Fatty Liver Syndrome in Cows: Hepatic Lipidosis Around Calving

Fatty liver syndrome, also called hepatic lipidosis, is a metabolic disease most often seen in high-producing dairy cows around calving. During this period, energy demand rises quickly for milk production, but feed intake often falls. When that gap becomes too large, the cow mobilizes body fat for fuel. The liver takes up a portion of those fatty acids, and in cattle it does not export triglyceride very efficiently, so fat can build up inside liver cells.

A small increase in liver fat is common in fresh cows and does not always cause illness. Trouble starts when fat accumulation becomes severe enough to impair normal liver function. At that point, the cow may show vague but important signs such as poor appetite, reduced milk yield, ketosis, weakness, or poor response to treatment for other transition-cow diseases.

This condition often overlaps with ketosis and may occur alongside retained placenta, metritis, mastitis, or displaced abomasum. Because the signs can blend together, fatty liver syndrome is easy to miss unless your vet looks at the whole transition-cow picture.

The main driver is negative energy balance around calving. A cow suddenly needs a great deal of energy for colostrum and milk, but dry matter intake usually drops before calving and may stay low for several days after. To make up the difference, she mobilizes stored body fat. Those nonesterified fatty acids travel to the liver, where some are burned for energy and some are turned into triglyceride. In cattle, triglyceride export is relatively slow, so fat can accumulate.

Cows at higher risk include those that are overconditioned at dry-off or calving, older cows, high-producing dairy cows, and cows with reduced feed intake from stress or illness. Rapid ration changes, overcrowding, heat stress, poor bunk access, unpalatable feed, and concurrent diseases can all worsen the energy deficit.

Fatty liver syndrome is closely linked with ketosis. In many herds, the same management factors that increase subclinical or clinical ketosis also increase hepatic lipidosis risk. That is why prevention focuses heavily on transition-cow nutrition, body condition management, and keeping cows eating well before and after calving.

Your vet usually starts with the cow’s stage of lactation, appetite, milk production, body condition, and any recent fresh-cow disease history. Because there are no pathognomonic signs, diagnosis is often based on a combination of findings rather than one single test. Many affected cows also have ketosis, so on-farm or laboratory ketone testing may be part of the workup.

Bloodwork may help assess energy balance and liver stress. Your vet may look at markers such as NEFA and BHBA, along with other chemistry values that help rule in metabolic disease and rule out competing problems. These tests are useful, but they do not always measure liver fat directly.

The most specific way to confirm fatty liver is liver biopsy, which allows direct measurement or assessment of triglyceride accumulation in liver tissue. In practice, not every cow needs a biopsy. Your vet may make a presumptive diagnosis based on timing, clinical signs, ketosis status, and response to treatment, especially when herd-level transition disease patterns support the diagnosis.

Prevention centers on transition-cow management. The goal is to avoid excessive negative energy balance while keeping cows eating consistently before and after calving. One of the most important steps is body condition control. Cows should ideally enter the dry period at a moderate body condition, not thin and not overconditioned. Overconditioned cows are at higher risk because they tend to mobilize more fat when intake drops.

Your vet and nutrition team may recommend dry-cow and close-up rations that support rumen fill, maintain intake, and avoid unnecessary energy overfeeding. Good bunk access, comfortable housing, heat abatement, low-stress pen moves, and prompt treatment of fresh-cow disease all matter because anything that reduces feed intake can increase liver fat accumulation.

In higher-risk cows, your vet may discuss preventive tools such as oral propylene glycol near calving or monensin in appropriate herd programs. These options are not right for every farm or every cow, but they can be useful in selected situations. Herd monitoring for ketosis, fresh-cow appetite, milk production, and body condition trends often catches problems early, before severe hepatic lipidosis develops.