cystic ovaries (ovarian cysts) | ringwomb | uterus infection (endometritis, metritis, and pyometra) | retained placenta
Introduction: A variety of situations can cause problems with the reproductive system in sheep and goats. The following section will address cystic ovaries, ringwomb, reproductive tract infections (metritis), and retained placentas.
Cystic Ovaries (Ovarian cysts)
Introduction: Cysts on the ovaries can appear on one or both ovaries and are usually thin-walled, fluid-filled structures. They are the result of follicles that fail to ovulate. This condition seems to be more common in goats than in sheep.
Causative Agents: Studies indicate that certain superovulation protocols like pregnant mare serum gonadotropin (PMSG), high estrogen intake, and possible phosphorus deficiency, genetic predisposition, and stressful conditions or other health problems during the birthing process or postpartum interval may cause cysts to develop on the ovaries. In goats, genetics seem to play a dominant role.
Diagnosis: The most obvious signs that a producer may notice relate to the animal’s estrous cycles. Animals with cystic ovaries will often have constant or frequent estrus. Other animals may be completely anestrus (not cycle at all). Some females may exhibit male-like behavior.
Treatment: Many animals may spontaneously recover from a cystic ovary problem; however, if treatment is required, the most common drugs given are gonadotropin-releasing hormone (GnRH) and human chorionic gonadotropin (hCG). It is recommended that 50-100 micrograms of GnRH or 750-1,000 IU of hCG be given.
Prevention: To prevent the development of cystic ovaries, start by
evaluating the animal's feed. Analyze the animal's entire diet for the proper
calcium to phosphorus ratio. It should be between 1.5:1 and 2:1 in the total
diet. Do not use moldy feed. Toxins found in moldy feed can be high in estrogen.
Because injectable estrogen products (estradiol cypionate - ECP) can cause
cysts, their use should be monitored by a veterinarian. Genetic predisposition
to ovarian cysts is possible; therefore, cull any animals known to produce
Introduction/Causative Agent:Ringwomb is a situation where the cervix fails to dilate normally during the birthing process. It is much more common in sheep than it is in goats. This problem is considered to be a genetic defect, and all animals that experience this problem should be culled. Sometimes a ringwomb situation can occur if a fetus fails to enter the birth canal and stimulate the cervix to dilate.
Diagnosis: This problem is often suspected when a ewe is in obvious labor, but no progress is made. A diagnosis is made by inserting a lubricated, sterile, gloved hand, when possible, into the vagina and finding a tight ring of cervical tissue that has failed to dilate.
Treatment/Prevention: There are three primary ways to deal with a ringwomb problem:
As mentioned previously, the most common method of preventing this problem in
the future is to cull all animals (mothers and offspring) involved with the
ringwomb problem, regardless of age. Ringwomb is a highly heritable genetic
fault, and can be transmitted to offspring.
Uterus Infection (Endometritis, Metritis, and Pyometra)
Introduction: Endometritis (inflammation of the lining of the uterus), metritis (inflammation of the uterus), and pyometra (infection or pus in the uterus) are uncommon problems in most ewes and does. However, dairy goats seem to be more susceptible to these problems. If not resolved, these problems will lead to estrus abnormalities, failure to conceive, and even death.
Causative Agents: Most problems in the uterus are caused by injury or infection that occur during or soon after the birthing process. One of the most common causes of a uterus infection is a retained placenta. Injury or contamination of the reproductive tract is also a common cause of uterus infection and can be the result of a difficult birth where manipulations have been made and/or medications have been given in the uterus. Abortions can also cause or lead to problems with the uterus. Selenium or vitamin E deficiencies and over-conditioning are also possible causes. The over-conditioning predisposes the ewe/doe to retained placentas, metritis, and other problems.
Clinical Signs: Most of the time a ewe/doe with a uterus infection can be identified simply by the discharge and odor coming out of the vulva. A reddish to brown discharge following lambing/kidding is normal in a female for about 2-4 weeks. However, if the discharge becomes foul-smelling or persists longer than 3-4 weeks, metritis is likely to be present. An infected uterus can also cause the ewe/doe to go off feed (anorexia), have a fever, be lethargic, not cycle, and suffer a drop in milk production. A culture of the uterine fluid and discharge can confirm an infection and help identify what organism(s) is causing the infection and what treatment would be appropriate.
Treatment: The most common treatment for ewes/does that have a uterus infection is the administration of prostaglandin (PGF2a) or oxytocin when the problem is diagnosed. Some veterinarians recommend that the uterus be lavaged or infused with some type of antiseptic solution. There are many different combinations of solutions that have been used. One of the most common is diluted povidone-iodine, mixed 20 parts saline to 1 part of 10% iodine solution. Other solutions infused into the uterus include penicillin and tetracycline. It is important to note that ALL antiseptic solutions infused into the uterus will cause some degree of irritation and inflammation to the lining of the uterus. This will delay healing and will often increase the days open. Because of this reason, many producers choose not to administer products into the uterus if it is at all possible.
For ewes/does that are sick and have signs of toxemia (fever, not eating, weakness), it is important to administer systemic antibiotics. Injections of ceftiofur, penicillin, or tetracycline are often given. Severely sick animals should also receive fluids and anti-inflammatory agents (flunixin meglumine, phenylbutazone) when necessary.
Causative Agents: A ewe/doe is said to have a retained placenta if she fails to expel the placenta within 12-18 hours of lambing/kidding. There are many things that can cause a ewe/doe to retain a placenta. They are often associated with ewes/does that give birth prematurely (abortions), have an excessively large fetus, or must have a cesarean section to have the lamb/kid. Abortions and still births are also common problems that can lead to a retained placenta. Problems such as dystocia, hypocalcemia (milk fever), and metritis can lead to a retained placenta. Infections with organisms such as toxoplasmosis, leptospirosis, listeriosis, and chlamydiosis can all cause premature death of the fetus and result in a retained placenta. Nutritional problems such as selenium and/or vitamin A or E deficiency can also lead to problems. Feeding a high hay ration, too much grain, a poor quality forage, or a lack of fresh forage have all been associated with retained placentas.
Clinical Signs/Diagnosis: A ewe/doe may normally take up to 12-18 hours to dispel the placenta. If the placenta is still attached after 12 hours, there is a problem and the placenta is considered retained. A ewe/doe that has retained the placenta will often have some of the placenta hanging out of the vagina. This can vary in length from a few inches to more than a foot or two. In some cases, there may not be any of the retained placenta that can be viewed from the outside. In these instances, all of the placenta is still contained within the uterus and vagina. When infection is present, ewes/does with a retained placenta will sometimes have a fever, act sick, and not want to eat. As the placenta itself decomposes and infection sets in, a very foul odor can be noticed and a dark, blood-tinged fluid may come out of the vagina. Most cases of retained placenta can be diagnosed by observing the ewe/doe.
Treatment: In all cases, it is important to not forcibly pull the placenta out of the ewe/doe. If some of the placenta can be seen hanging from the vagina, gently give it a light tug. If the placenta comes out easily, remove all that comes with the gentle tug. If it is still attached to the uterus and does not come with a simple tug, leave the placenta in place. Pulling or forcing a retained placenta from the uterus will only cause injury to the ewe/doe, delay healing, and increase the chances for severe infections.
The preferred treatment for most retained placentas is the administration of prostaglandin (PGF2a) or oxytocin when the problem is diagnosed. Some veterinarians recommend that the uterus be lavaged or infused with some type of antiseptic solution. There are many different combinations of solutions that have been used. (See the information previously given under "uterus infections" for details.)
Prevention: To help prevent this problem, minimize stressful conditions during the pre-lambing/kidding period and at birthing. Prevent diseases and problems such as dystocia, abortions, and milk fever. Vaccinate all animals for potential reproductive diseases. Evaluate all rations to make sure ewes/does receive proper nutrition. Give supplements if rations are deficient in calcium, phosphorus, magnesium, selenium, vitamins A and E, or carotene.