Hello, I'm Dr. Deb.
I recently came online and see that your question about Robbie hasn't been answered. I'm so sorry that you've had to wait for a response, but if you still need assistance, I'd like to help if I can.
There are any number of reasons why a dog this age might pant but it's at a very specific time, especially at night, then the first condition I'd consider would be Sundowner's Syndrome as is seen with Cognitive Dysfunction (CD) aka Doggy Alzheimer's. This is a poorly understood phenomenon in dogs but we do recognize that they can develop it. I think it may reflect confusion on their part but I can't know for sure.
Some patients will show other signs during the day such as staring off into space or acting confused or wandering/pacing but some will only show signs at night.
This is a difficult diagnosis to make; however, when a dog's behavior is consistent with it, then I tend to suggest various treatment options such as I'll list below. All of the supplements that I've listed should be available on the internet.
Since we often do not know which neurotransmitters or neuro-pathways are most affected by CD in each patient, a better response may be seen in our pets if a combination of several supplements and drugs are given as opposed to only one or two. This sort of combination can help to improve the level of neurotransmitters in the Central Nervous System (CNS) and reduce oxidative damage to brain tissue.
There are other modifications which can be made to lifestyle which may be beneficial which I’ve included below as well.
1. Cognitive supplements such as Neutricks, or Senilife
2. Combination of antioxidants such as Golden Years (Sogeval) , Antiox 5000 Ultra (Sovegal), Cell Advance 440 for small and medium sized dogs (Vetriscience)
3. Anti-inflammatory agents such as high dose fish oils (DHA> 300mg… not the total mg on the capsule but the DHA content).
4. Over the counter, human Melatonin which can be especially helpful if sleep issues are present but it also has antioxidant properties. 1-3 mg before bedtime. Just double check the label to ensure that it doesn't contain Xylitol since this can be toxic to dogs even in small amounts.
5. CNS stimulants such as Selegiline 5-10mg/day which is a drug licensed for use in CD but would have to be prescribed by your vet.
6. Consider a prescription diet such as Hills' B/D diet or Purina senior diet with MCT oil. There’s some evidence that calorie restriction can help some dogs with CD so reduce calorie intake.
7. Evidence exists that daily and sustained exercise has positive effects in reducing progression of CD. Exercise daily: 1/2-1 hour walk twice daily
8. Sensory stimulation such as touching, brushing, and massage therapy may also reduce progression of CD.
There are always other supplements which can be added; however, patient compliance may become an issue at some point. But, others to consider would be:
a. medium chain triglycerides i.e., unprocessed coconut oil. 1-2 tsp/day
b. SAMe manufactured by Virbac aka Novifit
I hope this helps although, again, my profuse apologies for the delayed reply. Deb