Growth Hormone
Bovine Growth Hormone (BGH) acts to increase somatomedin secretion in a manner similar to endogenous GH.  The physiologic effects of BGH is increased cellular glucose and amino acid uptake and lipolysis.  It is used in cattle to promote milk production.  The dose is 500 mg every 2 weeks.  Adverse effects include decreased food intake, decreased rate of pregnancy, and uterine complications (complications with gestation and delivery if conception does occur).

Gonadorelin (Gonadotropin Releasing Hormone, GnRH, Cystorelin®, Factrel®)
Gonadorelin increases the synthesis and release of FSH and LH.  It is used in the treatment of follicular cysts and may also be used to increase fertility in cows with previously retained placentæa.

Follicle Stimulating Hormone (FSH, F.S.H.-P®)
Stimulates follicular growth and œstrogen production in females and spermatogenesis in males.  It is used to induce œstrus for out-of-season breeding and to increase the sperm count in breeding males.

Luteinising Hormone/Human Chorionic Gonadotropin is used in females to control ovulation and to treat persistent infertility.  LH alone is used in male animals to increase testosterone production and cause testicular descent in cryptorchidism.

Œstrogens

The normal œstrogenic actions are similar to those observed in humans.  In veterinary practice, œstrogens are used in the following situations:
Treatment of mismating in dogs -- act as a contraceptive to decrease implantation and ovum transport post-coitus.

Correction of anœstrus in cows (possibly effective) and horses.

Pyometra (inflammation with purulent exudate of the uterus) and mummified fœtus.

Problems associated with spaying (urinary incontinence, vaginitis, dermatitis).

Androgen dependent tumours.

To stimulate growth (anabolic effects -- limited efficacy).

Adverse effects of œstrogens include vaginal or rectal prolapse and abortion (their use is contraindicated during pregnancy).

Steroidal œstrogens most commonly used in veterinary practice include œstrodiol (ECP®), œstrone, and œstriol.
Non-steroidal œstrogens

Zeranol (Ralgro®, Zerano®) -- a naturally occurring mycotoxin with œstrogenic activity
Zeranol exerts an anabolic effect, thus increasing growth in cattle and sheep.  The slaughter withdrawal times are 65 days and 40 days respectively.
Diethylstilbœstrol (DES, Silphostrol®)
DES is used primarily in the treatment of androgen dependent cancers and behavioural problems associated with spaying and also in the treatment of enlarged prostate in male dogs.  A notable side effect of DES in male animals is that the presence of the œstrogenic hormone in the male dog may cause it to appear to be receptive to unwanted affections of other male dogs!

Progestins

Physiologically, the progestins increase sex-glandular growth (in conjunction with œstrogens) and desensitise the myometrium to the effects of oxytocin (thus decreasing uterine contractions).
Altrenogost (Regu-Mate®) and melengœstrol -- Used orally in mares to synchronise or suppress œstrus.  If used to synchronise, œstrus will generally occur within 2-5 days of administration.

Megœstrol (Ovaban®, Ovarid®) -- Used as a contraceptive in bitches and to alleviate false pregnancy.  It is also used in the treatment of aggressive behaviour and unacceptable masculine behaviour in male dogs and in the treatment of urine-marking, aggression, and anxiety in cats.

Medroxyprogesterone (Provera®) -- Used in cats for the treatment of behavioural disorders and psychogenic alopecia/dermatitis and in dogs for the treatment of aggressive behaviours.

Androgens

Physiologically, androgens cause masculinisation and anabolic effects such as increase protein synthesis, potassium and phosphate retention, and increased bone/cartilage growth.  The general uses of androgens include the treatment of impotency and infertility in male animals, urinary incontinence and dermatitis in castrated male animals, contraception in bitches, promotion of growth, and as a teaser (œstrus detector) in cull cows, heifers, and steers.
Testosterone -- used primarily in the treatment of urinary incontinence in dogs and cats, dermatitis, and as a teaser in cows.

Boldenone (Equipoise®, Vebonol®) -- used primarily in horses to promote growth in debilitated animals.

Mibolerone (Cheque® Drops) -- used to prevent heat (œstrus) in bitches.  It should not be used in cats, due to a high incidence of hepatotoxicity and death.

Nandrolone (Durabolin®, Deca-Durabolin®) -- used primarily to stimulate erythropoiesis.  It may also be used as an appetite stimulant in small animals.

Stanozolol (Winstrol®) -- used primarily for its anabolic effects.  May also be used for the treatment of anæmias.  Additionally, it may possess fibrinolytic activity and has been successful in the treatment of feline aortic thrombo-emboli.

While not endocrine drugs, many prostaglandins are used as oxytocics or abortifacients or to induce œstrus.  Their specific effect is often dose and duration dependent.  The following summarises some of the more commonly used prostaglandin analogues and their specific uses.
Dinoprost (Lutalyse®) is used to induce labour in pigs, abortion and to induce œstrus.

Clorprostenol (Estrumate®) -- used to induce abortion, treatment of pyometra, and to induce œstrus in cows.

Fenprostelene (Bovilene®) -- used to induce abortion and induce œstrus in cows.

Fluprostenol (Equimate®) -- used to induce labour, abortion and to induce œstrus in horses.