How much milk can be given to a rat? - briefly
A rat can safely consume roughly 1–2 ml of milk per day, though many adults are lactose intolerant and may experience digestive upset. For most laboratory or pet rats, water is the preferred fluid, and milk should be offered only sparingly, if at all.
How much milk can be given to a rat? - in detail
Rats can ingest milk, but the quantity must be limited to avoid digestive upset and nutritional imbalance. An adult laboratory rat weighing 250–300 g typically tolerates 5–10 ml of milk per day, divided into two or three small feedings. Younger pups, which rely on their mother’s milk, can handle slightly higher volumes (approximately 10–15 ml per day) but only for a brief weaning period.
Key considerations:
- Lactose tolerance: Rats possess low lactase activity after weaning; excess lactose leads to diarrhea and dehydration. Use lactose‑reduced or lactose‑free formulations when providing milk to older animals.
- Nutrient balance: Milk is rich in fat and protein but lacks essential vitamins and minerals required for rodent health. Supplement with a complete rodent chow to meet daily requirements for calcium, phosphorus, vitamin A, and B‑complex vitamins.
- Caloric contribution: One milliliter of whole cow’s milk provides roughly 0.65 kcal. At the upper limit of 10 ml, milk contributes about 6–7 % of the total daily energy intake for a 300‑g rat, leaving the majority to be supplied by standard pellet diet.
- Feeding schedule: Offer milk in a shallow dish or via a syringe to ensure precise measurement. Observe the animal for signs of gastrointestinal distress (soft stools, reduced activity) and adjust volume accordingly.
- Safety precautions: Avoid flavored or sweetened milks, which contain added sugars that may exacerbate lactose intolerance and promote obesity. Do not substitute milk for water; rats require unrestricted access to fresh drinking water.
If the goal is to provide supplemental nutrition during recovery or weaning, a commercially available rodent milk replacer is preferable. These products are formulated with reduced lactose, balanced amino acids, and added vitamins, allowing safe administration of 5–8 ml per day for adult rats and up to 15 ml for juveniles.