Levavet

In cattle and sheep, levamisole is used to treat a variety of nematodes, including stomach worms (Haemonchus, Trichostrongylus, and Ostertagia spp.), intestinal worms (Trichostrongylus, Cooperia, Nematodirus, Bunostomum, Oesophagostomum, and Chabertia spp.), and lungworms (Dictyocaulus spp.). 

In pigs, it is used to treat nematodes such as large roundworms (Ascaris suum), nodular worms (Oesophagostomum spp.), intestinal thread worms (Strongyloides ransomi), and lungworms (Metastrongylus spp.). Levamisole has been used for treatment of endoparasites in dogs and as a microfilaricide. Macrocyclic lactones (e.g., milbemycin oxime or ivermectin) are considered a preferred heartworm microfilaricide.

Levamisole is an antiparasitic drug of the imidazothiazole class. It eliminates a variety of parasites via neuromuscular toxicity. Levamisole has an immunorestorative effect  in animals, but the mechanism of action on the immune system is unknown. It may activate and stimulate proliferation of T cells; augment monocyte activation; and stimulate macrophages, including phagocytosis and chemotaxis. It may increase  neutrophil mobility. However, it is not cytotoxic to neutrophils or immune cells.

ASPIRIN: Levamisole may increase salicylate levels
CHLORAMPHENICOL: Fatalities have been reported after concomitant levamisole and chloramphenicol administration; avoid using these agents
together

CHOLINESTERASE-INHIBITING DRUGS (e.g., organophosphates,
neostigmine): Could theoretically enhance the toxic effects of levamisole;
use together with caution
NICOTINE-LIKE COMPOUNDS (e.g., pyrantel, morantel, diethylcarbamazine): Could theoretically enhance the toxic effects of levamisole; use together with caution.
WARFARIN: Increased risk for bleeding

Adverse effects that may be seen in cattle can include muzzle foaming or hypersalivation, excitement or trembling, lip-licking and head shaking. These effects are generally noted with higher than recommended doses or if levamisole is used concomitantly with organophosphates. Signs generally subside within 2 hours. When injecting into cattle, swelling may occur at the injection site. This will usually abate in 7–14 days, but may be objectionable in animals that are close to slaughter.

Meat and Milk: 1 day