What is leptospirosis?
Leptospirosis (lepto) is a disease caused by a bacteria called
Leptospira interrogans.
These bacteria can infect multiple species of mammals,
including humans, dogs, rats, mice, raccoons, skunks,
opossums, cows and pigs. Both animals and people may
have a wide variety of symptoms, from no symptoms at all to
liver and kidney damage and even death. There are
vaccines for dogs that may provide protection against this
potentially serious infection. Contact your
veterinarian if you have questions about your pet and leptospirosis.
Leptospirosis in dogs in Los
Angeles County in 2021
In July 2021, Veterinary Public Health noted a large
increase in reported confirmed and suspected canine
leptospirosis cases. Most of the affected dogs
either live in or had exposures in locations on the west
side of the county or the San Fernando Valley. A
number of dogs were exposed at dog daycare/boarding
facilities but others may have been
exposed at dog parks or beaches. Many infected
pets required hospitalization and extensive care.
At this time, there have been no reports of people
becoming ill after exposure to the infected dogs.
The leptospira serovar canicola is the
likely cause of this outbreak. Dogs are the
primary reservoir for the canicola serovar, not wildlife
or rats. As a result, this outbreak is
driven by dog-to-dog transmission of the bacteria in
group settings such as boarding kennels or dog
daycare, leading to a higher number of cases than what
has been seen in recent years. With this recent increase in canine cases, it is very
important for veterinarians to consider leptospirosis as
a possible cause when dogs are seen at their veterinary
facility with lethargy, loss of appetite, reluctance to
move, increased thirst, increased urination, vomiting,
or evidence of kidney or liver damage on bloodwork.
Vaccination against leptospirosis is very
important to protect the health of dogs in LA County.
As of today this outbreak is
considered to be concluded.
Summary of the outbreak
Is it still recommended to
get my dog vaccinated against Leptospirosis?
Yes. Following this outbreak, the Leptospira
vaccine should be considered a core vaccine for dogs in
Los Angeles County. Dogs were the primary
reservoir for the serovar suspected in causing this
outbreak, but wildlife and rodent exposures pose a
continuous risk of infection as well. Vaccination
with the 4-serovar vaccine is recommended, even after a
dog has had natural infection, as cross-protection
against the various serovars after natural infection is
not well documented. The vaccine should be
boostered annually thereafter. Dogs should be
fully vaccinated prior to attending places where other
dogs gather such as daycare, boarding, dog parks,
training, groomers, etc.).
The epidemic curve for this outbreak
with information about daycare/boarding status is below:
*This chart includes cases reported to Veterinary Public
Health with onset date available.
If onset date was not available, lab confirmed date is
used. There are 5 additional
cases without a reported onset date or lab confirmed
date. These cases are pending investigation and
are not included in this chart. Six asymptomatic
cases are included, the lab confirmed date is used for
those.
|
Findings on reported cases
of leptospirosis in dogs in
Los Angeles County from
March 28, 2021 - February 6, 2022 (n=198)*:
|
|
|
|
|
Number of cases (total
reported to VPH = 201) |
|
Lab-confirmed |
184 |
|
Probable |
10 |
|
Suspect |
7 |
|
Missing data |
0 |
|
Deaths |
13 |
|
|
|
|
Asymptomatic |
6 |
|
Symptomatic |
172 |
|
Missing data |
23 |
|
|
|
|
Any boarding/daycare
reported |
101 |
|
No boarding/daycare reported |
53 |
|
Missing data |
47 |
|
|
|
|
Dog park visit reported |
51 (28
of these also went to
boarding/daycare) |
|
No dog park visit reported |
54 (26
went to boarding/daycare) |
|
Missing data |
96 |
*Although the outbreak is over, we are still
investigating cases. As such, this data is subject
to change.
PETS AND LEPTOSPIROSIS
How common is leptospirosis in pets and animals Los Angeles County?
From 2008-2020, 88 cases of leptospirosis in dogs were
reported in Los Angeles County. However, since some
dogs may be asymptomatic or have mild symptoms and may not
be tested, we believe it is likely underdiagnosed and
underreported, so the true local incidence in dogs is
unknown. We believe most cases in Los Angeles County
are contracted due to contact with infected wildlife or rodents,
however other forms of transmission may be more likely when
there is an increased incidence of disease. For
example, dogs that are in congregate settings and exposed to
large numbers of other dogs (boarding, daycare, training,
dog parks, beaches, grooming, etc.), may be at increased risk
of contracting the bacteria through direct contact or
through contact with urine-contaminated surfaces or water sources.
How do dogs and other animals get lepto?
The bacteria are spread through the urine of infected animals
which gets into water or soil and can survive there for
weeks to months. Animals and humans become infected
when they come into direct contact with the contaminated
water or soil. The bacteria enters through cuts in the
skin or through the eyes, nose or mouth (drinking
contaminated water) or through inhalation. If your pet
has become infected, it most likely came into contact with
the bacteria in the environment or was exposed to infected
animals including other dogs or wildlife. Your pet may have been
drinking, swimming or walking through contaminated water.
Since wildlife and rodent exposure is possible to pets even
in suburban or urban environments, this means that pets in
Los Angeles County could be exposed to infected wildlife or
their urine from their backyards or around their residence,
even without visiting a congregate setting such as a dog
park or daycare. Cats are more resistant to
infection but may show mild disease when infected.
How soon after exposure to lepto would my dog
develop symptoms?
The time between exposure to the bacteria and the
development of disease is usually 5 to 14 days, but can be
as short as a few days or as long as 30 days or more.
What are the signs of lepto in pets?
Contact your veterinarian if you suspect your pet may be
showing signs of leptospirosis. Symptoms are variable
and are most commonly associated with kidney damage which
may include fever, lethargy, low appetite, vomiting and
increased or decreased urination and thirst. Diarrhea
and liver damage or yellowed mucus membranes (gums) may also
be seen. Sometimes pets do not have any symptoms. Your
veterinarian can perform tests to determine whether your pet has the disease.
Is lepto treatable in dogs?
Lepto is treatable with antibiotics. If an animal is
treated early, it may recover more rapidly and any organ
damage may be less severe. Other treatment methods
such as hospitalization, fluids, or dialysis may be
required.
Is there a vaccine available for leptospirosis?
Yes there are lepto vaccines available for dogs, however the
vaccine does not provide 100% protection. This is
because there are many strains (serovars) of lepto and the
vaccines available do not provide immunity against all
strains.
Local data suggest that a variety of lepto strains may cause illness in dogs. Therefore
the 4-way vaccines (protecting against 4 strains of the bacteria) are a better choice for protection than the 2-way vaccines.
The 4-way Leptospira vaccine is recommended for
dogs living in Los Angeles County. 2 doses of the
vaccine are normally given 3-4 weeks apart, and should be
boostered again every year. Schedule with your
veterinarian to have your pet vaccinated against lepto.
If my dog had a lepto infection in the past, are
they considered immune for life?
No. Infection with lepto does not guarantee that a pet
is immune for life. It is important to get your pet
vaccinated even if they become sick with lepto because your
pet can be reinfected with a different strain of lepto
later. Discuss with your veterinarian when your pet
should be vaccinated after recovering from a recent
infection.
Are vaccine reactions to the leptospirosis vaccine
common?
Previously there has been concern about vaccine reactions
from the Leptospira vaccine. However, current
vaccines containing leptospiral antigen have not been shown
to be more reactive than other vaccines for dogs.
Speak to your veterinarian for more information about
whether the lepto vaccine is recommended for your dog.
How do I prevent my dog from contracting lepto?
-
Vaccinate your dog
against lepto (especially before
entering a congregate facility such as
daycare/boarding)
-
Keep dogs away from
wildlife
-
Do not attract
wildlife to yards by keeping bushes and
shrubbery trimmed and closing off
outdoor crawl spaces
-
Do not leave pet food
or water bowls outside and routinely
clean food and water bowls that may have
been contaminated by wildlife
-
Keep rodent problems
under control; call an exterminator if
needed
-
Do not allow pets to
drink from or enter contaminated bodies
of water
If my dog had lepto, when can they return to their
normal activities?
It is important to keep your dog at home and not go out to
public areas until they have been treated with antibiotics.
Generally, once your pet has completed the recommended
antibiotic course and is no longer symptomatic, they are
much less likely to release lepto in their urine and be
contagious to others. However, some dogs may still
release lepto in their urine intermittently for weeks to
months. We recommend consulting with your veterinarian
after your dog has been diagnosed and treated for lepto for
their recommendation on when it is safe to resume normal
activities or return to congregate facilities (daycare,
boarding, grooming, dog parks, beaches, etc.).
PEOPLE AND LEPTOSPIROSIS
Can humans contract leptospirosis?
Lepto is considered a zoonotic disease which means that
it can be transmitted between people and animals.
Humans are infected in similar ways as animals, such as
through contact with contaminated urine (or other bodily
fluids, except saliva), water, or soil. The bacteria
can enter the body through the eyes, nose, mouth or skin, especially
if the skin is broken from a cut or scratch. Normal
daily activities with your pet will not put you at high risk
for lepto infection. For humans, the most likely
exposure to lepto is when a pet is sick and pet owners or
veterinary staff have direct contact with their urine. It is
especially important to practice good hand hygiene around a
dog that is sick or recovering from lepto. Use gloves
when cleaning up urine, spray the area with a disinfectant,
and wash your hands immediately after removing gloves or
after having contact with a pet you are caring
for.
What are the signs of lepto in humans?
Symptoms
are variable and may include fever, severe headache,
and muscle aches. In severe cases, people may have
yellowed mucous membranes (gums), kidney damage and respiratory distress.
Click
here to learn more about lepto in people.
If you develop symptoms of lepto after exposure to an
infected pet, see your physician immediately and discuss
your exposure. Tests can be performed to see if you
have this disease.
How do I stay safe around my dog if they have been
diagnosed with lepto?
-
Make sure that your
infected pet takes all of their medicine
and follow up with your veterinarian as
needed
-
Wear gloves when
cleaning up waste, especially urine, or
any contaminated bedding from your pet
-
Wash your hands after
removing your gloves and after any
handling of your pet
-
To disinfect a
surface that was contaminated by pet
waste or urine, use an antibacterial
cleaning solution or a solution of 1
part household bleach in 9 parts water
-
Consider having your
pet urinate in sunny areas or areas that
will dry completely rather than
urinating in areas that will always stay
wet
-
Do not pressure wash
areas where animals have urinated as
this may cause the bacteria to
aerosolize and it can then be inhaled
-
As some dogs can
release the bacteria in their urine
intermittently for weeks to months after
recovery, it is important to follow
these precautions whenever you clean up
pet waste and urine
LOS ANGELES COUNTY VETERINARIANS ARE ADVISED TO:
-
Educate clients about
leptospirosis and steps that may be taken to
reduce risk, especially to rodents and
wildlife
-
Discuss vaccination with
each client and remind clients about
recommended boosters
-
Educate clients and
veterinary staff about the zoonotic
potential of leptospirosis and the
recommended ways to reduce exposure
-
Practice
good hand hygiene around a
dog that is sick or
recovering from
leptospirosis
-
Always
use gloves when cleaning up
urine
-
Veterinary staff should wear
proper PPE when handling
dogs suspected of having
lepto and use good hygiene
when disinfecting areas that
may have had contact with
urine
-
Properly
disinfect areas inside and
outside of the veterinary
facility where infected dogs
have urinated
-
Do not
use pressure washing to
clean urine contaminated
areas as this may create
aerosols
-
Report all cases of
confirmed or suspected leptospirosis in LA County to Veterinary Public
Health using this
reporting form.
If you have questions about leptospirosis or wish to
report a case, please call 213-288-7060 or email
vet@ph.lacounty.gov.
Additional resources for leptospirosis:
Vaccinate Dogs
for Canine Flu H3N2 and Leptospirosis - Help Stop Both
Outbreaks in LA County 
9.22.21
Los Angeles County Veterinary Public Health - Leptospirosis
in Animals
Center for Food Security and Public Health Fast Facts Sheet for Clients - Leptospirosis
2010 ACVIM Small Animal Consensus Statement on Leptospirosis
Leptospirosis - CDC
Last updated: March 11, 2022
