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Leptospirosis is a contagious disease that affects animals as well
as humans. Caused by a group of organisms called lepterospira
interrogans (within such species there are different strains), the
disease can lead to chronic liver and kidney disease and even death
in dogs. Eight of the different
strains give off different types and levels of disease which depends
upon the animal that they infect. The disease causes more
problems in dogs. Not until recently, the vaccines
that were available are only for two types of bacteria namely, Leptospirosis
canicola and L. icterhaemorrhagiae, has virtually wiped out the
clinical ailment associated with these strains between the immunized
dog population. Vaccines for two other additional types of bacteria,
L. grippotyphosa and L. Pomona are now readily available.
The leptospira organism
Leptospires grow well in water, appearing in a spiral shaped long
body with hooks on both ends. They are called "aquatic spirochetes".
They are of two species, Leptospira biflexa and Leptospira interogans
which cause disease in animals and humans. Leptospira interogans
is divided into strains based upon antigen (stimulates the production
of antibodies) types, providing very little cross immunity opposed
to one serovar and the host, which is the dog that has developed
resistance to one strain either by vaccination or through former
infection, will not be capable in repelling an infection brought
about by a different strain.
Sources of infection
Bacteria carriers are generally rats and other rodents, though
an infected dog can also be a source of infection. The most
significant means of transmitting the disease is through urine ingestion
and other forms of bacteria will penetrate very thin skin.
Leptospirosis transmission
The disease is transmitted when the animal comes in contact with
the urine of other infected animals, through bite wounds and absorption
of an infected tissue.
Indirect transmission happens when dogs wade in or drink contaminated
water or food. Since stagnant water provides a very appropriate
environment for the leptospira, dogs that wade in it get infected.
Infections are common in the fall and in summer because the survival
of the organism is highly reduced by freezing.
Symptoms
During the first four to twelve days following the infection, the
dog will have fever and experience shivering,
vomiting, appetite loss, depression, conjunctivitis and pain.
In severe cases, the infected dog may develop hypothermia (abnormally
low body temperature) eventually become depressed and die even before
a kidney or liver breakdown.
Diagnosis
A microscopic agglutination test is performed on a blood sample
of a suspected animal from a laboratory. This can test for
individual strains and the animal's level of antibody (titer) to
combat these strains.
Depending on the titer's level, a positive diagnosis to the precise
and specific strain can then be made. It will be helpful if
many samples are drawn and tested as titers may have negative results
in the first ten days after the infection, and former immunization
shots may give an elevated titer and should be taken into consideration
during the interpretation of the titers.
In dogs that are severely infected, they are expected to shed the
leptospira organism in their urine, thus when a urine sample is
taken and cultured, it can give a positive diagnosis. This
is not the best way however, because the individual getting the
sample may be at risk.
Treatment
Treatment usually will consist of antibiotics, fluid replacement
for rehydration through intravenous as well as controlling the dog's
vomiting through antiemetics and other problems related to liver
or kidney infections. Note that dehydration must be correct
within six to twelve hours.
Penicillin or one of its byproduct is the antibiotic that is given
to treat early infection, after which, doxycycline is used for cure
and prevention of possible continuing carrier state.
Prevention through vaccination
Currently, there are many vaccines
available for a large variety of species. Chemically inactivated
(killed species) vaccines are available for dogs and whole culture
vaccine which causes the dog vaccine reactions. Before, leptospiral
vaccines only protect against L. canicola and L. icterohaemorrhagiae.
Only in the year 2000 that a new vaccine was developed to also protect
dogs from L. grippotyphosa and L. pomona.
Prevention through other forms:
- Solve your rodent problem in the home, keep it well under control.
- Keep away stagnant water. Make sure to clean and take
stagnant water out every corner of your yard, so your dog will
not be tempted to drink and to play in it.
- Mow your lawn regularly.
- Always provide clean drinking water for your dog.
- Always be sensitive to your pet's condition. If he shows
any abnormal signs, take him to the veterinarian
immediately.
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