Understanding the Three Miracle Molecules of Whelping — Calcium, Glucose and Oxytocin
Breeders often discuss calcium, glucose, and oxytocin — and for good reason. These three miracle molecules work together to regulate and sustain a bitch’s contractions during labour. Each plays a distinct yet interdependent role:
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Calcium acts as the engine, driving muscle contractions.
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Glucose is the fuel, supplying energy for endurance.
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Oxytocin is the accelerator, stimulating and coordinating contractions.
If any of these are lacking, labour can slow or stall. Let’s explore each one in detail.
Calcium: The Engine Behind Every Contraction
Calcium is arguably the most critical molecule during whelping and lactation. Muscle fibres, including those in the uterus, rely on calcium to contract effectively. As labour progresses, the bitch naturally draws calcium from her bones to sustain uterine contractions. Without enough available calcium, contractions weaken — resulting in prolonged whelping, fatigue, and increased stress for both mother and puppies.
Supplementing Calcium During Whelping
Providing bioavailable calcium during labour can prevent uterine inertia (when contractions weaken or stop). Breeders typically give oral calcium between the delivery of each puppy.
Common supplement forms include:
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Syrups (e.g. Troy Calcium Syrup) – easy to administer and fast-acting.
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Powders and tablets – ideal for lactation but slower to absorb.
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Injectables – used only under veterinary supervision.
Important: Do not supplement calcium during pregnancy. Doing so can suppress the body’s natural calcium-regulating mechanisms and increase the risk of eclampsia after birth.
Eclampsia – A Calcium Deficiency Emergency
Eclampsia (also known as hypocalcaemia, milk fever, or puerperal tetany) occurs when blood calcium levels drop dangerously low during lactation. It is a veterinary emergency.
Symptoms include:
- Restlessness, panting, or whining
- Poor maternal behaviour
- Muscle tremors, twitching, or stiffness
- Disorientation or clumsy gait
- Fever and dilated pupils
- Vomiting or diarrhoea
If you observe any of these, contact your vet immediately.
Calcium Forms & Feeding Recommendations
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Syrups: Quickest effect during labour; also contain glucose for energy.
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Powders or tablets: Ideal for lactation once feeding is established.
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Injectables: Reserved for veterinary use.
During lactation, continue calcium supplementation as demand peaks in weeks two to four, when milk output is highest. Some breeders also include calcium-rich foods (like yoghurt or bone-based raw diets) if tolerated.
Glucose: The Energy for Endurance
Glucose provides the energy required to sustain strong, rhythmic contractions. As many bitches lose their appetite before labour, their glucose reserves may be depleted when whelping begins — especially with large litters.
When and How to Supplement
Administering glucose orally during whelping can boost stamina and prevent fatigue.
Popular options include:
These products combine glucose with essential vitamins and minerals, supporting both energy and recovery. They can be given directly into the mouth or mixed into small, palatable food portions.
Bitches often eat their puppies’ placentas, which are rich in protein and nutrients — another natural way to replenish energy. However, consuming multiple placentas can cause loose black stools the next day, which is normal.
Glucose, therefore, earns its place as the second miracle molecule in whelping.
Oxytocin: Nature’s Accelerator
The third molecule, oxytocin, is a powerful hormone produced by the hypothalamus and released by the pituitary gland. It drives uterine contractions, coordinates the delivery of each puppy, and assists in uterine involution (shrinking back to size between births).
Natural Oxytocin Release
Puppy suckling stimulates oxytocin production, promoting both milk letdown and maternal bonding. This is why it’s important to allow puppies to nurse soon after birth — it helps the uterus contract and deepens the mother-pup bond.
When Oxytocin Is Used Medically
Although once common, injecting oxytocin during whelping is now rarely recommended without veterinary supervision. Incorrect timing or dosing can cause the uterus to contract too strongly, trapping unborn puppies — a potentially fatal complication.
In clinical practice, veterinarians may administer oxytocin after a caesarean section to help the uterus contract and prevent infection, or occasionally after natural whelping to aid in cleaning out uterine fluids.
Final Thoughts
Together, calcium, glucose, and oxytocin are essential for a successful, healthy whelp:
- Calcium supports sustained contractions and milk production.
- Glucose fuels the hard work of labour and recovery.
- Oxytocin coordinates contractions and strengthens the mother-pup bond.
As breeders, we can safely support the first two through supplementation and nutrition. The third — oxytocin, the “hormone of love” — is best left to nature. Let mum and her puppies take care of that part.
✅ Key Takeaways for Breeders
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Begin oral calcium supplementation during whelping and continue through lactation.
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Use glucose supplements to maintain energy during long labours.
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Avoid unnecessary oxytocin injections — always consult your vet.
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Observe for signs of eclampsia in lactating bitches, particularly in weeks two to four.
