ClinQuiz: Increase your zoonotic parasite prowess

Figure 1

1) A 3-year-old spayed female cat that is allowed indoors and outdoors is presented for an annual physical examination. Fecal flotation by centrifugation reveals the eggs shown (see Figure 1). Without treatment, the cat will continue to shed these eggs, and the eggs will contaminate the environment, develop to the infectious larvae stage, and ultimately may be ingested by a person, usually a geophagic child. In addition to the more commonly occurring ocular and visceral larva migrans, which condition can be associated with zoonotic infections with this parasite?

A. Chronic urticaria

B. Cyclic alopecia

C. Lymphocytic colitis

2) A client who plans to become pregnant presents her 8-year-old indoor-only spayed female Persian for a physical examination. She would like the cat tested for Toxoplasma gondii because she is concerned about the risk of infection during her pregnancy and resultant congenital disease. What is the most appropriate way to mitigate the risk of zoonotic T. gondii infection for this client?

A. Perform a serologic assay to determine whether the cat has been exposed to T. gondii.

B. Perform a fecal flotation by zinc sulfate centrifugation to determine whether the cat is shedding T. gondii oocysts.

C. Educate the client about effective toxoplasmosis prevention strategies.

Figure 2

3) A 4-year-old spayed female Papillion is presented for evaluation of mild pruritus and worsening seborrheic dermatitis with a diffuse, bilateral distribution. A few weeks before the clinical signs appeared, the client—concerned that the dog would be stressed by her recent return to work outside of the home—enrolled her dog in a dog daycare program. Conditioning shampoos recommended by a groomer have failed to control the seborrhea. The client also reports that she has developed several focal pruritic, erythematous lesions on her own wrists and abdomen. Microscopic examination of flakes collected from the dog reveals the parasite shown (see Figure 2). What is the correct diagnosis?

A. Walking dandruff due to Cheyletiella yasguri

B. Covert sarcoptic mange due to Sarcoptes scabiei

C. Flea allergy due to Ctenocephalides felis

Figure 3

4) An adult intact male beagle is presented for evaluation of fever, lethargy, and myalgia. A complete blood count reveals thrombocytopenia, but no organisms are identified on a blood smear. You collect a bone marrow aspirate to examine for morulae and identify Ehrlichia canis on the Giemsa-stained smears (see Figure 3). Unfortunately, when cleaning up the procedure area, your technician accidentally sticks her finger with the needle used to collect the sample. She disinfects the wound and bandages it immediately before coming to tell you. What is the most appropriate course of action to take next?

A. No further action is needed; E. canis is not zoonotic.

B. Refer the technician to a physician for prophylactic antibiotics; E. canis can infect people and is directly infectious from blood.

C. Refer the technician to a physician; although E. canis itself is not zoonotic, she may have acquired another infection from the needle stick.

5) A client brings in an apparently healthy 5-year-old neutered male Schipperke for a physical examination. The client says that for the last six weeks she (the client) has been intensely pruritic; severe excoriations are evident on both her forearms. She reports that the condition worsens at night, and although she has not collected any specimens, she has the distinct impression that tiny spiders are emerging from the excoriations on her skin. Her family practitioner and two dermatologists have been unable to identify the cause. A physical examination of the dog reveals no evidence of fleas, ticks, mites, or any skin lesions. No parasites are seen after centrifugal fecal flotation and examination, and the dog is treated monthly with internal and external parasite control products. The client gives you her physician's card and says that he has requested you call him after examining the dog. Based on the information you have, what do you consider the most likely cause of the client's pruritus?

A. Delusions of parasitosis

B.Covert demodectic mange

C. An allergy to the dog's flea control product

Susan E. Little, DVM, PhD, DEVPC

This quiz was provided by Susan E. Little, DVM, PhD, DEVPC, Department of Veterinary Pathobiology, Center for Veterinary Health Sciences, Oklahoma State University, Stillwater, OK 74078.

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