Leptospirosis in Dogs
(Canine typhus, Stuttgart disease, Infectious jaundice)
Lepto thrives in waterways and is then spread to humans and other mammals through the urine of rats, dogs, cattle, swine, and wild life. This is a major zoonotic disease in the world.
Introduction: There are multiple strains of Leptospira, which is a bacteria (same family as syphllis) that affect many species of animals including cattle, swine, dogs, and humans.
In the United States, the problem used to be mainly seen in rural hunting dogs exposed to wildlife but now the disease seems to be shifting to the suburbs and urban areas. This is due in part to the huge number of people traveling to endemic areas of the world and then returning to the home as well as the huge increase of wild life in our suburban and urban areas.
Clinical Findings:
Dog of all ages may be affected, and there is no sex predilection. The incubation period is 4-12 days.
Nonspecific signs such as fever, depression, anorexia, and generalized pain may be seen during this time.
Diseases of the blood such as vasculitis, thrombocytopenia, and coagulopathy may develop.
Within a few days, additional signs of uremia such as dehydration, vomiting, and oral ulceration, are seen.
The liver is variably affected, and the degree of icterus often reflects the severity of the disease.
Meningitis, uveitis, and abortion have been rarely reported.
Laboratory findings include leukocytosis, lymphopenia, monocytosis, and thrombocytopenia.
Serum chemistry may reveal azotemia and electrolyte disturbances secondary to the renal failure, including hyponatremia, hypochloremia, and hyperphosphatemia. Serum levels of hepatic enzymes (AST, ALT, alkaline phosphatase) and serum bilirubin increases if the liver is affected.
Urine sediment usually contains RBC, WBC, and granular casts. Isosthenuria, proteinuria, and glucosuria reflect tubular damage.
Lesions seen in pathology or necropsy: In acute disease, the kidneys or liver, or both are swollen. Hemorrhages may be present in any organ. Other lesions may include any of those seen with acute uremia. In chronic cases, white or gray foci or streaks may be seen in the kidney and liver. Histologically, lesions in acute disease are those of acute uremia, including acute interstitial nephritis and possible hepatitis. In chronic disease, the only lesions may be chronic interstitial nephritis or chronic active hepatitis, or both.
Treatment: Renal failure and liver disease are treated with fluid therapy and other supportive measures to maintain normal fluid, electrolyte, and acid-base balance.
Antibiotic therapy consists of penicillin, tetracycline, or doxycycline to eliminate leptospiremia, followed by tetracycline or doxycycline to eliminate the renal carrier phase.
Tetracycline should be used with caution in azotemic animals. The fluoroquinolone antibiotics such as enrofloxacin also appear to be leptospirocidal.
Prevention/Prophylaxis:
To reduce the chances of exposure, owners are advised to engage in rodent control and keep their dogs leashed.
During epidemics, confinement to the owner's premises should be recommended.
Multivalent vaccines are available and should be administered every 6-8 momths to maintain a protective titer for dogs at risk, especially show, stud, or hunting dogs.
Many vets argue that most dogs in the United States are now at risk being exposed to yards and parks where deer, coons, possums, coyotes, and rats have urinated.
Because lepto is a bacteria, vaccination tends to give much short duration of protection than viral vaccines.
Also because the lepto vaccine is bacterial in nature, it is more likely to cause a vaccine reaction than other vaccines and is often omitted from the first puppy vaccine or in pets highly reactive to vaccines.
