Veterinarian administering Hydroxyethyl Starch to a dog with concerned owner

Hydroxyethyl Starch: Understanding Its Uses and Risks in Veterinary Medicine

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Reese Marlowe in Health & Wellness August 2026 • 4 min read.

"A comprehensive guide to hydroxyethyl starch (HES) in veterinary medicine, covering its applications, potential side effects, and safe usage for pets."


In veterinary medicine, maintaining adequate fluid volume is crucial for treating animals experiencing shock, hypovolemia, or undergoing extensive surgical procedures. Hydroxyethyl starch (HES) solutions are synthetic colloids frequently used to expand vascular volume and stabilize blood pressure in critical situations. This article will provide a detailed overview of HES, including its mechanism of action, clinical uses, potential risks, and administration guidelines.

Hydroxyethyl starch (HES) is a synthetic colloid volume expander derived from modified branched-chain glucose polymers. These polymers, sourced from amylopectin in potatoes, sorghum, or maize, are designed to remain in the bloodstream longer than crystalloid solutions, providing sustained vascular support. Several HES preparations exist, including hetastarch, pentastarch, tetrastarch (VetStarch), each differing in molecular weight and substitution patterns, which influence their behavior within the body.

While HES solutions can be life-saving in critical situations, it's essential to understand their potential risks and use them judiciously. Recent studies and clinical experiences have raised concerns about adverse effects such as kidney injury and coagulation abnormalities. This article aims to provide pet owners and veterinary professionals with the information needed to make informed decisions about using HES in veterinary practice.

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Widespread Use, Growing Safety Concerns

Hydroxyethyl starch (HES) is commonly used for volume resuscitation, yet it has been associated with serious adverse events, including acute kidney injury and death. Clinical trials of hydroxyethyl starch have produced conflicting results. In intensive care settings, its safety and efficacy have not been established in patients with severe sepsis.

HES as a Plasma Volume Expander

In medicine, hydroxyethyl starch solution is used as a plasma volume expander during intravenous infusions. In veterinary research, its effects are studied in vitro, as in an experimental study that diluted canine whole blood with HES 130/0.4 and HES 670/0.75 to assess primary and secondary hemostasis. Because such testing is limited to laboratory conditions, it does not capture full physiologic responses in living patients.

A Long History of Resuscitation Use

Hydroxyethyl starch has long been widely used for fluid resuscitation in intensive care units. A 2012 report in the New England Journal of Medicine highlighted that HES's safety and efficacy had not been established in patients with severe sepsis. Similar questions have since extended to veterinary settings, where HES has been evaluated in canine and swine models of hemorrhage and shock.

How Hydroxyethyl Starch Works

Veterinarian administering Hydroxyethyl Starch to a dog with concerned owner

Hydroxyethyl starch is a synthetic colloid volume expander used to maintain vascular volume in animals experiencing circulatory shock. It is derived from modified branched-chain glucose polymers obtained from sources like potatoes, sorghum, or maize. Different preparations, such as hetastarch, pentastarch, and tetrastarch, vary in molecular weight and substitution, affecting how long they remain in the bloodstream.

The effectiveness of HES lies in its ability to draw fluid into the vascular space, increasing blood volume and stabilizing blood pressure. This is particularly useful in cases of hypovolemia (low blood volume) and shock, where rapid restoration of circulating volume is critical. HES solutions have a duration of effective volume expansion lasting between 12 to 48 hours, providing prolonged support during critical periods.

Different types of Hydroxyethyl Starch preparations:
  • Hetastarch (6%): Has an average molecular weight of 200 kDa and a colloid osmotic pressure of approximately 30.
  • Pentastarch (10%): Has an average molecular weight of 200 kDa and a colloid osmotic pressure of 30-60.
  • Tetrastarch (VetStarch) 6%: Has a molecular weight of 130 kDa and a colloid osmotic pressure of 36.
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Veterinary In Vitro and Animal Studies

An in vitro experimental study assessed primary and secondary hemostasis following dilution of canine whole blood with HES 130/0.4 and HES 670/0.75. In a swine hemorrhagic shock model, 6% hydroxyethyl starch (130/0.4) was reported to ameliorate acute lung injury. Together these studies help clarify the effects of different HES formulations in veterinary medicine.

Adverse Events and Conflicting Evidence

Hydroxyethyl starch has been associated with serious adverse events, including acute kidney injury and death, and clinical trials of HES have yielded conflicting results. A case report described a healthy man with previously undiagnosed mild von Willebrand's disease who received 6% hydroxyethyl starch solution intravenously, which accentuated the bleeding disorder. Such findings raise caution about HES use, especially in patients with underlying hemostatic abnormalities.

Comparing HES Formulations

The in vitro canine study directly compared the hemostatic effects of HES 130/0.4 and the higher-molecular-weight HES 670/0.75 on diluted whole blood. In human perioperative care, a propensity score matched controlled observation study examined the impact of HES 130/0.4 on perioperative outcome. Such comparisons inform choices among HES products in both human and veterinary practice.

It's important to note that the molecular substitution of HES determines whether it is hetastarch, pentastarch, or hexastarch. Hetastarch has the most molecular substitutions, causing it to remain longest in the vasculature. However, it is cleared more slowly than tetrastarch and may accumulate in the reticuloendothelial system, skin, liver, and kidneys, which may contribute to potential adverse effects.

Making Informed Decisions About HES Use

While hydroxyethyl starch can be a valuable tool in veterinary medicine for treating hypovolemia and shock, it is essential to weigh the benefits against the potential risks. Recent studies have raised concerns about kidney injury and coagulation abnormalities, emphasizing the need for careful patient monitoring and judicious use. By understanding the different types of HES solutions, their mechanisms of action, and potential adverse effects, veterinary professionals and pet owners can make informed decisions about their use.

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Balancing Benefits and Risks

Clinical trials of hydroxyethyl starch remain conflicting, and its safety and efficacy have not been established in patients with severe sepsis. While HES continues to serve as a plasma volume expander in intravenous infusions, clinicians in both human and veterinary medicine must weigh resuscitation benefits against documented risks of acute kidney injury and death.

Toward Better Outcome Evidence

Propensity score matched controlled observation studies are being used to examine how HES 130/0.4 affects perioperative outcomes in clinical settings. Continued veterinary research, including in vitro canine blood studies and swine shock models, aims to clarify how different HES formulations perform and where they should be used.

Systemic Challenges in Resuscitation

The broad adoption of HES for fluid resuscitation in intensive care units has outpaced definitive evidence of its safety and efficacy in critically ill patients. Conflicting clinical trial results and associations with acute kidney injury and death create persistent uncertainty for practice guidelines and prescribing decisions. Veterinary medicine faces parallel challenges as HES is evaluated in canine and swine models.

Real-World Cases and Coagulation Risks

A case report of a healthy man with previously undiagnosed mild von Willebrand's disease who received 6% hydroxyethyl starch solution intravenously illustrates how HES can accentuate underlying coagulation disorders. Such individual cases underscore the importance of screening for hemostatic risk and exercising caution when using HES in both human and veterinary patients.

About this Article -

Written with AI assistance from published research, and reviewed by the Mystum team. See our About page for more information.

This article is based on research published under:

DOI-LINK: 10.1016/b978-0-323-24485-5.00300-4, Alternate LINK

Title: Hydroxyethyl Starch

Journal: Saunders Handbook of Veterinary Drugs

Publisher: Elsevier

Authors: Mark G. Papich

Published: 2016-01-01

Everything You Need To Know

1

How does hydroxyethyl starch work to increase blood volume in animals?

Hydroxyethyl starch, or HES, functions by drawing fluid into the vascular space, which increases blood volume and stabilizes blood pressure. This mechanism is especially useful in treating hypovolemia and shock, where the rapid restoration of circulating volume is crucial. HES solutions provide volume expansion that lasts between 12 to 48 hours, which can support animals during critical periods. Other colloids include albumin and synthetic colloids such as dextrans and gelatins.

2

What are the key differences between hetastarch, pentastarch, and tetrastarch (VetStarch) in veterinary applications?

Hetastarch, pentastarch, and tetrastarch (VetStarch) differ in molecular weight and substitution patterns, which influence how they behave in the body. For example, hetastarch has the most molecular substitutions, causing it to remain longest in the vasculature. However, it’s cleared more slowly than tetrastarch and may accumulate in the reticuloendothelial system, skin, liver, and kidneys, potentially leading to adverse effects. Understanding these differences helps veterinarians choose the most appropriate HES solution for a given clinical situation.

3

What are the potential risks and side effects associated with using hydroxyethyl starch in pets, and what alternatives should be considered?

Potential risks associated with hydroxyethyl starch use include kidney injury and coagulation abnormalities. Recent studies and clinical experiences have highlighted these concerns, emphasizing the need for careful patient monitoring and judicious use of HES. While HES can be life-saving in critical situations, it is essential to weigh these benefits against potential risks and consider alternative treatments if available. Alternatives might include crystalloid solutions or other types of colloids, depending on the specific clinical scenario.

4

When is hydroxyethyl starch typically used in veterinary medicine?

Hydroxyethyl starch solutions are used to expand vascular volume and stabilize blood pressure in critical situations such as shock, hypovolemia, or during extensive surgical procedures. Maintaining adequate fluid volume is crucial for treating these conditions in animals. The prolonged vascular support offered by HES makes it a valuable tool in stabilizing patients during critical periods. Conditions such as sepsis, trauma, or major blood loss often require such interventions to maintain organ perfusion and prevent further complications.

5

What is hydroxyethyl starch derived from, and how does its source affect its properties?

Hydroxyethyl starch (HES) is derived from modified branched-chain glucose polymers obtained from sources like potatoes, sorghum, or maize. These polymers are designed to remain in the bloodstream longer than crystalloid solutions. The modification process and source material are crucial as they influence the molecular weight and substitution patterns of the final HES product, affecting its behavior and duration within the body. For example, differences in the branching and hydroxyethyl substitution determine whether it is classified as hetastarch, pentastarch, or tetrastarch.

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