Hepatic Lipidosis in Sheep

Hepatic lipidosis means excess fat has built up inside the liver. In sheep, this usually happens when the body is forced to mobilize stored fat because it is not getting enough usable energy from feed. The liver then becomes overloaded trying to process that fat. In practice, this problem is often tied to pregnancy toxemia in late-gestation ewes, especially those carrying multiple lambs.

You may also hear related terms like fatty liver disease, ketosis, or twin lamb disease. These conditions overlap. A ewe in negative energy balance may develop low blood sugar, high ketones, and fat accumulation in the liver at the same time. As the cycle worsens, she often eats even less, which pushes the liver and the rest of the body into a deeper metabolic crisis.

This is not a condition pet parents should try to sort out alone. Some sheep look only mildly off at first, then decline quickly over hours to a day. Early veterinary care gives your flock member the best chance of stabilizing and may also help protect the lambs if she is still pregnant.

The main driver is negative energy balance. In plain terms, the ewe needs more energy than she is taking in. Late pregnancy is the highest-risk period because growing lambs take up abdominal space and increase calorie demand at the same time. If feed intake drops even briefly, the body starts pulling fat from storage. That fat floods the liver, where it can accumulate and impair normal liver function.

Ewes carrying twins or triplets are at especially high risk. Overconditioned ewes, thin ewes, ewe lambs, and older ewes with poor teeth can also struggle to meet energy needs. Poor-quality forage, sudden feed changes, overcrowding, storms, transport, heat or cold stress, concurrent illness, lameness, and anything else that reduces appetite can tip a ewe into trouble.

In many real-world cases, hepatic lipidosis is not a stand-alone problem. It develops as part of the same metabolic cascade seen with pregnancy toxemia and ketosis. That is why your vet will often look not only at liver involvement, but also at blood sugar, ketones, hydration, calcium status, and whether the ewe is close enough to lambing that induction or cesarean delivery needs to be discussed.

Your vet usually starts with the ewe's history and stage of pregnancy, then combines that with a physical exam. A late-gestation ewe carrying multiples, eating poorly, acting weak, or showing neurologic signs raises immediate concern for pregnancy toxemia with possible fatty liver involvement. Because several diseases can look similar, diagnosis often focuses on identifying the metabolic crisis and ruling out other emergencies.

Common tests include blood glucose, ketone testing or beta-hydroxybutyrate, electrolyte and mineral checks, and basic chemistry work to assess liver and kidney stress. Your vet may also use ultrasound to confirm pregnancy stage, count fetuses when possible, and help decide whether the ewe should be medically supported, induced, or considered for surgery. In some cases, liver changes are confirmed more definitively with pathology after death, but treatment decisions in the field are usually based on clinical signs and metabolic testing rather than waiting for perfect confirmation.

Because sheep can decline quickly, your vet may begin treatment while diagnostics are still in progress. That is often the safest path. The goal is to stabilize the ewe, improve energy balance, and decide whether continuing the pregnancy is realistic or whether delivery offers the best chance for the ewe and lambs.

Prevention centers on keeping late-pregnant ewes out of negative energy balance. That means matching nutrition to stage of gestation, body condition, and fetal number. Ewes carrying twins or triplets need more energy than those carrying singles, and they often benefit from closer grouping and ration planning. Good-quality forage matters, but in many flocks it is not enough by itself late in gestation. Your vet or flock nutrition advisor can help you build a ration that fits your forage, region, and production goals.

Body condition management is also important. Very thin and overconditioned ewes are both at higher risk. Try to avoid sudden feed changes, overcrowding, transport stress, and long periods without access to feed. Pay extra attention to older ewes with poor teeth and ewe lambs that are still growing themselves.

In practical terms, prevention also means watching closely during the last several weeks before lambing. Separate high-risk ewes when needed, make sure timid animals can reach feed, and act early if a ewe hangs back, eats less, or seems stiff or dull. Early veterinary input can prevent a mild energy deficit from turning into a life-threatening fatty liver crisis.