Melengestrol is a steroidal progestin and antineoplastic agent which was never marketed. An acylated derivative, melengestrol acetate, is used as a growth promoter in animals. Melengestrol acetate (MGA) is one of six steroidal hormone growth promoters approved for use in Canada and USA. These products are used to improve growth rate and feed efficiency, as well as to suppress estrus in beef heifers (CFIA 2008). They are not approved for use in any species other than beef cattle meant for slaughter. MGA is the only drug of its kind that is administered in animal feed, and its labelled dose in Canada is 0.4mg per heifer per day (CFIA 2008). A mandatory withdrawal of 2 days before slaughter is applied to any animal that is administered MGA.

Prezatide is a tripeptide molecule consisiting of lysine, glycine and histidine, also known as GHK (glycyl-L-histidyl-L-lysine), that forms a complex with copper ions. Prezatide is used in cosmetic products (skin and hair) and is known help wound healing. Prezatide increases the synthesis and deposition of type I collagen and glycosaminoglycan. It is thought to play a role in the modulation of tissue remodeling by increases the expression of matrix metalloproteinase-2, as well as tissue inhibitor of matrix metalloproteinases-1 and -2. Prezatide has antioxidant activity due to its ability to supply copper for superoxide dismutase and anti-inflammatory ability due to the blockage the of iron (Fe2+) release during injury.

Deslorelin is an GnRH agonist used in veterinary. It effects contraception by temporarily suppressing the reproductive endocrine system and preventing production of pituitary (FSH and LH) and gonadal hormones (estradiol and progesterone in females and testosterone in males). The observed effects are similar to those following ovariectomy or castration, but are reversed after the hormone content of the implant is depleted or the implant is removed. As an agonist, deslorelin first stimulates the reproductive system, which can result in estrus and ovulation in females or temporary enhancement of testosterone and semen production in males. Then, down-regulation follows the initial period of stimulation. Although deslorelin can also be an effective contraceptive in males of some species, manufacturer recommends its use primarily in females, since monitoring efficacy in females by suppression of estrous behavior or of gonadal steroids in feces is more straightforward than ensuring continued absence of sperm in males, since most institutions cannot perform regular semen collections. It can, however, be used to ameliorate aggression in males of some species, but higher dosages are usually needed. While the major application of deslorelin was initially male contraception, due to its two differing actions, either the stimulation of oestrus or the sterilization of fertility, its use has been increasing in the bitch as well. SUPRELORIN® F (deslorelin acetate) Implant is a once-yearly, subcutaneous implant that assists in the management of adrenal disease in ferrets.

Florfenicol (Nuflor) is a fluorinated synthetic analog of thiamphenicol. Florfenicol is indicated for the treatment of bovine respiratory disease (BRD) associated with Mannheimia (Pasteurella) haemolytica, Pasteurella multocida, and Haemophilus somnus, for treatment of bovine interdigital phlegmon (foot rot, acute interdigital necrobacillosis, infectious pododermatitis) associated with Fusobacterium necrophorum and Bacteroides melaninogenicus. Florfenicol is a broad-spectrum, primarily bacteriostatic, antibiotic with a range of activity similar to that of chloramphenicol, including many gram-negative and gram-positive organisms; however, florfenicol does not carry the risk of inducing human aplastic anemia that is associated with chloramphenicol. It also has activity against some chloramphenicol resistant strains of bacteria, possibly because it is less affected by the major enzyme produced in plasmid-mediated bacterial resistance against chloramphenicol and thiamphenicol. Although the activity of florfenicol against obligate anaerobes is not addressed in the literature, it is likely to be quite effective. Antibiotic principle of Florfenicol is similar to that of chloramphenicol and Thiamphenicol. Florfenicol inhibits protein synthesis by binding to 70S ribosomal 50S subunits of susceptible bacteria, leading to the inhibition of peptidyl transferase and thereby preventing the transfer of amino acids to extending peptide chains and subsequent protein formation. The bacterial receptor that is the site of action for florfenicol is also considered to be the same as that for chloramphenicol and thiamphenicol. Florfenicol has a fluorine atom instead of the hydroxyl group located at C-3 in the structure of chloramphenicol and thiamphenicol. This prevents the acetylation of bacterial acetyltransferase in this site as to allow florfenicol to be less susceptible to deactivation by bacteria with plasmid-transmissible resistance that involves acetylation of the C-3 hydroxyl group in chloramphenicol and thiamphenicol, and prevents their interaction with bacterial ribosomes.

Trenbolone is an anabolic steroid. It is used on livestock to increase muscle growth and appetite. Trenbolone compounds have a binding affinity for the androgen receptor three times as high as that of testosterone. Once metabolized, the drugs have the effect of increasing nitrogen uptake by muscles, leading to an increase in the rate of protein synthesis. It also has the secondary effects of stimulating appetite, reducing the amount of fat being deposited in the body, and decreasing the rate of catabolism. Short-term side effects include insomnia, high blood pressure, increased aggression, night sweats, and libido.

Tocophersolan (Vedrop, tocofersolan) or d-alpha-Tocopheryl Polyethylene Glycol 1000 Succinate (TPGS) is a watersoluble derivative of the natural active (d-alpha) isomer of vitamin E. The active constituent of the medicinal product is essentially vitamin E (alpha tocopherol). Chronic congenital or hereditary cholestasis is a clinical condition where vitamin E deficiency results from an impaired bile secretion. Decreased intestinal absorption observed in chronic congenital or hereditary cholestatic patients is due to decreased bile secretion and the resulting decrease in intestinal cellular absorption. As a result, fatsoluble vitamins (i.e. vit. E) are not absorbed properly and deficiency can occur. Tocophersolan (Vedrop) is used to treat or prevent vitamin E deficiency (low vitamin E levels). It is used in children up to the age of 18 years who have congenital or hereditary chronic cholestasis and who cannot absorb vitamin E from the gut. Tocophersolan (Tocofersolan) can be absorbed from the gut in children who have difficulty absorbing fats and vitamin E from the diet. This can increase vitamin E levels in the blood and help to prevent neurological deterioration (problems in the nervous system) due to vitamin E deficiency. No treatment-related findings were reported, as all clinical observations and findings at autopsy were similar in treatment and control groups. In many of the studies, the LD50 was not determined as tocofersolan was well tolerated.

Isoflupredone is a veterinary drug used in cows, pigs and horses for the treatment of wide range of conditions: ketosis, musculoskeletal disorders, hypersensitivity, infections, inflammatory diseases, etc. The drug belongs to the class of corticosteroids and exerts its therapeutic effect by binding to glucocorticoid and mineralocorticoid receptors of animals.

Amadione is a steroidal progestogenic antiandrogen. Its anti-androgenic properties were confirmed by blockade of androgen-induced increase in seminal acid phosphatase content.