The Roles of Calcium, Glucose and Oxytocin in Whelping.

Breeders will often discuss calcium, glucose and oxytocin, and it’s for a good reason. Together, they are the three main things that control and influence a bitch’s contractions during a whelp. The presence of all three is essential for a successful whelp. Calcium, glucose and oxytocin all have different functions in the process. Using a car as an analogy, we can think of calcium as the engine, glucose as the fuel, and oxytocin as the accelerator. You won’t get very far if any of them are missing because they all contribute to a smooth ride. Let’s go into detail about what each of these molecules has to offer and their role in your bitch’s whelp.

CALCIUM

We’ll start with calcium as the first of the three miracle molecules. It is the most significant overall during whelping and lactation. Calcium must be available within the muscle fibres for the muscle to be able to work and physically produce muscle. The uterus is also a muscle and produces uterine contractions during labour (or whelping). During whelping, the bitch naturally starts to draw available calcium from her bones (leeching) as the demand for calcium increases. Calcium made available this way helps the continuation of contractions (a whelp can take a long time). Lack of available calcium can slow down and weaken uterine contractions. This leads to prolonged whelping as well as stress on the bitch and the puppies.

Supplementing Calcium

Supplementing bioavailable calcium throughout the whelping process eliminates the lack of calcium as a possible cause of uterine inertia. During normal labour in dogs, the uterine muscles contract to push the puppies through the birth canal. However, in cases of uterine inertia, the contractions may be weak, infrequent, or absent altogether. This can result in prolonged or stalled labour, making it challenging for the dog to deliver the puppies naturally.

Most breeders administer calcium orally throughout a whelp, between each puppy being born. Calcium supplements are available in several forms, such as syrup, powder, tablet, and injection. Calcium syrup is the most common form to use during a whelp as it is easy to administer. 

During pregnancy, we do NOT recommend calcium supplementation. We recommend against supplementing calcium before the whelp. This can interfere with a bitch’s natural ability to regulate calcium levels, which can impact the whelp and subsequent lactation. It’s during the whelp this changes.

During a whelp, we recommend starting to supplement calcium for your bitch. This is to ensure she has enough calcium for muscle/uterine contractions. We highly recommend continuing this calcium supplementation during lactation as the demand to provide calcium in the milk increases.

Calcium Deficiency Emergency

Eclampsia (AKA hypocalcemia, milk fever, puerperal tetany, etc.) is an emergency medical condition associated with a significant drop in blood calcium levels in nursing bitches. Eclampsia can quickly become life-threatening.

If you are observing any of the following signs, you need to contact your veterinarian immediately: 

• Poor maternal behaviour
• Restlessness or panting
• Whining
• Vomiting
• Diarrhoea
• Clumsy walking, stiff gait, or tetany (entire body goes stiff)
• Facial itchiness
• Muscle tremors or convulsions
• Fever
• Dilated pupils

So, calcium definitely deserves to be one of the three miracle molecules.

Different Forms of Calcium Supplements

A liquid calcium syrup suspension, such as Troy Calcium Syrup, is the most straightforward and practical to administer, particularly during a whelp. As calcium syrups are essentially a sugar and mineral syrup in one, it also contains glucose, which during a whelp brings its own benefits (we’ll talk about glucose further down). After the whelp, you can continue supplementing the nursing bitch’s diet with calcium syrup. However, it is a more expensive form of calcium than the other types below.

Calcium tablets and powder are great during lactation and offer the best value for money during these four to five weeks. Providing your bitch’s appetite is good; it is also the easiest. Give the bitch calcium supplementation until the puppies wean to solids. Because calcium tablets take time to dissolve in the stomach, it takes longer for this calcium to be absorbed and available in the bloodstream. As calcium in this form is slower to become available for use, tablets are less efficient during whelping but are convenient during lactation. In particular, tablets are great for fussy bitches, who are reluctant to eat, as you know exactly how much they have had.

Calcium powder is the easiest to mix with food. The powder form is also the cheapest, saving you from administering tablets daily. However, this form of calcium administration relies on having a bitch that eats her food reliably and promptly, so you can be sure she has consumed the total dose. 

Calcium is also available as an injectable. It is most commonly used by veterinarians when treating cases of eclampsia. Usually, it is suspended in a medical saline solution and given slowly intravenously (directly into a vein). It is also sometimes given intramuscularly (directly into the muscle) to prevent eclampsia in bitches known to be prone to this as a preventative measure. Extreme caution must be applied if considering using calcium in this form. We recommend using it only if you have veterinary support and direction and know what you are doing.

Other Sources of Calcium

In the past, puppy kibble used to have elevated calcium levels, so it was used as a source of calcium supplementation for the lactating bitch as well. However, nowadays, this is only sometimes true. In particular, large-breed puppy formulas are now usually very low in calcium, as it may interfere with the development of large-breed puppies. You need to read the nutritional contents of the growth formula you use to confirm the calcium content.

It is still a great idea to feed a lactating bitch a puppy, growth, or performance formula because she has elevated nutritional needs (especially protein and fat). This will support her to produce an increasing amount of nutritious milk. Dogs have a very high fat and protein content in their milk, and as puppies grow and consume increasingly more milk, the bitch needs increasingly more food until puppies wean.

Therefore, it may be fair to assume that the bitch may also need increasingly more calcium supplementation during weeks two to four of lactation to meet her milk production and output. During this period, bitches are the most susceptible to developing eclampsia. Many breeders will also add calcium-rich foods, such as dairy products (if tolerated) and raw foods with appropriate digestible bone content (if this is their usual diet).

GLUCOSE

Glucose, the second of the three miracle molecules, provides a significant amount of energy. During whelping, glucose provides energy and endurance to the whelping contractions. It is the fuel the muscles need to sustain and persevere with the hard work of whelping multiple puppies.

Bitches often lose their appetite a few days before whelping. This is a natural behaviour, most likely to eliminate bowel contents prior to the whelp. However, it can be a bit concerning to you as their owner. As bitches most likely have only eaten minimal amounts in the days leading up to their whelp, their glucose levels may become low during whelping, especially if there are a large number of puppies. Once the bitch has begun to whelp, it becomes exceedingly difficult to get her to consume any food or nutrition.

Luckily, it is easy to supplement glucose and other minerals. Glucose is available in several forms. Nutripet, Energel and Nutri-Drops are the most popular, as they also contain added vitamins and minerals, which are beneficial if the bitch has not been eating well. They also contain glucose, as previously mentioned, so it can be a 2-in-1 solution for many. These supplements can be administered directly into the bitch’s mouth or, if she is eating, mixed in with some other energy-dense and nutritious food.

Your bitch will likely also eat the placenta for each puppy born. This is the natural urge, and most breeders will allow this to happen. For one, because it is the natural order of things, but also they contain nutrition. Placentas are rich in mainly proteins, some carbohydrates and a small amount of fats (and vitamins and minerals). If your bitch hasn’t eaten for days, it is some nutrition she will take willingly and benefit from. However, eating a large amount of placenta will result in very loose black stools the following day. This is normal but also very worth knowing.

From this we can also include Glucose as one of the three miracle molecules.

OXYTOCIN

Oxytocin is the third of the three miracle molecules and is quite a natural wonder. It is a hormone and neuropeptide mainly produced by the hypothalamus and released by the pituitary gland. Oxytocin is responsible for initiating and regulating contractions during labour. It is also responsible for the uterus involuting (decreasing the size of the uterus in between each puppy born). The involution of the uterus helps push puppies in the right direction down the cervical horn towards the birth canal. The involution also makes for a more efficient contraction.

Oxytocin also affects mammary gland milk letdown (milk production), and suckling naturally stimulates oxytocin production. Therefore, the production and effects of oxytocin are self-perpetuated. Consequently, it is essential to let newborn puppies suckle straight away after you have checked them over. Oxytocin is also the hormone mainly responsible for the parent-baby bond. It is not uncommon for bitches who have had a cesarean section to reject puppies. They have not had the opportunity to produce oxytocin through a natural whelp, and nurse and bond with their newborns.

These days it is rarely recommended to administer/inject additional oxytocin during a whelp. It can significantly interfere with a whelp’s natural regulation and progression. Extreme caution must be taken as too much oxytocin injected can involute the entire uterus. This will effectively vacuum-seal unborn puppies inside the uterus and trap them.

In a clinical setting, oxytocin is usually administered after a caesarian section to reduce the size of the empty uterus. This aims to reduce the size of the uterus as it hadn’t contracted naturally from the whelping process. This also helps prevent infection, as the uterus hasn’t naturally contracted/involuted. Oxytocin is also sometimes administered after a natural whelp to “flush out” the uterus. However, with an average-sized healthy litter, the same effects are achieved over a few days of nursing.  

Overall, it is informative to know about oxytocin and its role in the whelping process. However, it is rarely something you, as a breeder, will need to deal with directly. 

Oxytocin is our favourite of the three miracle molecules and the only one we most likely can’t manipulate ourselves easily. Only facilitate for.

Final Thoughts

Knowing what we know now, we understand that of these three miracle molecules. We can assist in the presence of two easily (calcium and glucose). Oxytocin has to be naturally achieved or administered via a vet. We strongly recommend that you have a form of calcium to use in the prevention of uterine inertia and eclampsia. Also, glucose to ensure your bitch’s energy and vitamin needs are satisfied. As for oxytocin, also known as the hormone of love, let mum and her new puppies handle that!