Cobalt is a trace mineral that your rabbit's cecal bacteria use to synthesize vitamin B12 (cobalamin). Since rabbits obtain virtually all their B12 from cecotropes, the cobalt available to those cecal bacteria matters — without it, B12 production declines. However, cobalt is needed in extremely small amounts, and a normal diet of hay and greens provides adequate cobalt for cecal B12 synthesis.
A handful of kale or dandelion greens (about 20g) provides trace amounts of cobalt — there is no established specific requirement for rabbits, but the minute amounts present in hay and fresh greens support the cecal bacteria that produce vitamin B12.
0.0% of daily nutrient intake
Cobalt makes up 0.0% of your domestic rabbit's total daily nutritional requirements by weight. That's a tiny amount — but it matters.
Cobalt deficiency would manifest indirectly as vitamin B12 deficiency: anemia, poor growth, lethargy, and neurological symptoms. This is theoretical in pet rabbits and has not been documented as a practical concern on a normal diet.
Cobalt toxicity from food sources is extremely unlikely. The amounts present in hay and vegetables are far below any harmful threshold.
| Life Stage | Size | Min | Max | Unit | Notes |
|---|---|---|---|---|---|
| Adult | — | 0 | 0.01 | mg | Trace amounts support cecal bacterial B12 synthesis. No established specific requirement. |
Source: general veterinary consensus
