I'm afraid to give Hydrocotyle just now since I believe it has a strong influence on the Hypothalamus and may have caused the aggression-aggravation in Gunda. Better to give remedies that will tone down his nerves right now - and for all of them.
I tried the snake and Spider poisons on my ravaged hand and was pleasantly surprised to see Spider being drawn. Lactrodectus 30 especially was drawn by both my hand and Kenchu. Aranea too, but not as much. I'll get back to Lactro. soon, but I read up the more frequently used Aranea for the dogs.
Because of it, I've settled on wet weather aggravation neural remedies. No need to work on the brain-spine so much just yet. I'm also continuing with the flower essence combo of Holly, Vine, Beech and Cherry Plum. I see no change in his behaviour to the other dogs.
Nash mentions wet weather list -- Aranea, Nat Sulph, Dulc, Nux mos, Rhus tox, Rhod.
From my experience, Rhod is wonderful before the wet season begins but Rhod increases the fits given late in the wet season.
Dogs don't draw Rhus often - I hardly know when to use that remedy because it is so rarely in tune with them. I like what I read about Nux mos but they don't draw it either. Dulc led to a massive aggravation in a previous set of dogs and I'm wary of it - never used it since.
Nat sulph I have had success with on and off but no cure. They draw it very high, 10m - cm but I can't see any positive changes when I've given it. Maybe I'll keep it in mind to try later - it could be useful in a specific period of the wet season.
I've only never tried Aranea. I've given it to them in 30 and I've seen a short aggravation (30 mins or so) in all of them including Gunda - an increase of irritability before they settle down. Fingers crossed that I get good results from this change!
I've had two aggravations from the Aranea - one is a kind of pain around my heart, the second is a frequent desire to pee. The dogs are all sleeping well.