Poodle Update - Summer 2022 - 3

POODLE Update
The first incidence of Bartonella
infection in a dog was discovered in
1993 in Dr. Breitschwerdt's laboratory.
" Tumbleweed, " a 3-year-old female
yellow Labrador Retriever, had been
unsuccessfully treated for nine months
when she arrived at the North Carolina
State Veterinary Hospital extremely
ill with endocarditis, an inflammation
of the inner lining of the heart
chambers and valves.
The infectious diseases team isolated
a new Bartonella subspecies
responsible for Tumbleweed's condition.
In collaboration with researchers
at the Centers for Disease Control
and Prevention, they named
the bacterium Bartonella vinsonni
subsp. berkhoffii. The risk factors
for bartonellosis fit Tumbleweed's
lifestyle: heavy flea and tick exposure
and a rural home environment.
Additionally, endocarditis associated
with B. vinsonii subsp. berkhoffii
occurs in large-breed dogs, such as
retrievers, that have a predisposition
for aortic valve disease.
" I wanted to know how we had
missed the diagnosis of bartonellosis
in the past, " Dr. Breitschwerdt says.
NEW STUDY COMBATS
BARTONELLOSIS
Bartonellosis is a zoonotic disease
in which contact with an infected
animal can make people sick. This
worries Dr. Breitschwerdt. " Owners
of infected dogs, veterinarians and
veterinary technicians are particularly
at risk of getting sick, " he says.
" Direct contact with body fluids, a
needle stick, scratch, or bite from an
infected animal puts a person at risk. "
In both species, three organ
systems are vulnerable to acute
or chronic clinical manifestations,
and more than one system may be
affected. Cardiovascular disease
may manifest as endocarditis, as
with Tumbleweed, or myocarditis,
inflammation of the heart muscle.
CLINICAL SIGNS OF
BARTONELLOSIS
* Fever
* Diarrhea
* Lameness
* Coughing
* Swollen or inflamed lymph
nodes
* Seizures
* Vomiting
* Inflammation inside the eye
Neurological effects include seizures
or paralysis, and rheumatologic signs
occur in joints and surrounding
tendinous structures.
Complex to diagnose, Bartonella
infection has a stealthy nature in
which the bacterium invades, thrives
and hides inside cells of blood vessel
walls throughout the body. Blood
smear tests do not detect the
pathogen. Eluding the immune
system, Bartonella may trigger
an infectious state that leads to
hemangiosarcoma.
Like Bartonella, HSA is a stealthy
canine cancer that often goes
undetected as it develops silently
and painlessly. Originating in bone
marrow cells, HSA settles in the thin
layer of cells lining the interior of
blood vessels giving tumor cells
access to the blood supply and
allowing them to metastasize to
virtually any organ in the body.
Tumor cells take hold and grow in
a vascular web that may contain
Bartonella infection.
About 50 percent of HSA cancer
cases occur in the spleen, an organ
responsible for eliminating vectorborne
pathogens such as Bartonella
from the circulatory system.
Although cardiac HSA is less common,
it is the most common heart
tumor in dogs. Less frequently, HSA
occurs in the liver, lungs, kidneys,
and skin.
3
Poodle Update - Summer 2022

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