Introduction
Theilerioses are a group of tick-borne diseases caused by eukaryotic obligate intracellular protozoan parasites from the Theileria genus. Many Theileria species are present in both domestic and wild ungulates across tropical and subtropical regions worldwide. The most significant species affecting cattle are T. parva and T. annulata, which lead to severe illness and high mortality rates.
Synonyms of the Disease:
- East Coast fever/ corridor disease: T. parva~ Rhipicephalus ticks
- Tropical theileriosis/ Meditterranian theileriosis: T. annulata~ Hyalomma
Life cycle
Vectors:
- T. parva~ Rhipicephalus ticks
- T. annulata~ Hyalomma
Pathogenesis:
Clinical signs:
Clinical signs of infection vary depending on the severity of the challenge, ranging from mild or inapparent to severe and fatal.
- Fever typically develops 7–10 days after parasite introduction by feeding ticks, lasting throughout the infection, and can exceed 107°F (42°C).
- As the number of infected lymphoblasts increases, lymph node swelling becomes prominent and widespread.
- Anorexia develops, and the animal loses body condition rapidly;
- Lacrimation and nasal discharge may also occur, pulmonary edema is common.
- In the terminal stages, dyspnea is common.
- Jaundice or hemoglobinuria in some cases.
- Just before death, a sharp drop in body temperature is typical, and pulmonary exudate often pours from the nostrils. Death generally occurs 18–24 days after infection.
Diagnosis:
The diagnosis of disease caused by T. parva and T. annulata is confirmed through microscopic examination of Giemsa-stained smears from lymph node needle aspirates, looking for schizonts in infected leukocytes. The intra-erythrocytic piroplasm stages can also be easily identified in stained blood smears.Definitive diagnosis can also be confirmed using antigen-specific ELISAs or PCR on lymph node aspirates.
Treatment:
Treat the infection: Buparvaquone, typically used with anti-inflammatory drugs and diuretics if pulmonary edema is present, is the only compound available for treating diseases caused by Theileria parasites. It is most effective when administered in the early stages of the disease, although multiple doses may be necessary. In advanced stages, when there is significant damage to lymphoid and hematopoietic tissues, treatment is less effective. Resistance to buparvaquone has also been reported in T. annulata.
Treat the clinical problems: Edema , Anemia, Fever, Anorexia, Jaundice,
(Meloxicam, Paracetamol),(Thiamine hydrochloride, Riboflavin, Niacinamide, Vitamin B12, Liver extract),(hematinic),((liver tonic),(Sodium acid phosphate),(Hydroxy ethyl starch in isotonic sodium chloride intravenous infusion 6%),(Frusemide),
Dosing: Buparvaquone @ 2.5 mg per kg of body weight , administered intramuscularly into the deep neck muscle. If the total dose volume exceeds 10 ml, it should be divided and given at different injection sites. Typically, a single dose is sufficient for treatment. However, in more severe cases, a second dose (at the same dosage) may be necessary 48 to 72 hours after the first administration.
Withdrawal Period: Meat: 42 days and Milk: 48 hours
Storage recommendations: Store below 25°C, Protect from light Jump here