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Treatment of Trypanosoma Brucei Infection in Horses
316
GENERAL ARTICLES.
TREATMENT
Director
0/
OF TRYPANOSOMA BRUCEI HORSES
INFECTION
IN
By J. L. STEWART, M.C., B.SC., M.R.C.V.S., Veterinary Services, Northern Territories, Gold Coast.
THERE is so little literature on the subject of T. brucei infections oi horses that the following ease notes, though eovering three animals only, may be of interest. In the Gold Coast, T. brucei infeetion in horses is virulent and reeoveries are very rare. The writer had never treated a ease sueeessfully until the instances now quoted. Case No. l.-A horse infeeted in August, 1938, was treated with a eombination of naganol, two doses of 2 grammes and one of 4 grammes, at weekly intervals as recommended by the manufacturers, interspersed with tartar emetic dosage from 12 to 15 grains: novarsenobillon was also given as a tonic. After the third dose of naganol, trypanosomes appeared again in the blood six days later; treatment was recommenced giving 4 gramme doses, after the second of which alarming symptoms appeared; the testicles were enlarged, the anus was ulcerated (this is a eommon toxic symptom of naganol) and six days after the second dose the horse developed an acute coronitis followed by laminitis. The animal was very lame and in great pain for several days: sepsis appeared under the coronary band and in the foot. However, the feet gradually recovered und er treatment but the horse again relapsed to T. brucei: antimosan combined with N.A.B. was substituted for the previous treatment and the trypanosomes disappeared from the blood; after two doses of antimosan naganol was again given but in 2 gramme doses only, which treatment was carried on for five weeks when the weekly dose was increased to 3 grammes for seven weeks, the naganol always being reinforced by a dose of 40 c.c. antimosan on the same day. No adverse toxic symptoms occurred during this phase save slight swelling of the sheath. Then a dose of 2·5 grammes of antrypol was substituted for the naganol, which caused tenderness of all four feet, but that disappeared rapidly. Treatment was then stopped to see what would happen and since then, the end of January, 1939, five months ago, no trypanosomes have been found in the blood and the horse has been gaining weight ever since. He has been exercised fairly severely and appears to be recovered but will be kept under observation. Case No. 2.-This horse became infected in early December and was put on the eombined antimosan and naganol treatment which was the second type of treatment whieh the first horse received. He was ten weeks on this treatment with the addition of N.A.B. but received 2 gram me doses of naganol only, no more. During this period he showed no parasites in the blood. Then on the arrival of antrypol from Britain, whieh had been recommended by a Medieal Officer as being less toxie than naganol, the horse was put on 3 gramm es of antrypol: after the second weekly injection of antrypol,
GENERAL ARTICLES.
317
the animal began to ~how the same toxic symptoms as No. 1 horse showed after his second course of naganol. His feet were worse than horse No. 1 and he was in such pain one day that destruction was contemplated but he became rather better the next day. No further treatment was given, the horse slowlv recovered from the toxic symptoms of antrypol and has shown no further trypanosomes in his blood and looks like a recovery. He has been working in a cart for two months. Case No. 3.-The third horse received a course of three injections of antrypol and tartar emetic. After the third dose, he showed a:dema of the chest, wh ich extended to the neck and throat. He became so weak that he was destroyed. Post-mortem lesions were indefinite and it is not clear whether death was due to the disease or to the treatment but this horse was in a very poor state when he arrived at the laboratory and had been infected for some time, the owner attempting treatment hirnself, of the wrong type. If the first two cases are recoveries and they appear to be, they are the first from T. brucei in the Gold Coast. This parasite is very fatal to horses, which appear to be very susceptible to naganol and antrypol, but both drugs are tolerated very weIl by human beings, who can easily stand half the horse dose. Little can be found in literature about treatment of equine T. brucei, which is why the above treatment was so experimental and that it was so opportunistic was due to the sudden appearance of toxic symptoms. 1t is proposed to treat future cases with the combined antimosan and naganol treatment, e;iving very small doses of nagano!.
BIBLIOGRAPHY.
Bennett. (1936). Toleration of naganol by horses. Journal 0/ Comparative Pathology and Therapeutics. Decernber. Tanganyika Territory. Annual report of the Director of Veterinary Services, 1931.
GENERAL ARTICLES.
TREATMENT
Director
0/
OF TRYPANOSOMA BRUCEI HORSES
INFECTION
IN
By J. L. STEWART, M.C., B.SC., M.R.C.V.S., Veterinary Services, Northern Territories, Gold Coast.
THERE is so little literature on the subject of T. brucei infections oi horses that the following ease notes, though eovering three animals only, may be of interest. In the Gold Coast, T. brucei infeetion in horses is virulent and reeoveries are very rare. The writer had never treated a ease sueeessfully until the instances now quoted. Case No. l.-A horse infeeted in August, 1938, was treated with a eombination of naganol, two doses of 2 grammes and one of 4 grammes, at weekly intervals as recommended by the manufacturers, interspersed with tartar emetic dosage from 12 to 15 grains: novarsenobillon was also given as a tonic. After the third dose of naganol, trypanosomes appeared again in the blood six days later; treatment was recommenced giving 4 gramme doses, after the second of which alarming symptoms appeared; the testicles were enlarged, the anus was ulcerated (this is a eommon toxic symptom of naganol) and six days after the second dose the horse developed an acute coronitis followed by laminitis. The animal was very lame and in great pain for several days: sepsis appeared under the coronary band and in the foot. However, the feet gradually recovered und er treatment but the horse again relapsed to T. brucei: antimosan combined with N.A.B. was substituted for the previous treatment and the trypanosomes disappeared from the blood; after two doses of antimosan naganol was again given but in 2 gramme doses only, which treatment was carried on for five weeks when the weekly dose was increased to 3 grammes for seven weeks, the naganol always being reinforced by a dose of 40 c.c. antimosan on the same day. No adverse toxic symptoms occurred during this phase save slight swelling of the sheath. Then a dose of 2·5 grammes of antrypol was substituted for the naganol, which caused tenderness of all four feet, but that disappeared rapidly. Treatment was then stopped to see what would happen and since then, the end of January, 1939, five months ago, no trypanosomes have been found in the blood and the horse has been gaining weight ever since. He has been exercised fairly severely and appears to be recovered but will be kept under observation. Case No. 2.-This horse became infected in early December and was put on the eombined antimosan and naganol treatment which was the second type of treatment whieh the first horse received. He was ten weeks on this treatment with the addition of N.A.B. but received 2 gram me doses of naganol only, no more. During this period he showed no parasites in the blood. Then on the arrival of antrypol from Britain, whieh had been recommended by a Medieal Officer as being less toxie than naganol, the horse was put on 3 gramm es of antrypol: after the second weekly injection of antrypol,
GENERAL ARTICLES.
317
the animal began to ~how the same toxic symptoms as No. 1 horse showed after his second course of naganol. His feet were worse than horse No. 1 and he was in such pain one day that destruction was contemplated but he became rather better the next day. No further treatment was given, the horse slowlv recovered from the toxic symptoms of antrypol and has shown no further trypanosomes in his blood and looks like a recovery. He has been working in a cart for two months. Case No. 3.-The third horse received a course of three injections of antrypol and tartar emetic. After the third dose, he showed a:dema of the chest, wh ich extended to the neck and throat. He became so weak that he was destroyed. Post-mortem lesions were indefinite and it is not clear whether death was due to the disease or to the treatment but this horse was in a very poor state when he arrived at the laboratory and had been infected for some time, the owner attempting treatment hirnself, of the wrong type. If the first two cases are recoveries and they appear to be, they are the first from T. brucei in the Gold Coast. This parasite is very fatal to horses, which appear to be very susceptible to naganol and antrypol, but both drugs are tolerated very weIl by human beings, who can easily stand half the horse dose. Little can be found in literature about treatment of equine T. brucei, which is why the above treatment was so experimental and that it was so opportunistic was due to the sudden appearance of toxic symptoms. 1t is proposed to treat future cases with the combined antimosan and naganol treatment, e;iving very small doses of nagano!.
BIBLIOGRAPHY.
Bennett. (1936). Toleration of naganol by horses. Journal 0/ Comparative Pathology and Therapeutics. Decernber. Tanganyika Territory. Annual report of the Director of Veterinary Services, 1931.