orpheous87 should be able to answer if the hair sample testing covers yeast infections.
Yeast issues was ID by skin samples for my dogs (like sticky tape that after sample is taken it is stuck on a slide). I did testing via my vets which cost a bomb and probably orpheous87 has a better result than I do with regard to how much the hair sampling covers.
I guess I was lucky malaseb 3x a week worked for mine (went through 2-3 other brands before finding one which worked), however I was doing it in total for about 5-6 months (with two dogs) before I got it under control and even now I have to keep eye on things to make sure it does not escalate again!
Vaccination disturbance - ill effects of vaccine Chemical Toxicity - due to pharmaceuticals, over the counter medications Skin Afflictions - symptoms of exposure to environmental radiation pH Imbalance - due to an excess of acidity
The test also indicated that the adrenal glands, the bladder, the heart and the sphenoid & ethmoid sinus are inflamed.
That should give you an idea of what's covered by the test. I would think, if your boy is allergic to a particular fungus, it would show up under the environmental section. Or, possibly under the skin afflictions section. On looking at the website again, there don't seem to be any remedies for yeast infections so I'm not 100% sure whether it would be picked up but you could always ask on their Facebook page before sending off for a hair test.