Ronidazole is an antiprotozoal agent. Ronidazole and the other nitroimidazole derivatives damage DNA following reduction of the nitro group. It is used in veterinary for prevention and treatment of various infections including histomoniasis in turkeys, trichomoniasis in pigeons, genital trichomoniasis in cattle, haemorrhagic enteritis in pigs and Tritrichomonas foetus in cats.

Rafoxanide is a halogenated salicylanilide used as a fasciolicide in cattle, sheep, goats, and horses. It is also active against nematodes, and the sheep nasal bot fly. Rafoxanide acts as by uncoupling oxidative phosphorylation of flukes, including reduced ATP levels, decreased glycogen content and accumulation of succinate.

Tenonitrozole is an antiprotozoal given in the treatment of trichomoniasis. It is given orally in a dose of 250 mg twice daily with meals, for 4 days.

Ethopabate is a veterinary drug used in the prophylaxis and treatment of coccidiosis in chickens. It is an arylamide containing one phenyl ring, belonging to monocyclic aromatics, is a very safe drug. It has anticoccidial activity especially against intestinal forms and lacks activity against E. tenella of caecal worms. This drug is a competitor of PABA for absorption by the parasite and interferes with folate synthesis. It has good activity against E. acervulina and some strains of E. maxima and E. brunette. It has been used only in combination with Amprolium first at 4 ppm and later at 40 ppm. This drug has peak activity on 4th day of cycle. Ethopabate is a component of marketed AMPROL PLUS (amprolium, ethopabate), indicated for use as an aid in the prevention of coccidiosis (1) in broiler chickens and (2) in replacement chickens where immunity to coccidiosis is not desired.

Aklomide is an anticoccidial drug, which was approved by FDA fr the prevention of coccidiosis in chickens (in combination with sulfanitran), but lately withdrawn by the manufacturer decision.

Phthalofyne (3-methyl-1-pentyn-3-yl acid phthalate) is a synthetic chemical compound demonstrated to have trichuricidal activity against both Trichuris vulpis and Trichuris trichiura. It was used in veterinary medicine against dog whipworm, Trichuris vulpis, under the brand name Whipcide.

Haloxon is an organophosphorus anthelmintic once used against nematodes of the abomasum and small intestine in ruminants. Haloxon is an organophosphorus cholinesterase antagonist. Laboratory and field trials with 7-day-old, 14-day-old and adult infections of the common gastrointestinal nematodes in 600 sheep showed that Haloxon at a dose rate of 30 to 55 mg. per kg. body-weight was a very highly efficient anthelrnintic. The drug was particularly effective against all stages of Haemonchus contenus, Trichostrongylus spp. and Coopería curticei; it was more active against adult than against larval Ostertagia spp" and Nematodirus spp. High activity was also reported against Strongyloides papillosus, Bunostomum trigono-cephalum and Oesophagostomum venulosumum but not against Trichuris avis nor Chabertia ovina.

Propamidine, an aromatic diamidine compound, is widely used as an antimicrobial agent. Propamidine isethionate, the salt of propamidine with isethionic acid, is used in the treatment of Acanthamoeba infection. Diseases caused by Acanthamoeba include keratitis and granulomatous amoebic encephalitis.

Phanquone is an orthoquinone that is the 5,6-diketo derivative of 4,7-phenanthroline. It derives from a hydride of a 4,7-phenanthroline. Phanquone (Entobex) is an anti-mycotic drug with anti-protozoal activity. Phanquone is active against a wide range of Gram-positive and Gram-negative organisms. Phanquone partically inhibited oxygen consumption by Escherichia coli and Staphylococcus aureus. It was also tried on cases of rheumatoid diseases.

Niridazole is used (but not officially recommended) for the treatment of schistosomiasis, dracunculiasis and tungiasis. The mode of action of niridazole is not fully understood. The major action of niridazole seems to be on the glycogen metabolism of the helminths. The drug also case structural damage to the reproductive system of female schistosomes. Another possible mechanism of action of niridazole involves the inhibition of DNA synthesis in schistosomes. It is metabolized in the liver. The most serious side effects were those connected with the nervous area (convulsion, hallucination, etc.).