This potion will grant you Telepathy for some time. A message will appear: "You sense a ...", usually starting with the nearest creature, including your pet.
Even after the time of the potion has expired, you will be able to sense the creatures that you sensed when drinking the potion. So, your pet(s) will be sensed for a seemingly never ending amount of time. However, if the pet(s) gain a level, the effect(s) will disappear.