6. WHAT IS THE BEST WAY TO TREAT LEPTOSPIROSIS?

While the ideal treatment of canine leptospirosis is unknown, the consensus panel recommends treatment with doxycycline (5 mg/kg intravenously or orally every 12 hours for two weeks). If doxycycline is not available or not tolerated by the patient, ampicillin (20 mg/kg intravenously every six hours) should be given. This dose should be reduced for azotemic dogs. Once the patient is able to take oral medications again, doxycycline should be administered for two weeks to clear the organisms from the renal tubules.

The prognosis for dogs that are treated appropriately and aggressively and that do not have complicating respiratory involvement is good. Renal parameters would be expected to return to normal by two weeks, although it may take more than four weeks in some cases. In some dogs, permanent kidney damage may occur. Once a patient is discharged from the hospital, follow-up examinations will vary depending on the severity of illness. The panel recommends, at minimum, a follow-up visit one week after discharge to perform a serum chemistry profile and urinalysis and, if indicated, a complete blood count.

Most human cases of leptospirosis in the United States result from recreational water activities. The incidence of transmission from pet contact is low; however, while the risks of zoonotic exposure require further study, appropriate handling of these patients is warranted.

Pregnant or immunocompromised individuals should avoid contact with patients suspected of having leptospirosis. Antimicrobial therapy may help lessen zoonotic risk by decreasing the amount of organisms shed in the urine. Movement of these patients around the hospital should be kept to a minimum, but because dog-to-dog transmission is rare and these patients typically require more intensive monitoring, the panel does not feel they need to be kept in isolation. Disposable gowns, gloves, facemasks, and protective eyewear should be worn when cages are cleaned or infected urine is handled. Because of the risk of aerosolization of infective organisms, pressure washing of runs should be avoided.

Patients should be allowed to urinate in a restricted area that can be easily disinfected, and disposable bedding should be placed in biohazard bags. Other bedding can be laundered normally to inactivate leptospires. Urine collected from infected dogs—such as those with indwelling urinary catheters—should be disinfected before disposal. A 1:1 combination with a 10% bleach solution is effective, as are iodine-based disinfectants, quaternary ammonium solutions, or accelerated hydrogen peroxide.

All blood, tissues, and urine from infected dogs should be handled as medical waste and disposed of according to local regulations. All personnel in contact with infected dogs should be informed of the risks so that proper precautions may be taken.

Once these patients are home, owners should still avoid contact with their dogs' urine until antimicrobial therapy is completed and should wash their hands after touching the dogs. Vaccination of other dogs in the household at risk of exposure may help decrease zoonotic potential.

The consensus panel recommends that other dogs in the household be treated with a two-week course of doxycycline if there is a common source of exposure. Monitoring of acute and convalescent titers in these dogs is also recommended.

8. WHAT ABOUT LEPTOSPIROSIS VACCINATIONS?

While there have been concerns in the past regarding the safety of leptospirosis vaccines, a large study published in 2005 found these vaccines to be no more reactive than other canine vaccines. At this time, there has been no evidence of leptospirosis in dogs that have received the four-serovar vaccines; however, data are insufficient regarding the prevalence of leptospirosis in this population of dogs. The consensus panel recommends that dogs considered to be at risk for leptospirosis infection be vaccinated annually with the four-serovar vaccine.

To read the complete consensus statement, go to onlinelibrary.wiley.com/doi/10.1111/j.1939-1676.2010.0654.x/full.

This "Hot Literature" was provided by Jennifer L. Garcia, DVM, DACVIM, a veterinary internal medicine consultant in Houston, Texas.