control, dogs with MRSP can recover and live healthy lives while minimizing the risk of recurrence.

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Summary

  • MRSP is a severe, drug-resistant bacterial infection that makes standard antibiotic treatments ineffective, leading to persistent or recurrent infections.
  • Dogs contract MRSP through direct contact, contaminated surfaces, or repeated antibiotic exposure, making multi-pet households, kennels, and vet clinics high-risk environments.
  • Symptoms include non-healing skin infections, abscesses, redness, swelling, and fever, which can worsen without proper treatment.
  • Accurate diagnosis through lab testing (culture and sensitivity) is essential, as misidentifying MRSP can lead to ineffective treatments and prolonged illness.
  • Treatment requires targeted antibiotics, medicated shampoos, and antiseptics, while Simini Protect Lavage is the only proven non-antibiotic solution for surgical cases.
  • Preventing MRSP involves strict hygiene, responsible antibiotic use, and early detection, helping reduce resistance and protect both pets and veterinary environments.

FAQs

Can humans catch MRSP from dogs?

MRSP is primarily a canine-associated bacterium, and transmission to humans is rare. However, immunocompromised individuals or those with open wounds may be at higher risk. Practicing good hygiene, such as handwashing after handling an infected dog, helps minimize the risk. Unlike MRSA, MRSP is not a significant human health threat but requires proper infection control.

How long does MRSP last in dogs?

The duration of MRSP infections depends on severity and treatment response. Mild cases may resolve in 4-6 weeks with targeted antibiotic therapy and topical treatments. However, severe or recurrent infections can last several months, requiring long-term management. Regular vet check-ups and strict hygiene measures help shorten recovery time and prevent reinfection.

What happens if MRSP is left untreated?

Untreated MRSP infections can worsen and spread, leading to chronic skin infections, deep tissue abscesses, or systemic illness in severe cases. Persistent infections may cause pain, discomfort, and hair loss, and in post-surgical cases, they can lead to serious complications. Since MRSP is antibiotic-resistant, early diagnosis and proper management are crucial to avoid long-term health issues.

Can MRSP come back after treatment?

Yes, MRSP infections have a high recurrence rate, especially in dogs with allergies, chronic skin disease, or weakened immune systems. Reinfection often occurs due to environmental contamination or incomplete treatment. To prevent recurrence, follow strict hygiene protocols, use antiseptic washes, and monitor for early signs of reinfection. Regular vet visits can help manage underlying conditions.

Are there vaccines for MRSP prevention?

No, there is currently no vaccine for MRSP. Prevention relies on responsible antibiotic use, good hygiene, and early detection of infections. Regular bathing with antibacterial shampoos, maintaining a clean environment, and avoiding unnecessary antibiotic use help reduce the risk of MRSP infections in dogs.

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Step #1

Getting Ready

Ensuring a clean surgical field starts with proper skin preparation. This video demonstrates the best practices for:

  • Shaving the patient – Achieving a close, even shave while minimizing skin irritation
  • The Dirty Scrub – The initial skin prep step to remove surface debris and reduce bacterial load before the sterile scrub.

Following these techniques helps reduce infection risk and improve surgical outcomes. Watch the video to see how it’s done effectively!

Step #2

Reduce Your Risks

Many surgeons are shocked to find out that their patients are not protected from biofilms and resistant bacteria when they use saline and post-op antibiotics.

That’s Where Simini Comes In.

Why leave these risks and unmanaged?  Just apply Simini Protect Lavage for one minute. Biofilms and resistant bacteria can be removed, and you can reduce two significant sources of infection.

Step #3

Take the Course

Preventing surgical infections is critical for patient safety and successful outcomes. This course covers:

  • Aseptic techniques – Best practices to maintain a sterile field.
  • ​Skin prep & draping – Proper methods to minimize contamination.
  • ​Antibiotic stewardship – When and how to use perioperative antibiotics effectively.

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