Piroplasmosis in pronghorn
Piroplasmosis in pronghorn is a blood parasitic disease caused by protozoans called piroplasms (parasites related to Babesia and Theileria). These microorganisms invade and destroy the animal's red blood cells. The pronghorn, a species nati...
What is it?
Piroplasmosis in pronghorn is a blood parasitic disease caused by protozoans called piroplasms (parasites related to Babesia and Theileria). These microorganisms invade and destroy the animal's red blood cells. The pronghorn, a species native to North America, can be affected through contact with ticks carrying the parasite. This disease remains rare and is mainly documented in wild pronghorn or those in captivity in areas where vector ticks are present.
Commonly observed signs
These signs are neither exhaustive nor specific. Only a veterinarian can establish a diagnosis.
Related signs — each one links to its page:
Signs often appear gradually after infestation. The animal becomes listless, eats less, and loses weight. The mucous membranes (gums, inner eyelids) become pale due to destruction of red blood cells. Fever may be present in the acute phase. In advanced cases, a yellowish discoloration (jaundice) of the mucous membranes and dark urine may appear, a sign that the liver is struggling to eliminate pigments from blood breakdown. The animal is fatigued, moves less, and may isolate from the rest of the group.
When to consult without delay
This list does not replace veterinary advice. It gathers situations that justify a prompt consultation.
Causes and risk factors
The disease is caused by piroplasm protozoans transmitted by ticks. These parasites enter the pronghorn's red blood cells, multiply within them, and then cause them to rupture (hemolysis). This massive destruction of red blood cells leads to anemia and release of pigments that overwhelm the liver.
Living in an area infested with ticks, sharing habitat with other hoofed animals that are healthy carriers, a climate that supports tick populations year-round, and an immune system weakened by stress (transport, captivity, or other illness) all increase the risk of developing clinical signs.
Transmission
Transmission occurs through the bite of infected ticks, which act as vectors by injecting the parasite into the bloodstream during their blood meal. There is no direct transmission from one animal to another without passage through a tick.
Diagnosis and care
Diagnosis is the veterinarian's responsibility, based on clinical examination and laboratory tests. Care is decided case by case.
Your veterinarian will rely on the history of tick exposure, clinical examination (pale mucous membranes, fever) and especially blood tests. A blood smear sometimes allows direct observation of the parasite inside the red blood cells. Additional blood tests evaluate the extent of anemia and effects on the liver and kidneys.
Treatment
Treatment is based on antiparasitic drugs targeting piroplasms, prescribed and adjusted by your veterinarian according to the animal's condition. Supporting care (fluids, supportive therapy) is often necessary to help the animal overcome anemia and the acute phase. Self-treatment should not be attempted, as these drugs have a narrow therapeutic margin in wild species.
Treatment depends on the cause and the animal's condition: it must be determined by a veterinarian. No self-medication.
Prevention
Prevention primarily relies on tick control: suitable external antiparasitic treatments, environmental management (clearing vegetation, reducing moist areas where ticks thrive), and regular inspection of the animals' coats. Limiting contact with asymptomatic hoofed animal populations in breeding facilities or zoos also reduces risk.
Possible complications
Untreated severe anemia can lead to multi-organ failure, particularly affecting the kidneys and liver. Stress from restraint or transport can worsen the condition of an already weakened animal. In severe cases, the outcome can be fatal, especially in young animals or those already compromised by other diseases.
When to see a veterinarian
The animal appears lethargic and refuses to eat for several hours.
The mucous membranes appear pale or yellowish.
Fever is detected or suspected.
The animal isolates itself from the group and remains lying down abnormally.
The urine appears abnormally dark.
Prognosis
The prognosis depends on how quickly treatment is started. When detected early and treated, piroplasmosis has a favorable prognosis in many cases. Without treatment or in severe forms with profound anemia, the prognosis becomes guarded, especially in young animals or those that are debilitated.
Frequently asked questions
Can piroplasmosis of the pronghorn be transmitted to humans?
No, this disease is not known to be transmissible to humans. It circulates only via ticks between animals.
Can a healed pronghorn become sick again?
Yes, a new bite from an infected tick can cause a new infection, especially if the animal remains exposed to the same risk areas.
How can I tell if my pronghorn has been bitten by a tick carrying disease?
There is no specific visible sign during the bite itself. Only the appearance of symptoms or a blood test can suggest the disease.
Should an infected pronghorn be isolated from other animals?
Since the disease is not directly transmitted between animals, isolation is not essential from that standpoint, but it does facilitate monitoring and care.
References
WOAH — Organisation mondiale de la santé animale (ex-OIE)
Content reviewed by the TunisieVet editorial team · Updated 06 September 2026
Comments (0)
No comments yet.
AT A GLANCE
Need a veterinarian?
Find a practitioner near you on TunisieVet, with their specialities, hours and contact details.
Find a veterinarianCategories
Affected species
This information is provided for educational purposes only and is not a substitute for a veterinary consultation. If you have any concerns about your animal's health, consult a veterinarian.
Thinking of welcoming a pet? Dogs and cats are waiting for a family in Tunisia, and adoption is completely free.
Adoption listingsTo discover
Related diseases and linked Animalia content.
Foot-and-mouth disease
Viral · Vaccine available
Gastrointestinal parasitism in pronghorn (roundworms)
Parasitic
TunisieVet in your pocket 📱🐾 Access your veterinary services wherever you are. [ Download the app ]
Learn more