One of a group of similar diseases (including pemphigus vulgaris, pemphigus vegetans, and pemphigus erythematosus) known collectively as the pemphigus complex, pemphigus foliaceus is a disease in which the body mistakenly produces antibodies that attack the outermost layer of skin. Though all breeds of dog are susceptible to this disease, the most common victims include Akitas, Dachshunds, Doberman Pinschers, Spitz breeds, and Bearded Collies.
Because pemphigus foliaceus affects the most superficial skin layer, it is fortunately very easy to spot and diagnose. It usually manifests at first as a scaly texture to the skin, which then results in blisters that quickly rupture and cause scabs and other pus-filled sores. The blisters tend to come to a head and drain rapidly so they may be hard to find, but in general the disease has a very distinctive look and feel that makes it hard to misidentify. Don't be so hasty to rule out other causes, however. If your dog has recently adopted a new medication, you should look into that avenue as very often outbreaks that occur due to allergic reactions to medication can mimic pemphigus foliaceus. In addition, more serious diseases such as systemic lupus erythematosus and various skin cancers can produce similar symptoms to pemphigus foliaceus, and leaving them untreated for an extended period of time could have disastrous consequences for the health of your dog. Because of this, though it might seem like an overreaction to what many would consider a simple rash, a you should consider a skin biopsy. It's the most effective and safe way to be certain of exactly what is causing your dog's symptoms, and the temporary pain it might cause your dog will more than outweigh the peace of mind you'll both feel after having ruled out more dangerous diseases.
Though in itself, pemphigus foliaceus isn't a particularly dangerous disease, there is always the risk that the sores will become infected and cause much more significant problems that would require emergency intervention to treat. This is usually a rare occurrence, however.
Treatment of all diseases in the pemphigus complex is usually handled by the use of a corticosteroid followed up with a secondary immune suppressing medication that will prevent the body from producing as many antibodies that mistakenly attack the skin. This can be a very effective form of treatment, but because the immune system is being artificially repressed, it does tend to put the dog at a much higher risk for other communicable diseases. As such, if your dog is being treated for pemphigus foliaceus with immune suppressive medications, it becomes all the more important for you to monitor his or her health with regular checkups so that any problems can be taken care of early on.