ClinQuiz: Eye on leptospirosis (Sponsored by Boehringer Ingelheim Vetmedica Inc.)

Case 1: A 7-year-old spayed female Maltese is brought to your veterinary clinic for an acute onset of lethargy, anorexia, and vomiting. The dog lives exclusively in the city and only goes for brief walks outside the home and occasionally at dog parks. On presentation, the patient is febrile, icteric, and 7% to 8% dehydrated. Laboratory results reveal azotemia, thrombocytopenia, and elevated liver enzyme activity. The dog's vaccination status is unknown.

Based on the history, clinical signs, and initial laboratory findings, what is your tentative diagnosis and what additional diagnostic testing would you perform?

A. This dog is likely to have leptospirosis. Submit blood samples for a microscopic agglutination test (MAT) for Leptospira antibody and a polymerase chain reaction (PCR) test. Begin therapy for presumptive leptospirosis.

B. Pyelonephritis is the most likely diagnosis. Infectious diseases, such as leptospirosis, are unlikely in this patient. Submit a urine sample for urinalysis and culture.

C. Neoplasia is the most likely diagnosis. Perform abdominal ultrasonography.

Case 2: A 12-year-old spayed female Labrador retriever comes into your clinic with a presenting complaint of polyuria and polydipsia. The dog was vaccinated against leptospirosis two months ago with a four-way commercial vaccine. As a part of your diagnostic workup, you submit MAT titers for leptospirosis and receive the following results:

Leptospira bratislava – neg

L. grippotyphosa – 1:200

L. icterohemorrhagiae – 1:200

L. pomona – neg

L. autumnalis – neg

L. canicola – neg

L. hardjo – neg

How do you interpret these results and what should your next action step be?

A. This dog has leptospirosis and should undergo treatment immediately; no additional diagnostic tests are required.

B. This dog probably does not have leptospirosis. However, convalescent titers and PCR should be considered to definitively rule out infection.

C. This dog does not have leptospirosis, and no further testing is necessary.

Case 3: A client brings in his 16-week-old pug puppy for vaccination. The puppy lives exclusively in an urban setting, and the client does not travel with his dog. The client tells you that he was told by the breeder not to vaccinate against leptospirosis, as these vaccines have been shown to kill small dogs.

What is your response to address this client's concerns?

A. Yes, it is true that there is a high risk of vaccine reactions in small dogs administered Leptospira vaccines. Therefore, we should not vaccinate this patient.

B. We should not vaccinate this patient because it is at a low risk for developing leptospirosis.

C. This patient should be vaccinated against leptospirosis. There is not a high risk of vaccine reactions against Leptospira vaccines, and the puppy is at risk for exposure to leptospirosis.

For more information on leptopsirosis and its prevention, visit www.duramunelepto.com or www.leptoinfo.com (which also offers owner-friendly information).

This quiz was provided by Carrie R. White, DVM, DACVIM, Staff Veterinarian, Department of Internal Medicine, The Animal Medical Center, New York, N.Y.

Dr. White completed a small animal internship at the Veterinary Referral and Emergency Center in Norwalk, Conn., and a small animal internal medicine residency at The Animal Medical Center in New York City. She is currently a staff internist at the Animal Medical Center. Her areas of interest include infectious disease and hematology.