Small Ruminant Management: Abortion Causing Diseases

Dr. Brady Campbell, Assistant Professor, State Small Ruminant Extension Specialist

For those raising sheep and goats in the Midwest, lambing and kidding season is in full swing. As we enjoy the victories and contemplate the challenges our management systems threw at us this year, it is important to note and document everything that happened so we can evaluate our outcomes at the end of the season. An important statistic to keep in any livestock operation is death loss. This number is valuable to quantify the efficiency of your operation, but without recording a reason for a loss or death in your operation, this statistic ends here. I know that it can be stressful and deflating when we encounter a loss, but understanding why it occurred and the reason behind it will pay dividends as you move forward. Although this discussion is a bit gloomy to talk about, it’s an important one none the less. Below, I have outlined some of the common diseases in sheep and goats that are associated with pregnancy loss, abortions, stillbirths, and birth deformities. Be sure to read each of these and compare them to your operation. Even if you don’t have issues today, these diseases can rear their ugly head at any given time. Keeping this information tucked away in your farming tool box will be well worth the read.

Campylobacter (Vibrio)
Campylobacter, or more commonly referred to as Vibrio, is caused by a bacterial infection with campylobacter jejuni or fetus. Ewes and does that contract this bacterial infection tend to abort during late pregnancy. For those that do not abort, lambs and kids may be carried full term and can be either born dead (stillbirth) or live. Those that are born live will be small and weak, thus needing further attention. Unfortunately, this disease is rarely detected and is not known until abortions occur. For those experiencing issues with this disease, there are a couple of options to prevent and control future losses. During an abortion storm, tetracycline antibiotics may be used to control current issues. Due note that a valid VCPR will be required to purchase over the counter antibiotics in 2023. For future concerns, commercially produced vaccines are available. Be sure to read vaccine use prior to purchase as initial treatment may consist of a booster. Once a vaccine as such is used with your flock, it must be repeated on an annual basis. Therefore, it is critical to have dead lambs and kids tested at your state diagnostic center to ensure that you are treating for the appropriate disease the reduce your chances of introducing a disease that is not already present.

Chlamydia is also a bacterial infection caused by chlamydia psittaci. Ewe and does infected with this disease will also abort during the last ~50 days of pregnancy. For those that do not abort, live offspring will be weak and will require special attention to ensure survivability. Just as noted above, antibiotics and vaccines can be used to control and prevent future outbreaks and issues. Some unique characteristics of Chlamydial infections is that it is easily spread from contaminated bedding that was previously exposed to infected placenta and birthing fluids. Therefore, it is critical to remove infected ewes from the flock and clean the area. Placenta and discharge from infected ewes is said to have a pungent and fowl smell. When purchasing ewes, be sure to acquire from clean flocks. Additionally, it is thought that mature ewe are immune to this disease if previously exposed.

Toxoplasmosis is an infection caused by the protozoa Toxoplasma gondii. These protozoal oocyst survive and remain active in the soil for several years and is therefore difficult to completely manage. Ewes and does that contract this disease during early pregnancy may abort or reabsorb the fetus. During late pregnancy, fetuses may be stillborn or live. Those that are live can either be weak or born normally. The vector that catches most grief due to association with Toxoplasmosis is the domestic cat. If you choose to keep cats in your barns for vermin control, keep only those that are spayed or neutered and those that are older as they tend to be less of an issue. Furthermore, storing feeds appropriately also ensures that vermin such as raccoons and opossum steer clear as they too are known to be carriers of the disease.

Cache Valley Virus (CVV)
Cache Valley has become a sour name over the past few years in the sheep industry. As the name states, this disease is caused by a virus and therefore is challenging to control. Animals contract CVV in the fall during or after the breeding season. Cache Valley is spread via mosquitos and biting midges. Ewes and does that are infected during early pregnancy may either reabsorb or abort their fetuses. Those that carry to full term usually result in stillbirth that have severe deformities. Unfortunately, at this time there is no vaccine available for this virus. It is however thought that animals that were previously infected will develop innate immunity to the disease. The best recommendation available at this point is to avoid wet, marsh like areas during and after the breeding season. Animals housed indoors should have access to proper ventilation to discourage insect accumulation.

Although not a disease that we commonly associate with abortions and one that is typically human induced, Listeriosis is a bacterial infection caused by Listeria monocytogenes. This issue is most common in systems that feed fermented feeds (i.e., silage, baleage, haylage) or feed hay that is stored and/or fed out doors. If the infection is severe enough, ewes and does will abort. Other indicators that an animal is facing challenges with Listeriosis is neurological symptoms that are associated with this infection. Infected animals may circle, press their heads against a wall as they attempt to relieve swelling of their brain, drooling, and incoordination. To avoid these issues, be sure to monitor feed spoilage by limiting the amount of time a fermented feed is offered before replacing with fresh feed. Additionally, fermented feeds should have a low ash content, a pH that is <4.5, and stored in an anaerobic (oxygen deprived) environment. Animals demonstrating signs of Listeriosis can be treated if detected early. Consult with your local veterinarian for the most appropriate treatment protocols.

Noninfectious agents (toxic plants, genetic, nutrition)
Last, but certainly not least, producers may face noninfectious agents that result in abortions in their flocks and herds. Plants, both natural and cultivated, can have unique livestock challenges through out the year. Does anyone remember the herd of goats this past year that all perished because someone thought that feeding yard and Christmas waste that contained yew was appropriately? This seemingly kind gesture turned into a devastating loss for the producer. Poisons and toxins in plants can create serious issues that may result in abortions if the dose is low enough that does not cause death. To minimize your chances of facing these issues, scout your pastures regularly for downed trees after extreme weather events or toxic plants growing or thrown across the fence line.

It is my hope that you won’t experience a loss in your flock or herd this year, but in the case that you do, please take a few minutes to truly investigate the cause of death. If you aren’t able to do so or don’t feel comfortable, find a mentor, neighbor, or fellow producer in the area that can assist. Determining the reason upon why a loss occurred is extremely important not only for your bottom line, but to also protect your animals and yourself from future challenges that could be more severe in the future. So the next time you have to dig a hole or turn the compost bin, make certain that you understand what happened to the animal that you lost and formulate a plan upon how you and your operation will over come the challenge.

Happy Shepherding!