Is our meat safe for consumption?

Most people consume products of animal origin such as meat, fish, eggs, milk (or dairy products like cheese or yoghurt) and honey. These products are a healthy part of our diet. Every now and then there are however incidents where safety of these products is up for debate, for example the problems with fipronil in eggs. In Europe a lot of measures are taken to guarantee the quality and safety of our food, including product of animal origin.

In this article we explain which precautionary measures are taken to make sure that everybody will be able to enjoy these products.

Acceptable Daily Intake (ADI)

Substances that are not naturally present in our food, such as feed additives and components used in veterinary medicines, have an Acceptable Daily Intake (ADI). This is the maximum amount of a substance that you can consume during your life without negative effects on your health. An ADI will only be determined when it is proven that a substance is not carcinogenic. Substances that may have a carcinogenic effect are not allowed to be used in the food chain and therefore do not get an ADI.

The ADI is usually determined through animal tests. The animals used for testing receive different doses of the substances to determine the highest concentration at which no negative effects are encountered (NOAEL: No Observed Adverse Effect Level). When several NOAELs are determined for the same substance, the lowest NOAEL is always used, unless it can be justified that another NOAEL is more appropriate.

The NOAEL is however not just taken on as ADI; two uncertainty factors are incorporated. The first factor is to compensate for possible differences between toxicity in the animals used for these tests and humans. The second factor compensates for the fact that some substances may be more toxic for specific risk groups such as elderly people, pregnant women, babies and children.

Often uncertainty  factors of 10 are used and the NOAEL is thus multiplied by 100 (NOAEL x 10 x 10). For certain risk factors a higher uncertainty  factor (such as 1000) is used.

Maximum residue limit (MRL)

MRL stands for Maximum Residue Limit. The MRL is important for food safety, because food of animal origin should not contain any residues in concentrations higher than the MRL.
A MRL is specifically determined for one active ingredient and should be determined for all pharmacologically active substances in veterinary medicines and biocides that are used in food-producing animals.

The ADI is taken as initial value for the determination of the MRL. The ADI is extrapolated using the intake of different foods according to a standard food package , or diet. This provides an overview of the food quantities that an average person will consume in one day. The standard food package is shown in the table below.

Table 1 Standard Food package for the determination of the MRL

Mammals Muscle 300 gram
Fat 50 gram
Liver 100 gram
Kidney 100 gram
Poultry Muscle 300 gram
Fat & skin 90 gram
Liver 100 gram
Kidney 100 gram
Fish Muscle & skin 300 gram
Milk 1500 gram
Eggs 100 gram
Honey 20 gram

The MRL should be determined in such a way that the exposure to the consumer is below the ADI. A lifelong exposure and ways other possible routes of exposure to the consumer of the same substance are taken into account here. When a substance for example is used in veterinary medicines, as well as in crop protection products, only 45% of the ADI may be used in the determination of the MRL for the use of this substance for veterinary use.

An overview of all determined MRLs can be found in table 1 of the Annex of Commission regulation (EU) 37/2010.

Risk assessment

The European Commission approves an application for the determination of a MRL and the level thereof on the basis of a scientific risk assessment by the CVMP (Committee for Medicinal Products for Veterinary Use, European Medicines Agency).

Amongst others, the results of the studies of the ADI and residue studies are taken in account. The risk of toxicological, pharmacological and microbiological effects on humans is taken into account as well. In addition, the pharmacological properties of the substance in the relevant animal species are examined. For substances that are used in food-producing animals, long-term exposure, possible effects on fertility in multiple generations and effects on pregnant animals, the embryo and the foetus are examined as well.

One of the things that is investigated, is the effect of a substance on the human intestinal flora. An assessment is made to determine whether the colonisation barrier could be disturbed. This barrier is formed by the normal intestinal flora and limits the invasion of exogenous micro-organisms and overgrowth of potentially pathogenic micro-organisms. It is also determined whether there is an increase in resistant bacteria.

Besides the characteristics of the substances and residues, the situation regarding the intended use of the substance is examined as well. This is done through a recommendation on risk management , including for example the following factors:

  • the availability of an alternative substance for the treatment of the animal species concerned;
  • the necessity of the substance to prevent unnecessary animal suffering;
  • consequences for the health of the people treating the animals.

No MRL required

Is an MRL always needed? No, there are exceptions. In some cases it is decided that residues in food are not dangerous for the consumer and because of this a MRL is not required. For example the use of vitamins of those it is known that they don’t have adverse effects, but are essential for humans and animals (for example biotin or folic acid).

A MRL is neither needed for substances that are pharmacologically inactive, which are only used only as excipient of preservative and are found to be safe. These substances then fall outside the scope  of the European MRL regulation.

Substances that are not allowed

Another exception occurs when it is concluded that the presence of a substance in food is undesirable, even if it is in low concentrations. This conclusion can for example be drawn when the presence of even very low concentrations pose a risk for human health. The substance will not get a MRL. Even when no definitive conclusion can be made on the consequences for human health, no MRL is determined. In such a case the substance is prohibited for use in food-producing animals. One example of such a substance is chloramphenicol. This substance is prohibited due to the possible risk on genotoxicity. This means that chloramphenicol possibly damages the genetic information in cells (the DNA), which could lead to mutations and eventually to the occurrence of cancer.

Withdrawal period

Finally, the MRL is implemented as the withdrawal period. This is the minimum period between the last administration of a veterinary medicine under normal conditions and the production of food derived from the animal. The objective of the withdrawal period is to make sure that there are no residues in food in concentrations that exceed the MRL.

For quick and easy access to the information , the withdrawal period is always mentioned on the Specific Product Characteristics (SPC) and on the package leaflet and/or packaging of the product.

Veterinary medicines for food-producing animals can only be registered when an ADI and MRL have been determined and it has been shown that the withdrawal period indicated is sufficient to prevent exceedances of the MRL in products of animal origin. This is shown in residue studies. In these studies the product is administered to healthy animals used for these test and the residues in tissues and other products of animal origin are determined at different time points after the last administration. The animals used in these tests are always of the same animal species as the animals for which the product will be registered.

Veterinary medicines are only allowed for use in food-producing animals when they are registered for the concerning animal species. This means that a withdrawal period is established for the given animal species.

Only to avoid unacceptable suffering in animals, a product that is not registered for the intended animal species and indication is allowed to be used (cascade). This is only allowed for substances for which a MRL is established (possibly in another animal species) or for which it is determined that no MRL is required. And of course there are rules to determine the minimal withdrawal period for the species in which the product is used.

Monitoring

All above mentioned studies have been executed before a veterinary medicine is registered. But does it mean that the measures stop as soon as the product is on the market? No! After the approval of the registration, several steps will be taken to ensure food safety too.

  • The farmer must keep a register with the administered veterinary medicines. This information is shared when the animals are slaughtered, in order for the slaughterhouse to be able to check whether the withdrawal period was respected.
  • The inspection body responsible carry out random checks of products from animal origin to test if any residues are present. In the Netherlands this is performed by the Dutch Food and Consumer Safety Authority (NVWA). They use a framework called National Plan Residues (NPR), based upon the European regulations, to carry out these inspections. In the Netherlands hardly any residues exceeding the MRL are found.
    The EFSA (European Food Safety Authority) annually reports a summary of the monitoring in the entire EU. In 2016 369 262 samples have been analysed for the presence of prohibited or permitted substances. 0.31% of the samples did not comply with the regulations. This corresponds with the results of previous years (0.25% – 0.37% in the last 10 years). A broad range of substances is evaluated: not only antimicrobial or antiparasitic products, but also minerals such as copper. The number of non-compliances per animal product group is shown in the table.
    When interpreting these data, it should be taken into account that the monitoring is aiming for detecting deviations. This means that the selection of samples is executed in such a way that predominantly high risk products are often selected for investigation. When the samples would be taken randomly, a lower percentage of deviations might be found.
  • When residues in concentrations higher than the MRL are found in food, despite respecting the withdrawal period, this has to be reported to the marketing authorization or medicine board in a country in relation to pharmacovigilance. Based on these reports, an assessment will be made to determine if the advised withdrawal period is (still) sufficient.
    When it appears that the withdrawal period may not be long enough to ensure that animal food products do not contain residues that could pose a health hazard to the consumer, the registration is suspended. Delivery of the veterinary medicine will be prohibited and the product will be withdrawn from the market.
    Only when the authorization holder can prove that the withdrawal period (or a modified withdrawal period) is sufficient to guarantee food safety, the registration will be re-approved.

Table 2 Results of the monitoring on EU level

Category of animal product Number of samples with residues above MRL % of total amount of samples tested
Beef meat 331 0.30%
Pork 295 0.25%
Goat- and sheep meat 82 0.49%
Horse meat 28 0.84%
Poultry meat 48 0.07%
Meat from farmed wild birds 17 1.06%
Meat form wild birds 165 6.69%
Rabbit meat 5 0.28%
Aquaculture 37 0.55%
Milk 38 0.16%
Eggs 44 0.35%
Honey 41 1.16%

Quality systems

Besides the regulations described above, there are some additional quality systems which ensure food safety of products of animal origin.

These quality systems often impose extra requirements, which are additional to the legal standards.

Conclusion

Although it can be concluded that the risk of exposure to a residue will never be zero, it can be concluded as well that many measures are taken to prevent residues from causing human health problems. In short these are:

  • always using the lowest NOAEL;
  • uncertainty factors of 100 to 1000 when determining the NOAEL;
  • safety margins when implementing the NOAEL to an MRL;
  • safety margins when implementing the MRL to a withdrawal period;
  • control systems by the government (national and European);
  • quality systems that provide extra supervision on the food safety of products of animal origin.

Besides, a risk on a possible negative effect is always taken very seriously when assessing the ADI, NOAEL, MRL and withdrawal period. Food safety is always the most important factor.

References

  1. Commission regulation (EU) 2018/782 of 29 May 2018 establishing the methodological principles for the risk assessment and risk management recommendations referred to in Regulation (EC) No 470/2009.
  2. Commission regulation (EU) 37/2010 of 22 December 2009 on pharmacologically active substances and their classification regarding maximum residue limits in foodstuffs of animal origin.
  3. Directive 2001/82/EG of the European Parliament and of the Council of 6 November 2001 on the Community code relating to veterinary medicinal products.
  4. EFSA Report for 2016 on the results from the monitoring of veterinary medicinal product residues and other substances in live animals and animal products.
  5. EFSA Scientific opinion on Chloramphenicol in food and feed.
  6. EMA Substances considered as not falling within the scope of Regulation (EC) No. 470/2009, with regard to residues of veterinary medicinal products in foodstuffs of animal origin.
  7. EMA Veterinary regulatory – Maximum residu limits (MRL).
  8. Regulation (EU) 2019/6 of the European Parliament and of the Council of 11 December 2018 on veterinary medicinal products and repealing Directive 2001/82/EC.
  9. Regulation (EU) 470/2009 of the European Parliament and of the Council of 6 May 2009 laying down Community procedures for the establishment of residue limits of pharmacologically active substances in foodstuffs of animal origin.
  10. Van der Merwe, D., Beusekom, C., van den Berg, M., Gehring, R. (2019) Fipronil en de volksgezondheid – Een toxicologisch perspectief. Tijdschrift voor Diergeneeskunde, Jan 2019.
  11. Voedingscentrum – Aanvaardbare dagelijkse inname (ADI).
  12. Voedingscentrum – Antibiotica.

Gastric ulcers in horses; ECEIM consensus statement

In 2015 the “European College of Equine Internal Medicine (ECEIM)” published the new “consensus statement” regarding gastric ulcers in adult horses.

This “consensus statement” is written by B.W. Sykes, M. Hewetson, R.J. Hepburn, N. Luthersson and Y. Tamzali. It was published in the “Journal of Veterinary Internal Medicine” (29: 1288-1299) and available as “open access” article. Below you can find a summary.

Terminology

“Equine Gastric Ulcer Syndrome” (EGUS) is the general term used for all erosive and ulcerative diseases of the horse stomach. Based upon the affected regions in the stomach, two categories can be distinguished: “Equine Squamous Gastric Disease” (ESGD) and “Equine Glandular Gastric Disease” (EGGD).

ESGD is further divided into primary ESGD and secondary ESGD. Primary ESGD affects horses with normal gastric emptying, while secondary ESGD occurs in horses with delayed gastric emptying due to underlying pathology such as pyloric stenosis. EGGD is specified further based upon the anatomical location and the appearance of the lesion.

Prevalence

The prevalence of gastric ulcers varies with breed, use and level of training. There is also a difference in prevalence between ESGD and EGGD. ESGD has the highest prevalence in thoroughbred racehorses. The prevalence of EGGD is less well understood. Most lesions of EGGD are found in the antrum pyloricum.

Epidemiology

Several studies show that there is a correlation between the presence of ulcers and the breed. The influence of age and gender is inconsistent which suggests that other factors, such as intensity and duration of training, are more important. Other factors, of which it has been described that they are a possible risk factor, are described below.

  • Grazing is shown to decrease the risk of gastric ulcers, but supporting evidence is contradictory.
  • Unlimited/frequent access to roughage is considered to reduce the risk on EGUS, but supporting evidence is not available. Besides, findings suggest that the impact of roughage without reduction of other risk factors might be less than expected. The occurrence of ESGD is more likely when straw is the only form of roughage provided. This suggests that also the type of roughage influences the prevalence of ESGD.
  • An increased interval (> 6 hours) between roughage meals increases the risk on ESGD, when compared to more frequent (< 6 hours) roughage supply.
  • An increased starch intake is consistently associated with an increased risk on ESGD in animals trained at different levels.
  • Intermittent water access increases the risk on EGUS.
  • Fasting is an often described risk factor for ESGD; intermittent fasting causes ESGD and increases its severity.

More large-scale research is needed to understand the epidemiology behind EGUS, especially behind EGGD.

Clinical symptoms

Stomach ulcers in adult horses are associated with a broad range of clinical symptoms: a decrease in appetite, slower eating, poor body condition score or weight loss, chronic diarrhoea, a bad coat condition, teeth grinding, behavioural changes, acute or recurring colic and bad performance. There is however no strong epidemiological evidence for the correlation between the presence of these clinical symptoms and the occurrence of gastric ulcers.

A broad range of clinical symptoms can occur in individual EGUS cases. On population level the different gradations of a decreased appetite and a poor body condition score are most common. Behavioural changes, including stereotypes, are inconsequent, but not unusual. EGUS can also contribute to bad performance, but considering the number of factors that can contribute to this, other factors should also be taken into account. Differences in clinical symptoms occurring with ESGD or EGGD are currently not known. Despite the large variety of possible symptoms, all these symptoms are badly correlated to the presence of EGUS. Diagnosing EGUS based on the presence of “typical clinical symptoms” should thus be avoided.

Diagnosis

Gastroscopy remains the only reliable ante-mortem method to determine accurately if a horse has gastric ulcers. The entire stomach, including pylorus and proximal duodenum, should be included because lesions in one of these regions are easily missed.

There is no correlation between the presence of ESGD and EGGD. The presence of one cannot serve as an indication for the presence or absence of the other.

There are currently no reliable haematological or biochemical markers that can be helpful in diagnosing gastric ulcers.

Ulcer grading

The 0 – 4 “Equine Gastric Ulcer Council” system is recommended as a standard scoring system for ESGD.

Due to a lack of data to support the validity of the hierarchical grading system for EGGD, the use of this type of grading system is not recommended. For EGGD it is recommended to describe the lesion based on the presence or absence, anatomical location, distribution and appearance.

The biggest challenge is to determine the clinical relevance of the individual lesions found. There is little evidence that the presence and grading of the lesions correlates with the presence of clinical symptoms. The clinician should try to interpret the results of the endoscopy in relation to the complete clinical picture, history, etc.

Pathophysiology

ESGD is caused by an increased exposure of the squamous mucosa to acids. The relation between exposure of the squamous mucosa to gastric content and fasting and training has been described clearly. During gaits faster than a walk, the acid gastric content will be pushed up to the squamous mucosa by the increased intra-abdominal pressure.

The pathophysiology of EGGD, on the contrary, is poorly understood. The glandular mucosa differs fundamentally from the squamous mucosa by the fact that it is exposed to gastric acid in physiological conditions. For this reason it is thought that EGGD is caused by failure of the normal defence mechanisms that usually protects the mucosa against the acid gastric content. There is still no evidence that bacteria are the direct cause of EGGD.

NSAIDs have the potential to induce EGGD in individual animals, but on population level they do not contribute significantly to the prevalence of EGGD. The ulcerogenic capacity of some NSAIDs has been shown when dosages were administered that are 50% higher than the recommended dosages. When the recommended dosages are administered, phenylbutazone and suxibuzone however do not induce gastric ulcers.

It is most likely that a combination of different factors contributes to the development of EGGD in horses.

maagzweren-bij-paarden

Treatment and prevention

The therapy of both ESGD and EGGD focuses on adequate suppression of acid production. The proton pomp inhibitor omeprazole is the first choice treatment. Omeprazole is superior to ranitidine.

The duration of acid suppression needed to heal ESGD and EGGD has not yet been described. Clinical studies suggest that a period of 12 hours during which the acid production is suppressed may be sufficient for the treatment of ESGD. GastroGard gives a consistent healing rate of 70-77% when administered at the registered dose of 4 mg/kg per os, once daily, during 28 days. A lower dosage and/or shorter period of administration can however be taken into consideration based on the evidence available.

The success rate of EGGD treatment is only 25%. The reason for this poor response is unknown. A longer duration of treatment may be indicated in the case of EGGD. Bacteria might also play a part. In the absence of evidence to support this theory and in the context of responsible antibiotic use, it is however not recommended to use antimicrobials in the routine treatment of EGGD.

Considering the role of mucosal defence mechanisms failing in the pathogenesis of EGGD, protecting the mucosa as part of the therapy seems legit. Sucralfate is best studied for this indication. The combination of omeprazole (4 mg/kg PO once daily) and sucralfate (12 mg/kg PO twice daily) improves the success rate of EGGD when compared to omeprazole only.

The pharmacological approach of the prevention of ESGD is comparable to the treatment. Omeprazole is used as prevention in a dosage of 1 mg/kg per os, once daily. The efficacy of omeprazole as prophylaxis for EGGD is unclear, but so far there is no difference in the prevention strategy of both.

Nutraceuticals are attractive because of the ease of use and their availability. Pectine-lecithine complexes have been shown to increase the total mucus concentration in gastric juice. Antacids seem to provide some symptomatic relief, but their effect is short-lived.

There is no strong evidence to support a specific nutritional advice. There is only little evidence for the role of the diet in the occurrence of EGGD and therefore the recommendations are primarily based on the well-known risk factors of ESGD. Continuous access to a good quality grass pasture is considered ideal. Unlimited or frequent (4-6 times daily) access to hay (at least 1.5 kg (DM)/100 kg bodyweight/day) can be an appropriate alternative. Straw should not be the only type of roughage, but it can be included safely in the diet with a maximum of 0.25 kg (DM)/100 kg bodyweight. Concentrates should be used as cautiously as possible. Sweet feed should be avoided. The diet should not contain more than 2 gram starch per kg bodyweight per day, or no more than 1 gram starch per kg bodyweight per meal. The interval between feeding concentrates should be at least 6 hours. Maize oil could help to decrease the risk of EGGD development. Water should always be available. When pastes with electrolytes are given orally, they should be diluted in water first, or mixed with the feed.

EMA advice on the withdrawal period of lidocaine in food producing animals

The EMA recently published a report on the withdrawal period of lidocaine for milk. In general, when veterinary medicinal products are used through the cascade, the minimal withdrawal period for milk is 7 days. Based on the EMA advice, the withdrawal period for lidocaine should be extended to 15 days.

advies-van-de-ema-over-de-te-hanteren-wachttermijn-bij-het-gebruik-van-lidocaine-bij-landbouwhuisdieren

The cascade

In the Netherlands lidocaine is only registered for use in dogs and cats. Lidocaine can only be used in food producing animals when the cascade is applicable. Lidocaine is mentioned on the list of active ingredients belonging to regulation (EU) no 37/2010. This is a prerequisite for the application of the cascade in food-producing animals. Other conditions are the need for treatment, particularly to avoid suffering in the animals, and the lack of a registered veterinary medicinal product for the species and indication concerned.

For equines, no MRL (Maximum Residue Level) is needed as long as the product is used for local or regional anaesthesia. For the other food producing species no MRL has been determined. When using a product through the cascade, the minimal withdrawal period should be at least as long as the withdrawal period mentioned in the SPC for the species concerned. When there is no withdrawal period mentioned for the species concerned, the withdrawal period must be at least 7 days for eggs and milk and 28 days for meat.

New insights

The MEB (Medicines Evaluation Board) in the Netherlands has requested the EMA in December 2012 to provide a scientific opinion on the usage of lidocaine in food producing animals. This request was made as a result of recent research studies in which it was shown that 2,6-xylidin is one of the most important metabolites of lidocaine in cattle and pigs. This metabolite is considered carcinogenic and genotoxic.

Besides the possible effects of exposure to the metabolite 2,6-xylidin, the MEB was also concerned about exposure to the active ingredient lidocaine. Humans are also capable of producing this carcinogenic and genotoxic metabolite of lidocaine.

What did the EMA think?

The CVMP (Committee for Medicinal Products for Veterinary Use) of the EMA concluded that 2,6-xylidin has indeed got a potential genotoxic effect, but that the conclusions drawn in different studies differ largely. A carcinogenic effect was however clearly shown according to the CVMP. Changes in the DNA could be a possible mode of action for this carcinogenic effect.

The CVMP recognised the potential risk of exposing people to lidocaine and therefore the possible formation of potentially carcinogenic and genotoxic metabolites. But it was also pointed out that, on the other hand, lidocaine is also registered for human use as a short-term oral or topical treatment. However, they did comment that the benefit-risk assessment done for the approval of lidocaine as human medicinal product also factors in the positive effects of treatment which do not count when consuming residues through animal products.

Horses

The MEB mentioned that when it was decided that no MRL was needed for equines, it was taken into consideration that the metabolite 2,6-xylidin is not produced in horses. The CVMP contradicts this and states that this metabolite is produced in horses, but to a lesser extent than in other animal species.

The CVMP did conclude that with the available information, there is no need to change the MRL for equines as mentioned in Regulation EU No 37/2010.

Cattle

Previously, it was not known if cattle were able to produce the metabolite 2,6-xylidin. Based on this it was decided not to allow a MRL for use in cattle.

Recent research has shown that 2,6-xylidin is the most important metabolite that is formed in hepatocytes and microsomes extracted from livers of cattle and pigs when exposed to lidocaine. This was an in vitro study. The metabolite was however also found in the urine of cattle and pigs after the intravenous administration of lidocaine.

Hoogendoorn et al have recently published a study in which the pharmacokinetics of lidocaine and its metabolite 2,6-xylidin were described in 8 dairy cows. In these animals lidocaine with adrenaline was injected subcutaneously and intramuscularly as is done for a caesarean. Five times 30 ml was used. This study group showed that both lidocaine and 2,6-xylidin can be found in plasma, milk, muscles and kidneys.

The CVMP has calculated values below which, in theory, there should be no risk for public health. This had to be done because there is no MRL available. Based on the studies done by Hoogendoorn et al a termination half-life of 17.7 hours was used. When a two-compartment model with a rapid elimination phase is used, the advised withdrawal period for meat would have to be at least 11 days. When the same method is used, the minimal withdrawal period for milk should be 15 days.

Based on these studies and the calculations made by the CVMP, the EMA concluded that a withdrawal period of 28 days for meat is sufficient. It was however advised to extend the withdrawal period for milk to 15 days.

Pigs

When it was determined that no MRL was required for equines, there was also no information available about the metabolism in pigs. Recent reports do not include information about the metabolism of lidocaine in pigs either. The metabolism in pigs is however similar to that of cattle. It can thus be concluded that the withdrawal period of 28 days for meat is also sufficient to ensure public health. For pigs, it was also taken into account that lidocaine is primarily used during castration, which is usually done within the first week of life, resulting in a long period between the administration of lidocaine and slaughter.

References

  1. Thuesen, L.R., and Friis, C. (2012) In vitro metabolism of lidocaine in pig, cattle and rat. Poster presentation EAVPT Congress 2012, The Netherlands.
  2. F. Verheijen, Medicines Evaluation Board Agency (2012) Request for a scientific opinion.
  3. European Medicines Agency (EMA), Committee for Medicinal Products for Veterinary Use (CVMP) (2015) CVMP assessment report regarding the request for an opinion under Article 30(3) or Regulation (EC) No 726/2004.
  4. European Medicines Agency (EMA), Committee for Medicinal Products for Veterinary Use (CVMP) (2015) Opinion of the Committee for Medicinal Products for Veterinary Use regarding a request pursuant to Article 30(3) of Regulation (EC) No 726/2004.
  5. European Medicines Agency (EMA), Committee for Medicinal Products for Veterinary Use (CVMP) (1999) Lidocaine Summary Report.

Clostridium assaults the intestines of poultry

In many flocks of laying hens the bacteria Clostridium perfringens causes a large amount of damage to the intestines. Other problems, like coccidiosis or worm infestations, facilitate the problems caused by clostridium.

“In one out of every four post mortems performed on chickens intestinal problems were the underlying reason for referral to the GD”, knows Noami de Bruijn, poultry vet and pathologist at the GD Animal Health Service. “And in one out of every three post mortems done, we actually did find enteritis”, she explained at the Poultry Relation Days held in Barneveld.

Bacterium

Acute intestinal problems are often caused by Clostridium perfringens. This bacterium is a natural inhabitant of the intestines and is always present. It is not exactly known yet why the bacterium sometimes suddenly turns pathogenic. “In practice, preventing stress is one of the most important preventative management measures that can be taken to minimize intestinal damage”, says poultry vet Pim Eshuis. “And that already starts in the rearing period”.

Deworming

Go and visit the rearer to discuss deworming and minimising the transition to the laying farm, advised Eshuis. “Give the hens a lot of attention, especially at the start of each new round”.

Research done at the GD Animal Health Services shows that in chickens with intestinal problems caused by Clostridium perfringens, coccidiosis often plays a part as well.`

Source: De Nieuwe Oogst.

Responsible use of veterinary medicines

Lately there has been a broad societal interest in the use of veterinary medicines and specifically the use of antimicrobials. The use of antibiotics and the need to reduce their usage are in the news regularly. Also the induction of resistance and the occurrence of zoonosis are discussed often.

Mitigate risks

Every time micro-organisms are exposed to antibiotics there is a certain risk for the development of resistance. Prolonged exposure, especially in low doses, can result in the selection of resistant bacteria. Theses resistant bacteria can be transferred to humans and thus pose a threat to public health.

Applying the advised withdrawal period is important. Residues of veterinary medicines in meat, milk or eggs can pose a potential threat to public health. To minimize the risks the usage of veterinary medicines could pose to public health, it is essential to increase awareness of the risks among veterinarians and farmers and to encourage preventative measures to avoid diseases and infections. Personal protection is an easy way to reduce direct contact with antimicrobials and the possible risks. Dopharma therefore has dust masks and latex gloves in their assortment.

Responsibility - street sign illustration in front of blue sky with clouds.

Recommendations

The Dutch society for Veterinary medicine and the FIDIN (board for manufacturers and distributors of veterinary medicines) have developed the following recommendations on the responsible use of veterinary medicines:

  1. A good treatment starts with the correct diagnosis: determine which causative agent is responsible for the disease and focus your treatment on this micro-organism specifically.
  2. Use registered veterinary medicines: check the registration number, read the label and, if applicable, the leaflet. Consult your veterinarian regarding the right treatment.
  3. Use the recommended dosage.
  4. Do not change the method of administration (e.g. injection, intramammary treatment, treatment via drinking water or feed or topical application).
  5. Complete the treatment, even though the animals seem to already have recovered. This is important to prevent re-occurrence of the disease and development of resistance.
  6. Do not combine veterinary medicines unless this is advised by your veterinarian.
  7. Think about your own safety.
  8. Avoid exceedance of the maximum residue levels (MRLs) in animal (by-) products.
  9. Document the important details of the veterinary medicines used.
  10. Evaluate the treatment on a regular basis with your veterinarian. Always report adverse events.
  11. Read the storage conditions as mentioned on the package and always apply them.