Pyoderma is the veterinary word for a bacterial skin infection, and it's rarely the whole story. It almost always rides on top of something else, an allergy, a parasite, a moisture problem, which is why treating just the infection so often fails.
Pyoderma is a bacterial skin infection in dogs, showing as red bumps, pustules, crusts, hair loss, and a musty odor. It's usually secondary to an underlying trigger like allergies, parasites, or skin folds, so lasting control means treating both the infection and its cause. A vet diagnoses it and may prescribe an antibiotic like cephalexin plus addressing the trigger; we never set doses.
If your vet prescribes it: we can supply cephalexin for dogs & cats after a licensed-vet review. The prescription is included — you pay only for the medication, and only if the vet approves.
What pyoderma looks like
Red bumps and pus-filled pimples (pustules), circular crusty patches, hair loss, scaling, and often a musty or unpleasant smell. It can be surface-level, in the skin, or deep, and it's one of the most common reasons dogs are prescribed antibiotics. [1]
Why it keeps coming back
Here's the core: pyoderma is usually secondary. Something disrupts the skin first, allergies (the most common), fleas or mites, skin-fold moisture, hormonal disease, or a wound, and bacteria move into the weakened skin. Treat only the infection and it clears, then returns, because the door it came through is still open. [2]
Diagnosis and treatment
A vet confirms it (sometimes with skin cytology) and typically prescribes an antibiotic such as cephalexin, often alongside medicated shampoos. Crucially, they also hunt for the underlying trigger, because that's what stops the cycle. Course length matters: stopping antibiotics early is a common cause of recurrence. Dosing is set by your vet.
Breaking the cycle
Lasting freedom from pyoderma means addressing the cause, allergy control (sometimes with Apoquel), flea prevention, managing skin folds, or treating an underlying disease, not just repeating antibiotics. When a vet prescribes cephalexin, we can supply it after review.
Frequently asked questions about pyoderma in dogs
Is pyoderma contagious?
Generally not to people or other pets in the usual sense; it's an overgrowth of the dog's own skin bacteria triggered by something else.
Why does my dog's pyoderma keep returning?
Because it's usually secondary to an untreated cause like allergies. Fix the trigger, not just the infection.
What antibiotic treats pyoderma?
Cephalexin is commonly used, at a vet-set dose and course. Finishing the full course matters.
Related skin & infection guides
Dog Skin Infection Treatment · Cat Skin Infection · Dog Yeast Infection Skin · Dog Hot Spot · Dog Wound Infection · Dog Ear Infection Yeast Or Bacteria
Sources & References
For educational use. PrepperPetSupply is a licensed, veterinarian-staffed pharmacy; prescriptions are dispensed only after review by a licensed veterinarian and are not a substitute for in-person veterinary care. Not for human use.