Metabolism of the essential fatty acids (EFAs), linoleic acid (LA; 18:2n-6) and -linolenic acid (ALA; 18:2n-3), is limited in the skin; long-chain derivatives of LA and ALA are therefore considered conditionally essential nutrients for skin.
Guinea pig food pellets, & fresh fruit and vegetables. Choosing a high quality, nutritionally-balanced dry food pellet which is manufactured specifically for guinea pigs, such as Oxbow Essentials, will provide many of the vitamins and minerals needed.

Several sources of information suggest that human beings evolved on a diet with a ratio of omega-6 to omega-3 essential fatty acids (EFA) of approximately 1 whereas in Western diets the ratio is 15/1-16.7/1.

Harris WS, et al. (2017). Omega-3 fatty acids and cardiovascular disease...

This particular example perfectly highlights why Guinea Pig Essential Fatty Acid And Thyroid Support is so captivating.
Journal of Nutrition and Metabolism: Omega-3 Fatty Acids and Weight Loss...