A Year-Round Threat: Vaccinating for Lyme Disease in Nonendemic Areas

Sponsored by Elanco

Lyme disease can cause serious health problems in dogs, and all pet owners may be aware that the ticks that carry Borrelia burgdorferi, the causative agent of Lyme disease, are spreading into new areas of the country.^1,2 These changes require veterinary teams to be more proactive in educating owners about the risks of vector-borne diseases and multimodal strategies for prevention.

Case Presentation

Ruby, a 12-week-old Labrador retriever, is presented for her first puppy visit at a clinic in Ohio. The owners want to make sure Ruby is well protected but are hesitant to vaccinate for diseases that she is at low risk for contracting or that are unlikely to make her sick. They do plan to use parasite prevention, but only seasonally, and they are concerned about giving parasite prevention to such a young puppy.

Assessing Risk Factors & Key Client Education Points

While taking Ruby’s weight and history, the veterinary team takes this opportunity to discuss noncore vaccinations, such as those for Lyme disease and leptospirosis, and why seasonal tick control may not be enough to protect Ruby.

Historically, the decision to vaccinate against Lyme disease has been based on environmental and lifestyle risk assessment. Dogs in rural areas or spending time in the woods have been considered at high risk. However, the distribution of Ixodes scapularis, the tick that transmits Borrelia burgdorferi, is changing due to many factors, including warmer temperatures, changing humidity, and altered distribution of hosts such as white-tailed deer and mice, which have moved into more urban areas.^2,3

In addition, ticks can now be found year-round in most areas of the United States, including where Ruby lives in Ohio.^3,4 The life cycle of Ixodes scapularis progresses through 3 life stages. Each life stage has peak activity times during the year, with nymphs being more active in the spring, summer, and fall and adults more active in fall and winter. Although ticks will usually become dormant when temperatures fall below 37°F to 40°F, any temperatures above this range, even for a brief time, can result in ticks questing for their next blood meal. This means that, in most areas of the United States, ticks can be active even in winter.

Once Ruby’s owners understand that dogs in all areas and of all lifestyles can be at risk for tick bites all year long, they ask the veterinary team what more they can do to protect Ruby.

Prevention Strategies

Prevention should be multimodal and include year-round tick control through use of environmental modification, preventives, and vaccination.

Environmental control does not eliminate the risk for tick exposure but can help separate tick-friendly environments from areas where dogs and their families spend most of their time. Landscaping should remove leaf litter, keep grass short, and minimize brush and vegetation near areas where dogs will be.⁵ Ruby’s owners live on a street with no wooded areas nearby, but she goes out in their small yard lined with bushes and walks through the neighborhood daily, often encountering patches of taller grass along the sidewalk.

Numerous tick preventives are available. The ideal prevention should prevent tick attachment and/or have a rapid speed of kill, such as the newer isoxazoline class of preventives.³ The veterinary team advises Ruby’s owners that year-round tick control also helps prevent other tick-borne diseases for which vaccines are not available.

Although available tick preventives are highly effective, client compliance is a concern.⁶ Maximizing protection against Lyme disease is done through vaccination. Ideal vaccines will protect against multiple outer surface proteins of Borrelia burgdorferi.³ The vaccines should be given as an initial series of 2 vaccines, given 2 to 4 weeks apart, then as annual boosters.⁷

Conclusion

Based on the increasing risk in their region and their desire to keep Ruby healthy while allowing her to explore her environment, Ruby’s owners elect to vaccinate her for Lyme disease at her first visit, and Ruby receives a combination vaccine that protects against both Lyme and leptospirosis. They are given a sample of the clinic’s preferred flea/tick preventive and schedule an appointment for a vaccine booster in 3 weeks. Because the veterinary team was proactive in educating her owners on the risks of tick exposure and tickborne diseases, Ruby is well protected from Lyme disease.