Many philosophers and some behavior scientists believe dogs do not have episodic memory, therefore, they cannot successfully serve and assist people with failing memory.
There are many types of memory so psychologists, who wished to understand this belief, divided memory into large groupings call “explicit” memories which are ones that can be described or called into mind at will and “implicit” memories are automatic and not really conscious such as learned skills.  An example of implicit memory is riding a bicycle; though you can remember how to ride it and can easily do it, trying to describe to someone else how to stay upright on the bike is impossible.
Explicit memories are easily brought into consciousness and described verbally.  These memories come in two varieties, “episodic” and “semantic”.  Episodic memory is for what you have experienced personally such as recalling what you ate for lunch, what clothes you wore yesterday or describing a first date.  Semantic memory involves memory for facts such as “Who was Abraham Lincoln?” or “What is the climate like on Mars?”  Episodic memory is based on only once in your life events and are not practiced or repeated.  Episodic memory contains specific data about “when”, “what” and “where”.
Many dog owners have a variety of “Find the object” phrases such as “Where is your toy?” or “Where is your Daddy?” to which their dog responds by dashing to find the object and bringing it back or locating the family member in question.  These are instances of episodic memory as the dog must remember where he saw the item last.  This memory has the required components of “when”, “what”, and “where” since the dog is being asked to locate a particular object based on when it was most recently seen in the dog’s personal experience.
For those suffering the absence of short-term memory, performing simple tasks become nightmares.  This is when the episodic memory ability of dogs becomes important.  A short-term memory sufferer can confidently go shopping with their memory aid dog and not have to worry about forgetting where they parked the car.  The memory assistance dog will lead his master back to the places that he can’t remember like the exit from a building or where his owner has parked his car.
Those suffering from short-term memory loss depend heavily on their memory assistance dogs.  It is the dog’s episodic memory which serves as a substitute for the episodic memories his master has difficulty retrieving.  It would be interesting to hear what these nay-saying philosophers and animal behaviorists might have to say about this.