Effective parasite control in your herd

Dear Dr. Othieno, Thanks so much for your insightful articles on animal health. I am a farmer from Kajiado County. I have lately noticed that many flies disturb my animals, I am not sure I can do anything about this. However, my biggest worry is ticks, which I am trying my best to control because I know they spread many deadly diseases. I'm also worried about internal parasites, which I might not see, yet they are eating up my animals internally. I would greatly appreciate any basic principles of internal and external parasite control that I can use on my farm.