Fat is an essential macronutrient that provides concentrated energy, helps absorb fat-soluble vitamins (A, D, E, and K), and keeps your guinea pig's skin supple and coat glossy. Guinea pigs are strict herbivores, so their fat intake comes entirely from plant sources — primarily hay, pellets, and small amounts in leafy greens and seeds found in fortified pellets.
While guinea pigs don't need much fat compared to omnivores, a diet too low in fat can lead to dry, flaky skin, a rough coat, and poor absorption of critical vitamins. On the flip side, guinea pigs are prone to obesity if given too many calorie-dense treats or pellets, and excess body fat puts dangerous pressure on their small cardiovascular systems.
The sweet spot is a modest fat intake — around 3 to 5% of the total diet — which a standard timothy hay and pellet diet naturally provides. There is no need to add oils or fatty supplements to a guinea pig's diet.
A healthy guinea pig diet should contain roughly 3 to 5% fat by dry matter. Timothy hay provides about 1.5 to 2% fat, and quality guinea pig pellets contribute the rest. No additional fat supplementation is needed.
4.24% of daily nutrient intake
Fat / Healthy Fats makes up 4.24% of your guinea pig's total daily nutritional requirements by weight.
Dry, flaky skin, dull or rough coat, poor wound healing, reduced absorption of fat-soluble vitamins (A, D, E, K), low energy, and cold sensitivity in cooler environments.
Obesity (visible fat pads around shoulders and abdomen), fatty liver disease (hepatic lipidosis), reduced activity, difficulty grooming, and increased risk of heart problems. Guinea pigs can become dangerously overweight surprisingly quickly on high-fat diets.
| Life Stage | Size | Min | Max | Unit | Notes |
|---|---|---|---|---|---|
| Adult | — | 3 | 5 | % of diet | Percentage of diet by dry matter. Timothy hay and pellets provide adequate fat. No supplementation needed. |
Source: NRC 1995, general veterinary consensus
