I have a 6 year old Retriever/Spaniel mix. He has been on phenobarbital for 3 years now due to cluster seizures that started when he turned 3. He hasn’t had any seizures in about 2 years but the vet (and myself) want him to stay on it just to be safe. He is now showing signs of joint pain in his hind legs. I’ve done the research but can’t come up with an answer as to whether or not it is ok to give him chewable glucosamine tablets while he is on the pheno. Any help would be appreciated!

My mum always gives her springer spaniel Yumove tablets as she is a working dog. These have Green Lipped Mussel and Pure Glucosamine in them, she said i should give them to my Chihuahua as they stop dogs from getting arthritis and other join problems. Is this true and is there any point in me getting these for my dog?
I have the dosage and everything from a vet i know so thats not a problem. will it be ok as he is only a young dog?