The "drunk" walk and "extra tired/depressed" symptons popped right out at me. I don't want jump to conclusions or come off as the whacked out over reactive griever on the boards but that is how Bruno acted Sunday and I lost him on Monday. I don't have the knowledge that everyone else on here has; only my recent experience.

Lori,
I know, it's very scary for me too because my last dog died of brain cancer. But the symptoms are different in that she's improving (rather than declining). She's now exhibiting normal energy levels (which are high), wants to play, and the eye movements are almost stopped or hardly noticeable.
A friend mentioned a toxicity to Advantix. A quick online search found lots of similar stories- but online sources are often sketchy. I put Advantix on both dogs on March 18. If I think back I may have noticed a slight decline in her after the original application, but I can't be sure on that.
Regardless of what caused the original and lingering symptoms, I am thrilled to see her waiting to greet me at the door when I come home with a wagging tail, and a happy grin despite the head tilt, and the continuing (but not nearly as severe) balance issues.
Lots of water and good food and attention. She's soaking it up.

Kiersten,

Good, I'm really happy to hear she is improving

Just an update.
Tessa's titer for erhlichia and Rocky Mountain Spotted fever were the highest our vet has ever seen. Both these diseases (tick borne) can cause nuerological signs. Both are treated with doxycycline.
She's on doxy now, and is doing quite well- very energetic, happy, alert and almost normal, except for a slight head tilt. I am so relieved, though I'll need to stay on top of the treatment protocol and probably run another titer in another few months.
The vet also recommended I get tested as well since my dogs and I were in the same areas, and we all encountered numerous ticks.
My other dog only has a low titer for Rocky Mountain.
Just a heads up for those of you in tick areas. Something to be aware of.

I myself had a tick thing about 2 years ago.
Suddenly I was exhausted all the time, my joints were sort of achy-especially knees.
Then I developed a cough, a productive cough. I thought,"this is IT, lung cancer" but it was anaplasmosis.

The knees never became 100% again. I did recall pulling a tick off in the shower about a month before I finally went to seek help

I just finished up the 6th week of doxycycline on Tuesday. Tessa slows down a bit in the heat, but today she was racing after my husky like she used to, and seems alert, energetic, and back to normal. If I pay close attention, I may notice a bit of a head tilt, but that seems to be gradually fading. Maybe a bit less agile and balance than before. The nystagmus was gone a few days after it started. I looked up Rocky Mountain Fever online and found quite a few scientific papers that included 'vestibular ataxia' as a symptom:
http://www.vet.uga.edu/vpp/clerk/otis/ (basic info)
http://www.ncbi.nlm.nih.gov/pubmed/11204476 (just the abstract- but I like the 100% survival rate)
http://www.cfsph.iastate.edu/Factsheets/pdfs/RMSF.pdf (by far the best and most complete article. Scroll down for animal information. For those of us with shepherds it states this breed is more likely to develop a severe infection).

I'm posting this update partly to warn people, and partly to ask what more I should or can do at this point. It sounds like it will be a slower timeline for 100% recovery (and may never happen), but given her improvement at this point, her young age, and her otherwise great health, I am optimistic we have a chance. Are there supplements you'd recommend for enhanced immunity/brain function? (the lesions from Rocky Mountain actually attack the brain stem- very scary). She's on vitamin E, but I was thinking maybe salmon oil, natural herbs?

She's also now on Frontline Plus or Advantix as long as we remain in tick country. I used to try the herbal route for tick and flea control, but it was maybe 10% effective (never had fleas, just lots of ticks). If you live in tick filled areas and run your dogs in the woods, I would recommend the hard core name-brand pesticides. I pay $50 for four doses right now. Not a bad price.

Mainly, though, I'm just looking for advice on what more I can do. Now that she's relatively healthy, I'd like her to stay that way!

Something I learned in 2008 when I was ill with a 'never figured it out' illness. Rocky Mt Spotted Fever is one of dozens of rickettsii that dogs and people can get from ticks. I had dozens of tests run and finally, before moving me to ICU to die they started me on doxy and roxephine (sp that wrong I am sure) and I started to improve.

No one knows what symptoms were illness and what weren't by the time I did start the antibiotics and improvement but I did have delirium but no one knew whether it was fever, illness or the massive amounts of morphine and other keen narcotics that I was getting in order to keep me from being in agony. And I mean agony. I had joint swelling and pain like nothing I have ever had and I had it to the point of immobility for three weeks before they finally turned it around. Now, two years later I still get swollen and achy joints and pain worse then ever before on top of the arthritis and crap of pushing 50 and having high mileage. I would have thought that if your dog had anything like RMSF she would have been a VERY sick dog indeed. But, like I said, there are dozens of rickettsii. That and dozens of other diseases that have similar troubles. Practicingmedicine.

Wow Sonya,
That sounds like a serious ordeal. Sorry you had to go through that.
From the reading (at this point I probably have read more scientific articles on this than my vet), RMSF doesn't attack joints as much as Lyme or other ricketsial diseases. Tessa's titers were very high for RMSF, so I think that is what she had. In dogs, RMSF distroys blood vessels, lowers platelets, causes lesions, and in 1/3 of cases causes the dizziness-nystagmus Tessa experienced, among many other things. One thing I've realized is that each person or dog reacts to a pathogen differently. My last dog nearly died from cardiac arythmia brought on by erlichia. He seemed just a little off, I brought him to the vet, she did the routine listen to the heart and freaked out. Basically told me his heart was so funky he could die right there. His basic bloodwork was normal at the time. When I rushed him to the vet school for a cardiac consult, platelets were low...and he had the faintest positive on the snap test for erhlichia. He tested negative at the vet's office hourse before. He was on prednisone for a week, doxy for a month. His heart beat strong to the end.You'd think I'd have learned about the ticks then.

I guess what I'm saying is, you're totally right. Each person reacts differently, and these ricketsial diseases can express themselves with strange symptoms. Again, dogs are stoic- I didn't notice limping or pain, but Tessa can't talk. Maybe she had major headaches- or other things going on before the neurological symptoms started. Right now, the way she's playing, I think she's feeling pretty good.

Sonya- I'm shocked by your experience. I hope things improve! That's the worst tick-related (?) illness experience I've heard about.

Wow, talk about scary. Thanks for the research, Kiersten, and I'm glad to hear that your dog is improving. At least it SEEMS as though the root cause is identified. That Doxycycline is amazing stuff. We have an Italian Greyhound who has been on it for over a year for chronic Uveitis. It was that or have his eyeballs removed. The Doxy has worked wonders on him.

Kiersten, I agree that your dog has age on her side. Given the rapid improvement you've already seen, I'm going to predict full recovery.

Sonya, your post makes me ache just to read it.

To think that all of that can come from one little bug the size of a pencil point.

Correction: our dog takes Cyclosporine, not Doxycycline.

Big difference. Obviously, I'm neither a vet nor a pharmacist, and better just stick to stuff I know something about