Episode 171: Nutrition for Healthy Growth

Growth is a challenging life stage. Understanding how key nutrients can support healthy growth and lifelong health helps to ensure puppies get off to a good start in life. It is essential to provide puppies with specific nutrients for healthy immunity, brain development and gastrointestinal health during development. Listen to Dr. Catherine Lenox, DVM, DACVIM (Nutrition) explain everything you need to know.

The website that Dr. Lenox references is: www.purinainstitute.com/centresquare

Watch the video version of this presentation here.

Transcript

Nicole Engelman  00:00

Welcome to the Good Dog Pod. Join us every other Wednesday when we discuss all things dogs, from health and veterinary care to training and behavior science, as well as the ins and outs of Good Dog and how our platform can help you successfully run your breeding program. Follow us and join Good Dog’s mission to build a better world for our dogs and the people who love them. 

Hi everyone. I'm Nicole. If you don't already know me, I'm Good Dog’s community lead, and today we are going to be hosting a presentation on puppy nutrition, key nutrients that support development, with our incredible guest, Dr. Catherine Lenox. So some things that we'll be talking about today, just to give a little bit of an overview: growth is just a challenging life stage in and of itself, and understanding how key nutrients can support healthy growth and lifelong health helps to ensure that puppies get off to a good start in life, which I know is the most important thing to all of the breeders that are joining us today. It's essential that we're providing puppies with specific nutrients for healthy immunity, brain development, gastrointestinal health during development, and today we're going to be talking all about that with a special emphasis on the unique nutritional needs of large breed puppies during development. And I wanted to share a little bit about Dr. Lenox before I pass things over to her for the bulk of the presentation. Dr. Lenox is a board certified veterinary nutritionist who works as a senior specialist of technical publications and education at the Purina Institute in St. Louis. Prior to working at Purina, Dr. Lenox led a nutrition service at a large specialty Veterinary Hospital in Houston. She is passionate about helping others to understand nutrition in a practical way, and has taught nutrition education courses at veterinary schools in the US and Canada. Dr. Lenox is also a frequent speaker at veterinary conferences in the US and abroad. She received her veterinary degree from the University of Missouri and then completed a small animal medicine and surgery internship at Colorado State University and a residency in small animal veterinary nutrition at the Virginia–Maryland College of Veterinary Medicine. So, amazing background. We are so excited to have her here today to talk about this topic with all of you. So I will stop talking now, and I'll pass things off to you, Dr. Lenox, to start the presentation.

Dr. Catherine Lenox, DVM, DACVIM  02:18

Thank you so much Nicole, and it's so great to be here everyone. I'm really excited. Nicole did not mention I'm also a Cavalier owner, so I am near and dear to the breeders who created my dog, who's perfect. You know, everybody says that, but my dog really is! Just kidding. Okay, so before I get started, I want to talk a little bit about the Purina Institute. I'm not sure if you're familiar with this entity within Purina; it's a scientific organization that's global. We talk about education and science and no products. So we will not be talking about any product today; we will mainly be talking about nutrients that puppies need to grow into healthy adult dogs, and some other fun topics, like large breed puppy versus small breed puppy nutrition. And I'm really excited to be here, so we'll go ahead and get started. So outline, just for today: we'll talk about the importance of nutrition for growing puppies. That's just a review for everybody. I know. Everybody knows that nutrients that support healthy growth provide energy for healthy growth and lifelong health. A lot of that is managing body condition score, so keeping dogs and puppies lean so they stay healthy throughout their life. Nutrition for healthy immunity and brain development, supporting the immune system, gastrointestinal health and a healthy microbiome, with prebiotics, and how to identify an appropriate diet for a growing puppy. So I know a lot of you guys know a lot about nutrition, but I know you also talk to clients about nutrition, so I want to just kind of review this aspect. Puppies need very specific nutrition for growth because it provides the necessary nutrients that are required for developing bones and muscles—just all tissue—and nutrition supports growth in addition to normal body functions. So puppies have an extra demand, because adult dogs just have to function, puppies have to function and grow. So there's a lot of extra nutrition that has to be involved. Nutrition can also support healthy immunity, so it helps protect puppies during a very vulnerable period when immune function is not fully developed, and when a puppy is not fed a diet that's complete and balanced for growth during development, that may lead to skeletal abnormalities, developmental, orthopedic disease, and just overall health issues. 

So what nutrients do puppies need? The essential nutrients fall into two categories, macronutrients and micronutrients. One of the macronutrients is water. We all know everybody needs fresh water at all times. The main macronutrients that provide energy are fats, carbohydrates, and proteins. And puppies need extra of all of these compared to an adult dog because of the extra demand on their body that they're taking on through growing and functioning just as is. Micronutrients are divided into vitamins and minerals. And there are several required vitamins and minerals that help puppies grow. You know, obviously calcium and phosphorus, but other ones as well. And then protein being a very important essential nutrient made up of amino acids, it supports fetal and neonatal growth and contributes to muscle development. So this is really what allows the muscles to grow, but it's also used for other things. So enzymes that allow for energy utilization are made from protein. Hormones are made from protein. So as dogs are developing, they need to make hormones of all kinds to allow them to develop and develop reproductive function, among other things—that's all coming from protein. It allows for normal immune function and impacts basically everything. So all body functions and all body systems relate back to getting enough protein. And when I talk about getting enough protein, I really talk about getting enough amino acids. And the essential amino acids, there are 10 for dogs listed here, and there are 20 total that make up the protein in the body; 10 are regarded as essential because the body either can't make them at all or can't make enough of it to contribute to the protein that the puppy needs to make. Then there's 10 non-essential that the puppy can make in sufficient quantities to contribute to those proteins. 

Protein quality is something that's talked about a lot, and that's dependent on two things. One is essential amino acid content, so a good quality protein is going to provide a lot of these essential amino acids in a good amount. But also protein digestibility, which is kind of like bioavailability. Basically, digestibility is the ability of the protein to be digested and absorbed and then utilized later on. And because growth is such a demanding life stage, the puppies are going to require more essential amino acids and more protein in general, just overall. So they need more of the building blocks and more protein overall. Fat is another essential nutrient. It's a very energy dense nutrient. So in pet food, carbohydrates and protein provide about 3.5 kcals per gram, where fat provides 8.5 kcals per gram of fat, so it's like over double the amount of energy in one gram of fat compared to a gram of protein or a gram of carbohydrates. So high fat diets provide a lot of calories in a small volume. Now that's great when you have a dog that's not a good eater, or they're recovering from surgery, or they're nursing, and they can't take in such a huge volume, but fat can be over consumed, obviously, and that would lead to weight gain because of that energy density of the fat. So fat, basically, it's a balance. It has to be provided in a higher amount than what's required for adults, because they have these needs that they require fat for growth—and we'll go over different types of fat in a minute—but you have to balance that with not making them gain weight too quickly because of the energy in the fat. So fat provides energy for growth and development. 

Specific types of fat: Omega-3 fatty acids. There's one called DHA that comes from mostly fish oil and pet food, but also algal oil—that specifically allows for brain and retina development and cognition and learning. So that's a very essential fatty acid for puppies: different types of Omega-3 fatty acids, including DHA and also Omega-6 fatty acids. And the Omega-6 versus Omega-3 is just like how the fat is structured. It's based on where a double bond is in the fat structure, but Omega-6 and Omega-3 fatty acids promote development of healthy skin, shiny coat. All of that is required to allow for healthy skin and coat, and then fat will also promote a healthy immune system. Carbohydrates are not technically required, and when I say that, people are like, “Oh, I don't need to feed it then,” but they provide a lot of benefits. So it's a readily available energy source that isn't as energy dense as fat. So we talk about providing energy, especially to large breed puppies: I don't want them to grow too quickly, so I don't want to give them a lot of fat, because that's super dense in calories. So carbohydrates allow you to provide energy that's readily available without providing an excess of energy, which is really nice. There's two types of carbohydrates: soluble carbohydrates (that's like sugar and starch) and then there's dietary fiber (which is, you know, everybody has heard of fiber). There's different types of fiber, and it's required for normal intestinal peristalsis, or movement of the intestines. It also supports the microbiome, or the collection of microorganisms living in the intestinal tract, and you cannot support that microbiome and support a healthy microbiome (which is essential for health) without providing food for them, and that food is actually different types of dietary fiber. And we'll talk about prebiotics in a minute, which is actually one of the primary sources of food for the microorganisms in the intestine, or the microbiota.

Dr. Catherine Lenox, DVM, DACVIM  11:50

So dietary fibers versus prebiotics. Dietary fibers is a larger category than prebiotics. So fiber in general, is a structural component of cells, storage carbohydrate, mainly from plants. Some yeast will provide prebiotics, but that's kind of the fungi category that's listed there. Not all dietary fibers have prebiotic effects, and most prebiotics are what are called fermentable or soluble fiber. So fermentable fiber is broken down by the microbiota in the intestinal tract. So if the microbiome can break it down, it's fermentable. If they can benefit from breaking it down, that makes it a prebiotic. And prebiotics serve as a great source of food for those organisms living in the intestinal tract that really support GI health and GI development in these puppies. So again, prebiotics or substrates are just like a molecule that's selectively utilized by microorganisms in the host or the puppy, that confers a health benefit. Mainly what that health benefit is that it supports healthy growth of the microbiome towards less pathogenic bacteria and away from more dangerous bacteria. It also provides immune stimulation. So it allows the gastrointestinal immune system (it's called the gastrointestinal associated lymphatic tissue is 70% of the body's immune system) so it really is important in these puppies. Especially as they're exploring their environments and putting everything in their mouths, it's really important for these puppies to develop a healthy immune system in their gastrointestinal tract, and overall. We'll kind of move back to prebiotics later. So if you still have some questions, I may answer them as we get further. I'm sort of just introducing the different nutrients right now. 

So minerals: I mentioned calcium and phosphorus. Other essential minerals as well, like magnesium, contribute to skeletal development, and both the amounts and the proportions and minerals are important during growth. So calcium and phosphorus is often expressed in just amount in the food, but it's also expressed as a ratio of calcium divided by phosphorus, or calcium to phosphorus. So the calcium to phosphorus ratio has to be tightly controlled for all growing dogs, because we don't want their skeletons to grow too quickly or too slowly. So you have to strike that balance. But it's especially important in large breed puppies, because they grow so much faster and they're doing so much more growing than smaller dogs. The goal for minerals is to meet the requirements that they have, but not exceed them too much and not greatly exceed them—for sure. Some minerals, especially calcium, have a maximum safe level. If you've looked at the nutritional adequacy statement or AFCO statement on a bag and it says “supports growth for large breed dogs,” there's a specific calcium maximum for large breed dogs, which AFCO considers over 70 pounds—which is not really what I consider the cutoff; I usually consider it to be about 55 pounds or so. But the thing that makes a diet appropriate in AFCO’s language for a large breed puppy is it doesn't exceed a certain number for calcium. 

Vitamins: most of what vitamins do, especially B vitamins—they facilitate metabolic reactions. They act as a cofactor, allowing these reactions to occur. A lot of B vitamins are involved in energy metabolism, so what ultimately gives the puppy the energy is this reaction that gives them energy, and the vitamins allow those to occur. So they're really, really needed to make sure energy can be utilized in the food. Some vitamins act as antioxidants, which support immune health and fat soluble vitamins. So a vitamin A, vitamin D, vitamin E and vitamin K, especially vitamin A and vitamin D, have a maximum safe level. So you can actually feed too much of them, because they build up in the body over time. Water soluble vitamins, so the B vitamins for the essential vitamins, vitamin C is also a water soluble vitamin. Those generally get urinated out and processed through the kidneys, so they don't build up the same way that fat soluble vitamins do, so there's not as much risk for excess in the body. One thing that I mentioned earlier is we really need to have enough energy, but not too much. And we want the slow, steady, healthy growth. The main way that I assess “Is this dog growing at a good rate?” is their body condition score. And I don't know how many of you guys are body condition scoring your puppies or training owners to body condition score, but that is the ultimate decision. If they're about a five out of nine (which is ideal for a puppy), sometimes a four out of nine (depending on the breed, like a greyhound or something like that). But I generally consider a five out of nine to be ideal for puppies, and this is what tells you you're feeding the right amount. You're not feeding too much energy, which will risk developmental orthopedic disease and obesity or too little, which will A) make the puppy underweight, but also B) result in abnormal growth because they're not getting enough nutrients. 

So one thing that Purina has done was a study on lifespan, and this was a 14 year study (actually came out in 2002 so it started in the 1980s) but they age match puppies at birth. And they were Labradors, and they fed one puppy in the pair. They're Labradors, so imagine this. They kind of let them eat as much as they want, within reason. They got up to a body condition score of about a seven out of nine. The other puppy was restricted feeding, so they maintained a body condition score of five or four out of nine throughout life. And what the study showed is that dogs that maintain a lean body condition throughout life and stayed at ideal body condition—they lived almost two years longer. So this is not just “I don't want to feed excess energy.” They had lower onset of health conditions at a young age. They lived 1.8 years longer on average, and they just did better. They were overall healthier. I cannot stress enough the importance of monitoring body condition throughout life, but especially during puppyhood, because that's the formative time when they really kind of set the stage for how they're going to do throughout life. So I kind of just summarized the study, because I get so excited talking about it, but they again, fed one of the puppies in each pair about 25% less than the other puppy, and they lived 1.8 years on average longer in the leaner group, and they had delayed onset of osteoarthritis, cancer. They had no adverse effects on skeletal maturation, structure, metabolism. They just generally did better throughout life, so that's really important: to get them started early on and a good feeding amount, and keep them that way. Lean dogs also had other benefits, such as greater insulin sensitivity. They were able to regulate their glucose better. They were able to maintain immune response over time. And I hate saying that age is the disease, but there's a certain point when dogs that you can tell they're just declining because of their age—and that occurred later in life, in the lean dogs that were in ideal body condition.

Dr. Catherine Lenox, DVM, DACVIM  20:42

From the immune system, I mentioned 70% of immune cells are located in the gastrointestinal tract. So the intestinal tract is actually an immune organ—in addition to being the side of digestion and nutrient absorption. These cells protect the body from invading pathogens that are ingested and support overall good health of the pet. Supporting gut health is very critical for puppies, because early in life, their immune system is not fully developed. They're still maturing, and like I mentioned earlier, these puppies are putting literally anything and everything they can find in their mouths in some cases, so they're exposed to a lot more than they maybe should be initially, because they're so explorative. And when I say when they should be, there's this thing called the immunity gap, and puppies get a certain amount of immunity at birth, mostly from consuming colostrum. They have a little bit of immune function when they're born before they consume colostrum, but about 90% of immune function at birth is obtained through colostrum, and then those antibodies that they absorb from their mother's colostrum over time start to decline, and their immune function starts to pick up. But there's this gap, kind of like four to 12 weeks, where their immune system is not functioning normally. It's about three to four months when it hits, kind of like the low, and this lasts to four to five months. This is what's called the immunity gap. So it's very important to provide a proper diet during this time to support immune function with antioxidants. It's especially important that they get colostrum, and all of this can help support their ability to fight off pathogens that they ingest through their development, through their exploration of the world. So again, the colostrum. I'm sure you guys are all familiar with this, but the first milk is called colostrum. It's generally produced for about two to three days, and then it slowly changes into mature milk. And you guys are all breeders; you know, the colostrum is very different from actual milk. It's lower in moisture content. It's very sticky and viscous. It's full of antibodies that the puppy absorbs through their gastrointestinal tract when the junctions between the cells are not quite as formed as they become within 24 hours. So the consumption of colostrum within the first 24 hours is essential to allow them to absorb these antibodies. This is called passive immunity. They didn't make it themselves. They're getting it from their mothers. They get antibodies and other compounds, so it's important for immune protection and growth factors and energy nutrients—all from this colostru—that they must consume in the first especially, 24 hours. It starts declining in antibodies, and their intestinal tracts sort of start sealing up within 24 and not much over 48 hours. It's pretty sealed by then. So how does colostrum strengthen immunity if the antibodies can't pass through the gut wall after about 24 hours? So remember that the intestinal tract is the largest immune organ in the body. Antibodies in the colostrum are able to be absorbed at first, and over time, these antibodies are still being utilized in the gastrointestinal tract. So once they are done, those junctions kind of seal up, and they can still use those antibodies to fight off. So that's why they need colostrum over a couple days, basically. And this helps activate the immune cells and at least a different type of immune responses. So there's a local immune response that would occur just in the GI tract, and when they absorb the antibodies through the junction, the more like gap junctions in the intestinal tract, they're able to elicit systemic immune responses with those antibodies. But those, again, decline over time, leading to the situation called the immunity gap. So you can actually supplement diets with bovine colostrum to provide some of these benefits past the two to three day mark. The antibodies are not being absorbed into the bloodstream, but they can still have a local effect and some systemic effects as well. So there was a study that looked at supplementing a diet with bovine colostrum, and they had a better and longer response to the canine distemper vaccine versus dogs fed a control diet without the colostrum in it, so it allows for a stronger immune response. They also had increased fecal IGA. So IGA is an antibody that's secreted into the gastrointestinal tract and primarily just works in there. Those dogs that received the colostrum and rich diet, had increased levels of fecal IGA, so they're creating more antibodies that can work in the gastrointestinal tract to support their immune system, defend their bodies. And then they had increased microbiome diversity, which supports overall gut health and stability under stress. So colostrum is good. Must be consumed within the first 24 hours, but it can also be beneficial if it's supplemented in the diet over a period of time. Again, the mothers will only produce it for a couple days, but you can provide it in the diet. 

Moving on to neural development, or neurological development: myelin is the fatty substance that surrounds the nervous cells that allows for nerve conduction. So DHA supports development of the nervous system in general, specifically the brain and retina. It supports myelination, so that allows nervous system pathways to be created and also allows nerve conduction to be better in nerve connectivity. There's increasing evidence in human scientific literature that nutrition in the fetal and early neonatal period, in terms of providing this Omega-3 fatty acid DHA, has a significant impact on neurodevelopment. So DHA is a long chain polyunsaturated Omega-3 fatty acid. It's provided, again, like I mentioned earlier, primarily by fish oil and puppy diets. It can be provided by algal oil, but that's a newer ingredient in pet food. DHA is essential for proper neurologic and retinal development. Providing dietary DHA from fish oil or algal oil during gestation and lactation, as well as during the growth period, impacts brain and vision development. Puppies that were fed a diet supplemented with this fatty acid DHA and other fatty acids from primarily Omega-3s from eight to 18 weeks of age—they showed improved problem solving ability and memory. So it really helps with learning and cognition. And these, again, are from fish oil. It is a required nutrient, DHA, and it optimizes brain, neural, and retinal development, allowing for these increased learning abilities as well as increased sight with retinal development. Most puppies that don't receive DHA and moms that didn't receive DHA don't really have as good vision or learning ability. I get a lot of questions from people: “What about flaxseed? It has Omega-3 in it.” It has a different type of Omega-3 fatty acid in it. It's called alpha linolenic acid, or ALA, is probably a better way to call it. So ALA is a shorter fatty acid. It doesn't have as many carbons. It has fewer double bonds in DHA, and the ability of a dog to convert ALA to DHA is very low. It's less than 10% ability to convert ALA to DHA. So I really do encourage use of diets, including fish oil, primarily. You don't really need to supplement on top of a puppy diet. You don't need to provide a supplement unless maybe the mother didn't get it, or something like that. A diet that contains fish oil is generally going to be sufficient. The requirement is not very high, but I really do encourage actually getting fish oil, and not flaxseed oil.

Dr. Catherine Lenox, DVM, DACVIM  30:21

So this was another study looking at complete and balanced diets with different amounts of DHA from eight to 52 weeks. There's a low DHA, there's a medium and there was a high DHA diet that these puppies got, and the puppies that were fed high DHA had significantly better results on cognitive tests. They had improved vision, that's electroretinography scores. They had better memory, better psychomotor function, better immunologic function and better retinal function. So overall, DHA is an essential nutrient for puppies, and it really helps with learning and memory and cognition and vision. I have a special interest in Omega-3 fatty acids. So I could talk about this forever, but I will move on. 

Prebiotics (I mentioned earlier) are generally a type of fiber that support growth of beneficial bacteria in the gastrointestinal tract, or beneficial microbiota. They basically provide a substrate for bacteria that can break them down. They're considered beneficial to health, so it leads to enhancement of the host benefit from those bacteria in the gastrointestinal tract. So overall, the microbiome is that collection of bacteria and microorganisms in the gastrointestinal tract. Fermentable fiber can be used by the bacteria. Prebiotics are usually a type of fermentable fiber that can benefit when the bacteria use them. They benefit the puppy. Prebiotics (as I mentioned earlier) can support the immune system, and this can be very important during development. It's usually a result of these SCFA as short chain fatty acids. They're just fatty acids that usually have four carbons or less. And prebiotics encourage bacteria to make the short chain fatty acid, and they can affect the immune system. So that's kind of how they work. 

Key time points for nutrition during puppy growth: the first 24 to 72 hours, again—more focused on the first 24—colostrum is really essential for immunity. After 72 hours, the milk starts to change. It's higher in fat, higher in protein and higher in energy versus colostrum, but it's higher in moisture content as well. So that kind of adjusts the percentage of milk that's protein, but overall, like if you just look at the calories, more calories are coming from fat and protein. Milk alone is adequate to support normal growth until about four weeks of age. I'm sure most of you start solid food about three to four weeks of age and then start weaning them soon after. But the first six months of life is a really rapid growth and development period, and the growth diet—I generally recommend feeding until 12 to 24 months, depending on the size of the puppy. And I know a lot of people talk about, “We don't want puppies to grow too fast, so we switch them to an adult diet.” That's not generally what I recommend, and there's obviously different opinions, but I generally recommend feeding the growth diet until growth is complete, but monitor very carefully that body condition score to make sure they stay lean and so they're not getting overfed if they're not over conditioned. Basically, that’s my theory. And I know a lot of nutritionists agree with the same line of thinking. As long as they're in a good body condition score, they're not getting too much food. If they're getting too much food, they're going to be overweight, if that makes sense, and too many nutrients. Growth diets are recommended because growing puppies have different needs for adult dogs. So compared to adult diets, growth diets contain higher levels of calories or energy. It's generally more controlled in large breed puppy diets than a small breed puppy diet. There's a higher level of protein, higher level of essential amino acids, just for development, appropriate levels and proportions of calcium and phosphorus for normal skeletal growth. Adult diets do not always have that, which is why I'm actually very cautious about maintaining large breed puppies on a puppy diet until they're done growing, because I know those puppy diets are going to control that calcium and phosphorus very tightly. Essential fatty acids, including DHA from fish oil or algal oil for cognition, and then antioxidants to support the developing immune system. 

So what I look for is a diet that's complete and balanced for growth. And again, the AFCO statement will say large breed or not, and so I always pay attention to that. A diet that's complete and balanced for growth means it has all essential nutrients. That's kind of what complete means. And then balance means that those nutrients are all in the proper amounts and proportions. So you want both of those things. You don't want balanced nutrients, but not have all the nutrients you need. And so complete and balanced kind of go together. And that's what that AFCO statement, or nutritional statement, is going to identify: the life stage. So you want it to be formulated for growth the size of the puppy. Now that's a newer thing! And the diet should always be complete and balanced for growth for puppies, because puppies don't have functional stores in the body, like, say, you have an adult dog and they're at ideal body condition. They have a little fat reserve, even if they're in ideal body condition. Being an adult dog is not as demanding as being a puppy. So if they are not fed enough of a nutrient, they may be able to kind of call from their reserves, but a puppy is not able to do that because it's so demanding. 

Treats and extras: I know this is really hard because of training, but they should not make up more than 10% of total daily calories. The reason for that is if you provide more than 10% of calories from something that is not complete and balanced—which treats and hot dogs, whatever you use for training, etc.; I know people use different things are not complete and balanced for puppies—so if you provide more than 10% of total daily calories, kind of everything gets off. And the whole diet as a whole is not complete and balanced. If you provide under 10% of total daily calories, generally, there's enough wiggle room within the diet to account for that. 

You want to monitor health, monitor body condition score on a very regular basis with these puppies, and again, that's to determine if they're growing too fast or too slowly, and how they're doing overall. The nutritional adequacy statement, or AFCO statement or nutrition statement, on the bag or can will tell you if the diet is complete and balanced. It tells you it's complete and balanced for puppies. It tells you if it's dog or cat—we're talking about puppies today—but it does tell you dog or cat. And life stage is especially important, so you would want either all life stages or puppy growth. And then it generally tells you, too, if it's a puppy diet, if it's for large breed puppies or not. 

So a couple things that I kind of take into account when I'm recommending a diet to my clients: nutrients are what the body really needs. Ingredients provide those nutrients so the puppies and all animals don't have requirements for specific ingredients. I'm more concerned about what those ingredients are providing in terms of nutrients, because that's what the body requires to support life. And again, puppy life stage is a very demanding life stage. Many of you may have more active breeds. That's going to be another increased demand on the puppies as well, if they're kind of getting more activity than others. And specifically large breed puppies have such a high growth rate. So this is kind of like a time to adult weight, and the x axis is months, and you'll see most of the small breed dogs reach their adult size by, if not earlier, 10 to 12 months. And that's generally when I recommend stopping the puppy diet for small breeds: about a year, as long as everything's going well with their health. Otherwise, I try to leave small breed puppies on a puppy diet for a year. But large breed dogs are so growing at that time, and they're still gradually getting bigger even after a year, so I do recommend feeding the puppy diet and maintaining ideal body condition over time, until they're done growing, which could take up to two years.

Dr. Catherine Lenox, DVM, DACVIM  40:08

So again, feed a diet that's specifically balanced for large breed puppies. Those are going to have a calcium phosphorus ratio between one to one and 1.6 to one, meaning the calcium is not more than 1.6 times higher than the phosphorus. Later in growth, like after a year for a large breed puppy, I could go up a little bit on that, up to 1.8 to one, but you can leave them on 1.6 and they will do fine. So that's not necessary. It's just sometimes harder to find a diet that meets those specific requirements. Large breed puppy foods will, but some of them are a little harder to find, or if they develop health issues, you want to put them on a joint diet, something like that. Moderate concentrations of dietary calcium are essential. Controlled energy content to avoid rapid growth. So to me, it's not the puppy diet that makes them grow. It's receiving too much food that makes them grow too fast—and too much calcium, too much phosphorus. So feeding a proper puppy diet formulated for large breed puppies in the proper amounts is going to keep them in good body condition and good health. Another important thing is I've heard a lot of pet owners like to supplement vitamins on top of a puppy diet, and that is absolutely not needed, so I don't recommend that, and adding calcium or phosphorus can throw off that balance that's already in the diet and contribute to abnormal growth. So nutrition during growth—many aspects of growth are difficult to manage. Nutrition is one that actually can be controlled, and I like that about nutrition. Nutrition can reduce the risk of health issues in the future, as long as dogs are fed the proper diet and the proper amount. Proper nutrition is vital for normal growth, keeping it not too quick and not too slow. Growing puppies do have unique needs compared to adult dogs, and I do recommend feeding a growth diet until a dog reaches maturity, and that is it! I know Dr. Ritter is going to ask me some questions, so I'm ready.

Dr. Nate Ritter  42:32

All right, fantastic. Dr Liz, thank you. That was fantastic. I share your excitement with lifelong studies. Those are, you know, obviously difficult to pull off, and the information gained is so valuable. Wanted to start: I don't think anyone asked this, but you referenced it a lot of times, and in practice, I found myself describing this for clients as well, relating to their dogs. In body condition scoring, what are your recommendations for people to kind of monitor that at home? What should they be looking for? What should they be feeling on their dogs?

Dr. Catherine Lenox, DVM, DACVIM  42:58

Yeah, that's a really good question. So the first place I palpate when I'm evaluating a dog for their body condition score is their ribs, and you should be able to feel each individual rib, but there should be a thin, fat covering over it. So you shouldn't feel them sticking out immensely, but you should be able to feel them with some light pressure. Another thing I'll do is look at the dog like, from an, like a bird's eye view, and they should have an hourglass kind of waist. If you look at them from the side, they should have an abdominal tuck, which is when my camera may be backwards, but their abdomen kind of goes up, as opposed to, like, sagging down. That's obviously a sign of them being overweight. I usually feel their spine. You should be able to feel it, just not immensely. So there's some things. If you go back to this website, the body condition scoring charts are on there, and each score out of it—scored out of nine—five is ideal for puppies. You'll see a description of each point on the body condition score scale, and it has been validated with DEXA to correspond to body fat.

Dr. Nate Ritter  44:09

Great. Thank you. And obviously, everyone should feel free to discuss with your veterinarian. Coat differences and confirmation differences sometimes make it a little bit more difficult.

Dr. Catherine Lenox, DVM, DACVIM  44:18

Yeah, breed differences for sure.

Dr. Nate Ritter  44:22

Exactly. You answered a lot of these, but no, it was good to repeat and then reinforce this information. What are the main differences between large breed puppy food and regular puppy food? And I know you gave us the general timeline of up to two years, but how long do you recommend large breed dogs continue to eat that puppy food? 

Dr. Catherine Lenox, DVM, DACVIM  44:39

So the main difference is the calcium and phosphorus ratio is a little lower in large breed puppy food than it is in small breed puppy food. And there's a calcium maximum—I think it is 1.8% dry matter, but I don't have the book in front of me. I believe that is correct. Calcium in large breed puppy food will not be over whatever that number is. I think it's 1.8% dry matter, so there will not be excess calcium in a large breed puppy food. There will be a tighter calcium to phosphorus ratio. It'll be under 1.6 or lower, and no lower than one to one. And then the energy is actually different. So small breed puppy foods tend to be very energy dense because they have a short and very rapid, in the short period, this burst of growth and then they're done. Large breed puppies grow more over time, so there won't be as many calories in the large breed puppy foods. That is actually why I really recommend focusing on getting a large breed puppy a large breed puppy food. 

Dr. Nate Ritter  45:50

Great. Do you prefer sticking to the puppy specific food? Or is all life stages okay? A lot of different people are asking that question.

Dr. Catherine Lenox, DVM, DACVIM  45:57

Yeah, that's a good question. So all life stages really means it's it means all the life stages, and puppy growth and reproduction are the most demanding, so it's 100% fine to feed an all life stage diet to a puppy, as long as if it's a large breed puppy, a lot of the all life stages diets may have a little more calcium, because those lactating mothers need to make milk, and milk has calcium in it, so just make sure it's appropriate for large breeds if you have a large breed puppy. That's the only watch out I have, but I'm fine with it otherwise.

Dr. Nate Ritter  46:38

Great. What is your opinion on home cooked diets for puppies? And you know, if okay, what about mixing in high quality puppy food with home cooked? What are your thoughts there?

Dr. Catherine Lenox, DVM, DACVIM  46:47

So I actually, when I was in practice, I formulated a lot of home cooked recipes, and it's very customized, like, if you have a nutritionist, formulate a home cooked diet for your dog. It is that weight; it is their requirements at that time. And puppies change so rapidly that it can be very difficult to keep up with their growth, especially if they're a large breed puppy. You kind of have to keep reformulating the diet as they grow to provide the calories they need, and then after they kind of reach the end of the rapid growth period, we kind of slow down on the calories even a little more. So it can be very difficult to keep that complete and balanced for that puppy, even if you're keeping up with it. So I don't tend to recommend it. You can feed other foods. I just recommend keeping it under 10% of total daily calories, and 90% of those calories should be coming from a complete and balanced diet.

Dr. Nate Ritter  47:49

Great. Thank you. This one is not necessarily puppy specific, but what is your opinion on grain free diets? I'm sure you've seen all those trends that are happening lately, and especially as a Cavalier owner. Interested in your thoughts there?

Dr. Catherine Lenox, DVM, DACVIM  48:01

Yeah, so there's a lot of research. The FDA kind of stopped looking into it for whatever reason. I don't know, but there is some compelling research that indicates grain free diets may be a problem, but there's not a lot of patterns that the FDA found in their cases, so I recommend just picking a high quality diet. What that means is complete and balanced. It has the nutrients the puppy needs, or the adult. If they're a breed like a Cavalier with a tendency to have heart disease, or especially if it's dilated cardiomyopathy, maybe not the Cavalier in that case, but like an Irish Wolfhound or a Doberman—I may be a little more wary, but the jury's still out on what actually is going on there. 

Dr. Nate Ritter  48:55

Great. Thank you. Time for one more before we pass it to Nicole for the conclusion. I know you mentioned complete and balanced diet. No need to supplement. We had some questions about vitamins and what have you. The last question—you know, I’ve definitely seen this, not just with puppies, but with adult dogs. I sometimes find the feeding instructions on a bag of food to be quite vague. Are the instructions based on age of the puppy, the weight of maturity for that particular breed, both, or are there any other factors you'd want to recommend? I find people going by the bag and then being surprised that their dogs are overweight. So, yeah, I wonder if you have any advice.

Dr. Catherine Lenox, DVM, DACVIM  49:28

Yeah, that's a great question. So the most reliable indicator that your dog is getting enough food is they’re in an ideal body condition. The information on the bag—think of it as a bell curve. So it's like this, and the top of the bell curve is where those bag recommendations fall. So there's always going to be animals that need more calories and need less calories, so monitoring their body condition is going to be the most important thing, because every individual dog is going to be a little different. Making blanket recommendations for every puppy is difficult, so monitoring body condition is going to be your best bet, but loosely follow them and adjust as needed is another kind of recommendation. Start with the bag, see how it goes. Monitor body condition. I usually increase or decrease in five to 10% increments and reassess body condition score in two to four weeks. So you can kind of recommend that to your puppy owners. 

Dr. Nate Ritter  50:31

Perfect. Absolutely. Nicole, over to you.

Nicole Engelman  50:34

Awesome. Thank you both. This was such a great conversation. So I want to thank first of all, you, Dr. Lenox, for leading such an amazing conversation. Thank you again for being here and leading us through such an amazing topic and presentation. And if you are not yet part of our Good Dog community, we would love to have you join by applying at Good Dog.com/join so you can stay up to date on all of our future events. Thank you all again for being here for being part of our community. 

Dr. Catherine Lenox, DVM, DACVIM 51:03

Thanks so much everyone.

Nicole Engelman  51:07

Thank you for listening to the Good Dog Pod. We'll be back in two weeks with another episode, so be sure to subscribe to the Good Dog Pod on favorite podcast platform.