Vet explains the dos and don’ts when using antibiotics in animals
Today I will engage livestock farmers on the important topic of animal protection and human health.
In particular, this is all about antibiotic use and the grave danger that inappropriate use of life-saving chemicals poses to human beings and animals.
Antibiotics are chemicals that are used to treat diseases by killing harmful bacteria in the bodies of humans and animals.
The chemicals comprise the widest range of drugs used in treating human and animal diseases.
Scientifically, antibiotics are drugs derived from living organisms while antimicrobials are synthetic forms of antibiotics.
For the purposes of our discussion today, I shall use the term antibiotics to refer to all drugs used in the treatment of diseases caused by bacteria in people and animals.
Before I move on, next week from 13 to 19 is the World Antibiotic Awareness Week.
The global community, led by the World Health Organisation (WHO), will use the period to raise awareness on proper use of the drugs.
In Kenya, activities will be led by the Ministry of Health, the Ministry of Agriculture, Livestock and Fisheries and WHO, among others.
Now, I will share three encounters that have put me at loggerheads with farmers on the use of antibiotics.
In the first, Kimani’s finisher pigs got an attack of swine pox, a usually mild viral disease that may heal without treatment.
Unfortunately, the pox wounds got bacterial infection due to flies feeding on them and there were only two options.
I either had to inject the pigs with tetracycline antibiotic or leave them to heal on their own for up to three weeks.
If I used tetracycline, then Kimani would have had to withdraw the pigs from slaughter for 15 days.
Some of the pigs were ready for slaughter and Kimani did not wish to keep them longer and incur feeding costs.
If I had left the pigs to heal on their own, they would have lost weight and take longer for Kimani to sell, hence reducing projected profit.
I settled on tetracycline use but Kimani was thoroughly unhappy with me. He said I should just have left him to decide what to do with his pigs.
Next is Purity. She had to discard 20 litres of milk per day for seven days because I treated her cow for mastitis with the antibiotic cephalexin.
You see, the milk had to be withheld from human consumption for three days of treatment and another four days from the time treatment was completed to ensure that the antibiotics in the milk were below the minimum level allowed.
Purity was not amused with me at all. She insisted the first three days withdrawal was sufficient.
Finally, in Ema’s case where I treated her 1,500 layers with tetracycline and she had to discard eggs for three days to avoid feeding people with the drug. I did not like the way she looked at me as she grudgingly agreed to withhold the eggs.
I empathised with the farmers but there is overwhelming scientific evidence that failure to observe proper antibiotic use results in bacteria developing resistance.
In addition, ingestion of small quantities of some antibiotics causes development of allergies in people.
The best way of ensuring humans are not exposed to dietary intake of antibiotics is to avoid contamination of foods of animal origin with antibiotics used in the treatment of diseases.
Bacteria develop resistance when they are subjected to low levels of antibiotics called sub-lethal doses.
This is either through dietary intake of antibiotics, under-dosing of antibiotics during treatment or frequent use of the same antibiotics.
RESISTANCE TO ANTIBIOTICS
Resistance renders antibiotics ineffective and people and animals get killed by otherwise treatable diseases.
When we use antibiotics in animals and consume their meat, milk and eggs before the designated withdrawal period elapses, we expose the bacteria in humans to sub-lethal doses of the antibiotics and therefore encourage the development of antibiotic resistance.
Again, frequent unnecessary use of antibiotics and under-dosing of the drugs in animals encourages the development of bacterial resistance to antibiotics.
Most disease-causing bacteria found in animals are also found in humans due to the close relationship between domestic animals and man.
Thus development of antibiotic resistance in one species of livestock is a real and present danger to human beings because the resistant bacteria may easily cross to people.
The reverse is also true because human disease-causing bacteria easily jump to animals.
Antibiotics used in humans are therefore also used in treating animals.
For example, cephalexin is used to treat mastitis in cattle caused by the bacteria E. coli, Staphylococcus and Streptococcus.
These three bacteria are also found abundantly on the human skin and digestive system where they cause various diseases.
CERTIFIED HEALTH SERVICE PROVIDERS
Cephalexin is used in treating such diseases.
People who should be directly involved in preventing development of bacterial antibiotic resistance are livestock farmers, animal health service providers, handlers of food of animal origin, medical services providers and any user of antibiotics.
In short, all of us have roles to play in ensuring that antibiotics continue being useful in disease treatment for a long time because new antibiotics take a long time and huge resources to develop.
Farmers must ensure that they observe withdrawal periods of drugs, use antibiotics only as directed by certified animal health service providers, vaccinate their animals against diseases and keep high levels of hygiene to prevent diseases.
Animal health service providers must create adequate awareness to farmers on antibiotic use and hygiene, practice judicious use of antibiotics and ensure they are not used for growth promotion in livestock.
Handlers of meat, eggs and milk must practice utmost hygiene, food storage and avoid using antibiotics as food preservatives.
Medical services providers should only use antibiotics where necessary and test disease organisms for antibiotic sensitivity before using the drugs.
They must create utmost awareness on proper antibiotic use to their patients.
Antibiotic users must only use the drugs as directed by certified health services providers and avoid self-medication.
In a nutshell, let us use more hygiene, more vaccination and biosecurity (infection prevention) in our livestock production to safeguard use our antibiotics.