The Texas A&M Veterinary Medical Diagnostic Laboratory, TVMDL, regularly performs testing to detect and mitigate the effects of pyoderma, a bacterial skin infection commonly found in canines. Clinical signs of pyoderma include redness, pustules, crusting, hair loss and itchiness around affected regions. The disease is classified into three categories based on the depth of infection: surface, superficial and deep. The most common form, superficial pyoderma, occurs when the bacterium Staphylococcus pseudintermedius damages the epidermis and hair follicles.
If left untreated, the bacteria may penetrate deeper into the skin and eventually enter the bloodstream, leading to bacteremia.
A multifaceted approach is essential for veterinarians managing pyoderma in their patients:
- First, a diagnosis must be confirmed.
- Next, the underlying cause should be identified.
- Finally, treatment protocols should be tailored based on diagnostic findings and antibiotic resistance.
Confirm diagnosis
Cytology
After clinical examination of a patient suspected to be infected with pyoderma, cytology is recommended as the first step in the diagnostic process. Veterinarians should begin by collecting plenty of material from the lesions. Collection should be performed by compression smears or by using a cotton swab or scalpel blade. Samples should then be examined under a microscope to identify abnormalities in the cells. Instead of performing an in-house cytological examination, veterinarians may consider sending samples to TVMDL, where material can be observed by clinical pathologists.
With advanced expertise and state-of-the-art equipment, TVMDL provides critical insights into cellular analysis and thoroughly examines patient samples from every angle. In addition to identifying S. pseudintermedius, clinical pathologists also screen for other organisms, including yeast and various pathogens. The cytology report might include recommendations for additional testing when necessary, helping to refine the entire diagnostic picture.
Cultures
In cases involving persistent and more severe pyodermic infections or when there is a concern about antibiotic resistance, bacterial cultures are especially valuable.
TVMDL can identify specific bacterial strains and perform antimicrobial susceptibility testing to determine which antibiotics will be most effective when treating the patient.
In recent years, treatment of S. pseudintermedius infections has been increasingly difficult due to multi-drug-resistant Staphylococcus species.
Thus, cultures are particularly important when evaluating a plan to combat stubborn bacteria or chronic infection.
Identify the underlying cause
Pyoderma occurs as a secondary infection, meaning that it is often triggered by an underlying issue that compromises dermal integrity. Common causes include allergies, ectoparasites, yeast and fungal infections and hormonal imbalances.
Essentially, any factor that disrupts the skin barrier or immune defenses can create an environment conducive to bacterial overgrowth.
Identifying the primary cause of the skin infection will help determine the appropriate therapy and prevent a recurrence.
Initiate a treatment plan
Depending on the classification of pyoderma, the root cause, and the presence of antibiotic resistance, the treatment regimen may need to be adjusted accordingly.
The administration of less common or more potent antibiotics may be necessary.
When treating surface level or localized pyoderma, topical treatments like medicated shampoos or ointments containing antibiotics or antiseptics are often sufficient; however, for severe cases, oral antibiotics are commonly prescribed.
The choice of antibiotics should be guided by culture and sensitivity results to ensure the most effective treatment and prevention of reoccurrence. Any concurrent conditions or presence of pathogens should be managed in parallel.
Most importantly, clear and consistent communication between the client and veterinarian is vital for a successful recovery. Veterinarians should emphasize the importance of keeping pet bedding clean, dry and well-cushioned to prevent reinfection and support healing. In addition, educating clients on proper medication administration, monitoring for signs of recurrence and scheduling timely follow-up appointments can greatly enhance treatment outcomes. For more information about diagnostic options at TVMDL, visit tvmdl.tamu.edu or call the College Station lab at 888-646-5623.
