News - Rubrieke
Monday, 23 June 2014 23:20
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Dr Liesel van der Merwe is a small animal medicine specialist. Send her your questions: This e-mail address is being protected from spambots. You need JavaScript enabled to view it .

Dr Liesel van der Merwe

It’s a scary thought, but our generation may live to see people dying from infections again, as before penicillin was discovered. The reason is antibiotic resistance.

Antibiotics are broadly divided into categories depending on their action. Penicillin-type drugs interfere with the cell wall of the bacteria, weakening the normal structure and affecting bacterial growth and replication. Others interfere with the DNA and interrupt cell functions, and some block essential enzymes.

Antibiotics are also divided into two types: bactericidal, killing the bacteria; and bacteriostatic, weakening the bacteria, which allows the body’s own defence mechanisms to kill the bacteria.

With exposure to antibiotics, bacteria develop methods to escape death and can transfer this “knowledge” to other bacteria. This is why it’s essential to use antibiotics correctly.

Antibiotics won’t help for a viral infection, such as flu, where you just treat symptoms. You may develop a secondary infection due to weakening of the immune system, which is more of a risk in elderly, young or otherwise compromised individuals.

You need to finish a course of antibiotics and take them correctly. Certain antibiotics need to be taken three times a day to maintain effective levels in the blood. As soon as levels drop below this, bacteria may be acquiring resistance due to exposure to “non- lethal” doses.

As a vet I am often told by clients that they have already started using some antibiotics left over from their pet’s previous illness. That means they did not finish the course. Even though the body cleared the infection, the remaining bacteria are the tough ones that put up some resistance against the antibiotic. They remember and pass this information on. 

The next issue I have is that antibiotics are often given unnecessarily. Dogs and cats are tougher than we think. As a vet I am sure you would imagine that my dogs are always treated for every little thing, but let me tell you that their lacerations, bite wounds, abscesses and diarrhoea are hardly ever medicated with antibiotics.

Yet I find that with clients’ animals many vets are scared not to prescribe antibiotics just in case something develops, and this is the wrong attitude. Antibiotics are to treat infection, not to be used prophylactically. 

Many lacerations and wounds just need to be kept clean and open for drainage and the patient only needs anti-inflammatories. Most mild diarrhoeas do not need antibiotics; the symptoms should be treated and food withheld for 24 hours.

Kennel cough is generally a viral disease, but some animals may develop a bacterial bronchitis. Treat the symptoms and see what happens. If the coughing gets worse and Fluffy is not her normal self in a day or two, then return for a follow-up visit.

As clients you need to stop requesting antibiotics and be prepared to first see how symptomatic treatment fares. If a wound hasn’t improved after two days then I would suggest antibiotics, but the majority of minor wounds will be fine. As a client you need to buy into this process.

Certain antibiotics are generally effective in certain conditions. Once the condition is recurrent or non-responsive, then throwing more types of medications at it will not help. We need to take a sample from the infected area and ask the laboratory for a culture and antibiogram. This means that they will grow the bacteria which caused the infection and test which antibiotics work against them. This allows the vet to use the correct antibiotic for the correct duration.

Unnecessary use of antibiotics has gotten us where we are. They should be used when there is an infection and not in case one might come.