No decline in ehrlichiosis forecasted in 2016by by Michael Yabsley, PhD, FRES and Emilio DeBess, DVM, MPVM
Ehrlichiosis continues to pose a problem for dogs in the United States this year, according to the Companion Animal Parasite Council (CAPC).
Although ehrlichiosis is generally common to western Texas, Oklahoma and Missouri, we expect these regions to have even higher activity this year, based on analysis of climatic variables. Higher activity is also predicted in southern California and the southeastern US, especially east of the Mississippi River. Arkansas, where ehrlichiosis is generally common, may see less activity this year, but prevalence is expected to remain high in the region, so continued vigilance and tick control are recommended.
Year-round protection, regular screening
Dogs are primarily infected with Ehrlichia canis via Rhipicephalus sanguineus (brown dog tick), although Dermacentor variabilis (American dog tick) is also capable of transmitting the bacteria. Amblyomma americanum (lone star tick) can transmit both E. ewingii and E. chaffeensis, while the latter can also be transmitted by D. variabilis.
The severity of signs can vary depending on the species of Ehrlichia, but dogs infected with E. canis often progress through three phases: acute infection with fever, anorexia and lethargy; subclinical infection with thrombocytopenia within 2-4 weeks of a tick bite; and the chronic phase, which may result in bone marrow suppression and a poor prognosis occurs months to years after a tick bite. Other signs of infection with Ehrlichia spp. may include lymphadenopathy, petechial and ecchymotic hemorrhages, epistaxis, as well as neurological and ocular signs.
CAPC recommends year-round tick control and regular screening for dogs for a number of reasons: Rhipicephalus sanguineus ticks can live indoors throughout the winter; ticks may harbor multiple pathogens; dogs may experience infections that are subclinical but may later become clinically ill; and some Ehrlichia species pose human health concerns. You can use the CAPC Prevalence Maps to support your recommendation by underscoring the risks in your area and in regions of the country your clients may travel with their pets.
A clinical diagnosis of ehrlichiosis is usually made based on a history of tick exposure, presence of clinical signs and positive serology for the bacteria. Learn more about ehrlichiosis.
The science behind the forecasts
How are the CAPC Ehrlichiosis Forecasts determined? Numerous factors are analyzed, including the number of positive tests and the influence of weather patterns, vegetation indices, the changing distribution of wildlife that may harbor the bacteria, and human population density. Leading parasitologists work in collaboration with a team of statisticians to identify regions of the country that may experience higher parasite incidence in the months ahead. While these forecasts predict the potential risk of a dog testing positive, they do not necessarily reflect clinical disease. Learn more
Drive office visits with local parasite data
In a recent study, 90 percent of pet owners surveyed said they want their veterinarians to provide them with local parasite prevalence data.1 With this information, 89 percent of pet owners are likely to make an appointment with their veterinarians.1 See why communicating parasite prevalence to clients is a public service they really want.
With the CAPC Parasite Forecast Maps, you can help alert pet owners of potential risks in the year ahead and motivate them to safeguard their pets. You can also use the Parasite Prevalence Maps to educate owners on the number of dogs testing positive for Ehrlichia spp. in your county, state and other areas of the country.
The CAPC mobile app makes it easy to provide owners with current information in the exam room. Download the free CAPC app from iTunes in the Medical category.
Because tick activity can change, CAPC can provide you with email alerts for your area. Sign up now.
As always, you are the best resource for pet owners on current parasite activity that could impact their dogs. Your recommendations can help protect your patients and reinforce the bond with your clients.
1 A nationwide survey of 2,000 pet owners conducted by CAPC and Bayer Animal Health. Connecting with today’s clients: the importance of local, timely parasite information, 2015.