Client Feature
Article of the Month
Client Center > Feature Article |
| LEPTOSPIROSIS |
| In recent years, there has been an
increased incidence of life-threatening infections caused by
the Leptospiral bacterial family. Our facility
alone has diagnosed and treated at least one serious infection
every month over the past few years. Although the majority
of patients survived with very intensive and often costly treatment,
sadly a handful of pets died of the disease despite aggressive
treatment. For this reason, the veterinarians at Westbridge
Veterinary Hospital are now including Leptospirosis in
their vaccination protocols for dogs. Additionally, our Doctors
are initiating treatment immediately in patients showing clinical
signs with Leptospirosis including high
fever, jaundice, vomiting, and in severe cases fatal kidney and
liver damage while awaiting results of Lepto titers. |
| The article below has been
prepared to give our clients more detailed information about: |
| |
 |
Leptospiral bacteria family |
| |
|
Westbridge Veterinary Hospital’s current
vaccination protocol |
| |
|
Common sources of infection |
| |
|
Prevent or decrease risk of exposure |
| |
|
Brief clinical course of the disease |
| |
|
Diagnostic methods |
| |
|
Basic treatment information |
| About Leptospirosis |
| |
Leptospirosis is a spirochete bacteria
that can cause serious disease in pets & humans if an infection
develops. In general, pets infected with Leptospirosis manifest
with signs of acute renal (kidney) failure and liver disease,
but Leptospirosis may also cause ocular disease, abortions in
pregnant animals, and weakness and debilitation in neonates born
to infected mothers. It is imperative to identify and begin treatment
for Leptospirosis almost immediately to maximize the chances
of a successful outcome. It is also important to recognize and
diagnose Leptospirosis due to the zoonotic potential to infect
humans and cause serious clinical disease in people.
There are several types of serovars or strains of Lepto that are capable of disease.
Traditional “Lepto” vaccines protected against 2 pathologic serovars,
Leptospirosis icterohemorrhagiae & L. canicola. The incidence of a severe
clinical infection caused by Leptospirosis used to be fairly rare-- in part due
to successful vaccination program in the 70's & 80's. For this reason, during
the 1990s, many veterinarians, including the veterinarians at Westbridge stopped
routinely vaccinating for Lepto because of the low incidence of clinical disease
at the time and that some dogs were experiencing hypersensitivity reactions after
receiving the Lepto vaccine. However, in recent years, veterinarians have seen
a resurgence of Leptospirosis in part being caused by serovars that were not
previously associated with disease. Our clinicians now consider Leptospirosis
to be a significant cause of acute kidney failure in dogs and are taking steps
to prevent more Leptospiral infections from developing through vaccination and
client education. |
| Revised Vaccination Protocol |
| |
In 2001, the Westbridge Veterinary
Hospital added Leptospirosis into their vaccination schedule.
The vaccine covers four serovars including L. grippotyphosa,
L. canicola, L. Pomona, & L. icterohaemorrhagiae. The protocol
calls for an initial dose of vaccine given with the annual “Distemper” vaccine,
followed by a booster for Lepto only 3 weeks after the initial
dose. After that, Leptospirosis should be given annually mixed
with the Distemper vaccine (one injection) at the yearly physical
exam visit. |
| Transmission Routes |
| |
Leptospirosis can be contracted directly
or indirectly. Direct transmission occurs when the bacteria penetrate
the skin, wounds, or mucous membranes (gums, inside the nose,
etc.) after direct contact with an infected animal. Indirect
transmission can occur when the dog has direct contact with soil
or swims in small bodies of fresh water contaminated with Leptospiral
bacteria- usually from the urine of infected wild animals such
as raccoons, skunks, etc. It has been shown the Leptospiral bacteria
can survive up to 180 days in soil (longer in wet areas) in temperatures
between 45-95 degrees. Massachusetts is an idea reservoir for
Leptospirosis with our native wildlife and the plethora of small
ponds and wet lands in the state. |
| Minimizing Risk |
| |
To minimize risk of exposure, kennels,
pens, and shared yards should be thoroughly cleaned and disinfected,
and rodents controlled. Owners are also advised to limit their
dog’s access to swamps, ponds, low lying areas and wooded
land heavily inhabited with native wildlife. |
| Clinical Course of the Disease |
| |
Once contracted, the Leptospiral
bacteria rapidly invade the blood steam and start to replicate
in the kidney within 4 to 7 days. Initially, a fever develops
followed by damage to the lining of the capillaries and larger
blood vessels, liver damage, and kidney disease. The kidney suffers
the most damage since this is where the Leptospiral bacteria
localize and replicate. If the infection is severe enough, the
animal will go into acute renal failure, and if left untreated
will die of acute renal failure or multiple organ failure (DIC)
due to overwhelming systemic bacterial infection (sepsis). |
| Diagnosis |
| |
A diagnosis of Leptospirosis is
made by measuring Lepto titers in the blood. A titer
measures the amount of antibodies the immune system has made
against a specific serovar of Lepto. In vaccinated animals,
titer levels will be detectable but low- typically less than
1:400. With clinical disease, initial titers in unvaccinated
pets can be as low as 1:100- 1:200, but follow-up titers 2-3
weeks later will show a significant increase typically greater
than 1:800 or 1:1600. Any positive titer detected
to a Lepto strain for which no vaccine has been developed or
in an unvaccinated pet is diagnostic for exposure to Leptospirosis with
the potential for infection. |
| Treatment |
| |
Treatment of Leptospirosis involves
aggressive IV fluid therapy, IV antibiotics, and supportive care
as needed to address kidney failure, liver disease, damage to
the blood vessel linings, and consequences of a systemic bacterial
infection. Many patients are very ill and require intensive care
for several days to more than a week to fully recover. Any dog
presenting with signs of acute renal failure should be treated
with antibiotics effective against Lepto until it is proven otherwise. |
| References: |
| |
Birnbaum N.
Leptospirosis. The Five Minute Veterinary Consult, Canine & Feline,
2nd edition. Philadelphia: Lippincott: 2000:780-781.
Greene CE, Miller MA, Brown CA. Infectious Diseases of the
Dog & Cat,
2nd edition. Philadelphia: Saunders, 1998:273-281. |
