Hot Spots in Bernese Mountain Dogs: When Skin Infection Happens in Hours, Not Weeks

A hot spot, known clinically as acute moist dermatitis, begins when bacteria that normally live harmlessly on the skin surface multiply rapidly in a small area of broken or irritated skin. What makes it different from the slower allergic itch cycle documented elsewhere for this breed is speed: instead of building over days or weeks, a hot spot can go from a small irritation to a raw, weeping, infected patch within hours, largely because the dog's own scratching and licking response actively spreads bacteria and breaks down more skin as it goes.

The dense double coat is the specific reason this breed is prone to the moisture side of the problem. Heavy seasonal shedding means loose undercoat can mat and trap debris and moisture against the skin underneath, and swimming, rain, or even heavy panting on a warm day leaves dampness sitting against skin that doesn't dry quickly through a thick coat the way it would on a short-haired dog. Bacteria thrive in that warm, damp, low-oxygen environment, and a mat sitting over one spot concentrates the risk in that exact location.

A hot spot typically starts as a small area of intense itch, and the dog's response, biting or scratching at it, is what turns a minor irritation into an open, infected sore. The affected area often looks red, moist and hairless once found, sometimes with a foul odour, and it can be surprisingly painful to the touch given how quickly it developed. Because it's frequently hidden under intact coat around it, owners often discover a hot spot by smell or by noticing their dog fixating on one spot, rather than by seeing it directly.

Treatment usually involves clipping the surrounding coat to expose the full extent of the affected skin, cleaning the area, and a short course of topical or oral antibiotics along with something to stop the itch-scratch cycle, since the dog will keep making it worse otherwise. Preventing recurrence means addressing the underlying moisture and matting rather than only treating each spot as it appears.