Figures and statistics

In 2023, 55,407 animal experiments 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 54,777 animals being used for experiments in 2023. An animal test, trial 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 2023 is slightly below the average of the previous period 2014-2022.

The number of animals being re-used in 2023 was higher than the previous years (630 versus 165 to 582 in the period 2014-2022).

Dierproeven: aantallenDierproeven: aantallen

Numbers of animal experiments at Ghent University since 2014

Annual fluctuations in themselves do not demonstrate any trend. Whereas in 2022 the number of experiments using pigs was very high (research on nutrition and welfare), the number of 2023 was the lowest since 2014. Some of the more striking general trends are the following. Looking at the period 2014 to 2023, the number of zebrafish, stayed high – this proportion was minimal in the years until 2016. Other fish were clearly much less present in 2019 to 2023 compared to previous years, as were domestic fowl. Research with privately owned cats in the context of veterinary medicine increased in importance in recent years. The high number of alpaca trials in 2023 is due to a health study on newborn alpacas coming to the clinic with their owner. Relatively unchanged , the number of trials involving mice keeps explaining about 75% of animal experiments. Ghent University does not conduct any animal experiments or tests using primates.

Animal testing: species

Species that were most frequently used in 2023

Number of animal experiments by species:

Animal testing: species per year

1 In 2023: seven lions and four tigers.
2 In 2023: 93 domestic pigeons, 81 budgerigars, 60 sandwich terns, 60 Japanese quails, 60 European herring gulls, 49 placid greenbuls and ten common waxbills.
3 In 2023: two Bauer's chameleon geckos, two golden spiny-tailed geckos, two northern spiny-tailed geckos and two eastern spiny-tailed geckos.
4 In 2023: 211 painted frogs.
5 In 2023: 72 mackerels.

Numbers of animal experiments in 2023 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 related to research aim

Animal testing: research aims

In many cases, animal research is conducted with an eye to direct or indirect application for human health. In 2023, for example, this was true of almost 98% of experiments using mice. The primary aim of research using rats and zebrafish is also to expand knowledge about humans and human health (resp. 99 and 100%).

Research with most other animal species, in contrast, is aimed at acquiring knowledge about the welfare of the animals. This is true, for example, for all experiments conducted using cattle, horses or cats in the context of research during the period 2014-2023. In the case of dogs this is true for 99.6% of experiments 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, experiments 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 experimentation. These activities are therefore always submitted as animal experiments 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 2023, are (in ascending order) nervous diseases, musculoskeletal diseases, gastrointestinal diseases, cancer, and, by far, the research on the immune system, accounting for almost 24% of the number of animal experiments in 2023.

Degrees of severity

According to the law, animal experiments or ‘tests’ refer 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 experiment 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 experiments 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 ‘experiments’ 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

Degrees of severity of animal experiments at Ghent University from 2014

Bred animals and privately-owned pet animals

The origin of animals used in animal experiments or tests 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 trials 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 2023, some 10% of animal experiments 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. 3% for mice, 46% for rabbits, 99% for dogs, 100% for horses).

Wild animals

In certain cases, it is not possible to use either specially bred animals or privately-owned animals. This is often true for research on wildlife. Think, for example, of behavioural research on birds, or ecological research on salamanders. 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 experiment 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