Feeding pregnant pets: the do’s and don’ts

There’s always a huge focus on the nutrition of puppies and kittens, especially once you pick up your new bundle of joy, but what about before they are born? I find that feeding pregnant pets can be extremely controversial, particularly as breeders usually have their own methods or chosen diets they’ve decided on and used for a very long time when breeding with their pets. I often get asked alot about supplementation during pregnancy aswell, so I thought it was important to discuss the actual nutrient requirements of gestation, and how to choose an appropriate diet for your pet during the most demanding lifestage.

So what do pregnant pets actually need?

The key nutritional factors for gestation in cats and dogs are listed in the tables below. The main things that stand out as important are the requirements for carbohydrates; this provides a source a dense, slower release energy that can be also be stored. I find this is the most important nutrient that is forgotten about, particularly in pregnancy; homemade/DIY diets that are often used to feed reproducing animals contain little to no carbohydrate source – this is in part due to the negative connotation around feeding a higher carb diet to pets, despite it being a valuable source of energy during gestation. Looking at the other Key Nutritional Factors, namely the Calcium: Phosphorus ratios, protein and fat levels, these are very similar to the amounts present in puppy and kitten foods, which is why these diets are usually the go-to recommendation when choosing a food. When choosing a food, you should be looking for a pet food that is formulated to meet the AAFCO/FEDIAF guidelines for growth as this gives you a good starting point.

Key Nutritional Factors for reproducing dogs (Source: Small Animal Clinical Nutrition)
Key Nutritional Factors for reproducing cats (Source: Small Animal Clinical Nutrition)

Should I supplement?

The main reason I get asked about supplementation is calcium – many breeders want to prevent (understandably) hypocalcemia occuring during lactation and to ensure the puppies or kittens recieve the correct amount to support their development. However, supplementing calcium, especially when feeding a balanced diet can easily result in excess which can be just as damaging as deficiency. The rule of thumb is not to supplement unless there is a diagnosed deficiency; there’s rarely any benefit to supplementing a nutrient when there isn’t a deficiency and if fed an appropriate diet throughout gestation, a deficiency of calcium is unlikely to result from lactation.

How to choose a diet for gestation

1. Diet and condition prior to mating: it is a good idea to ensure the bitch/queen is in good condition before mating as this actually has a very big impact on the health of the puppies and kittens – you may want to ensure the food you are feeding before mating matches the Key Nutritional Factors laid out above and then start planning what you may decide to switch her to once she is pregnant. You may want to select a diet that covers the Key Nutritional Factors for both mating and gestation, as mentioned in the images above.

2. Consider the needs of the litter: what is the expected size of the neonates? Do you know how many babies the mother is carrying? These factors also will need to be considered when choosing a food. Large breed dogs will have a slightly different requirement to a small or medium breed puppy, so when selecting the diet, it’s important to also ensure the litter will receive the correct nutrition to develop in the womb.

3. Consider how you will be offering the diet:
Depending on the size of the puppies, and the size of the litter, the bitch may need to be fed with meals or free-choice. For small to medium breed dogs, bitches should be fed in meals however bitches with large or giant breed puppies, should be fed free choice. If the litter is very big, it’s also recommended to feed free choice. So why is this important to consider when choosing a diet? Some foods are safer to offer as free choice than others (eg, dry food) whereas others may be better offered through meals.

4. Check the AAFCO statement: If the diet is labelled for growth, this is a good starting point when deciding what to feed during gestation. The nutrient levels in a diet designed for puppies and kittens is usually close or suitable for the requirements of the pregnant bitch or queen, but always confirm this by comparing to the Key Nutritional Factors. You may also want to feed an All Life Stages diet, as this is technically designed to meet the most demanding life stage which is gestation and lactation, so would also be a suitable alternative.

How much should I feed?

The calculation for Resting Energy Requirement is RER = 70(BWkg)^0.75.

To determine the Daily Energy Requirement for the pet, you must then multiply RER by a factor, which the factors depend on the pet’s activity levels, lifestage or production. See the values for gestation below:

For cats, the energy requirements increase linearly during gestation, so the energy intake should be increased to 1.6 x RER at breeding and gradually increased to 2 x RER at parturition. The food should be offered free choice.

For dogs, the first 42 days of gestation should be fed as an intact adult (1.8 x RER), then the last 21 days should be 3 x RER. However, this can be increased to maintain body condition, particularly in large breed dogs. This can be offered as meals or as free choice.

What not to do

The biggest mistakes I see people making when feeding their pregnant pets is largely due to the lack of good information out there. As I mentioned above, it can be very controversial when trying to decide on what to feed their pets, and feeding behaviour of breeders is often what has always been done that they simply don’t know what the right way is. The five things I tell people to avoid when feeding pregnant pets are;

1. Don’t supplement:

Supplements can do more harm than help. Calcium supplements can actually induce rebound hypocalcemia if you supplement pre-emptively before lactation. Feeding a multi-vitamin supplement is also unnecessary, since a good diet will already contain the right balance of nutrients for the pet’s needs, so adding more is either going to interfere and block the absorption of those in the diet, or induce a toxicity. Supplements are not required unless your pet develops a true deficiency, and the best way to avoid that is to feed a suitable diet for the duration of the pregnancy.

2. Don’t feed low carb or high risk diets:

Feeding low carb or single ingredient diets (often meat only), diets that have been home-prepared or diets that have the potential for bacterial contamination such as raw diets are dangerous and risky when fed to pregnant animals; not only for the potential vitamin and mineral deficiencies causing illness in the mother aswell as the litter, but also the risk of bacterial infection causing spontaneous abortion or developmental abnormalities of the litter. As mentioned above, carbohydrates provide valuable energy both during gestation aswell as lactation and help keep body weight and condition stable – a diet with little or no carb source can cause reproductive performance to be impacted, mating unsuccessful if body condition is poor and cause too much weight to be lost after birth.

3. Don’t feed a maintenance diet:

Adult foods are not designed for growth, and are therefore not supportive for pregnancy. These diets can be a trigger for deficiencies, and may also not be fatty or carb heavy enough to support the required weight gain during and leading up to pregnancy. They also lack the correct calcium to phosphorus ratio required for healthy skeletal development of the litter and healthy lactation. Often these diets can cause significant weight loss after the pregnancy, placing the bitch or queen’s health at risk.

4. Don’t feed the same amount from mating to lactation:

The amount fed to the pet, even if the diet remains the same, should be altered as the animal progresses through various phases of the reproductive cycle; the amount fed at mating should never be the same as what is fed in the final weeks of pregnancy, or at lactation. Refer to above to calculate how much to feed throughout gestation.

5. Don’t over or underfeed:

Obesity either at mating or during the pregnancy can significantly increase the pet’s chances of complications both during the birth, and impact the ability of the bitch or queen to fall pregnant. Underfeeding during the pregnancy can cause low birth weights in newborns, and can also impact their chances of survival.

Feeding pets during the most demanding lifestage is vitally important to get right to ensure the long term health of both the mother and her litter. If you have any questions about supporting your pregnant pets health, always seek the advice of your veterinarian and work with qualified professionals with a special interest in reproduction who can ensure the health and wellbeing of your pet.

What do you feed your breeding animals? How do you ensure their diet meets their demanding requirements? Let us know in the comments below!

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Mark Morris Institute (2019) Small Animal Clinic Nutrition 5th Ed., Chapter 15: Feeding Reproducing Dogs. Available online at: http://www.markmorrisinstitute.org/sacn5_download.html

Mark Morris Institute (2019) Small Animal Clinic Nutrition 5th Ed., Chapter 22: Feeding Reproducing Cats. Available online at: http://www.markmorrisinstitute.org/sacn5_download.html

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