A new study published in the June 15 edition of the Journal of the American Veterinary Medical Association compared 15 commercial dog milk replacers to genuine dog milk.

According to researchers, some of the imitators come closer to mimicking the real thing than others, however all could stand to have their formulas tweaked.

In the study, researchers tested 15 samples of dog milk replacers - seven liquid and eight powdered products - against five samples of real dog milk. They sought to compare the essential nutrient composition of products available in the United States to that of dog milk. 

Researchers analyzed the real and imitation dog milk to gauge concentrations of total protein, essential amino acids, sugars, total fat, essential fatty acids, calcium, and phosphorus, and also calculated energy density of each sample. They then compared the results from the milk replacers to milk samples from mature dogs as well as National Research Council (NRC) recommendations for puppy growth.

Wide variety of nutritional content

Researchers found that not all dog milk replacers are created equal, with some products containing healthier levels of macronutrients and mineral concentrations than others. 

Among their findings from analyzing the products:

• None of the 15 milk replacers could match dog milk in terms of nutritional content, researchers said. In fact, none of the milk replacers contained all essential nutrients within the range of the dog milk samples.
• Only three of 15 milk replacers contained gross energy within the range of the five dog milk samples.
• Two milk replacers had lactose concentrations that were 289 percent and 193 percent greater than the highest concentration in the dog milk samples.
• Eleven milk replacers had calcium-to-phosphorus concentrations less than the range for dog milk, and nine had ratios less than the minimum appropriate ratio for growth of dogs.
• Only three milk replacer products contained detectable concentrations of both EPA and DHA, and of those, only one had concentrations within or higher than the range in dog milk.

The authors also identified some concerns with product labeling on milk replacers that could potentially cause puppies to receive inadequate nutrition during the critical first weeks of life.

"Especially for novice puppy raisers, adherence to the feeding directions for some of the products could easily lead to substantial over- or underfeeding," the study's authors wrote. "Compounding the issue is that even though several package directions recommend weighing the puppies regularly, none provide guidelines on appropriate rates of weight gain to ensure adequate intake."

Room for improvement in all products

"Nearly all products would benefit from more appropriate calcium, amino acids, and essential fatty acids concentrations and better feeding directions," researchers concluded in the published study.

The study authors recommended additional research to determine the appropriate nutrient requirements and ideal nutrient composition of milk replacers for young puppies, considering that the proper nutrient requirements for puppies between birth and four weeks of age are currently unknown.

In addition, researchers said that because of the vast differences between milk replacer products currently on the market, the milk replacers should feature more clearly defined nutritional adequacy standards to allow education on product use.

Read the full study

Read the full study at the JAVMA website.