Joao B. Botelho, director of veterinary services in Mozambique, worked for a short time at the Veterinary Bacteriological Laboratories of Transvaal (later the Veterinary Research Institute) at Onderstepoort, in 1909. During his stay he continued experiments by a Mr Morphew (who had left) on the treatment of canine piroplasmosis [i.e., babesiosis, or biliary fever]. His results were reported in "Notes on the treatment of canine piroplasmosis with trypan blue" in the Report of the Government Veterinary Bacteriologist (Transvaal) (1909/10, pp. 151-156). Of 21 dogs infected with the disease and then treated with trypan blue, only six died. He concluded that trypan blue was the most effective treatment of the disease available at the time.
By 1913 Botelho was chief veterinary officer in the Department of Agriculture of Mozambique, stationed in Lourenco Marques (now Maputo). In that year the South African Association for the Advancement of Science held its annual congress in Maputo. Botelho became a member of the association, served as joint secretary of Section C for the 1913 meeting, and read a paper on "The sanitary state of the stock of the Lourenco Marques district". His paper was published in the association's Report for that year. Later he represented Mozambique on the association's council for 1926/27. At that time he had qualified as Doctor of Veterinary Medicine (D. Med. Vet.).
Botelho remained in Mozambique, later as director of veterinary services, until the nineteen-thirties. In 1931 he wrote a pamphlet, L'elevage en Mozambique (Cattle breeding in Mozambique; 1931, 8p) for the International Colonial Exhibition. In this publication he pointed out the possibilities the country held with regard to cattle breeding and summarized the numbers and economic value of its livestock. A few years later he published another pamphlet, Colonia de Mozambique: Servicos de veterinaria (1934, 8p). [This publication is listed in the book catalogue of the Onderstepoort Veterinary Research Institute, but could not be found.]