LICE AND IVOMEC TREATMENT

Question
I BOUGHT OUR GUINEA PIG 6 WEEKS AGO, AT THAT TIME HE WAS 4 WEEKS OLD, I TOLD HIM TO BE CHECKED OUT AND FOUND HE HAD LICE, THEY STARTED IVOMEC TREATMENTS AND HE HAS GOT A SHOT OF IT EVERY WEEK SINCE, HE IS ON HIS 4 TH SHOT AND STILLS ITCHY AND FLIPPING OUT , HOW LONG DOES IT TAKE TO KICK IN AND GET RID OF THESE? I CHANGE BEDDING EVERY OTHER DAY I SPRAY AND CLEAN IT WITH FLEA AND LICE SPRAY AS DR. TOLD ME TO DO, I GIVE HIM BATHS TWICE A WEEK, I WROTE TO THE COMPANY I PURCHASED HIM FROM BECAUSE I MUST HAVE BOUGHT HIM LIKE THIS AS WE HAVE NO OTHER PETS AT ALL, WE LOVE HIM AND WANT TO KEEP HIM BUT I HAVE ALREADY SPENT QUIT A BIT OF MONEY JUST ON DR. VISITS AND SHOTS AND TRIING TO FIGURE OUR HOW LONG THIS WILL TAKE TO TAKE EFFECT? THERE ARE ALOT LESS LICE ON HIM BUT HE IS STILL FLIPPING OUT, I TRY TO HELP HIM AS MUCH AS I CAN AND I FEEL BAD FOR HIM TOO! THANK YOU FOR ANY HELP YOU HAVE FOR ME!

Answer
Hello Carol,
I do not know why the vet is giving a shot of ivermectin when it should really be applied topically for the best results since the lice are on top of the skin and not under the skin. Also Advantage is also good at killing lice and you can apply .1cc per pound of guinea pig. Here is more information lice and treatment.
http://www.guinealynx.info/lice.html