This article was written by Kristy Blankers and Dr. Lisa Sharko.
Introduction
Pregnancy toxemia, also known as ketosis, is a metabolic disease in dairy goats that occurs during late pregnancy and is caused by an elevation in ketone bodies. Pregnancy toxemia most commonly develops one to three weeks before kidding. Late gestation is a period of high energy demand as the animal supports multiple fast-growing fetuses. If these energy demands exceed the goat’s intake, they enter a state of negative energy balance. Fat is mobilized from the doe’s fat stores and transported to the liver to be used as an energy source. The fat is broken down into ketones, which can be used as an alternative emergency energy source. However, high levels of ketones in the blood can be toxic, leading to sick goats and possibly the death of both the doe and kids.
Risk Factors and Prevention
Several factors increase a goat’s risk of developing ketosis. Goats carrying multiple fetuses are at a greater risk because the large uterus takes up a significant amount of space in the abdomen, reducing rumen capacity. This limits the amount of feed the doe can eat. Therefore, the animal is less able to fully meet their energy demands depending on the composition of their diet.
Under or over body condition also influences an animal’s risk. Goats that are too thin are unable to meet their energy needs and cannot mobilize body fat stores. Goats that are overweight have increased fat stores, which allow for a large amount of fat to be rapidly broken down and converted to ketones in high amounts. This impairs the liver’s ability to function properly, causing fatty liver disease. Does that are overweight respond to insulin poorly, limiting their ability to utilize glucose in their blood for energy, further contributing to their negative energy balance despite intakes.
Body condition should be assessed before breeding and mid-gestation to ensure that goats do not enter the last six weeks of gestation with a body condition score lower than 2.5. Feed management practices, such as sorting goats by body condition and number of fetuses, ration formulation, and adequate bunk space helps to reduce the percentage of thin and overweight does in the herd. Thin does should be fed separately, and if possible, fed based on body condition and number of fetuses. Health conditions contributing to an animal’s low body condition should also be addressed. Over-conditioned does (≥4 BCS) do not respond well to treatment and are at an increased risk if the feed is adjusted to decrease their body condition during late pregnancy.
Detecting and Treating Ketosis
Early diagnosis of ketosis is critical as treatment is often unsuccessful in advanced stages of the disease. In the early phase of ketosis, does may not have any signs of disease. Early warning signs include more time spent lying down and a decreased appetite. As ketosis progresses, the doe may develop worsening symptoms including teeth grinding, loss of coordination, blindness, and may no longer be able to stand. Blood or urine ketone levels can be measured to monitor or diagnose ketosis. Treatment involves administering energy sources such as propylene glycol and dextrose along with supportive care. When considering treatment options, it is important to talk to your veterinarian.
The risk of ketosis in the herd can be evaluated by testing the serum beta-hydroxybutyrate (BHBA) levels of 3 to 20% of the late gestation does. The average BHBA concentration of this sample can be used as an indicator of group herd-level ketosis risk (Table 1).
| Average BHBA Level (mmol/L) | Risk Level |
| 0.0-0.7 | Normal |
| 0.8-1.6 | Moderate |
| 1.7-3.0 | High |
Conclusion
Prevention and early diagnosis of ketosis is critical as the risk of mortality is high for does with advanced stages of the disease. Proper management of ketosis and associated risk factors can reduce disease and mortality
References
Grünberg, W., Van Saun, R.J., & Fthenakis, G. (2024. Pregnancy toxemia in sheep and goats – metabolic disorders. Merck Veterinary Manual. https://www.merckvetmanual.com/metabolic-disorders/hepatic-lipidosis/pregnancy-toxemia-in-sheep-and-goats
João Simões, & Gutiérrez, C. (2018). Nutritional and metabolic disorders in dairy goats. Springer EBooks, 1, 177–194. https://doi.org/10.1007/978-3-319-71855-2_11
Zobel, G., Leslie, K., Weary, D. M., & M.A.G. von Keyserlingk. (2015). Ketonemia in dairy goats: Effect of dry period length and effect on lying behavior. Journal of Dairy Science, 98(9), 6128–6138. https://doi.org/10.3168/jds.2014-9136
