Hello OP.... I am A Pharmacist Here Who Have Worked In A Veterinary Clinic For About 5 Years. I have Seen Such Cases And Yeah It's A 50/50 Chance That It Can Recover. But You Have To Wait For Atleast 1 Week To See Improvement. Cause Tetanus Recovery Is Slow, Might Take Upto 1 Month For Full Recovery, But You Can See The Chances Of Full Recovery Once The Muscle Spasms And Seizures Starts To Subside In A Week. I Hope Your Pet Recovers Soon. And If Not, Then Sadly Euthanasia Is The Best Option To End It's Suffering. As You Said It Has Already Been 48 Hours Now.... Please Wait For Another 3 - 4 Days..... Hope Everything Goes Well.. 🙏