Angus started having the same negative effects from the Ivermectin that he had last time. So, we had to take him to the vet as the Dr was uncomfortable leaving it over the weekend or having him continue the medication. Very lethargic, huge dilated pupils, very thick stringy drool and he has only been eating 1 meal a day for the last week. It has been such a struggle to get him to eat. He refuses every breakfast and has actually been losing weight. The vet was uncomfortable continuing him on the Ivermectin because it adds up in the brain. She said that if even built up in his brain, he could start displaying severe symptoms and start having seizures. He is off Ivermectin for 5 days and then on topical Advantage Multi every 2 weeks until further notice. While we were at the vet, I had them check out his leg and she stated that he has partially torn his ACL and that his knee is quite swollen, which is something I had noticed. I noticed the inside of his leg was kind of enlarged and lumpy. She told me that it was his knee and it was swollen. Angus has injured his ACL before as a small pup (trying to imitate his Biological sister who is a fence jumper. He didn't make the jump and fell). The vet said that at this point, it's bad enough that if he can easily tear it further which will be a full blow. She also said that if he injures it again, it will be a full blow. She referred to his ACL as a "ticking time bomb". When will this end?