She certainly looks bothered by something in the video. Does she ever stop moving her neck about? If you suspect wry neck, most people use human vitamin E 400 IU daily, plus a small amount of B complex for thiamine, and a few bits of scrambled egg for selenium. I would try getting the lice off...
Does she have symptoms of wry neck? Wry neck can be a problem if there is a head injury, vitamin E deficiency, frommheredity, or can happen with certain infectious diseases. What are you doing for the lice? Permethrin garden dust or the spray is good, but I‘m not sure that you can get it in Canada.