There is a growing spotlight across human and animal health on antibiotic usage.
This stems from the fact that an increasing number of antibiotics are succumbing to drug-resistant bacteria while there is also a significant death toll related to this issue.
A global strategy termed the One Health concept aims to tackle the growing problem of antimicrobial resistance (AMR). Achieving this goal requires co-operation and collaboration across species and all relevant stakeholders involved in the respective industries.
Ireland is committed to the initiative, with the Department of Agriculture having a major role in the One Health National Action Plan (iNAP), which it launched in conjunction with the Department of Health in 2017. A second plan is currently being worked upon and is planned to be released in 2021.
The code of good practice for the sheep sector was launched in September 2020
As part of Ireland’s goal to limit antibiotic usage, a code of good practice has been developed for each enterprise. This highlights the main areas where antibiotics are used and details advice to limit usage levels.
The code of good practice for the sheep sector was launched in September 2020 and is described as being a useful tool for sheep farmers in working to address the challenge of antimicrobial resistance.
The guidelines contained in the code of practice were developed by Veterinary Ireland, Irish Farmers Association and Teagasc and focus on the responsible prescription and use of antibiotics in farm animals. As such, a number of diseases which are linked to antibiotic usage in sheep systems are addressed.
Some farmers whose flocks have suffered from the disease have progressed down an avenue of administering antibiotics to lambs at birth
The primary section discusses health management of newborn lambs and pays particular attention to watery mouth disease. The condition is caused by colonisation of the small intestine by E coli, with rapid multiplication and the release of harmful toxins.
Some farmers whose flocks have suffered from the disease have progressed down an avenue of administering antibiotics to lambs at birth, typically in the form of spectinomycin. However, this option is not a realistic solution to the problem, with an increasing number of farms reporting resistance and finding themselves in a very tricky position.
The optimum manner of controlling watery mouth disease must therefore be to put a solid preventative programme in place and safeguard antibiotic usage for when an outbreak occurs or in exceptional circumstances.
The code of practice outlines that newborn lambs are probably the most immunologically naïve animals on the farm. Their immune system has not developed to a stage where they can recognise common bacteria and viruses in the environment and be in a position to fight them off.
Stress or exposure to high levels of pathogens in the environment will allow disease to quickly establish, with diarrhoea (scour) and watery mouth disease the most prevalent in newborn lambs. The document states the term watery mouth is a description which encompasses a collection of clinical signs in newborn lambs including lethargy, failure to suck, profuse salivation, bloating and retained meconium.
To manage the disease successfully, all of these risks must be addressed
The document goes on to say that these ailments all have something in common – they are caused by a combination of trademark factors such as a naïve immune system, insufficient or no passive transfer of antibodies from colostrum, a buildup of infectious agents in the environment (such as dirty bedding/equipment, poor operator hygiene when intervening at lambing or handling newborn lambs and any other stressors such as the movement of mixing of lambs between groups.
To manage the disease successfully, all of these risks must be addressed. The following are essential points aimed at preventing the disease having an opportunity to become established:
In terms of feeding equipment, syringes, stomach tubes, etc, should be washed in warm soapy water and sterilised between each use. Also, the navels of lambs should be disinfected as soon as possible after birth to reduce the risk of disease entering via this avenue.
Going “cold turkey” in using oral antibiotics is a difficult prospect for flocks that have built up a mindset of having to use them annually.
Stepping away from routine use and only treating high-risk lambs is one way to gradually break the link.
For example, some farmers have successfully stepped away by opting in year one to treat high-risk lambs such as those born in a triplet or higher litter size, lambs born to ewes with milk yield problem or yearling hoggets with insufficient milk or born late in the season followed by a further step back in year two.
The consequences of failing to do so are too great to comprehend, with reports in recent years of flocks suffering high mortality rates due to drug-resistant bacteria developing.
Vaccination can also play a role but, again, the basic principles of ensuring lambs receive sufficient colostrum are paramount. Where there are significant issues in a flock, then it is important to consult your vet so that samples or dead lambs can be submitted to identify what strain of E coli is responsible and identify the most suitable treatment approach.