Zoological Companion Medicine: Rabbits, Rodents, Reptiles, and Birds
Core concepts
Zoological companion medicine covers small mammals, birds, reptiles, and amphibians kept as pets. Candidates must understand species-specific anatomy and physiology: rabbits are obligate nasal breathers and prone to gastrointestinal stasis; guinea pigs and other rodents require vitamin C (guinea pigs cannot synthesize it); reptiles are ectotherms dependent on environmental temperature gradients for digestion and immune function; birds have a unidirectional respiratory system with air sacs and are sensitive to inhaled toxins.
Know common presentations: rabbits with anorexia and reduced fecal output (GI stasis, dental disease), guinea pigs with scurvy, reptiles with metabolic bone disease from improper calcium:phosphorus ratio and UVB deficiency, birds with respiratory signs from aerosolized toxins or infectious agents. Understand anesthesia risks - small body size means rapid heat loss and difficult vascular access; rodents are prone to hypoglycemia and dehydration.
Traps
Questions love to test species-specific drug toxicity: rabbits are sensitive to many antibiotics (clindamycin, lincomycin, erythromycin) that disrupt cecal flora; guinea pigs are sensitive to penicillin. Another trap is assuming a reptile's illness is infectious when it is husbandry-related. Also, birds mask illness until late, so a bird presenting with signs is often critically ill.
Worked example / rule of thumb
Rule of thumb: "Husbandry first, then infectious disease." For any reptile or bird with nonspecific signs, review temperature, humidity, UVB, diet, and enclosure before pursuing diagnostics. For a rabbit with GI stasis, prioritize analgesia, fluid therapy, and assisted feeding rather than immediate antibiotics.
Exam strategy
When a stem names a drug and a species, check for known toxicity before assuming the drug is appropriate.