Parasite Forecasts

Anaplasmosis Forecast 2019

Anaplasmosis is a tick-borne disease that can affect both dogs and humans.

  • Throughout much of the contiguous United States the risk of anaplasmosis in dogs is remaining the same compared to the previous seven years.
  • Risk of infection is expected to be high in New York and Pennsylvania, most notably eastern Pennsylvania, so pet owners should take care to use tick preventatives on their dogs and cats throughout the year and talk to their veterinarian to learn more about prevention.
  • The local variability in the risk of anaplasmosis is well demonstrated in Massachusetts. Although lower risk of infection is expected near the coast, a slightly higher risk is predicted in the western edge of the state.
  • Three areas are predicted to have a lower than average year: the Atlantic Coast of the New England States, particularly in Massachusetts; much of the upper Midwest, particularly Wisconsin and parts of Minnesota and the upper peninsula of Michigan; and southern Texas.

Anaplasmosis is a disease caused by the bacteria Anaplasma phagocytophilum that infect white blood cells or Anaplasma platys that infect platelets (cells that aid in clotting).  Both bacteria are transmitted through the bite of ticks. The black-legged tick transmits A. phagocytophilum, while the brown dog tick is believed to transmit A. platys. Similar to ehrlichosis, dogs may not show any signs of infection. If they do, common signs include fever, lethargy, poor appetite, and muscle and joint pain. Chronic infection has not been observed.

Although infection is not transmitted directly from an infected dog to humans or other pets in the household, an infected dog does mean that ticks carrying the bacteria are present in the area that could bite and infect other pets and humans. This may be particularly important should your pet be diagnosed after some recent travel where you and your pet were recreating outdoors together.

Most cases of anaplasmosis are seen in the Northeastern and upper Midwestern states because A. phagocytophilum is carried by the same tick that transmits the bacteria that cause Lyme disease. As a result, it is possible to have both of these diseases at the same time. Recent research suggests that the range of black-legged ticks is expanding, bringing anaplasmosis and Lyme disease into new areas of the US. For both these reasons, use of year-round tick preventatives is strongly recommended, even in dogs vaccinated against Lyme disease (because ticks can carry many other pathogens not covered by the Lyme vaccine).

Within any geographic area, there may be several different kinds of ticks and each tick can have several different stages (larvae, nymphs and adults that may look quite different from each other). Also, as noted above an individual tick may also harbor more than one disease-causing agent.  People generally consider the summer to be the only time that dogs and people are at risk of getting ticks; however, some species of ticks or stages, for example brown dog ticks and adult black-legged ticks, can be active throughout the winter. In addition, brown dog ticks can live indoors, increasing risk of year-around exposure. Even though avoiding tall grass and wooded areas can help to minimize your dog’s exposure to ticks, there is still a risk of infection.  That’s why CAPC recommends year-round tick control and regular screening tests for tick-borne infections in dogs.

There is no vaccine to prevent anaplasmosis, so it is essential to use a tick control product that’s recommended by your veterinarian as being right for your dog.  Even with tick control, it’s a good idea to carefully check your dog’s entire body and remove attached ticks as soon as possible. Always use tweezers or other tick-removal devices and wear gloves to prevent exposure to disease-causing agents.

Category: Parasite Forecasts