Gamithromycin, the active pharmaceutical ingredient of ZACTRAN is a novel 7a-azalide that has been developed for treatment and prevention of bovine respiratory disease (BRD). The compound belongs to the 15-membered semi-synthetic macrolide antibiotics of the azalide sub-class with a uniquely positioned alkylated nitrogen at the 7a-position of the lactone ring. Macrolide antibiotics in general have bacteriostatic action by inhibiting bacterial RNA dependent protein biosynthesis, but can also be bactericidal. They reversibly bind to 23S ribosomal RNA in the 50S-subunit of prokaryotic ribosomes and prevent protein elongation during the translocation process. In vitro data show that gamithromycin has both bactericidal and bacteriostatic actions at least at the higher concentrations found in lung tissue. The broad spectrum antimicrobial activity of gamithromycin includes Mannheimia haemolytica, Pasteurella multocida and Histophilus somni, the bacterial pathogens most commonly associated with BRD. Gamithromycin administered subcutaneously is well absorbed and fully bioavailable, and safe for the target animal receiving doses up to five times the recommended dose at 30 mg ⁄ kg body weight. Following s.c. administration, gamithromycin is extensively and rapidly distributed to lung tissue, the site of respiratory infection.

Acepromazine a potent neuroleptic agent with a low order of toxicity, is of particular value in the tranquilization of dogs, cats and horses. Its rapid action and lack of hypnotic effect are added advantages. Acepromazine is a commonly used tranquilizer/sedative in dogs, cats, horses, and other animals. Veterinarians typically prescribe acepromazine to quiet agitated animals or use it as a part of an anesthetic protocol. It is important to note that when used alone, acepromazine is not an effective pain reliever and does little if anything to relieve a pet’s anxiety or fear. Acepromazine can also be used to treat motion sickness and nausea associated with car or plane rides. The mechanism by which acepromazine decreases a pet’s alertness is not fully understood. It is thought to block dopamine receptors in the brain or inhibit the activity of dopamine in other ways.

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.

Tilmicosin is a macrolide antibiotic was prepared by chemical modifications of desmycosin, and is used in veterinary. It is recommended for treatment and prevention of pneumonia in cattle, sheep and pigs, associated with Pasteurella haemolytica, P. multocida, Actinobacillus pleuropneumoniae, mycoplasma species and other microorganisms found sensitive to this compound. Tilmicosin belongs to 16-membered ring group of class macrolides. The antimicrobial mechanism seems to be the same for all of the macrolides. They interfere with protein synthesis by reversibly binding to the 50S subunit of the ribosome. They appear to bind at the donor site, thus preventing the translocation necessary to keep the peptide chain growing. The effect is essentially confined to rapidly dividing bacteria and mycoplasmas. Macrolides are regarded as being bacteriostatic but demonstrate bactericidal activity at high concentrations.

Tylosin (trade names Tylocine, Tylan) is a bacteriostat feed additive used in veterinary medicine. It has a broad spectrum of activity against Gram-positive organisms and a limited range of Gram-negative organisms. It is found naturally as a fermentation product of Streptomyces fradiae. It is a macrolide antibiotic. Tylosin is used in veterinary medicine to treat bacterial infections in a wide range of species and has a high margin of safety. Tylosin is certified by the FDA but is only approved for use in livestock such as cattle, chickens, swine, and turkeys. The FDA has prohibited the use of tylosin in dogs and cats, except where it is specifically prescribed by a veterinarian. Tylosin has a bacteriostatic effect on susceptible organisms, caused by inhibition of protein synthesis through binding to the 50S subunit of the bacterial ribosome.

Cefovecin is a third generation cephalosporin with a broad-spectrum of activity against Gram-positive and Gram-negative bacteria. Cefovecin differs from other cephalosporins in that it is highly protein bound and has a long duration of activity. As with all cephalosporins, the bactericidal action of cefovecin results from the inhibition of bacterial cell wall synthesis through binding to the penicillin-binding proteins (PBPs). It is indicated for the treatment of skin infections secondary superficial pyoderma, abscesses and wounds. Some gastrointestinal adverse effects like vomiting, anorexia or diarrhea were observed.

Maropitant (trade name Cerenia in the U.S. and other countries), used as maropitant citrate is a neurokinin (NK1) receptor antagonist, which was developed by Zoetis specifically for the treatment of motion sickness and vomiting in dogs. It was approved by the FDA in 2007 for use in dogs, and was later approved for use in cats. Maropitant also has anti-nociceptive (analgesic) properties. Maropitant inhibits binding of substance P to NK-1 receptors. Substance P is an emetogen experimentally, and is found endogenously, along with NK-1 receptors, in the emetic center, chemoreceptor trigger zone, and in vagal afferent nerves in the gastrointestinal tract.

Xylazine was developed as an antihypertensive agent. During clinical studies in people xylazine was found to have excessive central nervous system depressant effects and it was subsequently introduced for veterinary use as a sedative, analgesic and relaxant. Xylazine is a potent alpha-2 adrenergic agonist. Xylazine in horses and Cervidae may occasionally cause slight muscle tremors, bradycardia with partial A-V heart block and a reduced respiratory rate. Movement in response to sharp auditory stimuli may be observed.

Embutramide is a veterinary, CNS active medicine used for euthanasia in dogs. The drug is marketed under the name Tributame in the USA and under the name Tanax in Europe. Human consumption of the drug is usually associated with suicide attempts.

Romifidine is an alpha2-adrenergic agonist, which as a sedative and analgesic in horses. The drug was approved by FDA under the name Sedivet. It has no use in humans.