Hello, I understand that you have some questions about tick bite paralysis and I'd like to help.
The toxin that causes the symptoms in tick bite paralysis is from the tick's saliva. It is injected into the animal's blood stream when a tick's saliva is injected into the animal's bloodstream at the beginning of taking a meal. A tick injects a small amount of saliva into its victim at the beginning of feeding as its saliva also has an anticoagulent which makes feeding easier.
The toxin has an affinity for, or is attracted to, the spinal nerve roots which leave the spinal cord and control movement or motor muscles. Once there the toxin interferes with normal nerve conduction chemically. An animal that has tick paralysis has function of all of its sensory, or feeling nerves, so it can still feel everything, it just loses the ability to move.
The only way the animal will get better is to remove the tick which removes the constant source of toxin. As the toxin is broken down by the animal's body the animal get better as less toxin is available for blocking the chemical function of the nerves.
Treatment for tick paralysis is purely supportive, removing all ticks form the body to stop toxin injection, keeping the animal hydrated, supplying food intravenously and oxygen if necessary, while waiting for the toxin to be broken down by the body.
Prenvention of the disease is by using tick preventatives such as Frontline Plus or Advantix so that ticks cannot attach and take a meal, thus they would be unable to inject the toxin.
Not all ticks carry the toxin, it appears to be primarily females, and not all dogs exposed will get sick. It is best however to prevent all ticks from attaching in the first place with appropriate tick preventatives.
Let me know if you have any further questions.