Also see Systemic Pharmacotherapeutics of the Reproductive System and chapters on the management of reproduction in cattle, goats, horses, pigs, sheep, and dogs and cats.
Increased demand for production efficiency, along with changes in management systems, have led to a shift in treatment strategies for reproductive disorders in several domestic species. Especially for food- and fiber-producing animals, the preferred therapeutic approach is often a combination of pharmacological agents and correction of management problems targeting the entire herd, with decreased emphasis on individual animals. This trend is also reflected in the prioritization of disease prevention and implementation of biosecurity programs. The increased use of hormonal pharmacological agents for reproductive management on a whole-herd basis is another aspect of this change. Other trends in the treatment of reproductive disorders in food animals are the result of consumer concerns regarding antimicrobial and hormone residues in animal tissues and milk, as well as increased interest in organic or natural foods.
In small animals, treatment strategy has undergone a different but equally dramatic transformation. Individual patients remain the focus of treatment efforts, but diagnostic techniques and treatments have become increasingly sophisticated, often reflecting or even presaging advances in human medicine.
More effective treatment of reproductive diseases comes with the risk of propagating a hereditary predisposition for lowered fertility. However, the heritability of most reproductive traits is rather low, so selection programs aimed at improving fertility require a longterm commitment to be successful.
Pharmacological Control of Reproduction in Animals
Exogenous hormone therapy can be administered to regulate or control reproduction. This control may take the form of suppression, or induction and synchronization, of reproductive activity. The same hormone may be given for both purposes. For example, progestogens are used to suppress estrus in mares, dogs, and queens but are also used in mares, cows, and sows to induce and synchronize estrus for managed breeding programs. Steroid hormones with estrogenic, androgenic, and progestational effects have a wide variety of applications.
Gonadotropins and GnRH are administered to alter gonadal function. Examples include superovulation of cattle with follicle-stimulating hormone, induction of ovulation in mares with human chorionic gonadotropin or GnRH analogues, and stimulation of testosterone production with GnRH for diagnosis of cryptorchidism in dogs and stallions.
Prostaglandin F2alpha is used primarily to terminate luteal function. Clinical applications include induction or synchronization of estrus in polyestrous species; treatment of pyometra in dogs, cats, and cattle; and induction of abortion in luteal-dependent species, such as goats, alpacas, dogs, and cats.
Depending on the species, glucocorticoids, prostaglandin, and oxytocin, alone or in combination, can be administered to induce or manage labor. They should be used with caution and at the appropriate time and dosage; the dam and fetus should be carefully observed for the development of any problems.
Assisted Reproductive Technologies for Animals
Many assisted reproductive technologies in general use today were first developed in animals used for research or commercial programs. Such technologies include artificial insemination (for breeding cattle, dogs, sheep, goats, pigs, and horses), as well as embryo transfer and in vitro fertilization in both cattle and horses. Somatic cell nuclear transfer (cloning) is less common but has been performed in a variety of animal species.
Antimicrobial Treatment for Reproductive Infections in Animals
Antimicrobial agents, most commonly antibiotics, are used to treat infections of the male and female reproductive tracts in all species (see also Antibacterial Agents). Whenever possible, drug selection should be based on microbiological culture and susceptibility test results. Dosage, route of administration, and interval between treatments vary among species. In food animals, proper withholding times must be observed for meat and milk after antimicrobial use. Careful consideration should be given to the selection of antimicrobials (or any drug) administered to pregnant animals, because these drugs can adversely affect the fetus.
Surgical Treatment for Reproductive Disorders in Animals
Surgical repair is indicated for acquired conformational damage to the genital system in both sexes. Examples include episioplasty, vestibulovaginal or cervical cerclage, and cesarean section in females, and repair of preputial or penile injuries in males. Surgical sterilization is also routinely done, either by gonadectomy in both sexes of most species or by ovariohysterectomy in female cats and dogs.
For More Information
Skinner MK, ed. Encyclopedia of Reproduction. 2nd ed. Elsevier, Academic Press; 2018.
