Anaplasma marginale is found worldwide and is transmitted by Rhipicephalus ticks. Anaplasma phagocytophilum is also found worldwide, mainly transmitted by Ixodes ticks. Other species that cause anaplasmosis in specific species include:

Cattle:
Anaplasma centrale - found mainly in South America, Africa and the Middle East
Sheep and goats:
Anaplasma ovis - found worldwide. There is a prevalence of 82.9% in sheep, and 74.9% in goats. This species is the most prevalent for causing anaplasmosis in sheep and goats, although Anaplasma phagocytophilium can also cause the disease. Anaplasma phagocytophilium has a prevalence of 11.9% in sheep, and 15.2% in goats. Morphology
There are many strains of Anaplasma marginale, all with differing morphology, antigenic properties, protein sequence, and ability to be transmitted by ticks. Major surface proteins (MSP) have been found to play a major role in the infection by Anaplasma marginale. Out of the six MSP found on this species, three of the major surface proteins do not seem to differ between all strains, those including MSP1a, MSP4, and MSP5. The msp1a gene, which codes for MSP1a, is used as a marker for the identification of Anaplasma marginale because it has shown to be conserved in the multiplication of rickettsia in cattle and ticks and has been shown to be involved in adhesion to bovine erythrocytes and tick cells.Anaplasma phagocytophilum is a gram-negative bacterium that does not have lipopolysaccharides or peptidoglycan. The outer membrane does not have a capsule, and is coarse with irregular periplasmic spaces.
The majority of subjects either had undergone pituitary surgery that did not cure Cushings disease or were not surgical candidates. In the 24-week, single-arm, open-label period, all subjects received a starting dose of 2 milligrams (mg) of osilodrostat twice a day that could be increased every two weeks up to 30 mg twice a day. At the end of this 24-week period, about half of subjects had cortisol levels within normal limits. After this point, 71 subjects who did not need further dose increases and tolerated the drug for the last 12 weeks entered an eight-week, double-blind, randomized withdrawal study where they either received osilodrostat or a placebo (inactive treatment). At the end of this withdrawal period, 86% of subjects receiving osilodrostat maintained cortisol levels within normal limits compared to 30% of subjects taking the placebo.The U.S. Food and Drug Administration (FDA) approved osilodrostat based on the evidence from one clinical trial (NCT02180217) of 137 subjects with Cushings disease. The trial was conducted at 66 sites across 19 countries (United States, Argentina, Austria, Bulgaria, Canada, China, Columbia, Germany, Spain, France, Great Britain, India, Italy, Japan, Korea, Netherlands, Russia, Thailand, and Turkey).There was one trial of 48 weeks duration that assessed the benefits and side effects of osilodrostat. The trial enrolled subjects with Cushings disease for whom pituitary gland surgery was not an option or did not work. The trial was divided in four periods. Subjects received osilodrostat two times a day in all four periods.