The Ultimate Guide to Pet Veterinary Diets: Unlock the Secrets to Your Pet’s Health!

Nutrition is a cornerstone of a pet's well-being, influencing everything from coat health and energy levels to immune function. Understanding the nuances of pet nutrition, especially the role of veterinary diets, is crucial for ensuring a long, healthy life for our animal companions. This article delves into the world of pet veterinary diets, exploring their purpose, selection, and benefits.

Understanding the Nutritional Needs of Dogs and Cats

Domestic dogs and cats, while both belonging to the order Carnivora, have distinct nutritional needs. Observations of feral canids indicate that their feeding habits are broad and include various parts of plants as well as both small and large prey. The genome of the domestic dog differs from that of the wolf. Domestic dogs have three gene mutations associated with key roles in starch digestion and glucose absorptions that are different from those of wolves. As a result, the domestic dog shows an increased adaptation to carbohydrate-rich food, and from a nutritional standpoint, dogs are considered omnivores.

Cats, on the other hand, have a more recent history of domestication, resulting in a more modest number of genome regions with strong signals of selection compared to dogs. The predominant genotypic changes in cats reported to date are associated with behavioral modifications. Nonetheless, a lean, healthy, adult domestic cat can adapt to alterations in dietary macronutrient intake, resulting in the ability of the cat to successfully metabolize foods in which a moderate amount of calories are coming from carbohydrates. Domestic cats also willingly eat diets containing plant-based nutrients, and they do have the ability to efficiently digest and absorb nutrients from plant origins, such as cooked starches, similar to dogs. However, from a nutritional standpoint, cats are still classified as obligate or true carnivores because they have metabolic adaptations that result in nutritional requirements that can only be met via a diet that includes animal tissues (ie, taurine, arginine, arachidonic acid, vitamin A, and vitamin D).

The Importance of Balanced Nutrition

Feeding a complete and balanced diet, defined as a diet that provides all the nutrients a healthy dog or cat requires for a specific life stage, is critical for overall health in dogs and cats. Balanced nutrition is the cornerstone of your pet’s overall health. It affects everything - from their shiny coat and strong teeth to their mood and immune system. When your pet’s diet is off-balance, the signs can appear gradually. You might notice dull fur, fatigue, or even behavior changes.

A balanced pet diet isn’t just about filling up on kibble or canned food. It’s about getting the right mix of nutrients that work together to support every aspect of their body. Protein supports muscle development, tissue repair, and energy. Healthy fats like omega-3 and omega-6 fatty acids keep your pet’s coat glossy and support brain function. Carbs provide energy and fiber for digestive health. Never overlook hydration.

Malnutrition in Pets

Despite the wide availability of commercially complete and balanced diets for dogs and cats, malnutrition still occurs. Malnutrition is defined as an imbalance of nutrients and includes nutrient deficiencies and excesses, imbalance of essential nutrients, or impaired nutrient utilization. Malnutrition can occur in pets that are underweight or overweight.

In recent years, obesity has become the most common nutritional disorder encountered in small animal medicine, and as of 2022, it was estimated that 59% of dogs and 61% of cats in the United States were overweight or obese. Obesity is a chronic inflammatory condition that can lead to a variety of related health problems as well as shortened lifespan.

Assessing Nutritional Adequacy

Body weight in combination with body condition score (BCS) is used in many species to provide an estimate of nutritional adequacy and can help determine ideal body weight. BCS is a semiquantitative assessment of body fat composition that ranges from cachectic to severely obese. Although body condition score is inherently subjective, as long as specific criteria are applied, it is a reliable way of estimating body fat levels in dogs and cats. In those circumstances, the correlation between BCS in dogs and percentage of body fat is highly statistically significant (r = 0.90). Physical examination, visual observation, and palpation are used to assign a BCS.

Two BCS systems exist for dogs and cats, a 5-point scale and a 9-point scale. In a 5-point scale, each 1 point change in BCS above or below ideal (3) represents a 10% change in body fat, whereas with a 9-point scale, each 1 point change in BCS above or below ideal (5 for cats and 4-5 for dogs) represents a 5% change in body fat. For example, a dog with a BCS of 8/9 would have an increase in body fat ~15% above ideal, and a cat with a BCS of 2/5 would have a decrease in body fat 10% below ideal. Percentage of body fat for ideal BCS is approximately 20%; however, in dogs, there are notable breed exceptions. For example, Greyhounds, and likely other sighthound breeds, have a higher muscle mass than other breeds. As a result, Greyhounds with a BCS of 5/9 have 7.2% body fat, as opposed to the average of 20%. Huskies and Rottweilers with a BCS of 5/9, however, have body fat levels of 31% and 32%, respectively. Parameters used to assess BCS include evaluation of fat cover over the ribs, down the topline (waist), around the tail base, and ventrally along the abdomen (abdominal tuck in front of hind legs). It is important to use both a visual assessment and a palpation to assign a BCS; see the table of parameters used to assess BCS.

Although BCS is a good assessment of body fat and nutritional adequacy, it does not assess muscle mass. Muscle condition scoring (MCS) is done to assess muscle mass, which can also be an indication of nutritional adequacy. Aging is associated with loss of lean body mass, and as pets live longer, this is an important assessment to perform in older pets. A loss of muscle mass can be a sign of protein malnutrition or other medical condition that results in sarcopenia. There can also be disparities between BCS and MCS; therefore, simultaneously assessing BCS and MCS may detect a patient with a condition in which fat mass may have stayed the same or even increased while muscle mass decreased dramatically.

Navigating Pet Food Labels and Selecting Quality Diets

Producing high-quality commercial pet food is a complex process, and it can often be difficult to find information on the pet food label that helps to determines quality. It is common for pet owners to focus heavily on ingredient lists when determining quality of pet food, such as looking for real meat listed first on the ingredient list or avoiding certain other ingredients. However, animals require nutrients, not ingredients, and two pet foods with very similar ingredient lists on the package label can differ in quality. It is also possible to sell a pet food that has never been fed to dogs or cats prior to becoming commercially available. Therefore, other considerations when selecting pet foods may include whether the company conducts research on their diets to support their claims and the safety of the food, or whether they employ a team of experts such as Board Certified Veterinary Nutritionists, experienced pet food formulators, animal nutritionists with an MS or PhD, food safety specialists, microbiologists, or toxicologists. The World Small Animal Veterinary Association (WSAVA) has more general, global recommendations for selecting pet foods.

Nutrition on the Internet: most pet owners consider the ingredient list to be the most important factor in choosing a pet food. However, the ingredient list gives no information on the quality of the ingredients and can be very misleading on the overall quality of the food. The WSAVA Global Nutrition Committee tool provides owners with recommendations on how to use more important information from the label to select a food for pets.

Commercial vs. Home-Prepared Diets

Numerous commercial diets are available; however, dogs and cats can also thrive eating a home-prepared diet formulated by a Board Certified Veterinary Nutritionist. When it comes to feeding your pet, owners often face a tough decision - should you go with store-bought food or prepare meals at home? Verdict: Both options can work well - the key lies in balance.

The Role of Prescription Veterinary Diets

While most pets do well on any high-quality, over-the-counter commercial diet that is appropriate for their lifestage, some pets will benefit from a prescription diet. Prescription diets are specially formulated to mitigate a specific medical condition. These diets should be fed only under the supervision of a veterinarian; their formulation may not be appropriate for all pets. There are a number of companies that produce prescription veterinary diets. Royal Canin® and Hill’s Prescription Diets® are the most commonly-utilized diets in most veterinary practices, but Purina ProPlan Veterinary Diets® and other manufacturers also produce prescription diets.

Veterinary healthcare teams are familiar with recommending veterinary therapeutic diets (VTD) for management of chronic disease states, but many of these diets are suitable for adult maintenance and growth. The term “therapeutic diet” has no legal definition; however, the Food and Drug Administration has guidelines for the labeling and marketing of canine and feline diets intended to diagnose, cure, mitigate, treat, or prevent diseases (Box 1). VTD are usually considered for managing specific medical conditions, such as kidney disease or osteoarthritis.1,2 Their ingredients and/or composition differ from OTC pet foods for a specific purpose, but this does not always preclude recommending these diets for healthy patients. Additionally, the quality control of their manufacture is often more stringent than that of OTC diets. Although some may carry statement reading “use under supervision of a veterinarian,” many VTD have AAFCO nutritional adequacy statements for adult and sometimes growth life stages (Table 1). VTD are formulated to assist in managing medical conditions based on known physiologic and nutritional differences between healthy individuals and those with a disease, or to contain nutrients that may have a functional role in managing a particular medical condition. For instance, VTD used for gastrointestinal (GI) disease are moderate in fat, calcium, and phosphorus. VTD may also contain anti-inflammatory nutrients, as inflammation is a component of many disease states. Formulated with omega-3 fatty acids,3 antioxidants,4 and other special nutrients, these diets attempt to modulate inflammation in GI, dermatologic, orthopedic, and urologic disease states.

Key Takeaways about Veterinary Dog Food

Veterinary dog food is developed based on extensive scientific research and feeding trials and, as a result, may be more expensive than regular dog food. Only a handful of companies produce vet diets because of the complex nature of developing these products. Vet diets carry label claims based on documented success of treating or managing specific medical conditions. Veterinary dog food requires oversight by a veterinarian, because they are used like other therapeutic treatments to manage specific conditions. Vet diets may not be safe for “normal” pets, due to adjustments in ingredients for therapeutic purposes.

The Science Behind Therapeutic Foods

Sometimes pet owners come to their veterinarians and ask why they can’t just buy XYZ diet because it has similar claims in improving health. After all, both are touted to improve kidney function, for example. True therapeutic foods are those scientifically developed and tested to produce the diet. This is done through analysis of cell structures and ingredients, versus loosely performed clinical trials done by pet food companies, that generally focus solely on taste and digestibility. Therapeutic diets are therefore more expensive because they contain better quality ingredients and can support their claims specific to the dietary formula. Quality control is also much better than in your average commercial diet found in the pet food aisle.

When to Consider a Veterinary Diet

Balanced nutrition is vital to all pets, but there are some conditions and diseases that can be helped through veterinary diets. Special diets may benefit many more pets than not because most pets do deal with conditions that come with aging. Any one of these problems may signal a need for a specialized diet and your veterinarian should be the first point of contact for in depth recommendations.

Common Types of Prescription Diets and Their Uses

Hypoallergenic Diets: Pets with food allergies may experience either gastrointestinal signs or skin inflammation. Either type of food allergy can be treated with a prescription diet. The most restrictive diets are hydrolyzed protein diets. These diets are processed in a manner that breaks dietary proteins into very small fragments, which are too small for the immune system to recognize. The other type of diet used to manage food allergies is limited-ingredient diets, formulated with protein sources that are less common. The use of a limited-ingredient diet to manage food allergies requires the owner to know which protein sources have been used in their pet’s previous diets, so that they can select a protein source that their pet has not been exposed to in the past.
Gastrointestinal Diets: Gastrointestinal diets are formulated to be highly digestible and low in fat and fiber. These characteristics minimize the effects of a variety of gastrointestinal diseases, including both acute and chronic conditions.
Hepatic Diets: Hepatic diets are formulated with low copper levels, moderate protein levels, and antioxidants to support liver function. Copper in hepatic diets is minimized for two reasons: some dogs develop liver disease secondary to copper accumulation (caused by a genetic abnormality), while other pets accumulate hepatic copper as a result of liver disease. Reducing dietary copper helps address both of these potential problems and is recommended for all pets with hepatic disease. Protein is limited to moderate levels, in order to minimize the metabolic load on the liver.
Joint Support Diets: As dogs and cats age, they may be diagnosed with osteoarthritis or other joint diseases. Prescription diets contain glucosamine, chondroitin, omega-3 fatty acids, and antioxidants. Glucosamine and chondroitin improve the health of the pet’s cartilage, while omega-3 fatty acids and antioxidants decrease inflammation.
Renal Diets: Prescription renal diets are typically formulated to be calorie-dense, with low levels of protein, phosphorus, and sodium. These diets are also formulated to be rich in antioxidants and omega-3 fatty acids. Caloric density is important to offset the inappetance that is common in renal failure. Reduced protein levels decrease the filtration load on the kidney, reduced phosphorus delays the progression of kidney disease, and reduced sodium decreases the risk of hypertension. Dogs with chronic kidney disease can live for many months (or even years!) with appropriate treatment. Because dogs with kidney disease often have a reduced appetite, it’s important to find a kidney diet that your dog enjoys eating.
Urinary Diets: In general, urinary diets serve two purposes: dissolution (of struvite stones) and prevention. Depending on the food manufacturer, the same diet may be used for both purposes or there may be two separate diets (one for dissolution, one for maintenance). Urinary diets used to address struvite and oxalate stones have low levels of magnesium, phosphorus, and calcium, all of which act as urinary stone precursors. Diets to prevent urate stones are formulated with low protein levels, which is the primary urate precursor. Symptoms of bladder stones in dogs can include bloody urine, straining to urinate, and discomfort. Some types of bladder stones can be dissolved with therapeutic dog foods or medicine, while others need to be physically removed via surgery or other treatments. Dogs who are overweight or obese are at a higher risk for developing certain kinds of bladder stones.
Weight Loss Diets: Like over-the-counter weight loss diets, prescription weight loss diets are formulated with a low calorie content. The primary difference between prescription and over-the-counter weight loss diets, however, lies in the nutrient concentration. If a client reduces the quantity of their pet’s over-the-counter food drastically, to promote weight loss, the pet may experience deficiencies in certain nutrients. Prescription weight loss diets are formulated to provide higher levels of nutrients per calorie, to prevent deficiencies in pets consuming a low number of calories.

Transitioning to a New Diet

If your veterinarian has recommended a therapeutic dog food, your next question is probably how to switch to the new diet. Gradually mix increasing amounts of the new food in with decreasing amounts of your dog’s old diet over a week or two. This gives your dog a chance to get used to the taste of the new food and gives their GI tract time to adapt. But there are times (when you’re dealing with a food allergy or intolerance, for example) when your veterinarian may recommend making a quick transition to a new food, so always follow your vet’s instructions. Therapeutic dog foods can reduce and sometimes even eliminate the need for a dog to be on medications or receive other forms of treatment.

Dispelling Common Myths About Pet Nutrition

Myth 1: "Grain-free food is always healthier." Not necessarily.
Myth 4: "My pet can stay healthy on dry kibble alone." Pets need hydration.

Consulting with a Veterinarian

Even with the best research, nothing replaces expert advice. Your veterinarian can assess your pet’s health, body condition, and nutritional needs. For example, pet owners in Pennsylvania often consult trusted professionals like those at a Southampton veterinary clinic for personalized nutrition plans and dietary recommendations.

Communicating with Your Veterinarian About Diet

When recommending a prescription diet for a pet, take the time to explain the diet to your client. Additionally, provide your client with clear expectations. Is this diet intended for short-term or long-term feeding? Will they see an improvement in clinical signs, or is the diet intended to slow the progression or recurrence of disease? Finally, encourage your client to ask questions. Ask them if they foresee any barriers to transitioning the food or to continuing on the food for as long as the veterinarian says is necessary.

The Importance of a Gradual Transition

Changing your pet’s food abruptly can upset their stomach. Monitor closely: Look for signs of discomfort, diarrhea, or vomiting.

Practical Considerations and Cost

VTD are often perceived as expensive compared to OTC diets. Table 3 shows average costs of therapeutic and OTC diets, based on information obtained via the Internet. Compared with human food packaging, pet food bag and can sizes vary greatly. This variability makes it difficult to compare costs on a “per bag or can” basis. We determined the costs of both VTD and OTC diets on a per 100 kcal basis for comparison, because calories consumed per day is the best common measure across all diets. VTD can be competitively priced when compared per 100 kcal.

When choosing diets to recommend for their patients, practitioners can access the complete nutrient profiles of VTD more easily than for many OTC diets. Caloric density is important in determining accurate feeding plans for pets at risk for becoming overweight/obese. It has been reported that >50% of the US pet population is overweight.8 Prescribing VTD with known kcal/kg density along with exact feeding plans can be used to help prevent excess weight gain in at-risk pets. We recommend owners use a gram scale for weighing canned and dry foods, similar to human weight management plans, to deliver exact daily caloric intake.

tags: #pet #veterinary #diets #explained