Evaluation of selected categories of pet treats using in vitro assay and texture analysis

Treats are important contributors to the economics of the U.S. pet product industry. Not only do pet owners use them to build an emotional bond or interact with their pets, but treats also can deliver functional or health benefits. The objective of this study was to evaluate the digestion and safety of selected commercial treats by measuring their in vitro dry matter disappearance (DMD) using the modified in vitro method of Boisen and Eggum, which was developed to simulate in vivo digestibility of nonruminant animals. Twenty-five commercial treats were classified into six categories based on their appearance, size, and functionality. These categories included biscuit, chew, dental, meat product, rawhide, and cat treat. Each commercial product was analyzed in triplicate and in vitro DMD was calculated after enzymatic digestion and incubation. A wide variation in DMD was observed among and within different treat categories in both gastric and gastric + small intestinal phases of digestion. For the gastric phase, DMD ranged from 8.40% to 92.20%, whereas intestinal phase digestion had a DMD range of 35.10-100% (P < 0.05). In general, treats from meat products, dental, chew, biscuit, and cat treat categories had a high DMD (>85%) after the intestinal phase, whereas DMD of rawhide treats varied from 35.10% to 95.70%. Principal component analysis, in addition, has visually shown that rawhide treats displayed the largest portion of variation from the other treats. A low DMD at gastric phase is a concern because it may pose a risk for gastrointestinal blockage and intolerance, particularly for treats of large size that remained intact during this phase. In vitro DMD results can be used as a potential predictor of in vivo digestibility, facilitate recommendations about pet treat safety for professionals and manufacturers in the pet industry, and assist pet owners in the treat selection process and with treat purchasing decisions.