ANSC 315 - Ch. 19 - Lyme Disease

What is the name of the bacteria that causes Lyme disease?

Spirochete called Borrelia burgdorferi

What is the vector for Lyme disease?

3-host ticks

What are some examples of reservoir hosts of Lyme disease?

Small mammals, birds, and deer

Where do bacteria multiply in the tick once its attached to the host?

In the midgut

How long does it take for the transmission to become efficient?

48 hours

What is the 3-host tick pathway?

Eggs → larvae → blood meal → nymph dormant → nymph → attach to second host → blood meal → adult → attaches to third hose → mating and laying eggs

Epidemiology of Lyme disease

90% of cases occur in northeastern and and upper central states of the US, particularly in Pennsylvania

Risk of infection

Opportunity of being bitten by infected tick

Density of vector ticks

Proportion of ticks infected

Duration and nature of susceptible host’s activities in infected area

Signs of Lyme Disease in dogs

Lameness, fever, anorexia (2 months after infection)

Arthritis (chronic)

Renal disease (can start acute and progress into chronic)

CNS disorders (in severe cases)

Myocarditis (inflammation of heart muscle)

T/F. It is possible for dogs to become infected with Lyme disease, but not show any clinical signs.

True

How are clinical signs of Lyme disease in cats described?

They are very slight to nonexistent

Diagnosis of Lyme disease

History of exposure to ticks

Antibody tests

Is it possible to distinguish exposure from infection?

No

Treatment for Lyme disease in dogs

Antibiotics

Need to look for clinical signs AND positive antibody test

Is the vaccine preventive against Lyme disease?

There is no research that correlates it to preventing Lyme disease

What is the most effective way to prevent ticks?

Reducing exposure to ticks

What are ways to reduce ticks?

Environmental control

Preventative collars

Thoroughly inspecting animals after being outside

Rapidly removing ticks

T/F. Dead ticks can still transmit bacteria.

True

Are dogs a source of infection to humans?

No, but they are able to bring ticks into the house