Moving to lawsuits and disputes. You need a report from your vet that your dog's condition is directly due to the use of the Hartz product, as...

You ask no legal question. This is a medical issue.

Any such claim would have to be brought under the Massachusetts Tort Claims Act. I doubt you have a cognizable case.

You vaguely imply that Banfield did some prior surgery which left a gauze inside your animal records from the Banfield operation, if there was one,...

You may have a claim. However, you should discuss it with an animal law practitioner in Colorado.

Step one is getting your injured dog to the vet. Step 2 is getting documentation of all the damages, and suing the negligent groomer accordingly.

Given the severity of the fine, you should retain council. You will also help protect your record.

Already asked and answered. Attorney Holcombe has done so again.

Document the assaults, call the police and animal control. Cameras are your friend - get some.

Moving to criminal defense. Document your ownership of the dog; vet records, vaccinations, etc. IF actually charged, retain counsel.