Distinguishing Dog Skin Fungus vs. Bacterial Infections

When your furry friend starts to exhibit symptoms like excessive shedding, dandruff, or bumps on their skin, many pet parents might mistakenly assume it's just a common dermatitis. They might resort to using iodine tincture for disinfection and erythromycin ointment for application, only to find that the condition doesn't improve and may even worsen over time. A veterinary visit reveals that the issue is actually a fungal infection!

It's actually not that difficult to differentiate between fungal and bacterial infections in dogs. Here's how you can tell the difference:

1. Symptom Differentiation

● Fungal Infection: Look for localized hair loss, broken hair, and areas where the fur can be easily pulled out in clumps. There might be a significant amount of dandruff, and the hair loss areas often appear circular or elliptical, spreading outward with clear boundaries.

● Bacterial Infection: You might notice skin itching, hair loss, redness, bumps, or pustules. There may also be an unpleasant odor, and the dog might frequently lick the affected area. Over time, this can lead to local dampness, inflammation, and scabbing.

2. Wood's Light Examination

Most fungal skin diseases in dogs are caused by Microsporum canis, a fungus similar to the one that causes athlete's foot in humans. This fungus will exhibit a fluorescence under Wood's light.

You can purchase a Wood's light to inspect your dog in a dimly lit environment. If you notice fluorescence on the affected skin, it's likely a sign of a fungal infection.

3. Skin Scraping Examination

When fungal infections have been present for a long time and the skin damage is severe, it's not always easy to distinguish visually. Some fungi may not show fluorescence under Wood's light either. Additionally, symptoms of bacterial dermatitis can be similar to mange, demodectic mange, allergic dermatitis, and other skin conditions. Given the possibility of mixed infections with multiple pathogens, a definitive diagnosis requires a skin scraping examination at a veterinary clinic.

Treatment Methods for Fungal and Bacterial Skin Diseases in Dogs:

1. Fungal Infection:

✔ Shave the area, and put an Elizabethan collar on your dog to prevent them from licking it;

✔ Disinfect the area with iodine tincture, even though it may temporarily stain the fur, the color will fade over time;

✔ Apply antifungal sprays or ointments containing clotrimazole, ketoconazole, or terbinafine;

✔ For extensive infections, oral itraconazole may be prescribed, but always under veterinary supervision.

2. Bacterial Infection:

✔ Shave the area, and fit your dog with an Elizabethan collar;

✔ Disinfect with iodine tincture;

✔ Apply erythromycin ointment, zinc oxide ointment, or mupirocin ointment;

✔ For larger areas, consider using pet skin antibacterial sprays and medicated baths. Pipette spray is effective for many skin conditions and is gentle on your dog's skin, helping to inhibit the spread of bacteria. For medicated baths, opt for antibacterial options, typically recommended once or twice a week for comprehensive antibacterial and disinfectant effects.

Important Notes:

1. Maintain a clean environment for your dog, regularly wash their belongings, and disinfect their living area. Dog beds can be sunned to kill any bacteria, fungi, or mites present.

2. Consider supplementing your dog's diet with Vitamin B and ultraconcentrated fish oil. Vitamin B can boost skin immunity and aid in mucosal repair, while fish oil has excellent antiinflammatory properties, improving your dog's skin and coat health.