Wow I mean I have never personally heard of this kind of behavior.
I mean to be frank, I have known a lot of teenage girls who have experienced far worst than a dog dying, and nearly have an accident on a bike?
I would go as far as to say the symptoms personally seem to be bizarre, I have never really heard of those type of symptoms in reaction to some moderately upsetting events.
Definitely only a professional is going to be able to help with this, but if these sort of symptoms are persistent, it sounds very serious to me.
Well, this is just my opinion - I'm not in the medical field.
I believe Conversion disorder is a common symptom of severe anxiety. It's a symptom, in my opinion, not really a "thing" by itself. It is an outward manifestation of chronic anxiety. And then when an incident happens, like the dog being killed by coyotes, that tipped her over until she could no longer handle her chronic anxiety and it "boiled over" into physical symptoms.
Chronic anxiety can also be the cause of major depression - you might want to google "adrenal fatigue".
This may be the case with your daughter (I don't know her - she may have in fact, been very happy-go-lucky and at ease before her dog was killed.
If not - if she has a history of being an anxious child, I would talk to her doctor about the possibility of treating her with anti-anxiety meds, instead of meds for depression that can worsen anxiety.
Best wishes. This must be very hard to watch.
In order to give you the best feedback possible- may I ask how old your daughter is? :)