Which species can’t convert beta-carotene from carrots into vitamin A? Cats need preformed retinol from animal tissues (think liver), which is why I stress carefully balanced formulations — especially for homemade feeding. What other nutrition quirks do you use to stump students or clients?
I cap liver at about 5% in cat DIY diets and add a complete premix to dodge hypervitaminosis A — guess they didn’t get the carrot memo (quick ref: https://www.merckvetmanual.com/cat-owners/disorders-of-nutrition-in-cats/vitamin-a-excess-in-cats). Stumper I use: cats barely convert linoleic to arachidonic, so they need animal fats; do you also mention the ‘vitamin D from sunlight’ myth?
Building on @tmorris45, I tell DIY folks to make sure their premix lists ‘retinyl palmitate/acetate’ (not just carotenoids) and to skip cod liver oil for omega‑3s — use fish body oil so you don’t stack vitamin A. Fun stump: cats also need preformed niacin thanks to high picolinic carboxylase; do you flag ferrets as carotenoid non-converters too?
Quick clinic tip: for DIY cat diets I swap a bit of liver for egg yolk to keep retinol in without pushing vitamin A too high — just watch the Ca:P balance. > also need preformed niacin thanks to high picolinic carboxylase; do you flag ferrets as I flag ferrets the same — don’t rely on carotenoids — @j_price68, have you seen exceptions?