Anaplasmosis in North Texas: Symptoms, Transmission, and Treatment

Of all the tick-borne diseases circulating in the DFW Metroplex, anaplasmosis is one of the most overlooked — partly because it is not yet as well-known as Lyme disease or Rocky Mountain Spotted Fever, and partly because its symptoms in the early stages look almost identical to the flu. But anaplasmosis is no minor inconvenience. In North Texas, where the Lone Star tick and black-legged tick both overlap in habitat, anaplasmosis exposures are more common than public awareness suggests, and severe cases can land patients in the ICU. Here is what every DFW homeowner and pet owner should know.

What Causes Anaplasmosis?

Anaplasmosis is caused by the bacterium Anaplasma phagocytophilum, which infects white blood cells — specifically the neutrophils that serve as the immune system’s first line of defense. The bacterium is transmitted through the saliva of infected ticks during feeding. Once inside the bloodstream, it suppresses the immune response, leaving the patient more vulnerable to both the bacterial infection itself and secondary infections. It is a reportable disease in Texas, tracked by the Texas Department of State Health Services, and case counts have been increasing nationally over the past decade.

Which Ticks Transmit Anaplasmosis in North Texas?

In the eastern United States and the Midwest, the primary vector is the black-legged tick (Ixodes scapularis), sometimes called the deer tick. In Texas, the epidemiology is less straightforward. While the black-legged tick does occur in East Texas and extends into portions of the DFW corridor, research also points to potential transmission by the Lone Star tick and the brown dog tick in some contexts. In practice, this means that North Texas residents face anaplasmosis risk from multiple tick species that are well-established in Tarrant, Dallas, and surrounding counties.

Symptoms: Flu-Like and Easy to Miss

Anaplasmosis symptoms typically appear within one to two weeks of a tick bite. The initial presentation is difficult to distinguish from influenza or a severe cold:

• Sudden onset fever, often above 102°F
• Severe headache and muscle aches
• Fatigue and malaise that can be profound — patients often describe feeling unable to get out of bed
• Chills and sweating
• Nausea, vomiting, or loss of appetite in roughly half of cases
• Rash occurs in fewer than 10 percent of anaplasmosis patients — far less common than in Rocky Mountain Spotted Fever — making clinical diagnosis harder

In immunocompromised individuals, the elderly, or patients on certain medications, anaplasmosis can progress to severe complications including respiratory failure, kidney damage, bleeding disorders, and opportunistic infections. Without treatment, case fatality rates in severe illness can reach 1 percent or more — still a meaningful risk when populations are large.

Diagnosis and Treatment

Diagnosis relies on a combination of clinical suspicion, blood smear examination (which can reveal bacteria inside white blood cells during acute illness), and PCR testing. Like other tick-borne infections in Texas, doxycycline is the treatment of choice for adults and children of all ages. Most patients improve rapidly — often within 24 to 48 hours of starting the antibiotic — which is both encouraging and diagnostically important. A patient who does not improve on doxycycline probably does not have anaplasmosis.

The critical mistake to avoid is waiting. If you have been in tick-prone areas of North Texas and develop a sudden fever with headache and body aches, call your doctor immediately and mention the tick exposure. Physicians familiar with tick-borne illness in the DFW region increasingly treat presumptively rather than waiting days for test results to confirm.

Anaplasmosis in Pets: Dogs Are Also at Risk

Dogs can contract anaplasmosis through the same tick bites that infect humans. Canine anaplasmosis, caused by Anaplasma phagocytophilum or the related Anaplasma platys, produces similar symptoms: lethargy, loss of appetite, painful joints, and fever. Severely affected dogs may develop bleeding tendencies or low platelet counts. If your dog is showing these signs and you live in the DFW area, a visit to your veterinarian with a mention of potential tick exposure can lead to rapid diagnosis and treatment.

Reducing Your Risk in North Texas

Anaplasmosis risk in the DFW Metroplex is tied directly to tick exposure — and that means reducing ticks in and around your yard is the most effective preventive step available. Focus on:

• Keeping grass mowed and edges trimmed, especially along fence lines and wooded borders
• Removing leaf litter, brush piles, and dense ground cover where ticks rest and wait for hosts
• Treating your dog with veterinarian-recommended tick prevention products monthly
• Performing full-body tick checks on family members and pets after outdoor activities
• Applying professional flea and tick control treatments to your yard to eliminate ticks at the source

North Texas Tick Risk Is Not Seasonal — It Is Year-Round

One of the most dangerous misconceptions about ticks in the DFW region is that they are only a spring or summer problem. While tick activity peaks from March through November, North Texas’s mild winters allow ticks to remain active during warm spells throughout the year. A professional yard treatment program that runs from early spring through late fall provides the most consistent protection — and the peace of mind that comes with knowing your family and pets are not walking through a yard full of tick hazards. For more on the range of diseases these ticks can cause, see our post on alpha-gal syndrome and the Lone Star tick.