Benazol Vet

Albendazole is labeled for the following endoparasites of cattle (not lactating): Ostertagia ostertagi, Haemonchus spp., Trichostrongylus spp., Nematodius spp., Cooperia spp., Bunostomum phlebotomum, Oesphagostomum spp., Dictacaulus vivaparus (adult and 4th stage larva), Fasciola hepatica (adults), and Moniezia spp. 

In sheep, albendazole is for treating the following:
endoparasites: Ostertagia circumcincta, Marshallagia marshalli,
Haemonchus contortus, Trichostrongylus spp., Nematodius spp., Cooperia spp., Oesphagostomum spp., Chibertia ovina, Dictacaulus filaria, Fasciola hepatica, Fascioides magna, Moniezia expansa, and Thysanosoma actinoides.
Albendazole is also used (extra-label) in small mammals, goats and swine for endoparasite control.
In cats, albendazole has been used to treat Paragonimus kellicotti infections. In dogs and cats, albendazole has been used to treat capillariasis. In dogs, albendazole has been used to treat Filaroides infections.
(Ref: Plumb's Veterinary Drug Handbook, 7th edition)

The drug is not for use in lactating dairy cattle. The manufacturer recommends not administering to female cattle during the first 45 days of pregnancy or for 45 days after removal of bulls. 

In sheep, it should not be administered to ewes during the first 30 days of pregnancy or for 30 days after removal of rams.
Pigeons and doves may be susceptible to albendazole and fenbendazole toxicity (intestinal crypt epithelial necrosis and bone marrow hypoplasia).

Benzimidazole antiparasitic agents have a broad spectrum of activity against a variety of pathogenic internal parasites. In susceptible parasites, their mechanism of action is believed due to disrupting intracellular microtubular transport systems by binding selectively and damaging tubulin, preventing tubulin polymerization, and inhibiting microtubule formation. Benzimidazoles also act at higher concentrations to disrupt metabolic pathways within the helminth, and inhibit metabolic enzymes, including malate dehydrogenase and fumarate reductase.

Pharmacokinetics: Pharmacokinetic data for albendazole in cattle, dogs and cats was not located.
The drug is thought better absorbed orally than other benzimidazoles. Approximately 47% of an oral dose was recovered (as metabolites) in the urine over a 9-day period.
After oral dosing in sheep, the parent compound was either not detectable or only transiently detectable in plasma due to a very rapid first-pass effect. The active metabolites, albendazole sulphoxide and albendazole sulfone, reached peak plasma concentrations 20 hours after dosing.

Adverse effects include anorexia, lethargy, and bone marrow toxicity. 

Leukopenia and thrombocytopenia are possible in dogs and cats. Albendazole has an affinity for rapidly dividing cells and may cause toxicity to bone marrow and intestinal epithelium. High doses have been associated with bone marrow toxicity in dogs and cats, and it should be used cautiously in small animals. In other species, at approved doses, there has been a wide margin of safety.

Dogs treated at 50 mg/kg twice daily may develop anorexia. Cats may exhibit clinical signs of mild lethargy, depression, anorexia, and resistance to receiving the medication when albendazole is used to treat Paragonimus.
Albendazole has been implicated in causing aplastic anemia in dogs, cats, and humans.

Doses of 300 mg/kg (30X recommended) and 200 mg/kg (20X) have caused death in cattle and sheep, respectively. Doses of 45 mg/kg (4.5X those recommended) did not cause any adverse effects in cattle tested. Cats receiving 100 mg/kg/day for 14–21 days showed signs of weight loss, neutropenia and mental dullness.

The drug is not for use in lactating dairy cattle. The manufacturer recommends not administering to female cattle during the first 45 days of pregnancy or for 45 days after removal of bulls. 

Adverse effects are more likely when administered for longer than 5 days. Avoid high doses.