A properly warmed Wood’s lamp produces no apple-green fluorescence in a cat with circular alopecia and broken hairs. Which interpretation and next step are most appropriate?

A student has prepared one fecal sample tube for centrifugation but has not prepared a second tube. What must occur before the centrifuge is started?

A dog is diagnosed with Sarcoptes scabiei var. canis, and two family members report new pruritic papules. Which plan best reflects the veterinary team’s role?

A dog with intense pruritus and compatible lesion distribution has a superficial skin scraping in which no mites are observed. The veterinarian remains concerned about Sarcoptes scabiei. Which conclusion best reflects sound diagnostic reasoning?

A dog that frequently eats raw crayfish develops chronic coughing. Fecal sedimentation reveals operculated eggs. Which exposure is most consistent with the suspected parasite?

A dog has recurrent mucoid large-bowel diarrhea and tenesmus. A previous fecal examination identified thick, bipolar-plugged eggs consistent with Trichuris vulpis, but today’s single fecal flotation is negative. Which interpretation best guides the diagnostic plan?

A flea-infested dog passes mobile rice-grain-like segments, and the image shows the diagnostic material recovered from the feces. Which parasite is most likely?

A dog presents with a firm subcutaneous swelling that contains a central breathing pore. A large fly larva is removed from the warble. Which parasite group best fits this finding?

A client uses an effective tick preventive but allows the dog to roam where mosquitoes are abundant. The client believes all vector-associated parasites are now prevented. Which explanation is most accurate?

A dog receiving a monthly macrocyclic lactone tests positive for adult Dirofilaria immitis antigen. The owner asks whether continuing the preventive alone will eliminate the adult worms. Which explanation is most accurate?