Hi, I'm Dr. Deb and I'll do my best to assist you. I'm sorry that it's taken so long for someone to respond to you and I'm sorry for this problem with Dotty.
It sounds like there could be either a medical or a behavioral explanation for the recent change that you describe:
1. I wouldn't expect an infection to trigger her reactions but I have seen some dogs with hypertension behave as you describe. It should be easy enough for your vet to check her blood pressure to determine if it is high. We often either treat with these dogs with Enalapril and/or Amlodipine.
Unfortuantely, primary hypertension is fairly uncommon in dogs; it's usually secondary to some underlying disease such as kidney issues, diabetes, Cushing's disease, hypothyroid disease, cardiac issues among others.
We can treat hypertension with drugs but until and unless the underlying cause is found and treated as well, drugs will only partially help with the problem.
So, if blood work hasn't been done on Dotty, then this is something to consider although I do understand your financial situation may make this difficult to do.
2. When it comes to rescue dogs, they often are damaged in ways that we can't even imagine, which I'm sure you know. And, while it may not always be easy to know what might trigger an anxiety attack, this can be a common phenomenon for some rescue dogs. It doesn't seem logical to us but then fears and anxieties rarely are.
Ways in which you can try to reduce her anxieties might be with products such as DAP which comes in a collar and a diffuser. This is a natural pheremone which is designed to install a sense of calm and reduce anxiety....somewhat similar to Rescue Remdy (although I personally have rarely found this product to be effective).
Simiarly some owners don't find DAP to work either but it should be easy enough to try it and see.
There is a similar oral product called Composure Chews which may also help in reducing anxiety.
A Thundershirt (LINK
) can also help some of these highly anxious dogs. It's available on the internet and in pet stores here in the States.
Some of these dogs actually need anti-anxiety drugs such as Xanax to help with their anxiety issues when they are really intense.
3. She's very young to have something like a brain mass as an explanation for her change in behavior but I include it to be complete ...and not to alarm you.
I hope this helps and that Dotty's anxieties can be reduced or eliminated. I know how distressing this must be for you both.