Chloride is the major extracellular anion, working alongside sodium to maintain fluid balance, blood volume, and proper pH throughout your horse's body. It is also essential for producing hydrochloric acid in the stomach, which is critical for protein digestion and killing harmful bacteria in feed. Chloride is the third electrolyte lost in large quantities through equine sweat, right behind sodium and potassium. Because sodium and chloride are typically consumed together as salt (sodium chloride), their supplementation strategies are identical.
A 500kg horse at maintenance needs about 20 grams of chloride per day — roughly the weight of four teaspoons of sugar. This is automatically covered when you provide adequate salt (sodium chloride), since table salt is about 60 percent chloride by weight. A standard salt block and normal hay ration meet maintenance needs. Working horses need proportionally more, supplied through electrolyte supplementation.
0.93% of daily nutrient intake
Chloride makes up 0.93% of your horse's total daily nutritional requirements by weight. That's a tiny amount — but it matters.
Similar to sodium deficiency: reduced appetite, dehydration, poor performance, and metabolic alkalosis (disrupted blood pH). Chloride deficiency rarely occurs independently of sodium deficiency since both are supplied by salt.
Like sodium, chloride excess is self-correcting with adequate water access. Isolated chloride toxicity is not a practical concern in horses.
| Life Stage | Size | Min | Max | Unit | Notes |
|---|---|---|---|---|---|
| Adult | — | 20 | 30 | g | For a 500kg horse at rest. Automatically met when adequate salt (NaCl) is provided. |
| Working / Active | — | 35 | 70 | g | Chloride losses in sweat parallel sodium losses. Electrolyte supplementation covers both simultaneously. |
Source: NRC 2007
