Stirling Products, a public animal health company that is developing patented applications in the area of animal growth agents that increase meat production, announced that it has received notice that its patent application for “Methods of decreasing fat deposits and body weight in mammals and birds” has been granted in New Zealand.


Patent applications have been filed in a number of different countries; this represents the first successful approval. The patent relates to the use of Stirling’s R-salbutamol compound and its potential application for reducing body weight in companion animals (dogs, cats and horses) and also in humans.

Dr Calvin London, CEO and Managing Director of Stirling Products said, “It is always good to get the initial validation that a patent application has been successful. We hope that this will be the start of a series of approvals in other countries where we have filed similar patent applications”.

Stirling has already conducted proof of concept studies on the compound for this application in laboratory models known as obese male Zucker rats (specifically bred to be overweight) and more recently conducted trials in the United States on obese dogs. These studies indicated that not only did R-salbutamol have the ability to reduce body weight, it also had an excellent safety profile which is of great importance in regulatory and consumer approval of obesity treatments. The initial trials in obese male Zucker rats, demonstrated that when obese male Zucker rats received either 1.25 mg or 2.5 mg of R-salbutamol, there was a significant reduction in weight gain; 57% and 79% respectively compared to the controls over a two week period.

In a later study, it was demonstrated in a number of trials that R-salbutamol, when administered orally to overweight beagle dogs at a dose of 0.08 mg/kg, produced no visible clinically significant side-effects and weight loss in the order of 2-3% over a week was achieved.

The patent approval also provides Stirling with a renewed opportunity to find technical or commercial licensing partners for the application of R-salbutamol in the treatment of human obesity. R-salbutamol is already prescribed to several million patients for the treatment of asthma and while the mechanism of action is different (not all asthmatics are thin); Stirling believes that the clinical experience supports the excellent safety profile of the compound.

The American Veterinary Medical Association estimates that 48 million of the total population of dogs in the United Sates (35%) are considered to be overweight or obese. Surveys in Europe and Australia reflect similar levels of obesity and a recent survey in the United Kingdom indicated that 8 out of 10 vets are seeing an increased number of obese animals. As in humans, a number of secondary disorders are associated with obesity that lead to diabetes, cardiovascular problems, respiratory disorders and orthopaedic disorders. The market for the treatment of obese dogs is valued in excess of US$500 million per annum and for humans, is at least 3 times that figure.