Forensic investigations in a case of aggressive behavior of three dogs: Identification of dietary supplements contamination by metandienone and confirmation by hair tests

After observing a modification in behavior of his three dogs, an owner consulted a laboratory to determine if a drug could be involved. Hair strands of each animal were collected from the neck area and sent to the laboratory for anabolic steroid screening. Initial screening by liquid chromatography coupled to high-resolution mass spectrometry identified the presence of metandienone, an anabolic androgenic steroid, in all three samples. In order to quantify metandienone in hair, a specific method was developed using a liquid chromatography to tandem mass spectrometry system. In addition, sixteen animal pharmaceutical products and food supplements that the dogs had received were tested for a possible source of contamination.The hair specimens of the dogs tested positive for metandienone at 42, 13 and 32 pg/mg. Final interpretation of these concentrations was difficult as there is no data about metandienone detection in hair collected from dogs. Analysis of the animal pharmaceutical and food supplements demonstrated the presence of metandienone in two supplements, with amounts at 25 and 452 ng/g.Simultaneous analyses of the hair of the dogs and their supplements enabled to make an association with the observed aggressive behavior in the dogs. Testing for anabolic steroids in the hair of the dog in case of aggressiveness can be useful to help to understand an unexpected behavior in dogs.