Synonyms: Piroplasma mutans, Theileria mutans, Theileria buffeli, Theileria orientalis.
Disease: Benign bovine gonderiosis, benign bovine theileriosis, Tzaneen disease, Marico calf disease, mild gallsickness.
Hosts: Ox, zebu. The water buffalo and African buffalo (Syncerus caffer) can be infected experimentally but without causing death.
Location: Lymphocytes, erythrocytes.
Geographic Distribution: Africa, Asia, southern Europe, England, USSR, Australia, North America.
Prevalence: G. mutans is endemic thruout Africa, in the great part of Asia, and in many areas of the USSR and southern Europe. It has been reported by Splitter (1950) in Kansas.
Morphology: The forms in the erythrocytes are round, oval, piriform, comma-shaped or anaplasma-like. About 55% are round or oval. The round forms are 1 to 2 u in diameter and the oval ones about 1.5 by 0.6 u. Binary and quadruple fission occur in the erythrocytes.
There are relatively few Koch bodies in the lymphocytes of the spleen and lymph nodes or free in these organs. They average 8 u in diameter but may range up to 20 u. They contain 1 to 80 chromatin granules from 1 to 2 u in diameter, and are practically all of the macroschizont type. Merozoites have apparently not been seen, but they must occur.
Life Cycle: The vectors of G. mutans in Africa are Rhipicephalus appendiculatus and R. evertsi. In addition, Boophilus annulatus has been found to be able to transmit this species experimentally. Transmission is stage-to-stage. The stages in the tick vectors are unknown.
Pathogenesis: G. mutans is seldom more than slightly if at all pathogenic, altho an acute form of the disease may develop in cattle imported into an endemic area and exposed to massive tick infestation. The mortality is less than 1%.
The signs, course of the disease and lesions resemble those of mild G. annulata infections. Anemia, if present, is slight. Icterus is sometimes present, and the lymph nodes are moderately swollen In acute cases the spleen and liver are swollen, the lungs may be edematous, there are characteristic ulcers in the abomasum, and infarcts may be present in the kidneys„ Hematuria is absent.
The incubation period following tick transmission is 10 to 20 days with a mean of 15 days. The disease lasts 3 to 10 days with a mean of 5 days.
Splenectomy may cause the appearance of parasites in the blood, and indeed Splitter (1950) first observed them in a splenectomized calf.
Immunity: Animals which have once been infected with G. mutans are premunized. There is no cross-immunity between G. mutans and G. annulata, G. lawrencei and T. parva.
Diagnosis: Same as for other species of Gonderia and Theileria.
Treatment: None known.
Prevention and Control: These depend upon tick control.