Reddit reviews Nature's Way - Pau D'Arco Inner Bark, 545 mg, 180 capsules

I've got a 7 month old and he broke out in a wart last month and then promptly shared it with one of our other dogs. I'd suspect your pup's lump, though it doesn't resemble a wart, to be something along those lines. Puppies are at risk of a suppressed immune system due to vaccinosis, or over-vaccination. Papilloma viruses (warts) are the most common outbreaks, but lumps, rashes and other such things are prone to occur at a young age, and pibbles, I've found, are unfortunately more prone to skin issues than many of the dogs I've ever had.

Regardless of what the official diagnosis is, I would highly recommend picking up an immune system booster. I've tried a couple over the years to great success. This one I've used most recently for the pup with the warts, and it has outstanding reviews, mine included. This one, though a little more expensive, was excellent for our older dog some years ago with an epic skin infection. In addition to the Amazon product, we also used a pau d'arco supplement, because the wart had a slight resurgence on just the zenapet. I'm happy to report that the wart on the pup is finally withered back and is almost gone with this combination. This is just after only two-and a half weeks. They say that warts should be allowed to run their course, but that they'll go away after 1 to 5 MONTHS. As far as I'm concerned, supplements are the way to go.

Here's more info on immune support supplements.

Hope this helps a little.