As Lyme
disease cases rise in the United States, not only humans are at risk; dogs are
increasingly vulnerable to this tick-borne illness. The disease's spread is
facilitated by ticks, which thrive in tall grasses and wooded areas and
symptoms in dogs can range from fever and joint pain to more serious conditions
like kidney damage if left untreated. This article dives into what dog owners
should know about Lyme disease, from its transmission and symptoms to
diagnosis, treatment, and practical prevention strategies.
The
number of human Lyme disease cases in the United States has climbed in recent
decades, but Lyme disease affects more than just humans. Wild and domestic
animals, including dogs, can also contract the disease.
Lyme
disease is caused by bacteria from the genus Borrelia, with Borrelia
burgdorferi being the most common species responsible for the disease
in North America. These bacteria are transmitted to humans and animals through
the bite of infected ticks, specifically the black-legged tick (Ixodes
scapularis) in the northeastern and north-central United States and the
western black-legged tick (Ixodes pacificus) on the Pacific Coast.
Also
called the deer tick, the black-legged tick picks up B. burgdorferi when
it bites an infected animal (usually a rodent), and when it feeds on another
animal, it transmits the bacteria.
Blacklegged
ticks are small, ranging from about the size of a poppy seed to a sesame
seed.
The
Transmission Mechanism
Understanding
the transmission mechanism of Lyme disease is helpful for prevention. The
black-legged tick undergoes three life stages: larva, nymph, and adult. Each
stage requires a blood meal to progress to the next; during these meals, the
tick can acquire or transmit B. burgdorferi. Larvae and nymphs
often feed on small rodents, which are reservoirs for the bacteria. Nymphs and
adults can transmit the bacteria to dogs and humans. Awareness of this cycle is
helpful to understand the risks at different times of the year and the importance
of tick control measures.
Where is Lyme disease transmitted?
Black-legged
ticks thrive in tall grasses and in the woods. Ticks hang out on the tips of
leaves and other vegetation, waiting for an animal or person to walk by so they
can grab on and crawl until they find a place to bite.
While Lyme disease was traditionally thought to be limited
primarily to the Northeastern United States (the disease is named after the
town of Lyme, Connecticut, where it was first described in 1976), positive
cases of canine Lyme disease have now been reported across the U.S., with 39
states reporting high and moderate prevalence.
The black-legged tick's range has expanded significantly
over the past few decades, which means the tick and the Lyme-causing bacteria
are present in Virginia. Climate change is significantly impacting the
distribution of the black-legged tick, leading to an increase in Lyme disease
cases in areas once considered low-risk. Warmer temperatures and milder winters
allow ticks to remain active longer and expand into new territories.
In 2015, Professor Emerita Anne Zajac co-authored a paper on vector-borne and zoonotic diseases in
which researchers collected hundreds of ticks from Giles and Pulaski counties.
They found that one-third of those ticks carried B. burgdorferi!
Dogs tend to be bitten by infected ticks in the early
spring and late fall when adult ticks are most active, but animals and humans
can contract Lyme disease any time of year.
Lyme disease in dogs
Black-legged ticks and B. burgdorferi may
be uncomfortably common, but the good news is that most animals with Lyme
disease show no signs of illness. Symptoms of Lyme disease in dogs can vary
widely and may not appear for months after infection.
Some dogs may exhibit more subtle signs or more severe
reactions. Those symptoms might only appear months after infection for dogs who
show symptoms. Those symptoms include:
· Fever
· Joint pain or
swelling
· Swollen lymph nodes
· Lethargy
· Appetite loss
· Increased thirst and
urination
If left untreated, the disease can damage the kidneys,
nervous system, and heart and cause chronic joint pain. Kidney damage from Lyme
disease is typically fatal, and damage to the nervous system can lead to
seizure disorders. Heart damage due to Lyme disease is rare.
Diagnosis, treatment, and
prevention
To diagnose Lyme disease, your dog's veterinarian will
examine its clinical signs, exposure to black-legged ticks, and test results.
Dogs produce antibodies 4-6 weeks after infection, which can be detected
through testing.
Lyme disease is treated with antibiotics, typically for
around a month. Most symptoms clear up quickly with antibiotic treatment. The
choice of antibiotic and the duration of treatment can depend on the severity
of the symptoms, the stage of the disease, and the dog's overall health. While
antibiotics are effective in most cases, it's critical to complete the entire
course of treatment, even if symptoms improve, to prevent the recurrence of the
disease and reduce the risk of complications.
Like so many diseases, the best treatment is prevention.
Consistent usage of tick-preventative products can help your pet stay
tick-free, and it's important to avoid tick hotspots like fields with long
grass.
Your veterinarian might suggest vaccinating your dog
against Lyme disease, depending on its needs and exposure to ticks.
When would it be
appropriate to get your dog vaccinated for Lyme?
Jenny Marin, clinical assistant professor in
Community Practice at the Veterinary Teaching Hospital, said, "We
recommend vaccinating all dogs for Lyme in this area (SW Virginia) starting
when they are puppies."
Beyond vaccination and tick-preventive products, reducing
exposure to ticks through environmental management is a critical strategy in
Lyme disease prevention. This includes maintaining lawns, clearing brush and
leaf litter, and creating tick-safe zones using wood chips or gravel barriers.
Personal protective measures, such as checking dogs for ticks after outdoor
activities and promptly removing ticks, are also good steps. Prompt tick
removal is important — it typically can take 1-2 days for the bacteria to
transmit from the tick to the animal.
One last reminder: Remember that your dog can't directly spread Lyme
disease to you or your other pets; the disease-causing bacteria can only be
spread through tick bites!
Contact:· Andrew Mann 540-231-9005
Article (Source): https://news.vt.edu/articles/2024/04/vetmed-lyme-disease-dogs.html