Animaloid companion robots represent a very interesting paradigm. An increasing number of studies on this topic has been carried out in the past, involving such robots and older users affected by some kind of cognitive disease, from mild cognitive impairment (MCI) to more severe stages of Alzheimer's disease and other types of dementia. In the study described in this paper, an AIBO robotic dog was programmed and used to show simple reactive behaviors during the interaction with old adults. Experimental sessions were carried out with a group of 24 older subjects with cognitive deficits of relatively small entity (MMSE>23). Preliminary results seem to show the acceptability of this approach especially in subjects with a good relationship with technology. In the next future, the interaction between the robot and the old adults will be tested in more complex situations.