Nutritional Management of a Growing Puppy with Food-Responsive Enteropathy

Chronic enteropathies (CEs) are a group of diseases exhibited by intermittent or chronic gastrointestinal (GI) signs. Groups can be subcategorized according to treatment response as food-responsive, antibiotic-responsive, or immunosuppressive-responsive. The most prevalent is food-responsive enteropathy (FRE; 50% to 65%),¹ which can often be successfully managed with individualized dietary modification. FRE may include a true food allergy, for which a strict dietary elimination trial is indicated to determine which protein sources are allergens for that dog, or it may include more of a food intolerance, in which patient improvement is based on the composition of the diet (e.g., fat, fiber, digestibility).

Dietary manipulations that have been successful for some patients with FRE include hydrolyzed diets, novel protein (and ideally novel carbohydrate) diets, lower-fat diets, or highly digestible home-cooked diets (often novel protein as well). In addition, altering fiber content may benefit some dogs with CE because adding beneficial fiber can act as a prebiotic for the microbiota and help strengthen the microbiome, resulting in production of short-chain fatty acids, lowered colonic pH, and impeded pathogen growth; conversely, removing fiber can improve digestibility for some dogs that do not tolerate fiber supplementation.² Different types of fiber can be used in a trial-and-error fashion to see which produces the best response.

A subset of dogs with CE may have intestinal lymphangiectasia characterized by pathologic dilation of lymph vessels within the GI system, which can lead to protein loss (protein-losing enteropathy) and is often best managed nutritionally with an ultra–low-fat diet.³ Determining which dietary modification will be effective for a patient is currently conducted by trial and error because there are no tests that can clarify how a patient will respond to dietary manipulation or clarify the type of manipulation needed¹; however, localization of clinical signs can help direct dietary modification as a starting point (TABLES 1 AND 2). After the correct diet has been identified, GI signs in patients with FRE typically improve within 2 weeks.⁴

Nutritional management of puppies requires excellent communication with clients as well as close monitoring to help maintain appropriate growth rates and healthy body condition. Appropriate amounts of essential nutrients (at least 90% of total caloric intake) should be provided by feeding a complete and balanced diet appropriate for the size of the puppy while maintaining approximately 10% of calories as treats for training and bonding purposes. Clients with puppies that may grow to large-breed size (>31.8 kg [70 lb] as adults) should be counseled to feed a diet that is appropriate for growth of large-breed puppies as these diets have controlled nutrient profiles (particularly calcium and phosphorus) and will help the puppy grow at a more appropriate rate while minimizing the risk for growth abnormalities and joint disease. Clients should be informed that to help reduce the risk for health issues associated with excess weight, they should maintain their puppy at a body condition score (BCS) of 4/9.

Nutritional planning for puppies also requires a training plan as appropriate play and training will often require food or treats as motivation. Similarly, bonding with a growing dog often involves food, and high-value and high-calorie treats that are unbalanced or fed in excess of the recommended 10% treat allowance can lead to an unbalanced diet and nutritional deficiencies that could result in growth abnormalities.

The following case presentation outlines the nutritional approach used for a growing puppy with an FRE and the steps taken to help manage it over time.

Primary Care Veterinarian Workup

At initial assessment by the primary care veterinarian, the patient was an estimated 9-month-old spayed female shepherd mixed-breed dog, weighing 23.2 kg (51 lb) and having a BCS of 3/9 (bit.ly/46hd89G) and normal muscle condition score (bit.ly/3EKXN5w).

She had been recently adopted from a local rescue shelter, where she had been spayed and had at least 3 acute episodes of mixed or large bowel diarrhea that never entirely resolved. These episodes were described as a mild to moderate increase in frequency or urge to defecate and normal to slightly decreased volume of soft stool with no melena, frank blood, or mucus noted (fecal score typically 5/7 to 6/7; bit.ly/45W2wwS). The episodes were attributed to dietary indiscretion or excessive access to treats during training sessions and were managed with supportive care (i.e., dietary modification with over-the-counter diets, addition of unknown amounts of canned pumpkin to a home-prepared unbalanced diet of cooked chicken breast and white rice, deworming with fenbendazole and praziquantel, and antibiotic treatment with tylosin or metronidazole). Stool consistency improved briefly but returned to softer, poorly formed stool after completion of the antibiotic regimen.

The patient was up to date on vaccinations and was receiving heartworm/flea/tick preventive medications. At initial examination, the clients described her as having a poor appetite but enjoying treats during training and play sessions and said that she would try to sneak food off the kitchen floor during food preparation or on walks.

Referral Workup

The initial referral assessment of the 9-month-old patient was conducted by a board-certified veterinary nutritionist via telemedicine consultation with the client and also by communication with the referring primary care veterinarian. The referring veterinarian reported that the physical examination had been grossly normal. In agreement with the referring veterinarian’s observations, the patient appeared bright, alert, and responsive with appropriate hair coat and no observed abnormalities on neurologic assessment. Although weight loss had not been reported, the patient was underweight at 23.2 kg with a BCS of 3/9, but no muscle wasting was noted. Rectal palpation resulted in a small amount of soft brown stool on the glove, but no blood was noted. Abdominal palpation did not elicit pain and the abdomen was soft on palpation.

Diet History

Before presentation to the veterinary nutritionist, the patient’s diet had been varied; in an attempt to achieve better stool quality, the clients had fed many over-the-counter diets and offered many different treats during training sessions (of multiple unknown brands that the clients were unable to remember but were typically beef, chicken, or lamb). Because complete information regarding diet history was unavailable, a full dietary antigen list could not be established. For almost a month, the patient had been fed a veterinary therapeutic hydrolyzed diet (Purina Pro Plan Veterinary Diets HA Hydrolyzed Chicken Flavor dry and canned formulas; purina.com), and stool quality improved slightly (no longer 7s), although the patient was still experiencing soft stools (5s or 6s) (TABLE 3).

Diagnostic Testing

Laboratory tests (blood, urinalysis, and fecal polymerase chain reaction) were conducted by the referring veterinarian when the patient was 9, 11, 19, and 24 months of age, and results were communicated to the veterinary nutritionist to facilitate necessary modifications (TABLE 4). At the 9-month telemedicine presentation to the veterinary nutritionist, laboratory testing findings were slight hypocalcemia, mild hyperphosphatemia, and hypoalbuminemia, all of which resolved over time with nutritional management.

Treatment Options

Nutrition can significantly affect patients with CE, and for patients with FRE, proper dietary management can play a central role in diagnosis and therapeutic intervention. Nutrient modifications (e.g., increased digestibility of GI diets, novel protein/limited-ingredient diets, hydrolyzed diets, low-fat diets, fiber-enriched diets) can all be potential therapeutic options for management of FRE. The duration of a diet trial to manage signs of CE depends on response to the diet. It should be clearly communicated to the client that if one management strategy is not effective, another strategy may be. Some patients may require a highly digestible hydrolyzed protein diet, others may require a highly digestible low-fat diet or a fiber-enhanced diet, and even others may require formulation of an ultra–low-fat diet. For difficult cases, seeking a board-certified veterinary nutritionist to help manage patients is recommended.

Patients that do not respond to nutritional therapy alone may require immunosuppressive or antibiotic therapy but can often still benefit from appropriate nutritional management, which may enable lower doses or shorter courses of medications.⁵ Other treatment options or adjuncts include attempts to correct dysbiosis by providing probiotics or synbiotics to modify the intestinal microbiota and exert a positive effect on the microbiome. Although probiotics can often be helpful for patients with acute gastroenteritis, their use in patients with CE is more difficult to interpret because different probiotics and strains are used.¹ Fecal microbiota transplantation (FMT) is used to transfer functional microbiota from a healthy donor to the patient; however, considerations include donor selection, FMT delivery method, and FMT schedule (some patients may require multiple treatments).⁶

When managing patients with FRE, carefully evaluating key nutrients in previously fed diets can help determine the next step. Considering essential nutrients of concern will help guide choices based on previous responses to diets. For the patient presented here, consideration of fat content, fiber content, and particularly calcium and phosphorus content (for the growing puppy) affected the trial diets (BOX 1); the patient’s response, including stool quality and appetite, influenced diet choices (TABLE 5).

Continued Management

11 to 19 Months

At the 11- and 19-month rechecks, the patient had improved after being fed veterinary therapeutic GI diets. Stool quality had moderately improved and appetite was adequate; however, at the 19-month recheck the patient’s appetite was declining again (TABLE 3).

19 to 24 Months

At the 19-month recheck, the patient was transitioned onto a highly digestible higher-fat GI puppy diet due to declining appetite. Stool quality mildly improved, as did appetite very briefly, and at the 24-month recheck a highly digestible low-fat diet was discussed. Considering that a lower-fat diet may further improve stool quality, veterinary therapeutic GI low-fat diets were fed as a trial after 24 months of age; stool quality improved but patient acceptance was poor (TABLE 3). Palatability was a concern due to the patient’s history of poor appetite and demonstrable dislike of commercial veterinary therapeutic low-fat diets. Because the patient’s body condition score was ideal (4/9) and her skeletal frame was reported to most likely be full size, the clients elected to transition to a home-cooked diet. Muscle condition was not reported at that time but was reportedly normal throughout the approximate 24 months of nutritional management.

2.5 Years

During the 6 months between rechecks, veterinary therapeutic low-fat diets were trialed but palatability was poor and a transition to a home-cooked diet with tilapia as the protein source was formulated and initiated at 2.5 years of age (TABLE 6). The home-cooked diet was highly digestible, contained a novel (according to the patient’s known diet history) protein, and was determined to be palatable to the patient. White rice was the chosen carbohydrate source because it is a low-fat ingredient and highly digestible. Although rice was not a novel carbohydrate and carbohydrate sources can have protein that can result in problems, rice was tested and determined to be tolerated. A small amount of corn oil provided a source of linoleic acid, an essential omega-6 polyunsaturated fatty acid for dogs. In addition, fish oil provided a source of eicosapentaenoic acid and docosahexaenoic acid at 128 mg/kg^0.75, a dosage associated with benefits for management of dogs with inflammatory diseases such as inflammatory bowel disease.⁷ To ensure adequate essential vitamins and minerals, a supplement was added to the diet (slowly, to evaluate patient tolerance) and no palatability problems were reported (TABLE 6).

Because at 2.5 years of age the patient was an adult, the diet was formulated to meet nutrient requirements of adult dogs based on the Association of American Feed Control Officials guidelines (aafco.org). The diet provided approximately 1434 kcal/day with a caloric distribution of 21% protein, 14% fat, and 65% carbohydrate on a metabolizable energy basis. A treat allowance of 10% (~143 kcal/day) in addition to the diet was also provided to account for treats and training if still needed. The diet was initiated and gradually transitioned to the fully home-cooked diet over 2 weeks to allow for adjustment to the new diet.

Follow-up and Outcome

At the most recent follow-up visit (2.5 years of age), the patient had continued to maintain a healthy body weight (~30.4 kg [67 lb]) with appropriate BCS (4/9), and the client has consistently reported adequate stool quality (typically 3 with occasional 4s), with no urgency or frequency, and a small volume of stool appropriate for intake. The patient maintains a good appetite for the home-cooked diet. She enjoys very occasional treats of watermelon or cucumber, which are reported to be well tolerated. Muscle condition was not reported at every follow-up visit but according to the referring veterinarian was consistently normal throughout the approximate 2 years of patient nutritional management. Fiber supplementation was discussed with the client and was not necessary to achieve appropriate stool quality.

Summary

Episodes of vomiting or diarrhea in puppies can occur for myriad reasons, and acute episodes can range from mild and self-limiting to severe life-threatening disease. If diarrhea becomes a chronic problem, dietary management through use of appropriate growth diets can provide opportunities to determine if the CE is food responsive and can help mitigate the use of antibiotics or steroids (partially or entirely).

Ensuring appropriate intake of a complete and balanced diet (90% of total caloric intake) appropriate to the life stage and puppy size is essential, particularly for large-breed dogs. Providing appropriate treats within a 10% treat allowance can ensure that essential training and bonding can occur without risk of unbalancing the diet, inducing nutrient deficiencies, causing potential growth abnormalities, or causing further GI upset. Regular follow-up visits, client communication, and patient monitoring are essential to help achieve a positive outcome.