"Happy" is not happy anymore.

No energy, don't chase the garbage collectors, just lift up his head when there is a territorial fight, etc etc.

I don't know his age so maybe he is just getting old.

Deworming any dog is doing it a favour. From the sound of your post, though, there may be something more radical wrong with him.

Deworming any dog is doing it a favour. From the sound of your post, though, there may be something more radical wrong with him.

+1

Blood parasites cause lethargy and general malaise. Worthwhile talking to a vet or Dog Rescue about giving a course of appropriate treatment - cheap and effective if started early enough. Treated the soi dog outside our office this way as impossible to take him to the vet. If it is blood parasites dog will get progressively more anaemic (pale gums a tell tale sign) and disease is ultimately fatal.

Deworming any dog is doing it a favour.

I don't agree here.

Deworming a dog that has a worm infestation is doing a dog a favor.

Deworming a dog that does not have worms is NOT doing a dog a favor.

Better is to take a feces sample and have it checked before sticking a pill in his mouth.

From the sound of your post, though, there may be something more radical wrong with him.

I do agree here. Same as Bluebell advices: better to bring the dog to a vet and have it checked: blood, liver, kidney, snap test, feces, and maybe urine as well.

Yes, Nienke, in the best of all possible worlds. But OP was talking about a soi dog and, while he's obviously prepared to take some trouble for it, taking it to a vet and having all these tests done is, frankly, pie in the sky.

Most vets here seem to give a worm pill as routine for any dog, and with a soi dog, the chance that it does NOT have worms is minimal.

My apologies for contradicting you; I admire the trouble you take for dogs... and I wish we had more people like you.

I dewormed him and now "happy" is happy again.

Three fights today to show his dominance in the pack.

The other dogs had started to get cocky.

It's hard to get "happy" to see a vet, refuses to be put on leech or getting into a car.

Although he accepts the tick/flee collar.

....

But OP was talking about a soi dog and, while he's obviously prepared to take some trouble for it, taking it to a vet and having all these tests done is, frankly, pie in the sky.

Most vets here seem to give a worm pill as routine for any dog, and with a soi dog, the chance that it does NOT have worms is minimal. ..

Agreed 100%, IB. These things are fine with "personal" dogs, but they are not only expensive (one snap test alone is around 1,000 baht) but if positive require a series of follow up injections and daily medication which is often simply impractical if not impossible, however desirable it may be.

I'd support de-worming for any soi dog under these circumstances, as I would a rabies injection.