Oral consumption of Pep19™, a 10 amino acid intracellular peptide, has been associated with weight loss in rodents and humans via induction of nonshivering thermogenesis. This study aimed to test its safety and tolerance in dogs. Eight healthy adult neutered university owned beagles (4 female and 4 male) were individually housed in runs and fed an extruded kibble in a quantity historically associated with weight stability. They were administered Pep19™ (5 mg/dog/day, 0.32 – 0.49 mg/kg/day) as a once daily oral dose for 28 days. Health screening, including physical examination, body weight, body condition score (BCS), complete blood count, chemistry, total thyroxine, thyroid stimulating hormone, and urinalysis were collected at baseline, day 14, and day 28. Faecal score, appetite, and overall animal temperament and condition were assessed daily. At baseline, average age, weight, and BCS were 3.8 ± 0.3 years, 12.68 ± 2.11 kg, and 6.4 ± 0.7/9, respectively. There were no adverse effects and all blood and urine analyses remained normal. At study termination, average weight, and body condition score (BCS) were 12.53 ± 2.01 kg, and 5.6 ± 0.7/9, respectively. Despite no changes in diet or calorie intake, seven of the dogs lost between 0.7% and 3.8% of their body weight (p<0.01); this was associated with a reduction in body condition score (p<0.05). This initial study shows that Pep19™ is safe for dogs. Future clinical research should investigate its utility as a new approach to reduce excess body fat in dogs.