What is doxycycline?

• A. Antibiotic
• B. Antiemetic
• C. Antihistamine
• D. Steroid

Answer: (A)

Doxycycline is an antibiotic. It belongs to the tetracycline class and works by inhibiting bacterial protein synthesis, binding to the 30S ribosomal subunit to block the addition of aminoacyl-tRNA, which stops bacteria from making essential proteins and slows their growth. This makes it useful for treating a variety of infections in animals, especially tick-borne diseases like ehrlichiosis and anaplasmosis, as well as certain respiratory and urinary tract infections. It’s not an antiemetic (that would control vomiting), not an antihistamine (that treats allergy symptoms), and not a steroid (which reduces inflammation through a different mechanism). Practical notes: give with a full glass of water to prevent esophageal irritation, and use caution in very young animals due to effects on developing teeth and bones; photosensitivity can occur in some patients.