Nutritional assessment for dogs and cats — why it's so important

By placing an emphasis on nutrition during examination, it is possible that fewer pets will be subjected to invasive diagnostic procedures and illnesses requiring drug therapy.

Nutrition has long been recognized as an important part of the overall clinical assessment of both healthy and sick pets. In veterinary colleges, students taking nutritional courses are taught the intrinsic value of a healthy diet and how to take a nutritional history during a routine examination. Clinicians are also acutely aware of the importance of nutrition in companion animal health.

Despite this seemingly inherent understanding, medical records often reflect a different scenario. For example, at the Western College of Veterinary Medicine (WCVM), from October 2012 to October 2013, only 1.5% of case records included diet as part of the patient history, and only 0.4% of the cases mentioned nutrition in the plan or assessment.

As a profession, we have already acknowledged the importance of nutrition in contributing to the well being of a client’s pet over his lifetime, yet the statistics clearly illustrate that formal dietary records are not being kept on all patients, whether for wellness or illness. In a small veterinary practice, where a veterinarian becomes familiar with his clients’ pets, records are ideal but perhaps not necessary due to the often uninterrupted continuation of care. In a large practice, or in an academic institution, where this type of relationship does not exist, these records are essential for continuity and patient well being.

Without any record of what pets are currently being fed, or a record of veterinary recommendations, it is nearly impossible to critically track and evaluate the impact of nutrition on ongoing changes in health. Many retrospective nutritional research studies also rely on this information, and because of a lack of records, owner recall is often relied upon.

Where to begin – each patient is an individual

Each assessment is as unique as the owner and the individual pet, and needs to include the owner’s level of nutritional knowledge, lifestyle, age, family size, income, and the number of pets in the house. Also needed is information on the pet, including current health, past medical history, breed, gender, age, level of activity and temperament.

Always have the owner bring in plastic bags containing the amount of food and treats they are giving their pet each day, along with labels from these products. From this information, you can determine if the client is overfeeding or underfeeding. If diets are freshly prepared, have the client bring in an example of one day’s diet, and a log of what was fed for the week, including treats. You can educate your client on how to interpret labels and evaluate the ingredients. You can also help her determine the cost of feeding the pet per day. All this takes time, but if done properly on the first visit, the client will know what you need and will be educated and prepared for the next visit. Training your animal health technician to do much of the initial data collection can help you in your assessment and allow you to work with more clients.

Ancillary testing

Experienced veterinarians may use blood, saliva or hair to get a better understanding of the nutritional status of a pet. I personally would not use these tests on the initial assessment unless you’re dealing with a growing puppy with developmental orthopedic disease, or a dog with health problems related to nutrition or responsive to dietary changes such as allergies, diabetes, obesity and/or renal, hepatic or heart disease.

1. Blood tests

A routine CBC and chemistry panel can give you some information, especially if you are monitoring a pet’s response to a therapeutic diet. You may want to include a trace mineral panel as well. Specialized blood samples that measure vitamins and hormones will likely be done on an individual basis. Inflammation can alter the values, causing plasma iron, zinc and vitamin A to drop, and plasma copper to increase. Low red counts can be associated with chronic infections. Dogs on raw meat diets will have increased blood urea nitrogen (see sidebar on page 20). Growing puppies will have a higher level of plasma phosphorus than calcium until their growth plates close, as the level of phosphorus in the blood is highly correlated to growth hormone levels.

2. Saliva tests

Saliva tests are non-invasive and can be used to monitor hormone changes, keeping in mind that saliva is different for each species. The most useful saliva test measures the IgA and IgM to determine food allergies (Hemopet).

3. Hair samples

Hair samples are used to investigate the presence of trace elements and toxic metals. They also can give you a time estimate of when ingestion occurred and whether it is ongoing. For best results, I recommend you contact the laboratory that analyzes the hair and ask how to take a hair sample and from how many sites on the body. You must determine whether you require hair that is mature or growing.

The type of hair coat can influence the results, and the sample must be prepared properly to avoid external contamination. Because of breed and environmental variability, an appropriate reference standard must be used. Shedding, stage of growth, surface contamination and over-processing of the hair can lead to errors.

Diet analysis

Any homemade diet should have its nutrient content analyzed to assure there are no imbalances, deficiencies or excesses. This should be done in a recognized feed testing laboratory, either human or animal. If your client changes ingredients or ingredient sources, the analysis should be repeated. Depending on the season of the year, the soil’s nutrient composition can change, thus altering the nutrient composition of the plant material used. The season can also influence the nutrient composition of organ meats. When purchasing alternative diets (such as raw frozen or dehydrated), make sure the company has done validated nutrient analysis on all their products. This website lists all the AAFCO-approved feed testing laboratories worldwide:

Assessing foods

Veterinarians must be familiar with the commercial food industry, how ingredients are sourced and processed, and their composition. This is necessary in order to match the claims made by the company to the quality of their ingredients. The research must be transparent and valid, and support the claims. Veterinary therapeutic diets should stand out as superior in every respect, when compared to over-the-counter diets. In the case of homemade and packaged fresh food diets (frozen and dehydrated), ingredient sources, preparation, freshness and appropriate formulations must be investigated. Each diet should be species and metabolically appropriate. The veterinarian has a significant responsibility to independently evaluate the diets in order to separate fact from fiction, and eliminate any bias.

The meaning of “complete and balanced”

“Complete and balanced” is an industry term that has more to do with marketing than nutrition. The term suggests there is a strict standard governing the nutrient content of pet foods. But it simply means the diet has met AAFCO’s minimum nutrient standards for growth, gestation, lactation or maintenance, and/or has passed AAFCO’s feeding trials, which are minimal at best. “Balanced over time” is a term used by proponents of alternative diets, which mimic our own diets. Nutrient requirements are not static and vary with age, level of activity, season of the year, stressors, and a host of other factors that render the term “complete and balanced” meaningless.

Considering obesity

According to the Association for Pet Obesity Prevention, which surveys veterinarians on an annual basis, US pet obesity rates continue to increase. In 2012, the number of overweight cats reached an all-time high, with 58.3% considered overweight to obese by their veterinarians. The same survey found that 52.5% of dogs are overweight or obese.1 In most practices, an overweight animal is automatically a candidate for a special diet. But is this the right solution? Looking at several weight loss diets, we see a wide range of protein percentages, while fat and carbohydrate ranges are more consistent. Each of these diets may achieve its goal – but so might the dog’s regular diet plus exercise. The veterinarian must be aware of this since many clients are leaning to read labels. Veterinarians independently trained in nutrition are aware of the pathophysiology and the reasons for obesity, and could formulate or recommend a healthier, whole food diet.

In summary

By placing an emphasis on nutrition during examination, it is possible that fewer pets will be subjected to invasive diagnostic procedures and illnesses requiring drug therapy. Nutrition is the key to maximizing health. Embracing nutrition as a valuable diagnostic tool provides a lower-cost, yet effective, first line of treatment. Use saliva, blood and hair analysis when needed to assess the nutritional needs of each patient. Finally, select the best diet from the many choices you have investigated and chosen as possible sources of good nutrition.