Hello and welcome to Just Answer. I am a licensed veterinarian and would be happy to answer your questions.
Has the vet checked any bloodwork or urine from her recently?
In between these episodes, is she normal? responsive?
No bloodwork or urine work on Saturday (the post-lost dog check up), but bloodwork, etc. after vestibular episode was normal.
The behavior began Monday afternoon and continued until she wandered away and was lost Monday evening. When we found her again Friday morning, she was exhausted, ate and drank ravenously and slept all day long. Between infrequent sleeping, she is awake, frantic, panicky, drooling, shaking, urinating in house, panting, pacing, disoriented. She is "responsive" in that she recognizes me but she remains focused on her missive of panting, pacing, etc.. My presence provides her small relief, but shee seems grateful I am weathering the storm with her, in that she prefers to be frantic in my company rather than alone. PS - she is stone deaf and has been since she was little.
Her symptoms are very suspicious of a condition called cognitive dysfunction syndrome. It is a condition that we see in older dogs with signs that vary from dog to dog. For lack of a better comparison, it is similar to Alzheimer's disease in humans. IN the early stages, the signs can be difficult to recognize, but as it progresses, is usually much more obvious.
I am including an information sheet about it for you as well as a checklist for you to use with your veterinarian.
CDS checklist - this is a checklist used to help owners chart the progress of treatment if they treat with meds, but it does list of the signs.
maturedogs.com - This is also a website devoted to older dogs and has a whole section about CDS.
Here are some of the most common signs seen, but there are many others as well:
general confusion - your pet doesn't greet or seem to recognize you as before, your pet gets 'lost' in the yard or house
inappropriate vocalization - barking or meowing in the middle of the night, or for no 'good' reason? (I know, some dogs don't need a reason to bark.)
getting day and night mixed up - sleeping all day, awake all night?
confusing indoor and outdoor - a previously housebroken pet soiling in the house?
personality changes - i.e. a formerly outgoing pet becoming timid or aggressive?
I have seen a good number of dogs affected by this and all have exhibited different signs, especially in the early stages. Some dogs I have seen have responded to diet change alone. Hill's b/d diet is a good choice. If not, the medication called Anipryl® is very effective for many dogs.
I generally start with the supplements first (+/- diet change to b/d if there are no other dietary restrictions needed). I usually recommend increasing the omega 3's in the diet as well. The active ingredient of fish oil is EPA (Eicosapentaenoic Acid) and DHA (Docosahexaenoic Acid). You just want to make sure you are seeing those on the label as an ingredient and not just the words "fish oil" as these are the important part of the fish oil and not all fish oil capsules have them in it, especially the cheaper ones. Aim for 180mg EPA and 120 mg DHA per 10 lbs body weight daily. There is a large range of safety and it doesn't have to be that amount exactly but this gives you some guidelines.
There are various additional supplements on the market to help with brain health. The three most readily available are: Cholidin, Senilife and Novifit. As far as which supplement to try first, I do not think there is any general agreement on that. Between the cholidin, senilife, and novifit I would make my decisions on which to use based on cost, ease of administration and availability. I do not see a problem with using them all if cost is not an issue and you have a dog who doesn't mind taking oral supplements. There may be more benefit to starting with multiple approaches for a greater combined effect and backing off to a minimum effective combination if you get a favorable response. It is not always easy to track response as the symptoms can be variable and intermittent.
I would add the Anipryl if needed for better effect or as the cognitive dysfunction progresses. No treatment is immediate and so you need to give it a little time to evaluate the response.
I hope that helps. Please let me know if you have any further questions.
In my experience with treating this condition, when a dog responded, usually all of the symptoms improved to some degree. They seemed more alert/aware, less forgetful, less agitated, etc. Sometimes the changes were more gradual, over a few weeks, but if there was a response usually by 2-3 weeks, the owner would definitely see some degree of improvement (that is where the checklist helps). Unfortunately, even if they respond, the condition does seem to progress in time and they will likely return at some point.
Because her symptoms seem more severe than some other dogs I have seen, I would be tempted to go right to the anipryl and/or b/d diet versus starting with just the supplements. I see no problem with starting all at once to give her the best shot at response.