Leptospirosis is a bacterial disease which can affect many animals. Rare in cats, but more common in dogs.
"Lepto" is a zoonotic
disease, meaning it can be passed from animals to humans.
Leptospirosis is caused by a complex group of closely related bacteria
of the genus Leptospira. There are several strains that occur in
different locations and tend to affect certain species more than others.
Leptospira bacteria survive especially well in warm, humid areas,
and are often found in stagnant water (e.g. ponds). Wild animals can
carry Leptospira. Therefore, dogs with a higher potential for
exposure to contaminated water and wild animals and their urine are at a
greater risk (e.g., living in rural areas, hunting dogs).
dogs, males, and large breed dogs appear to have a higher rate of
infection. However, any dog can be exposed, since urban wildlife
such as rodents may carry the bacteria. Most infections happen in the
summer and early fall, and outbreaks sometimes follow flooding.
bacteria are shed in the urine of infected animals, though they can be
found in other body fluids and tissues. Dogs can become infected by
exposure to contaminated water (both through ingestion or contact with
mucous membranes or broken skin), exposure to urine from an infected
animal (e.g. contaminated food, bedding, soil, etc.), bite wounds, and
ingestion of tissues from infected animals.
Leptospira bacteria get into the body, they spread to many types
of tissues. The immune system may clear the bacteria from most of the
body, but the bacteria may "hide out" in the kidneys, and the
bacteria can be shed in the urine for many months after infection.
Treatment with antibiotics may help prevent long term shedding in the
Signs and Symptoms of Leptospirosis
The severity of symptoms varies, and depends on the dog (age, immune
response, vaccination status), the strain of Leptospira, and
other factors. Some dogs may have mild symptoms or no symptoms at all,
but severe cases can be fatal. Signs and symptoms may include:
or muscle pain - this may manifest as a reluctance to move
from nose and eyes
urination - may be followed by lack of urination
of the gums, membranes around the eyes, and skin (jaundice)
A definitive diagnosis is usually made by demonstrating the presence of
the bacteria in samples, usually urine, or finding increasing levels of
antibodies to Leptospira over time, which shows an active immune
response through a test called MAT. A single antibody test may be
positive due to past exposure to Leptospira bacteria (e.g. an infection
with no symptoms) or vaccination.
is also important to note that Leptospira bacteria can be found
in the urine of dogs that may not have active symptoms due to the Leptospira,
so it is important to clarify if the symptoms are due to Leptospirosis
or other possible causes. A variety of other laboratory tests and
radiographs can help confirm the diagnosis.
Antibiotics are used to kill Leptospira bacteria and are often
given in two stages: one type of antibiotic to treat the initial
infection, followed up with a different kind of antibiotic to combat the
shedding of bacteria in the urine. The earlier treatment is started, the
kidney and/or liver failure is present, the prognosis for recovery is
worse. In these cases, aggressive treatment is vital, including
intravenous fluids, medications to reduce vomiting and treat other
effects of kidney and liver failure, and dialysis. However, depending on
the severity of disease, treatment is not always successful when organ
failure is present.
Vaccines against leptospirosis are available and recommended in areas
where leptospirosis is common. The vaccines are only produced for a few
specific varieties of Leptospira, and don't offer long-lasting
immunity, so need to be repeated often.
the vaccines are not 100 percent effective and do not protect against
all types of Leptospira, vaccination is still recommended to help
prevent a potentially serious disease that can be transmitted to people.
Recommended vaccines and vaccination schedules should be discussed with
your vet based on your dog's risk factors.
Rodent control measures reduce the chances of infection, and in areas
where Leptospirosis is common, preventing dogs from swimming in ponds
and slow-moving water can also help.
Home Care for a Pet with Leptospirosis
Leptospirosis can cause flu-like symptoms in people, which in some cases
can progress to serious illness. If your pet has been diagnosed with
Leptospirosis, the risks can be managed, primarily with careful hygiene.
In reality, pets that do not show signs of infection (and therefore are
not diagnosed and treated with antibiotics to stop the shedding of
bacteria in the urine) probably pose a greater risk for transmission to
However, if your pet has been diagnosed with Leptospirosis, steps to
prevent infections include the following:
contact with urine if possible, and wear protective clothing
(gloves, etc.) if you need to handle urine.
good hygiene including careful hand washing.
surfaces where infected pets have urinated (antibacterial
disinfectant or diluted bleach solution).
your vet's advice for treatment and make sure all medications are
given as directed.
any people in contact with a dog diagnosed with Leptospirosis become
ill, be sure to mention the dog's illness to health care providers (as a
rule of thumb, it is always a good idea to mention pet exposure to
health care providers when people in the family are ill).
For detailed information at CDC: Center
for Disease Control-Leptospirosis
consult with your Veterinarian for treatment or before treating your dog
with any medication