Many people have tragically put their dogs down due to unexplained aggression. A perfectly nice dog has moments of growling, biting, fear-aggression, or just plain aggression. Never put down a dog with aggression problems until they have been tested for Lyme disease. Lyme is known to cause this behavior as well as other neurologic symptoms such as canine confusion, irritability, and disconnected type behavior. A simple blood test will tell you if they have Lyme disease. Dogs respond much better to the treatment with Doxycycline (2-5mg per lb body weight once or twice daily for at least 14 days…30 is better…and some chronic (long-term) cases could be on it for months…and possibly need retreatment for relapses or re-infections (a new Lyme tick bite) ). Dogs are known to respond much better than people, even with chronic infections. Don’t forget to consider getting yourself tested too. Your dog probably got it while on a walk with you. Ticks love us too.