@ashleyignacio - Like noted many breeds have chicken allergies... not just Basenjis. Lamb is many times a trigger too. Corn for sure or beet pulp.... sometimes you can see the allergy very young, sometimes as they mature. One of my Basenji became so allergic to corn that she would just about bite the pads on her feet... once stopped NO issues.
Since the trigger might be the chicken, best to stop that and see if it gets better. Will take a few days for it to get out of their system. Not that a Vet visit is a not a good idea to rule out anything else. Since you have already noticed a difference, see if it continues to improve.
Another note, please be careful using tea tree oil. I do not use it as it can be toxic.
Online it says the following-
Although products containing low concentrations of tea tree oil are not expected to be a problem in pets, the use of pure tea tree oil directly on the skin is potentially very serious in pets and should never be used. Exposure may cause ataxia, salivation, lethargy, coma and tremor.