Stinging Nettles – 1 capsule per meal mixed with food
Elderberry without fruit and other artificial flavorings – 1 capsule
Olive Leaf extract – 1-2 capsules (note: this tastes bitter, so mixing in food doesn't go over well)
Andrographis Paniculata – an ayurvedic herb sold under many names not limited to Andrographis such as Kan Jang – 1 pill
Propolis tincture – 2 drops with the alcohol boiled off in 1 Tbsp warm water (might still have a strong taste even after diluting)
Grapefruit Seed Extract (GSE) – 1-2 pills if you suspect the illness is likely to turn into an infection or in the very early stages of an infection. Avoid the liquid which is extremely bitter and can burn mucous membranes.
L-Lysine* – 500mg for up to a week, then 250mg maintenance dose
Colloidal Silver <30 ppm - 1 dropper 2-3x a day for a week as one would use an antibiotic, then stop or taper down to 1 droppeful for a few days.
Lactoferrin - 250mg OR Bovine colostrum – particularly effective in the case of orphaned kittens