Best alternative to Advocate please

[DancingDucks]

My lab has always had Advocate but the last time I gave it to him he seemed to have a terrible reaction to it. He cried for two days and was so out of sorts. Vet has suggested trying again in case it was a one off but I'm really not keen - he's an old man of 12 now, deaf and has arthritis and I really don't want to stress him out. He has drontal too, which he never has any issues with. Any suggestions please?

Bravecto is our go to.

I test for worms. You can buy test kits online, Wormcount for instance.
And I use Billy No Mates for fleas and ticks. And Biospotix in summer.

We only use organic methods now and I am going to do a worm test. These medications are toxic to dogs and the environment.

Bravecto

My Lab has had Simparico Trio monthly, since he was very young, and Droncit quarterly. Spaniel has Milpro monthly and a Seresto collar for fleas and ticks.