Lecture 26: Lyme disease

What causes lyme disease?

Borrelia burgdorferi

What does borrelia burgdorferi cause?

Fever, polyarthritis, nephritis

How is lyme transmitted?

• Transtadial infection in ticks

• OspA and OspC cause bacterial adhesion to epithelial and salivary gland cells

• VIsE protein evades immune response

• Bacteria attach and proliferation in skin of dog → replicate and migrate through tissues, morph from spiral to spherical and back

• Most exposures are asymptomatic, presumably because bacteria do not invade connective tissue

• CS caused by inflammatory response

• NK/CD8+ T cell response causes protection against damage

• Gamma interferon expression causes clinical disease

What CS are seen with lyme?

Fever, lethargy, anorexia, shifting leg lameness, edema or effusion w/PLN

CBC findings with lyme?

Anemia, leukocytosis or leukopenia, thrombocytopenia

Chem findings with lyme disease?

Hypoalbuminemia

Most definitive diagnosis but hard to do due to low bacterial numbers

Culture

__ protein on VIsE protein of Borrelia indicated natural exposure

C6

True or false, most clinicians do not treat asymptomatic lyme disease

True

Treatment of lyme disease

Doxycycline, corticodsteriods, PLN, tick control

How can you monitor lyme disease?

• C6 antibody in symptomatic dogs being treated

• Relapses because organism can remain in tissues

• CKD, hypertension, thromboembolism

How do you prevent lyme disease?

• Tick control

• Vaccination, DO NOT vaccinate infected dogs

What is the etiologic agent of Lyme disease in dogs? a) Anaplasma phagocytophilum b) Ehrlichia canis c) Borrelia burgdorferi sensu lato d) Rickettsia rickettsii

c) Borrelia burgdorferi sensu lato

What is the primary mode of transmission for Lyme disease in dogs? a) Direct contact with infected dogs b) Ingestion of contaminated food or water c) Bite of an infected Ixodes tick d) Flea or mosquito bites

c) Bite of an infected Ixodes tick

Which of the following proteins is involved in Borrelia burgdorferi's adhesion to the midgut epithelial cells of the tick? a) OspC b) VlsE c) OspA d) C6

c) OspA

What is the role of the OspC protein in Borrelia burgdorferi infection? a) Bacterial adhesion to midgut epithelial cells of the tick b) Bacterial adhesion to salivary gland cells of the tick and evasion of the host immune response c) Facilitating bacterial migration through tissues d) Causing direct tissue damage

b) Bacterial adhesion to salivary gland cells of the tick and evasion of the host immune response

Most dogs exposed to Borrelia burgdorferi will: a) Develop severe clinical signs immediately b) Require immediate antibiotic treatment c) Remain asymptomatic d) Develop chronic kidney disease

c) Remain asymptomatic

Which of the following is a common clinical sign of Lyme disease in dogs? a) Vomiting and diarrhea b) Coughing and sneezing c) Shifting leg lameness (polyarthritis) d) Jaundice (icterus)

c) Shifting leg lameness (polyarthritis)

Lyme nephritis in dogs is characterized by: a) Increased urine production without protein loss b) Acute, progressive renal failure with proteinuria (membranoproliferative glomerulonephritis) c) Formation of kidney stones d) Bacterial infection of the bladder

b) Acute, progressive renal failure with proteinuria (membranoproliferative glomerulonephritis)

Which of the following diagnostic tests is considered the most definitive for Lyme disease, although difficult to perform? a) C6 Antibody test b) PCR of affected tissue c) Culture of Borrelia burgdorferi d) ELISA or Western blot

c) Culture of Borrelia burgdorferi

The C6 antibody test for Lyme disease in dogs: a) Indicates the presence of Borrelia burgdorferi in the dog's tissues b) Can differentiate between natural infection and vaccine-induced antibodies c) Directly correlates with the severity of clinical disease d) Indicates natural exposure to Borrelia burgdorferi

d) Indicates natural exposure to Borrelia burgdorferi

Which of the following is the recommended primary antibiotic treatment for Lyme disease in dogs? a) Enrofloxacin b) Doxycycline c) Amoxicillin-clavulanate d) Gentamicin

b) Doxycycline

For symptomatic Lyme disease with polyarthropathy, what adjunctive treatment might be considered? a) Antifungal medications b) Antiviral medications c) Corticosteroids d) Phosphate binders

c) Corticosteroids

According to the sources, when is it generally NOT recommended to treat a dog that tests positive for Lyme antibodies? a) If the dog is showing signs of polyarthritis b) If the dog has proteinuria c) If the dog is nonclinical, nonproteinuric, and seropositive d) If the dog has a high quantitative C6 antibody titer

c) If the dog is nonclinical, nonproteinuric, and seropositive

Monitoring of symptomatic, treated dogs with Lyme disease may involve: a) Repeated blood cultures b) Quantitative C6 antibody testing c) OspF antibody testing d) Regular ELISA or Western blot tests

b) Quantitative C6 antibody testing

Which of the following is a recommended method for Lyme disease prevention in dogs? a) Avoiding travel to endemic areas b) Routine antibiotic prophylaxis in endemic areas c) Tick control d) Keeping dogs indoors at all times

c) Tick control

Lyme disease vaccines for dogs work by: a) Directly killing Borrelia burgdorferi in the dog's body b) Preventing ticks from attaching to the dog c) Inducing antibodies against outer surface proteins while the bacteria are in the tick d) Eliminating Borrelia burgdorferi from the environment

c) Inducing antibodies against outer surface proteins while the bacteria are in the tick

Vaccination against Lyme disease is generally NOT recommended for: a) Healthy, seronegative dogs in endemic areas b) Seropositive asymptomatic nonproteinuric dogs in endemic areas c) Sick or proteinuric Lyme positive dogs d) Dogs with a history of tick exposure

c) Sick or proteinuric Lyme positive dogs

In the USA, the main vectors of Borrelia burgdorferi are: a) Rhipicephalus sanguineus (Brown dog tick) b) Dermacentor variabilis (American dog tick) c) Ixodes scapularis (Black-legged tick, deer tick) and Ixodes pacificus (Western black-legged tick) d) Amblyomma americanum

c) Ixodes scapularis (Black-legged tick, deer tick) and Ixodes pacificus (Western black-legged tick)

The "bull's-eye" rash (erythema migrans) seen in human Lyme disease: a) Is a common and easily identifiable clinical sign in dogs b) Is the primary diagnostic criterion for Lyme disease in dogs c) Has been anecdotally reported in dogs but is less severe and transient than in humans d) Indicates a more severe form of Lyme disease in dogs

c) Has been anecdotally reported in dogs but is less severe and transient than in human

Which of the following dog breeds has shown a potential predisposition for developing Lyme disease or Lyme nephritis? a) Boxer b) German Shepherd c) Bernese Mountain dog d) Poodle

c) Bernese Mountain dog

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Lyme disease in dogs is considered a zoonotic disease because: a) It can be directly transmitted from infected dogs to humans b) Humans and dogs share similar clinical signs c) Humans can acquire Lyme disease through the bite of infected ticks, and canine exposure indicates a risk for human exposure d) The same bacterium, Borrelia burgdorferi, affects both humans and dogs

c) Humans can acquire Lyme disease through the bite of infected ticks, and canine exposure indicates a risk for human exposure