Babesia bovis

Introduction

• These species are found in erythrocyte of cattle.
• Small, piroplasm measuring 2.4 µm and slightly larger than divergens.
• Trophozoites in erythrocytes are pyriform (pear-shaped), round or irregular.
• Vacuolated signet ring forms are especially common.
• Vectors: Boophilus microplus, Rhicephalus bursa, Laxdesricinus. Transmission is transovarian usually, except stage to stage through bursa.
• Clinical signs, diagnosis, treatment are similar to bigemina. Incubation period is 4-10 days.

Species found in sheep and goat

• Four species of Babesia infects sheep and goat. One is large form and three small form.

2. motasi: Large form; 2.5-4x 2µm. Occurs singly or pair forming acute angle. Vector: Dermacenter silvarum, Haemaphysalis punctata, Rhicephalus bursa.
3. ovis: Smaller form, Piroplasms are round and lie in margin of erythrocytes, Trophozoites are pyriform shaped and form obtuse angle.
4. foliate: Leaf-shaped. Trophozoite lie centrally in RBC.
5. taylori: Small form.

Species in Horse

Two species occurs in horse: One large form and other small form.

a. B. cabali:

• Large form and resemble bigemina.
• Occur in pairs forming acute angle
• Pyriform in shape and measure 2.5 – 4 µm in length.
• Round or oval form may also occur.
• Vector: Dermacenter marginatus, Hyalamma sps., Rhipicephalus bursa.
• Incubation period is 6-10 days. Hemoglobinuria is rare in horse.

b. B. equi (Theiloria)

• Small form measuring 1-3 µm in length.
• Parasite has tendency to divide into four daughter organisms which appear like ‘Maltese cross’.
• Pyriform, round, amoeboid or annular forms are found.

Babesias in dogs and cats

• Four species of Babesia occurs of which three infect dogs and one infects cats.

1. Dogs: canis, B. gibsoni, B. vogeli
2. Cats: felis