Abstract:
Only 3 out of 8 South African isolates of Plasmodium durae used in 524 turkeys in 161 passages caused
approximately 50% mortality, a further 3 produced approximately 10% mortality while 2 were found to
be apathogenic. Exoerythrocytic schizonts were the main pathogenic stage. In most survivors the effect
on mass gains was minimal.
Twelve drugs currently available for use in poultry, as well as chloroquin phosphate, were tested for their
activity against experimental infections with Plasmodium durae in domestic turkeys. While chloroquin
phosphate showed a certain degree of effectivity, Amprolium, Amprolium + Ethopabate, Maduramycin,
Toltrazuril, Metronidazole, Furazolidone, Enrofloxacin and Sulfamethoxypyridazine + Trimethoprim were
ineffective. Halofuginone and Penta-Sulfa at a high dose had some protective effect. At high doses
Sulfachloropyrazine protected from mortality without affecting the parasitaemia, while Sulfamonomethoxine
suppressed parasitaemia without entirely protecting from mortality. From these data it is concluded that
Halofuginone has a potential as possible chemoprophylactic. While a combination of Sulfamonomethoxine
and Sulfachloropyrazine could be used in the treatment of outbreaks in the field.
