Background

Cattle fever ticks—Rhipicephalus 

(Boophilus) annulatus and 

R. (B.) microplus—are the most 

dangerous cattle ectoparasites 

in the United States. These ticks 

have been a threat to American 

agriculture for generations 

because they spread the disease 

bovine babesiosis, commonly 

called cattle fever. This disease 

caused enormous economic 

losses to the U.S. cattle industry 

in the late 1800s and early 1900s.

A Deadly Cattle Disease

Cattle fever is caused by 

either of two protozoan blood 

parasites carried by cattle fever 

ticks. The parasites, called 

Babesia bigemina and Babesia 

bovis, infect, reproduce in, and 

eventually rupture an infected 

animal’s red blood cells, 

releasing the parasites and 

hemoglobin into the animal’s 

bloodstream. This results in 

anemia and lowered oxygen 

levels in the blood, which can 

cause lowered milk production, 

weight loss, increased 

respiratory rate, and death. 

In addition, infected animals 

sometimes have red-colored 

urine because of the hemoglobin 

the kidneys filter out of the 

blood. This is why the disease 

is also called “red water.” 

Pest Alert Veterinary Services

April 2010

Cattle Fever Ticks and Cattle Fever

Disease Spread

Cattle fever ticks ingest the 

protozoa while taking a blood 

meal from an infected animal. 

The ingested protozoa develop 

and eventually migrate to the 

tick’s reproductive system and 

are passed on to any eggs laid. 

Tick larvae that hatch from these 

eggs are already infected with 

the protozoa when they begin 

to feed on a new animal. This 

is how the infection is passed 

between tick generations and 

between host animals.

Potential hosts of cattle fever 

ticks include, but are not limited 

to: livestock (mainly cattle and 

horses), white-tailed deer, and 

exotic hoofstock, such as nilgai 

antelope and red deer. Cattle 

fever ticks do not attach to 

humans.

Cattle Fever Tick 

Life Cycle

Cattle fever ticks develop 

through three life stages while on 

the host animal: larva, nymph, 

and adult. Each adult female tick 

Figure 1. Three of the cattle fever tick’s 

four life stages are (from left to right): larva 

(six-legged and looks like a small black dot), 

nymph, and adult. Nymphs and adults are 

eight-legged.

Figure 2. This figure shows various female 

ticks, including (from left to right) Rhipicephalus (Boophilus) spp., a cattle fever 

tick; Dermacentor spp.; and Amblyomma

spp.

Figure 3. This photo shows various male ticks, including (from left to right) Rhipicephalus 

(Boophilus) spp., a cattle fever tick; Dermacentor spp.; and Amblyomma spp.
mates while on the host animal. 

After engorging with host blood, 

it drops off to lay 4,000 or fewer 

eggs on the ground. The eggs 

hatch into larvae, which attach 

to animals that walk by the larval 

cluster—and the cycle continues. 

Up to four generations of ticks 

can be produced each year.

Eradication Efforts

The U.S. Department of 

Agriculture’s (USDA) Cattle 

Fever Tick Eradication Program 

(CFTEP) has been fighting the 

spread of these ticks since 

1906; however, in recent years, 

cattle fever tick infestations have 

increased significantly in number. 

Because cattle fever and the 

ticks that spread it are common 

to parts of Mexico, the CFTEP’s 

mounted patrol inspectors 

routinely perform patrols along 

horse trails that they maintain 

alongside the Rio Grande, to 

monitor for signs of stray or 

smuggled livestock from Mexico 

that might carry fever ticks into 

the United States. Intercepted 

animals are inspected, sprayed 

with the pesticide coumaphos, 

and quarantined. Land the 

intercepted animals have 

traversed is also quarantined. 

Inspectors also watch for illegal 

livestock movements. Currently, 

there are seven permanent 

CFTEP work areas in South 

Texas, from Brownsville on the 

eastern end to Del Rio on the 

western end (fig. 5).

Report Suspected 

Cattle Fever Ticks

We need your help. If you suspect 

that you have found a cattle 

fever tick, please contact one of 

the area offices at the numbers 

listed below. The area supervisor 

can also provide you with more 

information regarding cattle fever 

ticks and the eradication program.

Contact Us

To report a suspected cattle 

fever tick or learn more about 

these pests, please contact the 

closest area office.

Area 1-Brownsville:

(956) 546-6004

Area 2-Mission:

(956) 580-3355

Area 3-Rio Grande City:

(956) 487-5007

Area 4-Zapata:

(956) 765-4911

Area 5-Laredo:

(956) 723-3051

Area 6-Eagle Pass:

(830) 773-5565

Area 7-Del Rio:

(830) 775-5452

Photo Credits: All photos were either 

taken by USDA employees or are part of 

the photo collection of USDA’s Animal 

and Plant Health Inspection Service.

USDA is an equal opportunity provider 

and employer.

United States Department 

of Agriculture

Animal and Plant Health 

Inspection Service

Program Aid No. 2045

Issued April 2010

Figure 5. Map of South Texas counties 

showing CFTEP work areas. For work area 

contact numbers, refer to “Contact Us.”

Figure 4. The distribution of cattle fever 

ticks before the CFTEP began in 1906 is 

depicted in blue. This same area could 

become infested again if current infestations are left uncontrolled.