ClinQuiz: Ectoparasites - Answer 3B Aug 14, 2008 By dvm360.com staff VETERINARY MEDICINE Incorrect. This organism is a morula of Ehrlichia ewingii, within a neutrophil. Penicillins are not effective against rickettsial infections. Try again View references Hot topics on dvm3605 ways to wow pet owners (and pets) 10 steps to take when a practice owner dies dvm360 sits down with Dr. Pol Ack! How do you spell that again? "Best. Veterinary Practice. EVER."