The “It’s easy to believe that vets don’t know anything about nutrition…” article is my most popular so far. It was even featured by Dr. Andy Roark’s site. Thanks for sharing!
I’m incredibly happy to report that the “Top 10 nutrition frequently-asked questions” series at Western Veterinary Conference was a success. I had a large, full room, and lots of extra questions and interaction. Thanks to the organizers, and especially to everyone who came to participate!
Tomorrow, I’ll be headed to Las Vegas for The Western Veterinary Conference, and I’ll get to wear one of those fancy “speaker” ribbons on my badge.
I’m presenting a series of talks for veterinarians on my top 10 frequently-asked nutrition questions, an idea from Bill Porte, a friend and veterinary mentor who wouldn’t steer me wrong.
While a top 10 list doesn’t sound particularly novel on the surface, this one actually is. Preparing these talks was part of the inspiration for my “It’s easy to believe that vets don’t know anything about nutrition…” post, and the positive response I got to it reinforces that this series is needed. The novelty is that I’m emphasizing not how to DO nutrition, but how to TALK ABOUT nutrition with pet owners.
Wish me luck, or, if you’re attending the conference, come see me!
Labrador Retrievers seem to stay puppies longer than other large-breed dogs; there seems to be a component of refusal to grow up. While the (long) puppy stage is fun, it’s also exhausting; and adulthood is nice (if you’ve done things remotely right, you have an amazing companion by now); but for me, there’s no better friend than a senior Labrador Retriever. I’m just a sucker for the gray muzzle.
Many owners of senior pets feed commercial pet food marketed as “senior diets.” However, most probably don’t know that there isn’t an official nutritional definition for senior diets like there is for puppy/kitten and adult diets. Commercially-available senior diets are variations on adult maintenance diets; but the variations vary by manufacturer. There is no other unifying feature. While this isn’t necessarily problematic for most healthy senior pets, I believe that more so than almost any other group of pets, seniors need a tailored approach. There is so much potential for them to benefit from a diet that considers and addresses their unique combination of needs.
Now I’ll introduce Winnie; a 13 year-old Labrador Retriever. Her owner, also a veterinarian, had contacted me about making sure she was giving Winnie all the support that she could, and I was happy to help.
In many ways, Winnie is typical of older dogs of her breed. She had trouble getting up and around and tended to be a bit itchy; she always had. Many pet owners would say that “she’s just getting old” and shrug their shoulders. Winnie’s owner took a different approach and I’m glad.
While age is not a disease in and of itself, age is a predisposition to a number of diseases; arthritis is a good example. With that in mind, Winnie’s owner set out to make sure that she knew exactly what was (and was not) going on with Winnie.
It was already known that Winnie had significant arthritis affecting her knees and elbows, as well as her other joints to a lesser extent. She’d been receiving acupuncture treatments and hydrotherapy (exercise done in water to reduce impact on sore joints) to keep her joints comfortable and her muscles strong. She received several types of pain medication, including a non-steroidal anti-inflammatory drug, for her arthritis as needed.
Through a somewhat tedious process of trials with flea preventative medication and an elimination diet, Winnie’s owner had already determined that Winnie’s itchiness was due to environmental allergies. This is similar to a person who has watery eyes and sneezing in response to certain types of pollen or other allergens, but dogs tend to manifest this as itching and licking at their feet.
While Winnie appeared to be completely healthy otherwise, to find out if there was anything else that she needed to know about, Winnie’s owner/veterinarian submitted Winnie’s blood and urine samples for analysis. This screening labwork showed that Winnie’s kidney function was beginning to decline. This was good to know, since non-steroidal anti-inflammatory drugs used to treat arthritis pain can be harmful to a pet with inadequate kidney function. The labwork indicated that Winnie had no other problems.
Winnie seemed to be doing “okay” on her current commercial maintenance diet, but it didn’t specifically address any of her medical concerns. In addition, since it was formulated for healthy adult dogs, it would not be appropriate for Winnie’s chronic kidney disease.
Winnie’s owner knew that many diets for chronic kidney disease in dogs are low in protein (which is helpful in later stages), and that Winnie was already experiencing some loss of muscle mass due to her arthritis, so this didn’t seem like the right choice for Winnie. In addition, she wanted to provide Winnie with a home-prepared diet where she could control the ingredients and make adjustments as Winnie’s needs changed.
In order to create a special diet that provided Winnie with everything she needed, Winnie’s owner/veterinarian contacted Veterinary Nutrition Care. Dr. Farcas reviewed Winnie’s medical and diet history, and spoke at length with Winnie’s owner to make sure she understood what was important for Winnie and her owner. She explained what features of a diet could be used to help Winnie’s arthritis, environmental allergies, and manage her chronic kidney disease.
While nothing can be done to reverse the bony changes that occur within an arthritic joint, treatments (including diet) can be aimed at reducing the inflammation associated with those changes. To achieve this, Winnie’s diet would provide a fairly high dose of anti-inflammatory long-chain omega-3 polyunsaturated fatty acids (from fish oil). Winnie was already at a healthy weight, but had this not been the case, a weight loss plan would have also been needed, since carrying even a few extra pounds can make arthritis pain significantly worse.
A similar approach is taken to address environmental allergies with diet; as this is also an inflammatory process, anti-inflammatory long-chain omega-3 polyunsaturated fatty acids (from fish oil) can help. In addition, making sure that Winnie’s diet provided enough linoleic acid, an essential omega-6 fatty acid was important, since this contributes to the skin’s ability to act as a good barrier to water loss and environmental allergens. Other minerals such as zinc and copper are needed to maintain skin health, so making sure that Winnie’s diet was balanced would also benefit her skin condition.
Lastly, Winnie’s new diet would be designed to accommodate her early stage of chronic kidney disease. At this stage, patients don’t show any symptoms, so treatment is aimed at delaying progression of the disease. One important aspect of this is limiting phosphorus intake. It’s the kidneys’ job to excrete excess phosphorus, but if the kidneys aren’t functioning properly, excess phosphorus is retained and drives a process called renal secondary hyperparathyroidism, which results in worsening of kidney function. So, to keep that from happening, dietary phosphorus must be limited.
Another aspect of protecting Winnie’s remaining kidney function was already to be included in her diet; besides the anti-inflammatory effects of the long-chain polyunsaturated fatty acids from fish oil, these fatty acids can also help to manage blood pressure within the part of the kidney that acts as a filter for the blood, thus protecting it from further damage.
People often discuss protein restriction for pets with chronic kidney disease. This is important at a later stage of the disease when, in addition to worrying about delaying progression, we also want to manage symptoms of chronic kidney disease. The symptoms of poor appetite, vomiting/nausea, oral/stomach/intestinal ulceration, dry mouth, and others that are associated with chronic kidney disease are attributable to a group of compounds, collectively called uremic toxins that accumulate when the kidneys lose the ability to excrete normal by-products of protein breakdown. At this point, less protein = less by-products = less uremic toxins = pet feels better. That said, every pet has an absolute requirement for certain amounts of protein every day, and inadequate protein intake is detrimental as well. Finding a balance can be tricky, but is absolutely worth doing.
There’s no evidence to suggest that a low-sodium diet (to avoid high blood pressure) is needed for pets with chronic kidney disease, since sodium intake doesn’t appear to drive hypertension in healthy pets. However, as long as Winnie’s sodium requirement was met, there would be no harm in also making her diet low in sodium.
While I’m never happy when a patient has multiple diseases to manage, it makes life easier for everybody when the nutritional management strategies for the different diseases don’t conflict with each other. Read about Cheeka for an example of a patient with conditions requiring opposite nutritional strategies.
Winnie’s new home-prepared diet would provide her with a high dose of fish oil, be restricted in phosphorus, moderate in protein, and low in sodium. Rather than using a separate fish oil supplement, Winnie’s owner was happy to use salmon as the protein source to supply long-chain omega-3 polyunsaturated fatty acids. Salmon provides calories as both protein and fat. A small amount of a plant-based oil provided linoleic acid and some calories as fat, and the remainder of Winnie’s calories came from white rice, which is low in phosphorus. Using these 3 ingredients alone, or even with added fruits and vegetables would mean that Winnie’s diet would be deficient in several important vitamins and minerals (including calcium). For this reason, a vitamin and mineral supplement was also included to make sure that the diet was balanced to meet all of Winnie’s needs.
Once the specific amounts of each ingredient needed to provide Winnie with the right amounts of calories and nutrients were determined, a detailed recipe and preparation instructions were delivered to Winnie’s owner/veterinarian. Along with this came recommendations to monitor Winnie’s weight, response to the new diet, and to continue to monitor Winnie’s kidney function parameters.
Winnie’s owner gradually transitioned her to the new home-prepared diet. Being a good Labrador Retriever, Winnie loved the new diet. She initially lost a bit of weight, and a slight increase in the amount fed per day was all that was needed to correct that. This is not uncommon when changing to a new diet if the exact amount of food (and treats) that the pet ate previously isn’t known.
When Dr. Farcas checked in on Winnie a few months later, she was thrilled to hear that Winnie’s owner had been able to transition her completely off of her non-steroidal anti-inflammatory drug, and that Winnie was happy and more active. Her itching, while not completely resolved, was improved, and her coat was full and soft. Repeat labwork showed no progression of Winnie’s kidney disease. Happy to hear that Winnie had done so well with her new diet, but wanting to determine if the response was due solely to the diet, Dr. Farcas asked more questions; Winnie’s owner/veterinarian answered them all and assured her that nothing else had changed. She attributed the changes she was seeing in Winnie to her customized home-prepared diet and was very happy with the results.
For Winnie, her owner’s proactive approach means that she gets all the support she needs so that while she’s not acting like a puppy again, she’s happy and comfortable. Since her medical status is known and appropriately managed, her owner knows that she’s providing the best care possible to Winnie. The fact that Winnie’s owner is a veterinarian doesn’t affect very much about the story; a pet owner with any other background dedicated to proactive care could accomplish the same for their own pet with the help of an involved veterinarian and a resource like Veterinary Nutrition Care.
I’m a big believer that most “black and white” statements about nutrition are oversimplified, frequently to the point of being inaccurate; and that the longer, grayer story is really the better one.
While I could (and just might) write an entire series based on this introduction, today’s long-overdue post addresses a mostly-inaccurate statement that is frequently made by those offering pet nutrition advice online, and even occasionally by veterinarians. I’m referring to the myth “veterinarians don’t know anything about nutrition.”
First, some truths. All graduates of US veterinary schools, no matter when they graduated, have nutrition integrated into their curriculum, whether it was a required course labeled “Nutrition 407” or whether it was sprinkled into other aspects of medicine, it’s in there. Some nutrition knowledge is also requisite to pass examinations for veterinary graduates to practice in the US. I’ll be the first to agree that some veterinary institutions don’t provide enough nutrition training; however, even those institutions have curriculum that incorporates critical thinking, research, and the importance of continuing education. To maintain licensure to practice, veterinarians are required to complete a certain amount of continuing education each year, and there are many options available for veterinarians to either brush up on nutrition or pick up where vet school left off. It’s just a matter of making an effort to do so. There really isn’t a good excuse for a veterinarian to be ignorant when it comes to nutrition.
All that said, I just revealed my feelings about black-and-white statements about nutrition, so I’ll also say that I absolutely have met a (very) few veterinarians who appear to have completely blocked nutrition from their memory and have no interest in learning something new. They exist, but they’re exceptionally rare. I do, however, stand behind the black-and-white statement that there just isn’t a good excuse for this. What can I say? No profession is perfect.
So, if (nearly) every veterinarian practicing in the US truly has some nutrition knowledge, how can it be that this myth is so prevalent, even to the point that some veterinarians say it about themselves?
While a study on veterinarians’ self-reported level of nutrition knowledge, comparing it to their educational records, and correlating these with how they approach nutrition in practice would be an amazing tool for improving nutrition care within US veterinary practices, and the best way to answer this question, it doesn’t exist, to my knowledge. What I do have to offer, is my assessment of the situation, based on my own veterinary and residency training, my time spent teaching at veterinary universities, and several years of speaking with veterinarians and pet owners about their experiences. This is not a substitute for a more evidence-based approach, but it’s what we have.
The way I view veterinarians’ nutrition deficiencies focuses not on knowledge, but on communication.
First, we have to go back 20-30 years to consider that things have changed relatively recently when it comes to nutrition. There were drastically fewer options for pet owners to choose from when it came to pet food, and pet food marketing was fairly simplistic. The body of knowledge about pet nutrition and diet formulation was much smaller, and internet access wasn’t a factor in people’s decision-making. Because of this, there was a tendency for pet owners to ask veterinarians for nutrition advice when it was needed, and to take that advice at face value. Easy.
Now, all of those factors have changed. Pet owners think about nutrition much more than they did in the past, largely due to the ease with which information is available now. There has been an explosion in the number of pet food options available, and along with this, some very smart marketing that has even managed to look like unbiased information has entered the pet food market. In addition, science has progressed so that we now know much more about pet nutrition, and pet food and the internet has brought the general public a ton of information (some useful, some useless, much confusing). With all of these changes, people’s expectations of their veterinarian, when it comes to nutrition, have changed.
Pet owners are no longer asking for advice (even if they phrase it as such). They’re asking for a dialog. Rather than the basic instruction that would have been acceptable in the past, pet owners now want to know that their veterinarian recognizes their concerns and the energy that they’ve devoted to learning about the subject. They want the vet to be willing and able to engage in a conversation about it and they want to play an active role in determining the course of action.
Like most aspects of both veterinary medicine and life in general, having this conversation takes practice. Incidentally, it’s not something that gets talked about a lot, but one of the most important things that veterinary students in their clinical year, and new graduates, do is refine their explanations of common diseases and medical concepts. It takes time to figure out the most effective and efficient way to convey the most important information; and it’s different for everybody.
So, 20-30 years ago, veterinarians never had to be good at talking with pet owners about nutrition, because no one was asking if a grain-free diet would help their pet with diarrhea. No one was asking if a raw-meat-based diet would improve a skin problem, and no one was trying to balance a home-prepared diet using whole food ingredients. Again, black-and-white statements here- I don’t mean literally anyone, I just mean few enough people to justify not having to learn to have these conversations.
While nutrition is absolutely present in the veterinary curriculum in the US, talking about nutrition: not so much, with the exception of teaching by a few of my very proactive colleagues. It’s been up to vets to learn it on their own. By far, the vast majority of veterinarians that I talk to who’ll say that they “don’t know anything about nutrition” are actually able to make perfectly reasonable nutritional recommendations in most instances, but where they fall down is in answering the pet owner’s question about why they made the recommendation. They haven’t had the practice. It’s not a knowledge issue, it’s a communication issue.
While the pet owner may be asking “is diet x good for my pet?” it’s not a yes-or-no question anymore. Veterinarians don’t usually recognize that exactly what and how a pet is fed can potentially say a lot about the pet owner, and the pet owner may have invested much energy in the subject and determined that diet x is the way to go. Some pet food marketing has given many pet owners some false ideas about what is and is not important in pet food, and when a veterinarian outright disagrees with the results of a pet owner’s research, it’s natural for that pet owner to be offended. As a generally peaceful bunch, most veterinarians don’t enjoy being put in these situations, so it’s easy to see how “I don’t know” may be the easier (though incorrect) answer. Another scenario where “I don’t know” may incorrectly come up is in response to claims such as “feeding abc diet will cure your pet’s medical condition.” Veterinarians are trained in critical evaluation of information, so if there isn’t any valid evidence-based information on which the veterinarian can advise otherwise, “I don’t know” is the alternative to the full explanation of the importance of evidence-based medicine.
While I don’t believe that “I don’t know” is the right answer in either of these scenarios, when veterinarians are managing hospitalized patients and returning phone calls from worried pet owners in between running a hospital, surgeries, appointments that are never long enough, walk-in patients, and emergencies, with a little bit of perspective, it’s easy to understand how saying “I don’t know” and not having a 40-minute conversation about nutrition may be the answer that keeps the day on track.
I’ll try not to sound like a marriage counselor here, but if the problem is communication, then the solution is to understand the other person’s perspective and taking steps to accommodate it.
My calls to action:
Veterinarians: Ask owners of pets requiring nutritional care or clients with concerns about feeding their pet to schedule an appointment to discuss nutrition. Consider that criticism of your client’s current feeding choices is indirectly criticism of your client and their lifestyle. Focus on providing background in evidence-based medicine and the medical basis for your recommendations. Point out the level of evidence that informs each idea being discussed. Find a gentle (but honest) way to suggest making changes, and keep the focus on the fact that you both want to provide the best care possible to the pet. Contact a veterinary nutritionist if needed. Use this opportunity to develop your approach to talking about nutrition. You’ll say “umm” a lot and feel like it’s your first week in practice for a while, but it will become second-nature. Your client will leave with the impression that you care, that you listened, and that you do know something about nutrition.
Pet owners: It’s tricky to navigate pet nutrition advice. There’s a lot of it, and it ranges from excellent to terrible. Often terrible is cleverly disguised as excellent. There are resources for dog and cat owners that can help, but your vet is really the best person to help sort it out. However, understand that while “is diet x good for my pet?” sounds like a simple question, it isn’t. Not if you want an intelligent answer. The answer actually involves your pet’s medical needs (the easy part because your veterinarian already has a handle on this); your pet’s current and possibly previous diets, and his/her response to them; and the logistics of feeding and lifestyle in your home. If you are honestly interested in your veterinarian’s opinion of your pet’s diet (you should be), it’s only fair that you give them an opportunity to give you a good answer. Asking about nutrition as a “by the way” as your vet is leaving for her next appointment isn’t fair. You probably won’t be satisfied with the answer, and your veterinarian won’t get the chance to provide your pet with the best possible care. Just as you’d schedule an appointment with your vet if you had questions about your pet’s itchy skin, go ahead and schedule one for your questions about diet.
It’s not the easy way out (surprise), but between veterinarians’ expanding knowledge base in nutrition, more practice with talking about it, and a bit of perspective, the myth that veterinarians don’t know anything about nutrition can hopefully be put to rest.
Making a diet change for a pet sounds easy, but can actually be a daunting task. Depending on the reason for making the change, it can even be life-saving, or just make your life easier. Either way, here’s an article I wrote for Vetstreet.com with my take on how to make it happen.
This is the story of one of Veterinary Nutrition Care’s patients. It is presented to illustrate the benefits of including nutrition in a pet’s care plan. Many complex aspects of medicine and nutrition have been over-simplified; it is not intended to be taken as advice on nutritional management of any other pet. If you have questions about applying these strategies to your own pet, please contact your veterinarian.
Imagine the nicest little old lady Chihuahua-terrier mix dog you could ever want to meet, and keep in mind that with the Chihuahua (and the terrier) comes a bit of spunk.
You just met Cheeka.
Like many older small-breed dogs, Cheeka has degenerative valvular disease. This means that her heart valves no longer create an effective seal; they allow blood to leak backwards when the heart’s beat should be pushing blood forward. This leak is no small matter. Because of it, she has an impressive heart murmur and fluid that accumulates in her abdominal cavity; this has to be removed periodically to keep her comfortable.
Cheeka’s dedicated owner and stellar veterinary team have done an amazing job in managing her care. She’s happy and comfortable, eats well, takes her medication without too much fuss, and loves her owner. Cheeka’s labwork is repeated routinely to make sure everything stays on track.
When Cheeka started having diarrhea, which was quite distressing to both her and her owner, the team went into action. She’d been started on a probiotic supplement and medication for the diarrhea. There was intermittent improvement, but nothing seemed to make a true difference. At this point, Cheeka’s veterinarian recommended a visit with Veterinary Nutrition Care.
Cheeka’s owner made arrangements for the visit and provided Cheeka’s diet and medical history details beforehand. When Cheeka and her owner met with Veterinary Nutrition Care, Dr. Farcas reviewed Cheeka’s history to make sure that nothing was missing and asked a few more specific questions. She asked Cheeka’s owner if there were any other concerns that they’d need to discuss, then explained the likely cause of Cheeka’s diarrhea: without the heart working as well as it should, circulation to Cheeka’s intestines is not as effective as it should be. This means that the intestines aren’t able to do their job of absorbing nutrients from Cheeka’s food, and if the intestines aren’t absorbing them, those nutrients get utilized by the bacteria in the intestinal tract. While those bacteria are normal, when they get “fed” different amounts or types of nutrients than usual, a change in the numbers and types of bacteria present can occur. The numbers and types of bacteria present in the intestinal tract are important because they affect stool quality, as well as other aspects of health. This is an interesting area of research, and we are always learning more about these effects. In Cheeka’s case, these bacterial changes were causing diarrhea, so this became a focus of her nutritional therapy.
There are several potential nutritional approaches to managing diarrhea in dogs. Feeding specific ingredients, or changing the amount and/or type of dietary fiber intake, and probiotic therapy are common and potentially-sensible approaches. In Cheeka’s case, her usual diet was a home-prepared diet made using a barley-based premix for dogs. Given that her current barley-based diet was likely moderate in dietary fiber, Dr. Farcas elected to start with a low-fiber approach for Cheeka. Unfortunately, because total dietary fiber isn’t required in pet food labeling, it wasn’t possible to know the dietary fiber content of her current diet, so the plan would be to start with a very low-fiber diet and add known amounts of specific fiber sources while assessing her response to this new, well-defined diet.
Another focus for Cheeka’s nutritional therapy is supporting her heart function. Cheeka’s cardiologist and Dr. Farcas agreed that Cheeka should be on a low-sodium diet to reduce the heart’s workload. Because Cheeka’s barley-based diet was intended for healthy dogs, it likely included more salt than was recommended for her. Cheeka also has an arrhythmia, so the inclusion of a concentrated source of long-chain omega-3 polyunsaturated fatty acids was important in her diet plan. One of Cheeka’s heart medications has the side effect of causing loss of potassium in the urine, and her labwork reflected low potassium levels, so her diet would also have to provide extra potassium. Finally, since some pets with heart disease (including Cheeka) experience a loss of muscle mass over time, and because some of her body’s protein is lost each time fluid is removed from her abdomen, making sure that Cheeka’s diet provided enough protein was essential.
Further, Cheeka’s routine labwork has indicated that she may be experiencing a decline in kidney function. Heart disease and later stages of chronic kidney disease are difficult to treat together, since their management strategies when it comes to fluid balance and protein intake are essentially opposite, so protecting her remaining kidney function is critical. There are a few nutritional strategies that can help delay progression of chronic kidney disease. One of these, inclusion of long-chain omega-3 polyunsaturated fatty acids, had already been incorporated into Cheeka’s diet plan. The other, phosphorus restriction, would also be included. While a low-protein diet is often used to manage patients with later stages of chronic kidney disease, this was not indicated at this point for Cheeka.
So, to accommodate Cheeka’s diarrhea, heart disease, and early stage of chronic kidney disease, her diet would have to be low in dietary fiber, low in sodium, potassium-supplemented, high in long-chain omega-3 polyunsaturated fatty acids, moderate in protein, and low in phosphorus. In addition to this, the rest of Cheeka’s body still needs to be supported, so her diet must also be complete and balanced to meet the rest of her nutrient needs and fed in an amount that provides her with enough calories to maintain her weight. Because even the most perfectly-designed diet is a failure if it isn’t eaten, the diet would also have to be palatable to Cheeka. Cheeka’s owner prefers to continue home-cooking for her, which was good, since it was unlikely that a commercial diet could meet all of these needs.
While this may seem a daunting task, it was possible to design just such a diet for Cheeka. Cheeka was transitioned first to the diet’s main ingredients alone, and then a specific concentrated fish oil supplement was introduced, followed by incorporation of a specific vitamin/mineral supplement. The plan would be to monitor Cheeka’s stool quality and weight for a week, and make changes as needed to either the diet or the amount fed based on these findings. Cheeka continued eating well, but still had diarrhea. While just having Cheeka’s diarrhea improve right away would have been ideal, this trial was still helpful. Now that Dr. Farcas knew Cheeka’s response to a very low-fiber diet, she could begin to test her response to the addition of known amounts and types of fiber.
Dietary fiber is interesting, and can even seem a bit magical, as it can be used to treat both diarrhea and constipation. It’s not really magic, but chemistry and physiology. Different types of fiber draw water into the stool in either a structured (insoluble fiber) or an unstructured (soluble fiber) way. Dietary fiber also influences numbers and types of intestinal bacteria, which affects stool quality.
For Cheeka, Dr. Farcas recommended a low dose of a specific mixed (soluble and insoluble) fiber source. When she checked in a few days later, Cheeka was still doing fairly well overall. Her owner reported some improvement, but Cheeka was still having either soft stools or diarrhea. Since this fiber supplement appeared to be having a beneficial effect, Dr. Farcas recommended doubling the dose and monitoring for a few more days. If Cheeka was still having diarrhea, the plan would be to change to a supplement providing a different type of dietary fiber. Happily, the next update was a good one. Cheeka’s owner reported that Cheeka had been having normal stools. Cheeka’s team celebrated.
Until more research is done on the effects of specific types of dietary fiber in dogs and cats, using it to manage either diarrhea or constipation can be a trial-and-error process, but taking a methodical approach reduces the amount of error involved.
While Cheeka’s customized therapeutic diet plan isn’t going to address the root cause of her diarrhea (inadequate circulation to her intestines), it has effectively managed it. In addition, it’s giving Cheeka all of the support that her heart, her kidneys, and the rest of her needs to keep being her sweet, spunky, self.
Most cat caregivers have come to accept that cats just aren’t very adventurous when it comes to their food. But why?
In plant-eating animals, bitter taste receptors (taste buds) alert the eater that the plant being eaten may contain toxins (which taste bitter), thus limiting consumption of potentially toxic plants. Smart.
Another smart thing that nature does is getting rid of stuff it’s not using. For instance: cats evolved eating meat, which contains more than enough taurine (an essential amino acid for cats) to meet their needs. While their distant ancestors possessed the enzymes needed to make taurine from other amino acids, the cat never used them, as it got all the taurine it needed from its diet. Maintaining working enzymes takes a fair amount of energy in the body, and if an enzyme isn’t being used, there’s a survival advantage to the individual who manages to get rid of it (by either deleting or not expressing the genes for that enzyme).
So, with that in mind, it makes sense that an animal that evolved as a carnivore would have lost those bitter taste receptors that are protective for plant eaters.
A group of researchers at the Monell Chemical Senses Center in Philadelphia recently published research that aimed to determine if that was the case.
In this study, the group isolated taste receptor genes from cats, and made cells in culture (petri dishes) express these genes. The experiment was designed so that when the cells were exposed to a compound that is bitter (according to cat taste receptors), a detectable reaction would occur.
If it was true that cats had lost the ability to taste bitter compounds since they no longer needed to be able to tell which plants were toxic and which plants are good to eat, then the cells in culture wouldn’t react to any of the substances tested. But, that’s not what happened. The researchers found that the cat taste receptors reacted to a wide variety of bitter compounds.
Now we know that cats can and do taste bitter compounds in their food, which gives some explanation for why cats can be so finicky with food. Rather than assuming that evolution just didn’t happen here, or hasn’t caught up yet, it seems that cats are using these receptors for something other than what we’d thought. Exactly what that is, we don’t yet know.
Typical cats. Keeping us guessing.
If you become a regular on Veterinary Nutrition Care’s blog, you’ll probably see more of Austin. Full disclosure: he’s my dog. I’m writing about him not because he’s my dog and he makes me smile every day, but because he’s been my most challenging and interesting nutrition patient. Sharing his story also gives you a bit more about who I am and how I approach my work. This post is longer than I’m planning for usual, but read on. It’s a good story.
Austin is a German Shorthaired Pointer, presumed to be mixed with a Lab. My husband, Nic, and I adopted him as a total goofball with no manners at about a year of age. With a lot of work and patience, he became a reasonable pet by the time he was five or so. Those of you with dogs who don’t have the “I want to be a good dog because it makes you happy” mentality can relate. He’s now about to be ten years old, and worth every bit of home-repair he’s caused.
In 2012, just before I completed my nutrition residency at UC Davis, we sold our house and moved to a rental. We checked the yard- no problems, enough cool, shady, spots. It seemed like a safe place for Austin to stay while we were at work. One night, a few months later, Austin was “off,” but not showing us what was wrong- not dehydrated, not painful, pink gums- it was hard to say. Until, that is, he began vomiting during the night. Not just vomiting, but vomiting grapes. A short time later, he was feeling terrible, and by then, he was getting dehydrated.
For those who don’t know already, grapes (and raisins) can be toxic to dogs. Exactly why this happens, and why it only happens in some dogs, is still not known.
Huh? He certainly wasn’t accidentally fed grapes, and he couldn’t have gotten any off
of the counter or out of the refrigerator. Not only was he not prone to do things like that, even with his favorite foods- we didn’t even have any grapes in the house. We investigated the yard. Uh-oh. In the time since we’d done our inspection, grape vines from the neighbor’s yard had grown over (and through) the fence and commenced with production. It wasn’t possible to know how much he’d eaten, but it could have been a lot.
So, then there was the trip to UC Davis’ Emergency Service. Some testing was started, and given his sky-high blood concentrations of blood urea nitrogen (BUN), creatinine, and phosphorus, which the kidneys are supposed to be getting rid of; among other things, a tentative diagnosis of acute kidney injury due to grape toxicity was made. In acute kidney injury, the kidneys are essentially shut down for a while; they can’t filter the blood, and they can’t make urine. The kidney does have some capacity to recover, but if it happens, it takes some time. And it doesn’t always happen.
Treatments, including IV fluids and anti-nausea medications were started. Time is the real medicine for acute kidney injury. The rest of the care is supportive, meaning that it brings relief from the (horrible) effects of kidney failure while the body’s repair mechanisms work. In theory, and maybe depending on his “dose” of the “mysterious grape toxin,” his kidney function may come back in the short window of time until he became too sick to go on. Treating these patients is tricky; because they need to receive fluids- they’re dehydrated. On the other hand, they can’t get rid of fluids, so they go very quickly from being dehydrated to being over-hydrated. Having worked with patients in the same scenario, I knew in my gut that when the morning came, we’d have to be talking about dialysis.
Dialysis can’t fix injured kidneys, but when the kidneys can’t do their job of filtering the blood, “bad stuff,” called uremic toxins, builds up. These uremic toxins were responsible for Austin’s feeling terrible, vomiting, and a lot of other, more subtle, issues. Dialysis removes the uremic toxins so that a pet can feel well enough to wait for the kidneys to repair themselves. It buys time. The other thing that dialysis can do is to correct over-hydration.
Sure enough, in the morning, the last day of my residency, despite the best supportive care under the sun, Austin hadn’t produced any urine overnight, he felt awful, and was now over-hydrated. The usual mischievous sparkle in his eyes was gone. There was no way to continue like this.
Even before meeting my colleagues from dialysis, I knew we’d have to make a big decision: either dialyze or euthanize. Just writing this now makes my stomach hurt.
I sat with him in his kennel and cried. I asked him to tell me what he needed. He could barely lift his head, but he put his warm and dry nose up to my cheek and sighed. I managed a small laugh. This was a weak attempt at a behavior that had always annoyed me. He’d never been one to lick your face, but given the opportunity, would shove his nose way too close to your face for a second and sniff. Almost, but not quite touching. I’d never realized before that he’d been trying to say “I love you.”
I met with the dialysis team: Dr. Larry Cowgill, veterinary dialysis guru; Dr. Kayo Kanakubo, then the intern in dialysis; and Dr. Bing Zhu, then an internal medicine resident. They proposed a plan. An initial dialysis treatment, then repeat treatments as needed (when the uremic toxins build up high enough that he starts feeling poorly again) until his kidneys recover, with continued supportive care. He was guessing that this would be over a month or so, but he’s had patients require dialysis for six months to recover. In Dr. Cowgill’s experience, half of dogs in Austin’s position go home, and of those that do, half go home with chronic kidney disease.
I talked with my husband. We cried some more. Dialysis was an expensive proposition, and with both of us residents at UC Davis at the time, there wasn’t a big chunk of “dialysis money” set aside. We could manage it for a month, we thought, but may be in the same hard place a month down the road if Austin’s kidneys hadn’t come on-line yet. Before we had Austin, when we’d talked about our clients that were in similar do-or-die situations, we’d both thought that we’d try to be practical, and could make the hard decision to let our pet go when faced with odds that were not necessarily favorable. I realized then that we’d never considered whether we could live with ourselves if we’d made that decision. Standing in those shoes, with only a 25% chance of coming out really okay, we could only choose to go forward with giving Austin a chance.
I went back to check on Austin and promised him that if he came through this with us, I’d never get mad at him for sticking his nose in my face again. I stopped by the Nutrition Service’s office to give my colleagues an update. I was told that my few remaining loose ends could wait, and to take the day to take care of Austin. Veterinary nutritionists are nice people.
I called Dr. Cowgill back, and we got started. Austin would be anesthetized for placement of a dialysis catheter (a giant IV catheter in his jugular vein that attaches to the dialysis machine) and feeding tube, then would receive his first dialysis treatment immediately. Patients with acute kidney injury are usually hospitalized in the ICU, at least initially, because there’s a lot to do to keep them comfortable, hydrated, fed, and medicated and because there’s a lot of checking to do to make sure things stay on track. That said, equipment-wise, the needs are relatively simple- he wouldn’t be attached to a ventilator, EKG, or oxygen. Dr. Zhu had the crazy idea that since I’d just finished my residency, and wasn’t starting my graduate program for a few weeks, that we’d hospitalize him at home, with me and Nic doing round-the-clock care and monitoring, and bringing him back to the hospital mornings and evenings for her to examine. Basically, my house was an extension of the hospital, she was the attending clinician, and Nic and I were the nurses. This would allow us to reduce the cost of Austin’s nursing care to stretch our resources for further dialysis treatments. I told Austin’s doctors that I would be the most compliant pet owner they’ve ever given orders to, but, despite being a veterinarian, that I wanted no clinical input on Austin’s medical management. I wanted to make no decisions, other than for his nutrition.
Please note: this home-hospitalization plan could ONLY be possible with an unemployed (and maybe slightly insane) veterinarian as the pet’s owner. If your pet is ill and requires hospitalization, do not suggest to your veterinarian that you can do it at home. If you’re lucky, he/she will just smile and tell you it’s not a good idea. If not, you may get laughed at, which may be hard to take in the moment. While it’s do-able for a veterinarian, it takes many years of training. In the long run, hospitalizing your pet costs much less than vet school.
The first nutrition decision came right away. Dialysis patients have a waxing and waning appetite, since they eat when they feel good after dialysis takes away all of the uremic toxins, but the toxins build up again, and they won’t eat. That said, dialysis patients have extremely high energy requirements. The treatment literally takes a lot out of them, so they need to be fed, regardless of what their appetite is like.
I’d managed nutrition for Dr. Cowgill’s dialysis patients before, and knew that he had (at the time) a habit of using a particular long and narrow feeding tube in large dogs. In my experience, the veterinary students and nurses had a very hard time with these, since it was difficult to push the large volumes of pureed diets we fed to these dogs through. That wasn’t going to happen with my dog.
A few months prior, I was at the exhibit hall of the American College of Veterinary Internal Medicine’s annual conference and came across one of many medical device vendors. On display was a large variety of tubes, used for various purposes. I picked up a chest tube (designed to remove air from around the lungs in patients who’ve had open-chest surgery or trauma) with a nearly 1-cm diameter, waved it at Dr. Jennifer Larsen, one of my nutrition mentors, and said; only half-jokingly, “This is what we should be using for Cowgill’s big dogs.” We bought one on the spot, just in case. It was a little extreme, but it would at least make the point that what he’d been using wasn’t working very well. Little did I know that it would go into my dog.
It felt a little weird giving “the guru” orders, but I had to put my foot down. There was no way we were going to use the long, narrow tube to feed this dog. I was already on the edge, and being frustrated with not being able to feed my dog just wasn’t an option. We rifled through the hospital’s supply of feeding tubes, but didn’t find one I could agree to, so I went back to the nutrition office and brought out the big chest tube. “Here. We’re using this” I said. Dr. Cowgill was taken aback for a second. I’m not sure if it was my tone or the size of the tube, but either way, Dr. Cowgill is well-dressed, composed, and confident. He’s hard to rattle, so it was mildly amusing to see.
Placement of the dialysis catheter went fine, though there was a bit of work to devise a method to place such a big feeding tube. Once that was figured out, dialysis ensued. Dialysis treatments take several hours, and though Austin started his treatment anesthetized, he recovered on the warm and padded dialysis table. By the time he finished his treatment, he was brighter, wanted to be petted, and while not 100%, seemed much more like himself. Even though I knew this would be temporary, it still felt like relief.
Once he was liberated from the dialysis equipment, I grabbed a plastic bowl (wishful thinking that there would be urine to collect) and took him outside to see the sun for the first time that day. We walked down a path to a strip of grass outside the Center for Companion Animal Health. He stretched. Sniffed. Lifted his leg. And peed! I was so excited; I almost forgot that I was supposed to be collecting urine. I caught what I could and relaxed a bit, thankful for the good news.
There were cheers when I walked back into the dialysis room with a bowl half full of urine. It’s funny what veterinarians can get excited about. I left Austin with Dr. Kanakubo, and John Kirby and Sean Naylor, the dialysis service’s amazing technicians, and headed down to pharmacy and central service for drugs and supplies. I took the case of IV fluid bags (yes, case; the first of several), a bag of miscellaneous syringes, packages of bandaging material (for the wrap that protected the dialysis catheter and feeding tube placed in his neck), and what felt like a hundred medications out to my car, then went back to the nutrition office for the case of canned therapeutic diet that I’d be feeding through the tube. In the mean time, Dr. Zhu wrote my orders for his overnight care, and sent them to my email.
By then, Nic was done for the day. We picked Austin up from dialysis and thanked Sean and John for the care package of things I’d not thought to get from central service, but could immediately see the need for, and we headed out the door to set up our ICU. Just before the door closed, I heard Sean say something. We went back. “What was that?” we asked. Sean repeated. “Did Cowgill tell you his head is going to swell?” Great. It made sense: his fluid balance was better, but still fragile, plus the hole that was put into his jugular vein to accommodate the giant dialysis catheter meant that the wrap around his neck had to be snug, to say the least. Yeah, his head is going to swell.
Once home, we got IV fluids running, gave a round of medications, and I sat down to make Austin’s feeding plan using the canned diet I’d brought home. It was the best fit, but still needed to be modified a little. Austin’s diet plan was basically a lot of calories, enough protein (but not too much), not a lot of fat, low phosphorus, extra potassium, low sodium, and a double-dose of his usual fish oil. Our canine dialysis patients often develop pancreatitis, and one way to manage (and we thought maybe prevent, in Austin’s case) pancreatitis is by feeding a low-fat diet.
Please note: there is debate among the nutrition community about whether low-fat diets are useful to treat pancreatitis, and certainly using one to “prevent” pancreatitis was a stretch, but when it’s your dog, and it doesn’t cause another problem, you’ll try anything that makes even a little bit of sense.
I blended the canned diet I picked with the amounts of salt substitute and fish oil that my calculations told me I needed, and enough water to be able to draw it into the syringe. It looked like a chocolate milkshake, but smelled like, well, canned dog food and fish oil. Austin looked interested. I thought he might just eat it. He sniffed, but not quite. I’d calculated how much I intended to feed over the next day, as well as how much water this would provide. I started at less than half of what I’d determined his energy requirement to be, not because he didn’t need the nutrition, but because feeding too much, too rapidly, to a sick patient can make them feel poorly or have even more serious effects. As badly as I wanted to make sure Austin was getting everything he needed, a gradual increase up to the amount I wanted to feed was the way to go. His kidneys were making some urine, but we weren’t sure yet if that part of kidney function was completely back on line, so we still had to be careful about his fluid intake relative to his urine output.
I set up everything I’d need for the first tube-feeding: syringes filled with diet slurry, syringes filled with water, paper towels for wiping up drips, a big towel because it just seemed like it would come in handy. I crushed the medications he was due for, mixed them with water, and drew each suspension into smaller syringes. I laid those out next to the food syringes. When it came time to feed, I first flushed the feeding tube with water. No problem. I switched syringes to one with food and started pushing. This was kind of a “moment of truth” instance for me, since I’d never gotten the chance to actually “test” this tube by pushing food through it when it wasn’t already a patient. The tube was fantastic! The only resistance to feeding came from the syringe itself. I breathed a sigh of relief for the second time that day. I’d have hated to have to tell Dr. Cowgill that the tube I demanded he use wasn’t such a good idea after all.
Overnight, there were some kinks to work out, but things mostly went okay. And yes, his head swelled. Not freakishly, but definitely swollen. At least it wasn’t a surprise, and I knew it didn’t hurt. Austin was a little brighter as we headed back to the hospital to check in with Dr. Zhu. She rechecked some labwork and was happy with how things were going. She reminded me that him feeling this well would be temporary; as the uremic toxins that had been removed by the dialysis treatment built back up, he’d start feeling more and more poorly until his next treatment. Dr. Zhu liked that I was able to tell her, between IV fluids and what I’d fed through his tube, Austin’s exact fluid intake, as well as his urine output, which I’d been collecting and measuring using a (now dedicated) Nalgene bottle. With this information, we were able to match his fluid intake to match his urine output to maintain his hydration. Having more information allowed us to customize Austin’s care. Dr Zhu agreed with my plan to begin increasing the amounts he was being fed to give him as much support as possible.
This continued for a few more days, and, as expected, each day he was a bit dumpier, the morning of his next dialysis treatment, he vomited. In hindsight, it was probably because I’d been palpating his abdomen (feeling around to make sure he was comfortable and that everything seemed normal) before I gave his anti-nausea medication, but there was also nothing to prove that this wasn’t the beginning of pancreatitis. Pancreatitis can be severe, painful, and life threatening. There was no contraindication to changing his diet (meaning that there was no good reason not to), so I formulated a balanced home-prepared mixture of eggs and egg whites, rice, and a vitamin and mineral supplement. Still not so appetizing by the time it was prepared, but it was much lower in fat, and it did everything else I needed it to do for Austin’s nutrition. I again figured out how much water it would take to get the slurry through into the syringe and through the feeding tube, and then how much water per calorie that would be delivering.
By this time, Austin’s urine production had increased to be just about normal (2-3 mL/kg/hr), though it was expected to continue increasing, since the next phase of the kidneys coming back to functioning normally is a period of post-obstructive diuresis, where they allow way too much urine to be made.
We’d weighed Austin each time he returned to the hospital, and he was generally trending downward with respect to weight. At first this is expected, since he was over-hydrated and getting rid of excess water, but once he is normally hydrated, the weight loss is real. In dialysis patients, the weight loss is muscle, it can be profound, and it can happen really quickly.
The second round of dialysis was uneventful. Austin’s urine production kept climbing, so in addition to IV fluids, he was receiving syringe after syringe of water, on top of a nearly-liquid diet. For every bit of urine output over “normal,” there’s an increase in the number of times a dog has to go outside to pee. When that urine output climbs to, say 17 mL/kg/hr (keeping in mind I said that normal is closer to 2 mL/kg/hr), you have to make some changes.
First, you have to move your bed into the living room next to the sliding door to the backyard, because otherwise you can’t get the dog outside fast enough.
Second, when your dog is producing that much urine, you’re out in the yard every hour, day and night, you get a little batty (not to mention irritable). When you need to collect and measure that urine so you can determine how much more water you need to give (in addition to that from the slurry and IV fluids) to match the urine output at 3 am, it’s way too easy to make a mistake. I’d been trying to let Nic sleep, since he was still in his residency, with early mornings and late nights, but in order to not make some kind of scary middle-of-the-night mistake, I had to admit that even though this phase would be temporary, I couldn’t do hourly 24-hour care by myself. Nic’s much more of a morning person, so he started doing the routine between about 2 and 6 am so I could get some sleep.
I designed an Excel sheet to keep the many things to do straight. I set it up to convert amounts fed to amounts of water this provided, and keep track of the total amount of fluid intake over the day, then compare that to the total urine output for the day. For each hour, it would determine how much additional water was needed to match “ins” to “outs.” It would also allow us to know if medications had already been given to avoid missing, or repeating, treatments.
At the time, my family was eager to have a next generation, and they were eyeing Nic and I. “This is great training for having a baby” my mom said. “If you can handle this, the baby will be no problem.” Thanks, mom. We were irritable, and literally in “survival mode.” Definitely not the time to be talking about a baby.
Now that our son is a year old, I can say that I see what Ma was getting at: being up all night and day caring for a helpless creature that you’re crazy about. But it’s different. My son was (is) healthy, and while being up all hours of the night with him was hard, I wasn’t worried about the same things with my healthy baby as I was with my very sick dog. It’s hard to find people who really understand that feeling.
Austin’s weight was still trending slightly downward, but he wasn’t showing the dramatic muscle atrophy that we sometimes see with dialysis. He seemed to take everything in stride, though after another four days or so, he was feeling bad and needed another dialysis treatment. The good news though, was that his BUN and creatinine weren’t going as high as they had before, and were staying lower for a bit longer. Hopefully this meant that the kidneys were starting to do a better job of filtering the uremic toxins out of the blood.
If all goes well, the kidneys regain their ability to concentrate urine (keep water from being lost as urine and retain it for the body), but it’s hidden because we’re busy giving extra fluids to match the recent output. Even kidneys that work really well will produce huge volumes of urine if your intake is huge. When this happens, it’s the end of the post-obstructive diuresis period. This means that there is a time when you stop matching “ins” to “outs” and instead match only, say, 90% of the output to see if the kidneys can handle it, and Dr. Zhu said that the time had come. I reconfigured my Excel sheet, and Austin stayed normally hydrated, despite getting less fluid. The next day, we matched 80%, and so on.
Gradually, very gradually, Austin began returning to normal. He started drinking water and eating on his own. He required less nursing care and fewer trips outside. I still measured his food and water intake and supplemented with the tube, but this was real progress. We were able to stop giving IV fluids altogether, and gradually tapered off of some of his medications. Since I wasn’t worried about pancreatitis anymore (false alarm), I went back to the canned therapeutic diet to make life a little simpler. There was a first time we “slept through the night” (back to that baby-prep talk) without having to take the dog outside. When the day arrived that I wasn’t giving any additional fluids with the tube, I was nervous. We’d been checking his bloodwork and urine concentration daily or every other day since this started, but this was a real test of whether his kidneys were able to hold their own.
He did it. His concentrations of BUN and creatinine were close to normal, and his urine concentration was reasonable. A few days later, things looked even better. It’s hard to describe how relieved I was. Shortly after, we removed Austin’s feeding tube, and he went on about life as a normal dog. He’d made it. Not only was he one of the 50% that get to go home, he was one of the 25% that go home without chronic kidney disease.
Months later, I ordered routine screening bloodwork, in addition to a parathyroid hormone (PTH) concentration. It’s is an early indicator of chronic kidney disease. It goes up long before other changes show up. Not only were the screening tests normal, but so was the PTH. Not even “high-normal.” Just normal. I eventually got brave enough to change his diet back to a non-therapeutic adult maintenance diet. Since then, I’ve repeated these tests several times and they’ve remained normal.
Austin is back to being the fastest dog at the dog park. I assume that the “grape incident” as it has come to be known, did some permanent damage to Austin’s kidneys that we can’t yet detect. Our labwork isn’t perfect, and each kidney function test has a “threshold” for how much damage has to exist before the test result becomes abnormal. So far, if that’s the case, he hasn’t reached any of those thresholds. If/when Austin does show a decline in kidney function, you’ll see another entry about how I manage his changing needs. Until then, I’m grateful for the care that Austin received, and the care with which Nic and I were treated by Austin’s team.
There are many technical details that I’ve left out of the story; details about estimating energy and protein requirements, formulating diets, adjusting electrolyte intake, slurry preparation and administration, measuring body composition, and so much nutrition minutiae it would make your head spin. Those could each be their own very long blog post. I’ll just say that whether we talk about the big picture or the details of nutrition, Austin’s taught me a lot.