Figures and statistics

In 2021, 54,156 animal tests or other procedures involving animals were conducted at Ghent University. Since some animals were re-used (in accordance with the law), this is equivalent to 53,909 animals being used for experiments in 2021. An animal test or experiment is defined by law as one experiment on one animal. For example, a study that uses 30 animals to take a single blood sample is counted as 30 animal experiments.

If you want to see where Ghent University stands in relation to the figures for Flanders and Belgium, you can compare these below with the statistics provided by the Flemish service for animal welfare (in Dutch). You can find figures for the European Union here.

Numbers per species

This figure shows numbers from 2014 onwards. The number of experiments in 2021 is slightly lower than the average of the previous period 2014-2020. The number of animals being re-used was rather low in 2021 as compared to the average of the previous years (247 versus 165 up to 577 in the period 2014-2020). The highest figures for re-use date from before 2018.

Dierproeven: aantallen

In 2020, the measures for Covid-19 have had an impact on the figures: a number of non-urgent studies were postponed. In 2021, the Covid situation normalised somewhat, and research could be continued or caught up.

Annual fluctuations in themselves do not demonstrate any trend. Some of the more striking general trends are the following. Looking at the period 2014 to 2021, the number of mice, by far the most commonly used species, first increased – both in absolute and relative terms – and then slightly decreased again in recent years. The number of zebra fish showed the same trend. Other fish were clearly much less present in 2019 to 2021 compared to previous years, as were domestic fowl. Tests with privately owned dogs and cats in the context of veterinary medicine increased in importance in recent years. The sharp increase in the number of experiments with pigs in the last two years can also be explained by research in the field of veterinary medicine (nutrition and welfare). Ghent University does not conduct any animal research or tests with primates.

Animal testing: species

Number of animal tests by species

Animal testing: species per year

1 In 2020: 100 lesser black-backed gulls (Larus fuscus), 100 European herring gulls (Larus argentatus), 50 Japanese quail (Coturnix japonica), 20 common waxbills (Estrilda astrild), 20 red avadavats (Amandava amandava), 17 black-rumped waxbill (Estrilda troglodytes) and nine turkeys (Meleagris gallopavo).
2 In 2021: three boas (Boa constrictor) and one bearded dragon (Pogona vitticeps).
³ In 2021: 75 painted frogs (Discoglossus pictus).
4 In 2021: 1.584 common carp (Cyprinus carpio), 15 European bass (Dicentrarchus labrax) and one cod (Gadus morhua).

Number of animal tests in 2021 by species, excluding and including re-use

Animal testing: tests by species (re-use)

1 Re-use refers to the number of animals that were used previously in another test. There are strict rules governing re-use (cf. severity rate, see welfare of laboratory animals).

Numbers according to research aim

Animal testing: research aims

In many cases, animal tests are conducted with an eye to direct or indirect application for human health. In 2021, for example, this was true of 98% of tests on mice. The primary aim of tests on rats and zebrafish is also to expand knowledge about humans and human health.

Tests on most other animal species, in contrast, are aimed at acquiring knowledge about the welfare of the animals. This is true, for example, of all tests conducted on cattle, horses or cats in the context of research during the period 2014-2021. In the case of dogs this is true of 99.56% of tests conducted over the same period; since 2019 this is 100%.

People often forget that veterinary medicine also draws heavily on insights from human medicine. The two areas of expertise cannot be completely separated from each other.

In the context of training, tests are also often indirectly focused on animal welfare. This applies to mammals in particular. When students of veterinary medicine practice skills for palpation and handling of pets this is also considered animal testing. These activities are therefore always submitted as animal tests and are assessed by the Ethics Committee, meaning they are therefore also included in the annual figures. You can read more about the use of laboratory animals in the context of training.

The use of animals at Ghent University has evolved over the years, in line with the evolution of research projects and disciplines. The main research themes at UGent, in terms of animal experiments in 2021, are (in ascending order) nervous diseases, animal diseases, gastrointestinal diseases, cancer, and, by far, the fundamental research on the immune system, accounting for over 21% of the number of animal experiments in 2021 (and 34% for the period 2014-2021).

Degrees of severity

According to the law, animal ‘testing’ refers to procedures and practices that are likely to cause as much, or more, pain, suffering, anxiety or lasting harm as the insertion of a needle in accordance with good veterinary practice. Of course, not every test has the same effect on every animal. It is also important for a researcher to assess in advance what adverse effects any tests may have, and take this into account when compiling the research proposal. On the one hand, researchers have to try and minimise the severity of the procedure, while, on the other hand, still being able to justify the expected (maximum) degree of severity. And of course, humane endpoints are always defined and observed (so that animals do not undergo anything more than the maximum permitted level of suffering).

As is logical, procedures that are categorised as ‘severe’ must provide serious justification in advance to the Ethics Committee. Studies requiring a relatively high number of severe tests relate to research on the immune system, infectious diseases, and nerve diseases, or they are part of multisystemic studies. Here we find a large number of serious illnesses that are still poorly understood or difficult to treat.

Despite what is suggested in the above-mentioned legal definition of animal testing, many animal ‘tests’ included in the statistics for Ghent University are also non-invasive and cause minimal discomfort. These include, for example, ultrasound tests on cattle, fitness tests on racehorses, and palpation exercises for veterinary students.

Animal testing: degrees of severity

Bred animals and privately-owned pet animals

The origin of animals used in animal testing is also subject to strict rules. Most animals come from breeders who are approved and registered in the European Union, which should guarantee the quality and origin of animals, and animal welfare. In a number of cases, if there is a good reason, it is possible to deviate from this.

Often scientists also use privately-owned pet animals. In many ways, for example when developing and evaluating a drug for dogs, it is better to seek permission for testing from dog owners whose pets already have a particular condition, rather than raising dogs especially for this purpose, trying to provoke the condition (if this is even possible) and then evaluate treatment. The same logic applies to cats, horses and cattle, amongst others.

In 2021, some 7% of animal tests at Ghent University were conducted on animals that did not come from a breeder registered and approved in the EU. This figure varies greatly by animal species (e.g. 0.06% for mice, 68% for dogs, 91% for horses). In other words, 127 tests were done using test dogs, and 270 were done using privately-owned dogs.

Wild animals

In certain cases, it is not possible to use either specially bred animals or privately-owned animals. This is often true of research on wildlife. Think, for example, of behavioural research on birds, or ecological research on salamanders. For example, if one takes a blood sample from an animal, or fits an animal with a transmitter (to monitor its movements), this also counts as an animal test and is included in the statistics.


Within the faculty of veterinary medicine, a successful adoption programme has been launched. The table below shows figures for adopted animals from 2015 onwards.

Animal testing: adoption