There will always be unscrupulous competitors in any sport who try to gain an unfair advantage through the use of performance enhancing drugs. Fortunately, in the sport of pigeon racing, this remains a rare activity considered by only a very few. In pigeons, the principle drug abused in this way is cortisone, although others have also been tried.
Some may question the wisdom of providing this type of information here, but I believe that presenting accurate information is important if pigeon governing bodies are going to adequately and correctly regulate this unfortunate, but small, aspect of the sport.
Cortisone Use In Pigeons
Cortisone is one of the body’s natural secretions. It is produced by two small glands called the adrenal glands that sit just in front of the kidneys. Cortisone is one of the body’s great regulators in that it is involved in controlling many of the body’s metabolic processes. The mechanism of cortisone production in the body is fascinating. As blood flows through a gland in the brain called the pituitary gland, the gland registers the level of cortisone present and then, via a hormone, tells the adrenal gland either to stop producing cortisone or to produce more, so that the body’s cortisone level is kept within a healthy range. Cortisone is involved in a whole array of the body’s processes, including maintenance of normal fluid and electrolyte levels, sugar metabolism, bone, feather and skin growth, immune and inflammatory responses, appetite and sex drive, to name only a few. Abnormal levels of the substances that control the body’s processes lead to an imbalance, which confuses the body’s regulatory mechanisms, leading to health problems. Cortisone is no exception.
Effects of Cortisone
As most fanciers will be aware, it has become the practice of certain fliers, more so in some countries than others, to give their birds cortisone. Why would they do this? The reason is that, when we give cortisone and confuse the natural hormonal messages, some of the results can be useful for racing in the short term. These effects are:
• Effect on moulting. Cortisone is one of the hormones involved in controlling the moult. If cortisone levels become high, the moult will stop. This has obvious benefits for young bird racing, where the birds can be raced with a full wing of nest flights.
• Effect on inflammation. Cortisone has an anti-inflammatory effect. If cortisone levels rise, this inhibits the body’s normal inflammatory response and, to some extent, any soreness associated with it. This means that tiring race birds are more likely to fly on at speed.
• Effect on ‘frame of mind’. Cortisone is a mood-altering drug. It promotes a general feeling of well-being. Youngsters on cortisone are described as being tireless, being happy to fly for extended periods around the loft, and taking well to any motivation system used.
The problem is that, in inducing these changes, we also get all the less desirable effects of cortisone overdose, which include suppression of the immune system leading to an increased vulnerability to disease, interference with the deposition of calcium in bones leading to the formation of a weak skeleton, and interference with growth generally, so that birds given cortisone, particularly early in life, cannot grow into normal strong pigeons.
Large amounts of cortisone, given suddenly, interfere with the normal body’s metabolic processes to such an extent that the birds become severely unwell. So, when giving cortisone, only small amounts must be given initially. The dose given is then gradually increased. In this way, as the level of artificial cortisone gradually rises, the pituitary gland, trying to keep a normal level, tells the adrenal gland over a period of time to gradually produce less and less of the body’s own natural cortisone. Slowly, a tolerance is built up to the artificial cortisone and, eventually, with continued supplementation, the cortisone level becomes higher and higher; much higher than it would be normally. Supplementation is then continued until there is sufficient cortisone in the body for the above effects to be seen.
A veterinarian can give a gradually increasing dose of cortisone to a pigeon by injection or tablet. However, these options are not readily available to fanciers, and so cortisone eye drops are used. When drops are placed in the eye, they flow down the tear duct into the back of the throat, where they are swallowed. Using the drop as the unit of measure, both the number of drops and frequency can be increased with time. For example, one drop may be placed in the eye every third day, before increasing to one drop every second day and then two drops every second day. Once the required threshold is passed and there is sufficient cortisone in the system, this dose is maintained for as long as the fancier wants to exert the effect, or the bird starts to become unwell with cortisone overdose (usually after about eight weeks).
If cortisone treatment is suddenly withdrawn, the birds also become severely unwell, and can die. This condition is called Addisons disease. Because the adrenal gland has not had to produce cortisone for a period of time during supplementation, it temporarily loses the ability to produce normal levels. This means that, if cortisone treatment is suddenly withdrawn, the blood level of cortisone will fall. The pituitary gland will register this and immediately tell the adrenal gland to produce a lot of cortisone. It cannot do this immediately, and so the cortisone level plummets, with the bird becoming unwell. This means that, in the same way that cortisone supplementation has to be gradually built up, it must also be gradually withdrawn.
Dangers of Cortisone Use
Is cortisone such a bad thing? It could be argued that it is simply another drug that can be used to advantage in, say, the same way that canker drugs are used to lift performance in lofts with a wet canker problem. The counter argument is that the bird’s whole metabolism is generally disrupted, leading to general ill health after a relatively short period of time and only a few of the drug’s effects are of benefit to racing.
Cortisone compromises growth and predisposes the pigeon to disease. Cortisone directly suppresses the functioning of the immune system, making the growing youngster more vulnerable to health problems such as canker and eye colds. In the longer term, cortisone has serious effects on health and the bird’s quality of life. Medications like those for canker improve health, while cortisone, in the longer term, damages health. There are cases in the veterinary literature of pigeons dying after a single topical application of cortisone.
Monitoring Cortisone Use
How is cortisone use monitored? Mature birds that are carrying baby nest flights or are behind in their body moult and are not on the darkness system, always make one suspicious. Laboratory tests used in horses and dogs to monitor cortisone levels in blood have been adapted to measure cortisone levels in droppings. Tamper-proof collection bags are supplied and a Federation official collects droppings from perches and the loft floor at random, in the owner’s presence. Several Australian metropolitan Federations have incorporated in their rules the right to collect droppings from members, if they feel it is appropriate.
Other doping agents
Other drugs have been considered by certain fanciers as potential doping agents. These include the bronchodilators (for example, aminophylline) and various stimulants (such as caffeine, theophylline and theobromine). It is unlikely that these have any performance-enhancing capacity on the day of the race in pigeons. Although these drugs are not registered for use in birds, and therefore have not undergone the extensive testing that would reveal their pharmacodynamics (mode of action, excretion rate, etc.) in birds, we can extrapolate to some extent from their effect and actions in mammals.
What we do know is that other drugs, such as antibiotics, have to be given at higher doses to be effective in birds than in mammals, because birds, with their higher metabolic rates metabolise these drugs much more quickly. Racing pigeons leave their lofts and owner’s care on average 12–36 hours before the event. Drugs such as caffeine only persist in the body for up to five hours in a mammal. In a bird they are likely to persist for under half this time. This means that, by the time the birds are actually competing, medications such as these would have gone from the bird’s system and would not be exerting any effect.
The testing of this type of drug is problematic. The detection techniques that are used to test dog and horse blood have been adapted to test pigeon droppings. The level of any doping agent will be higher in droppings than in blood. This is because some of the drug is not absorbed after being given orally (and will therefore be passed unabsorbed in the digested food component of the dropping) and because the kidney concentrates and excretes body toxins (therefore leading to a higher level in the urine component of the droppings).
It is therefore important not to compare pigeon dropping drug levels with mammal blood levels. Also, blood is usually collected from horses and dogs soon after the event, and therefore gives a good indication of the level in the animal during competition. Pigeon droppings are often checked before the event. As the drugs are quickly metabolised, the levels in the bird during competition 12–36 hours later will be much lower. It is important that any results returned by a testing laboratory are fully and completely evaluated. A result that may seem high in a dropping sample 12–36 hours before a race may not indicate a ‘doping’ level during the event.
An additional point to consider when a fancier’s bird registers a positive test result (particularly for cortisone) is the possibility that his tested bird ingested vomited grain from another fancier’s doped bird in the race basket. Further work needs to be done on the pharmacodymanics of these drugs in birds to establish accurately what does, in fact, represent a doping level in birds.
Doping – how are we going to manage this in Australia?
The first pigeon race occurred in Belgium in 1818 from a distance of about 160km. This means that the sport of pigeon racing has just passed its 200th birthday. An incredible milestone. Such longevity helps to give our sport a real legitimacy. However unfortunately, as in other sports, doping has become a major issue and doping controls have needed to be implemented. Belgium continues to be one of the countries leading the world in pigeon racing and has proven itself to be a leader in doping control. The Royal Federation Colombophile of Belgium (ie the RFCB or KBDB) has established a set of rules regarding doping that serve as a useful framework in dealing with this issue. Corticoids, non-steroidal anti-inflammatory drugs, anabolic steroids, pain relievers and narcotic analgesics, bronchodilators, drugs acting on the central nervous system and other drugs, all have the potential to enhance or at least alter performance.
Substances and methods used in an attempt to alter performance in racing pigeons have changed along the years. In the 1970s, empirical usage of high vitamin doses, food supplements, coffee beans and even strychnine or arsenic (Fowler liqueur) were reported. In the 1990s, the use of corticosteroids and anabolic steroids appeared and quickly emerged as a key issue in pigeon racing due to animal welfare concerns. This resulted in the publication in Belgium of a Royal Decree on the 14 February 1995, identifying prohibited performance enhancing substances in pigeons and establishing penalties for those using these substances on their birds. Shortly after, the first regulations for combating doping in pigeons were implemented by the KBDB. In Belgium, protection of pigeons during competition is regulated now by rules not only from the KBDB, but also by laws from local government. Animal welfare has always been one of the major concerns. The aim of these laws is to not only establish a list of prohibited products that may alter the performance of pigeons, but also to suppress any fraud associated with pigeon racing, including the use of doping substances. The aim of these laws is essentially to ensure that only healthy pigeons can participate in competitions and that competition requirements must not exceed the physiological capabilities of the entered pigeons. With these measures in place, Belgium is likely to be the leading country in doping control.
The KBDB stipulates precisely what are considered as “doping practices” and how they will be sanctioned. They also stipulate how and what type of samples may be taken. Refusal by the owner or the inability to obtain a sample, is considered a violation of doping control rules. The list of banned substances is precisely defined in the KBDB rules and includes corticosteroids, bronchodilators (including β-agonists), anabolic steroids, nonsteroidal anti-inflammatory drugs, narcotics, analgesics, substances that influence the nervous system (including caffeine), synthetic hormones, growth stimulators and mucolytics. This list of prohibited substances is detailed in a “Red List” document, to better inform pigeon owners. Distinctions are made between substances that can naturally be found in the body (such as cortisol) and those that are not (such as caffeine). A distinction is also made between substances that could be linked with consumption of contaminated food and substances that might never be found in the body of pigeons as a result of dietary contamination.
Substances not found naturally in the body must not be present in doping samples regardless of the concentration. Substances that can occur in the body and substances which may occur naturally in food (for example as a food contaminant) are only prohibited if they are detected in doping samples in amounts indicative of artificial administration.
The pigeons to be tested are either selected at random or based on the behaviour or results of particular birds. Regional federations actively monitor competition results and identify those that might be unusual. They inform the head of the national anti-doping control committee who then contacts the team of doping controllers, one of whom will then travel to the suspected loft to perform sampling. The owner is deemed to be fully responsible for any substance that his pigeons have received. The competent bodies of the KBDB are authorised to conduct the collection of droppings and or feathers and/or blood of race birds, at any time and in any location, in order to search for the presence of prohibited substances. Therefore, for all racing pigeon competitions, all pigeons must remain in their fancier’s loft for control by the KBDB or by the organiser, for a minimum of 5 working days from the end of the competition. Samples may also be taken from the drinking water within the loft. Samples may be taken in the absence of the owner, who must indicate the details of a representative contact person if he is not able to be present.
Currently, most of the anti-doping controls are carried out after a race. However, the possibility of carrying out specific targeted controls before a race, i.e., at basketing of pigeons, is being strongly considered.
Samples - The KBDB has authority to collect for testing, samples of faeces, blood, feathers and drinking water. Faeces and drinking water are the two most commonly used. Faeces can be collected from individual birds (after placing them in a basket) or from the loft generally.
Some fanciers don’t like having blood collected from their birds, saying that this may compromise subsequent performance (even though this is not correct). One difficulty with blood testing is that the maximum concentration of a substance in blood, often quickly decreases and falls below the limit of detection. This is critical in pigeon racing as the delay between basketing and the return to loft can reach several days.
When feathers are tested they are ground. Feathers are readily available, easily collected and drugs in them can be stable. The disadvantage is that drugs are only assimilated into feathers when they are growing, which makes detection hard unless the birds were moulting while they were being raced (and perhaps illegally doped). Also a positive result does not necessarily mean that the birds were doped during the racing season. A fancier could argue that his birds were treated when they were moulting, but not during the race season. There are also difficulties with detecting elevated levels of substances that naturally occur in the body and differentiating false positives, from seed contaminates and substances from other sources, that naturally accumulate in the feathers.
Saliva and crop contents have also been considered as test samples, but their use has never been the subject of published studies and they are not currently used for doping control in pigeons.
In pigeons, droppings are the usual sample that is collected and tested. Droppings in birds are a mixture of faeces and urine and although it is possible to cannulate a ureter (the tube that brings urine from the kidney to the cloaca), it is thought that it is not practical to use this technique routinely. Two samples of droppings, each of four grams, are collected and homogenised. The samples are clearly labelled and sent to the lab for testing in tamper proof containers. The first sample (A) is tested. If this is positive, the fancier is notified and he can request that the second sample be tested. If this second sample (B) is negative, testing stops and the KBDB covers costs. If the second sample is positive, the doping officer notifies the fancier by registered letter. The fancier then has 10 days to respond with a counter argument. The results and correspondence are then forwarded to a Scientific Advisory Committee (SAC) anonymously. The committee of three must be unanimous in its recommendation. The SAC evaluation is forwarded by the doping officer to the KBDB and then to all parties – the fancier, lawyers etc. Penalties are defined by the KBDB. In human and equine testing, samples A and B are tested by different labs. In pigeons, because not all labs have expertise with this testing, both samples may be tested by the same lab.
Laboratory Analysis - The control of doping in racing pigeons presents an extremely difficult challenge when compared with human, greyhound, or equine, competitive sports. This is partly due to three factors, namely :-
1/ Races may last several days from the moment pigeons leave their loft until the time they return home.
2/ The choice of samples for doping control presents another problem. In mammals urine is an easy sample to collect. In birds, droppings consist of both faeces and urine.
3/ Additionally, there is a lack of pharmacological studies dedicated to pigeons.
Frustratingly the amount of published material on testing in pigeons compared to horses, humans and even camels, is very low. Between 1990 and 2019 only 4 scientific papers on pigeon doping testing were published. The tests are very sensitive and can detect substances down to one part per billion and even one part per trillion. The difficulty comes in interpreting the results. Contrary to what has taken place in horse racing, no internationally recognised threshold (i.e., the drug concentration in a sample at which this sample is considered as positive for doping control) has been established, for substances which might occur naturally in pigeons. Similarly there is no internationally recognised threshold for substances not occurring in the body naturally, or that might come from the consumption of contaminated feed. The establishment of a threshold is regarded as the responsibility of each national organisation. In Belgium, thresholds have been set for certain drugs by the SAC. These were established by statistical analysis of samples that were indisputably negative. So far, these thresholds are confidential to the Belgian authorities.
Unfortunately, the sample detection time (i.e., the amount of time a substance can be detected in a biological sample collected after administration of a specific drug and the effect that the dose, route of administration and the drug formulation have on that time is virtually unknown in most if not all substances likely to be used to dope pigeons.
All testing in Belgium is done by just two labs and most of the work is done by just one. In this lab a negative result (ie no detection of banned substances) is defined as lower than the detection capability. Positive tests for substances that do not naturally occur in the body are reported if the test result is greater than the decisive limit as indicated by that country’s testing of indisputable negative results. All other prohibited substances, ie substances that naturally occur in the body and those that might come from consumption of contaminated food products, are quantified and reported in parts per million and deemed to be positive if the result is higher than what might occur naturally.
Even so the interpretation of results is not easy. There are only a limited number of pharmacological studies that have been performed on pigeons and most drug doses and dosages in pigeons are either extrapolated from other bird species or indeed mammals or may simply be empirical. This applies both to the drugs used in the treatment of sick pigeons and to the substances that are potentially abused in a doping context. Because of this an accurate withdrawal time (ie how long a drug takes to clear the system,) is not known for most substances. This means that it is not clear to a fancier how long before going to a race he must stop treating his birds to avoid a positive doping test and conversely that a potential cheater does not know when to give a substance so it will have an effect. In addition to this, not all individual birds are the same. Some individual pigeons may metabolise drugs more rapidly or indeed slower than others. Moreover while some drugs are excreted at similar rates in different species other drugs are not. Excretion rates and other pharmacological characteristics of drugs vary, not only, between different species of birds but also between birds and mammals. Pharmacokinetic data on mammals can hardly be extrapolated to birds as such. So ideally the information that is used should be based on pharmacological data specific to pigeons. However, with virtually no pigeon specific results available, test results are indeed interpreted based on levels extrapolated from testing done on other animals. Variability is particularly apparent in drugs that are not excreted from the body through the liver.
Retrospective testing on stored faecal samples and the rate of degradation of various substances in pigeons all need to be studied.
Drugs Used - There is no published research study dedicated to the improvement of racing performances in pigeons following administration of specific drugs (e.g., double-blind comparison of flight performances of “doped” and control pigeons in a standardised flight test). However, field observations and confidential comments from pigeon fanciers and veterinarians clearly indicate that some substances have obvious effects on sports performance.
In the absence of an official investigation carried out on a large scale by competent authorities and officially published, it is exceedingly difficult to know precisely the drugs and methods used in doping. However European researchers have estimated the frequency of use of substances potentially administered by pigeon fanciers with the aim of influencing the sporting performances of their pigeons based on confidential field reports, on direct observations or on unpublished confidential results of a survey conducted in 2017 in Belgium. There were many substances that were found to have been used but the main ones were corticosteroids and non-steroidal anti inflammatory drugs (NSAIDs). The most common steroids used were prednisolone and methylprednisolone. The most common NSAIDs were meloxicam, salicylic acid (aspirin), diclofenac and flunixin.
Corticosteroids - Synthetic corticosteroids such as prednisolone, are the most frequently used doping agents in pigeons. Generally administered in the form of eye drops or in the drinking water, they are known to have been used as doping agents in pigeon sports for a long time and might well remain in use today, especially in the form of drops for human use that pigeon fanciers obtain either illegally from overseas or via personal medical prescriptions.
One of the main effects of corticosteroid treatment for doping in pigeons is the inhibition of the natural moult of primary flight feathers. Thus, the young birds treated retain all their flight feathers and therefore have a higher aerodynamic efficiency than the birds with moulted flight feathers, particularly if the last 4 primary flight feathers are involved. In Australia this means that the latebred pigeons are not going to drop flights during the season particularly in the later long distance events. Corticosteroids also promote a feeling of general well-being and are potent anti- inflammatory drugs. As such they restrict pain associated with inflammation such as muscle pain associated with exertion. They also increase blood fat (triglyceride) levels that are an easily usable energy supply for pigeons both during short and long distance flight. The down side is that in the long term, the muscles become damaged and a variety of other health problems occur. Fatty degeneration of the liver and kidneys, infertility in both cocks and hens, osteoporosis (low bone calcium), impaired energy release (due to inpaired ability to absorb sugar from the blood) and impaired functioning of the immune system and an increased vulnerability to infection are all well documented side effects of corticosteroid use.
The fortunate thing regarding doping control is that with prednisolone being the most commonly used doping agent, it is straightforward to detect and interpret it’s test results. This is because in birds corticosterone is the main naturally occurring corticosteroid while in mammals it is cortisol. This is significant because there is no corticosterone product on the market and it is only cortisol that can be converted in the pigeon to prednisolone. This means that if there is any prednisolone in the birds system then it is likely to have been given to the race bird as a doping agent and the fancier is vulnerable to detection as a drug cheat. Despite this prednisolone remains the most commonly used doping agent.
Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) - NSAIDs are perhaps the most common class of analgesic (pain killing) drug prescribed in small animal veterinary medicine. Despite the lack of specific studies in birds, it is usually assumed that NSAIDs have a similar mechanism of action in both mammals and birds. Adverse effects of NSAIDs have not been fully substantiated in birds but they might be the same, with the most common reported adverse effect of NSAID usage in avian species being damage to the kidneys. No commercial formulations are available for use in birds including pigeons, pet birds and poultry but off-label use of these drugs in birds occurs frequently. The most common NSAIDs used in avian medicine include drugs called meloxicam, carprofen, ketoprofen, celecoxib and piroxicam. In Australia, meloxicam is particularly commonly used in small animal and avian practice to provide pain relief. Meloxicam at a dose of 0.4 mg/kg once daily for 5 days has significant anti-inflammatory effects in pigeons with only limited observed adverse secondary effects. While administration of meloxicam at 2.0 mg of meloxicam/kg, given by intramuscular imjection, immediately after surgery and then 2.0 mg/kg, orally, every 12 h for 9 days provided quantifiable pain relief that appeared safe. In the framework of doping, all NSAIDs for both veterinary and human use are likely to be considered by some pigeon fanciers.
Salicylic acid is the active metabolite of acetylsalicylic acid (aspirin). Some food supplements and “herbal teas” given to pigeons by some fanciers contain variable levels of salicylic acid. The presence of salicylic acid during doping control could be linked with consumption of contaminated food. To avoid false-positive doping, a control threshold (for confidential use by the KBDB) was established for salicylic acid. However not all birds metabolise these drugs at the same rate.
The half-life of meloxicam and salicylic acid in pigeons was around three to five-fold longer than in the other bird species such as ducks and chicken. But even so in pigeons the half life of meloxicam is 2.4 hours and that of salicylate acid is 15 hours meaning that they would have all been excreted from the body before the birds even reached the race point.
Diclofenac(“Voltaren”) appears to be rapidly toxic in pigeons, damaging the kidneys and liver, with a 20% mortality at a dose of 0.25 mg/kg for 7 days, and up to 60% mortality at 20 mg/kg for 7 days.
The harmful effects of carprofen at 2, 5, or 10 mg/kg by intramuscular injection once daily for 7 days have been tested in pigeons. No clinical signs developed after administration of carprofen in pigeons suggesting that carprofen by injection may best be reserved for short term use in birds with acute injuries. However, neither the anti-inflammatory effects nor the analgesic effects have been studied
Anabolic Steroids - Anabolic steroids such as nandrolone laurate have been used as doping agents in pigeons but neither their pharmacological effects on pigeons or their enhancing performance abilities have been studied to date. Anabolic steroids might increase the muscle mass of pigeons and could reduce the recovery times after racing. Testosterone, boldenone, and nandrolone are natural steroids that can be detected in pigeon droppings. Because these substances do occur naturally and also vary between sexes and also the type of bird, it is important to establish normal thresholds. This has not been undertaken to date.
Pain Relievers and Narcotic Analgesics - All vertebrate animals, including humans and pigeons have similar anatomy and chemical responses to pain. So, although pigeons can appear very stoic or indeed not to feel pain at all, this is not the case. Birds that are prey species, such as pigeons, have evolved to demonstrate pain in very cryptic and subtle ways and so it can be difficult to determine if pain medication is actually doing anything.
The efficacy of pain relievers and narcotic analgesics as doping agents would be linked to a reduction of muscle pain during flight. For opioids, some form of euphoria that results from stimulation of the brain’s reward system, might also play a role.
Paracetamol, also known as acetaminophen, is one of the most popular and widely used drugs for the treatment of pain and fever in humans. Paracetamol has been shown to have an analgesic effect in pigeons without damaging the kidneys. Paracetamol occupies a unique position among analgesic drugs, both for the type of pain relieved and the side effects. Paracetamol is ineffective for intense pain. It is also ineffective in pain arising from the gut and other sites that have smooth muscle (ie muscles beyond conscious control). Paracetamol is entirely synthetic and does not occur naturally. Paracetamol abuse has already been found in pigeon racing in Europe.
The action of narcotic analgesics is based on binding to specific membrane receptors κ, δ and especially the µ receptors located in the central and peripheral nervous systems. Opioids have not been well studied in birds generally. The effect of these drugs is likely to be different than in mammals because the distribution of the various membrane receptors is different. For example, in the pigeon forebrain, 76% of opiate receptors appear to be of κ type. Basically just how the use of an opioid would make a pigeon feel and how long the effect would last is not known. My personal feeling is that a “stoned” pigeon is less likely to perform well.
In Europe there are registered veterinary drugs containing buprenorphine, butorphanol, fentanyl, methadone, and tramadol. The abuse of these drugs as doping agents in pigeons is unknown.
Butorphanol is commonly used for avian analgesia in Australian avian veterinary clinics, before and after surgery. Its use however has never been fully studied in pigeons.
Interestingly in 2016, a positive case of doping with morphine was detected by the KBDB but was eventually considered as a c ase of food contamination due to the consumption of poppy seeds (Papaver somniferum) that are regularly integrated into food supplements for pigeons, and known to contain varying concentrations of morphine, codeine, thebaine, noscapine, and papaverine The latex of the opium poppy (Papaver somniferum) contains up to 80 different alkaloids. Mature poppy seeds do not contain latex but can be contaminated with opium alkaloids. Pigeons do not willingly consume poppy seeds and if given free choice of seeds, show a preference for larger seeds. However, to avoid false-positive doping controls, a threshold (for confidential use in KBDB) was established for morphine.
Bronchodilators - Bronchodilators remain the basic treatment for airway disorders such as asthma and chronic obstructive pulmonary disease in human and non-avian veterinary medicine Their relatively short duration of action, even for long-acting bronchodilators severely limits the value of their use in pigeon racing. Also because the anatomy of the respiratory system in birds and mammals is very different, the action of these drugs is hard to predict. Their use does however have the potential to have adverse side effects such as a “racing “ heart and muscle trembling.
Clenbuterol abuse has been reported in pigeons and clenbuterol may be detected in faeces up to one day after administration of a single dose (0.8 µg/kg, orally) The performance-enhancing effects of clenbuterol in pigeons remain unknown.
Drugs Acting on the Central Nervous System - Methylxanthines (caffeine, theobromine and theophylline) with their known stimulating effects on the brain and spinal cord resulting in improved cognitive, physical and occupational performances can be potent doping agents. The pharmacology, metabolism and mechanism of action of caffeine has recently been reviewed. An increased muscle activity resulting in faster and more powerful muscle contractions was demonstrated. Caffeine is administered to pigeons mainly in the form of tea that usually also contains other alkaloids such as theobromine and theophylline which are additionally considered as doping agents. As in humans, it can be assumed that low doses of caffeine do not present a problem. Conversely, large doses could adversely affect animal welfare. However, no studies have been performed in pigeons to date. A threshold (for confidential use by the KBDB) was established for caffeine.
Ephedrine and pseudoephedrine are natural substances derived from the Ephedra plant. Their ability to improve athletic performance is still unclear. Amphetamines are synthetically prepared substances, with a structure and action similar to that of ephedrine. Both drugs often make the user feel more alert and energetic. Amphetamines suppress fatigue and may lead to improved physical performance though this effect is still debated. One amphetamine positive case was detected in pigeons in Europe in 2016.
Other Drugs and Methods - While the concentration of red blood cells and the amount of haemoglobin in red blood cells are key determinants of aerobic capacity and exercise performance in humans this relationship has not been demonstrated in pigeons. Birds, like mammals, respond to blood loss and blood destruction by increasing production of a hormone called erythropoietin. This stimulates red blood cell production. Human erythropoietin has no effect of red blood cell production in pigeons thus human erythropoietin drugs registered on the market are not active in pigeons.
Intramuscular injection of ACTH (a hormone that stimulates the release of cortisone by the adrenal gland) at a dose of 50 µg or 125 µg in healthy pigeons, causes a ten to hundred-fold increase over baseline corticosterone concentrations. Therefore, ACTH could be used as a performance enhancing drug in pigeons.
Since 2017, mucolytics (ie drugs that break up mucous) such as bromhexine and ambroxol were added to the list of prohibited substances in the KBDB rules. Both drugs have been reported in test samples in pigeons.
Although they are not on the ‘Red List’, the abuse and misuse of antibiotics are a concern in pigeon racing. A Belgian survey showed that in Flanders, race birds were treated on average every ten days with an antibiotic during the race season. Antibiotics are mainly used by fanciers for preventative and subclinical infections, to overcome periods of stress, or as an attempt to improve sport performance. In some countries contrary to recommended veterinary practices and legal obligations, some of these antibiotics are acquired illegally, that is, without a prescription or the supervision of a veterinarian.This has led to high levels of antibiotic resistance even for critically important antimicrobials. Based on recommendations for the use of antibiotics which limit their use to sick animals and on the legal basis which prohibits sick animals from participating in races, the KBDB and many veterinarians believe that measures should be taken to control this situation.
Conclusions - In Belgium, doping controls to date are managed primarily by the KBDB which operates with utmost diligence to track down illegal drug use in pigeon racing. Droppings remain the most suitable sample for doping controls in pigeons as they are easily collected and allow the detection of most doping agents. However, there is a great need for further research to better understand the real effects of drugs on the performance of pigeons and to determine withdrawal and detection times. A balance must be found between the obligation to eliminate cheaters and other purposes such as the need to treat sick or injured pigeons during the racing season. The acceptable levels of substances that occur naturally and those that might be incidentally found after eating contaminated food compared with the concentration range classifiable as doping needs to be determined.
Corticoids, anabolic steroids, bronchodilators and amphetamines have no beneficial properties in pigeon medicine, at least during the racing season and so their detection at any level is significant.
NSAIDs and pain relievers should never be administered at the owner’s discretion, which notably, is illegal in Belgium and should only be used under veterinary supervision. This implies a precise reporting of the administered substances (doses, time, pigeon ring number, ...) and partly places the risk and burden of a positive control on the veterinarian, which is unreasonable given withdrawal times remain unknown.
Methylxanthines and salicylic acid can be found in teas given to pigeons as part of a daily care routine. The amount of methylxanthine and salicylic acid may vary greatly between teas, but are far below the level found in commercial drug preparations. Regardless, avoidance of herbal teas can be recommended when the food composition and/or analysis are not clearly stated.
As with other sports, there may be a gap between the number of drugs available and the number detectable, however, great efforts are made in Europe to ensure the integrity of the sport remains as sound as reasonably possible and that animal welfare is protected. This is not only extremely important in the context of animal welfare activist groups, (some of which advocate the removal of animals from sport-use altogether), but also in order to maintain a reliable selection of racing pigeons making sure that the best pigeons win, and that the value of winners in the national and international pigeon trade is protected. In Australia we are a long way behind. No testing has been done to establish what could be regarded as “normal” levels of potential doping agents. Although for some exogenous substances this would not be required, no list of potential doping agents has been developed. We have the technology to do the testing but have no formal structure in place to collect, submit and deal with results. This is particularly so where suspect positive samples could lead to penalties. The VRPB will continue to investigate the doping issue.
I would like to thank Dr Didier Marlier for access to his paper “Doping in Racing Pigeons: a review and actual situation in Belgium, a leading country in the field”, for providing the majority of the above information. Didier reviewed over 120 published scientific papers to make much the above information available.

Doping Update
Last year I summarised the current information available and recently more information has become available. The IVPA, ( International Association of Pigeon Veterinarians, of which I am the Australian rep ) in early 2022, released a document addressing several concerns regarding testing for doping.
Following on from the earlier update ,the main concern is the difficulty in interpreting the results of doping tests. Frustratingly, there is very little scientific research available in racing pigeons to fall back on when assessing and interpreting the results of studies done on droppings. In Belgium, the Scientific Advisory Committee (SAC ) studies the results and, on the basis of available scientific data and information, gives advice to the NRB (National Board of Directors) of the KBDB/RFCB about a concentration of a prohibited substance that has been found. This advice helps the NRB to decide if further action needs to be taken against a fancier whose birds have returned a positive result. The SAC’s advice is vital because some prohibited substances are found quite normally at certain levels in the body . It is a matter of deciding if the detected level is sufficiently elevated to possibly be due to a malicious intent.
Particular concerns are
1/ A relatively high number of positive A samples yield different results than the B sample. This raises questions about the composition, collecting, processing and storage of the dropping samples. The IVPA has contacted several experts who have given several possible reasons for this :
a/ the sample is a collection of droppings from throughout the loft. It is vital that the sample is truly homogeneously mixed. For example if only one pigeon of 12 in a loft section is positive then if the droppings from that birds are not evenly mixed with the others this will skew the results . It has been suggested that testing individual birds is more reliable.
b/ Uniformly collected and stable samples are essential for accurate testing. Temperature fluctuations can lead to degradation Ongoing bacterial activity in the sample can alter substance levels and persistent moisture in the sample can also affect the results. It is therefore suggested that all samples are immediately frozen after collection.
c/The tests are very sensitive. Detected levels can be very low. Sample contamination through human error can occur. The people collecting and handling the samples must be aware of this.
d/ There are also concerns over substances that occur naturally in plant products that might be fed to pigeons such as cereals, seeds and herbal mixtures. For example, poppy seeds may be fed. These contain opiates that can break down to morphine which is a prohibited substance. Further complicating matters is that opiates are quite quickly metabolised so that the time from ingestion until the time of testing very much influences the result.
e/ Some prohibited substances , in particular cortisols , are naturally produced within the body. Not only are these substances present but their level naturally fluctuates as part of the pigeons normal physiology. This makes interpretation of a positive result very challenging. Anecdotally ,prednisolone ( a cortisol ) use is very common in Belgium . Cortisol and corticosterone can be produced by pigeons under stress and cortisol can be converted to prednisolone by some bacterial enzymes further compounding interpretation. Zero tolerance is therefore inappropriate . Currently a residue concentration of 0.5 micrograms of prednisolone per kg of droppings ie 0.0000000005 grams of prednisolone per gram of droppings is regarded as positive for doping.
The debate regarding doping continues. Doping affects the pigeon fancier, the producers of feed and food supplements, the veterinarian and the sport itself. The IVPA is organising a discussion for veterinarians in conjunction with the KBDB later this year to bring more clarity to the sampling and testing of samples.