The strategies of dogs to get food, when an, until then, unknown object hiding the food is used, was taken into account in this study. 16 dogs took part in this study. The food was hidden in three tests by a "Pylon", a "Knepig"TM and a "Klurig"TM (Figures 1-3). Dogs had to scratch the objects in the first 2 tests and pull a wooden stick with their mouth in the third test. Each test was repeated in a series of 5 trials. The dog owner attended the experiment.

	Figure 1. Pylon
	Figure 2. KnepigTM
	Figure 3. KlurigTM

The whole test was videotaped. The main parameters were the preferred strategy and latency of reaching the food, the frequency and duration of looking at and making contact with the experimenter or owner, as well as the frequency of coping strategies. The average latency of reaching the food in the five trials improved from 93 - 7 s. The dogs were not necessarily faster in the last of the five trials. Nevertheless, the correlation between the mean time of reaching the food and the trial number was negative for all three tests; but just for the "Pylon" significant (Spearman, p=-1.0, P<0.000). Sniffing at the experimenter hands was shown by the dogs in each trial once. The frequency of looking at and making contact with the experimenter was exhibited significantly different by the dogs among the tests (Friedman, P<0.05). On average the dogs made contact with the experimenter 0.33 - 2 times in the trials. The duration of looking at and making contact with the experimenter varied from 0.52 - 7.57 s. The longer the whole experiment went on, the more direct contact the dogs tried to make with their owners. Blinking and licking of the own nose and mouth were behaviour patterns which the dogs displayed only in interaction with the experimenter or owner. Sniffing and looking around as less effective problem-solving abilities reached from 4.67 - 0.33 times with an average duration from 0.81 - 16.72 s in the single tests. The dog owner attendance was chosen in dependence on the need of dogs to look at their owners when they encounter difficulties. Positive affiliation behaviour with the experimenter was mainly displayed by the dogs because the owner was sitting passively on a chair. Dogs which were able to solve all three hidden food tasks rapidly have excellent relearning abilities and a high frustration tolerance level.