Leptospirosis is an emerging zoonotic disease found throughout most of the United States. Leptospirosis in dogs affects many organ systems and varies in severity; clinical signs range from none or mild and self-limiting to severe with acute kidney injury, hepatopathy, and vasculitis.
Dogs become infected when their mucus membranes or abraded skin comes into contact with Leptospira-infected urine or substrates contaminated with infected urine (e.g., water or soil) from a reservoir host. The most common reservoir hosts are wild animals, such as rodents. Leptospira serovars have adapted to reservoir hosts, where a carrier state is established, and leptospires are intermittently shed in reservoir hosts' urine.
Several tests are available for diagnosing leptospirosis, and high accuracy is achieved using a combination of different tests. Although many patients require aggressive therapy, the prognosis is ultimately good if appropriate care is provided.
Signalment of Leptospirosis in Dogs
Leptospirosis has conventionally been thought to most commonly affect young adult, male, large-breed, or hunting dogs living in rural areas. Indeed, some studies have found intact male dogs and working dogs overrepresented among leptospirosis patients. However, other studies have found similar seroprevalence among dogs of large and small breeds, both sexes and all age groups.
Signs of Leptospirosis in Dogs
• Lethargy
• Arthralgia and myalgia
• Polydipsia and polyuria
• Oliguria or anuria
• Altered hydration status (overhydration with oliguria/anuria or dehydration with polyuria)
• Gastrointestinal abnormalities (decreased appetite, vomiting, diarrhea)
• Icterus
• Bleeding tendency (petechia, melena, hematochezia, epistaxis)
• Tachypnea
• Conjunctivitis
