Arthritis and Elbow Dysplasia

Hi, wondering it anyone can help me? My 7 year old labrador has arthritis and elbow dysplasia. He was diagnosed 2 and half years ago. Since then been on all kinds of medication etc. He is currently on gabapentin, onsoir, memantine and paracetamol. 2 days ago he wouldn't put weight on his front right leg however went to bed and woke up fine. Yesterday he woke up and refused to put weight on it again and wouldn't walk at all. We took him the vet where outside he walked about (as best as he could) but still not really putting weight on the leg. We were not allowed in with him due to covid so vet called and explained they could give him some kind of opioid injection into muscle and just said he may be a little sleepy etc. We agreed for this to go ahead. We brought him home at 12.30pm yesterday and since then he has been distressed, vocalising his discomfort and really not himself. We did take him back to emergency vet at 7.30pm who explained that a painkiller like that can have side effects like seeing 'pink elephants' and his stats were fine so we agreed to take him home and try settle him. I have to add he wasn't vocalising any pain before he went the vets but hasn't stopped since. Yesterday his back legs also looked shaky which seems to have gotten better today buy I feel like the drug he had must have effected his whole body. My question is would side effects of a drug like this mean he would be this distressed and last for this long 18 hours +? He is exhausted but hasn't gotten a break so far. I don't feel like I was properly informed of the implications when the vet mentioned it. I will be calling them this morning to discuss this. Thanks and I appreciate any feedback.

Hello! - and I'm sorry that your labrador is having such a a grim time of it.  It sounds as if there has been some kind of acute injury over the top of his pre-existing chronic complaint.  I'm afraid you haven't told me what the drug was, so I am unable to list side effects, although it is possible that something like low-dose Ketamine may have been used, which can have that sort of effect in some dogs.  In any case, it sounds as though the drug combination isn't having the desired effect and most such injections would have worn off by now.  Your dog still sounds to be in pain so it would make sense to call your own vet if possible, or if not the emergency folk, and find out what they feel the next logical step to be.  Best of luck.

On re-reading I see that you have probably already been to the vets, so hopefully things are better now?  There are many different pain-killing combinations;  if one doesn't work, another will often succeed.  It may also be necessary to review the underlying complaint. Please do let us know how you got on.