meat; pastures; livestock

Livestock production: Spotting the first signs of disease

Observing your livestock’s general health costs nothing and you don’t need special equipment – but it can save your animals’ lives.

It takes very good stockmanship to spot abnormal behaviour in your animals.

Daily observation of normal behaviour and a step-by-step investigative approach if they do not behave as usual.


Disease goes through various phases over a period of time, which can be measured in hours or days.

Early recognition of the disease and timeous treatment generally ensure a positive outcome. The exceptions are specific diseases, such as pulpy kidney, which develop so fast that the first sign of illness is the dead animal.

For such diseases, prevention through prior vaccination is the only remedy.

Also read: Spring is here – vaccinate for pulpy kidney

When disease-causing germs (organisms) enter an animal’s body, they start to grow and in the process destroy the part of the body on which they are growing.

Think of the behaviour of green mould growing on a loaf of bread. At first there is a tiny piece. A day later, half the loaf is covered by mould. Another day later, the entire loaf of bread is covered by the growing mould.

During this process, the mould also breaks down the bread to obtain food for further growth. The same process happens in the body, but it cannot be seen from outside, as mould can.

Which signs of disease will be observed depend on the body part on which germs grow after entering the animal’s body. Different types of germs target different parts of the body, for example, the lungs, intestines or udder. They destroy the normal working of such body parts and this can then be seen as signs of abnormality or disease.


  • Remember that, at first, there are only a few germs but they will multiply over time, and the animal will only show signs of disease when enough damage has been caused to the body part.
  • Signs of disease only become visible when the normal working of the body part has been affected.
  • That is why very close observation is needed to spot the first signs of disease.
  • If it is possible to stop further growth of these germs – with antibiotic treatment, for example – the damage will be limited, the animal will survive.
  • Furthermore, the body will repair itself.

Let’s look at an example:

  • The most appropriate one for the end of winter is pneumonia.
  • In this disease, the germs get into the lungs of an animal and cause what is called an infection of the lungs.
  • The germs start to grow and cause damage to the lungs.
  • In the normal (healthy) lung, air that is breathed in passes over to the blood which transports the dissolved air (oxygen) to all the parts of the body that need it for normal functioning.
  • In infected lungs this can’t take place and the animals die because they do not get any air.


  • To be able to see the first signs of disease the animal owner must look closely at healthy cattle, sheep or goats.
  • Study normal behaviour, movement and breathing – what the eyes, nose and mouth look like. Any abnormality will then be obvious.
  • When the first signs of abnormal behaviour (or disease) are seen, the animal must be examined more closely.
  • The first thing to do is to take its temperature, using a thermometer.
  • If there is a fever, the temperature will be higher than 39ºC.
  • In the case of pneumonia it is usually above 40ºC.
  • If there is an infection, such as pneumonia, the animal’s temperature will go up very early on in the process.
  • Even before the first signs of disease become visible.
  • Animal owners must have a thermometer and know how to take their animals’ temperature.

If pneumonia is identified early and antibiotic treatment is started immediately, the animal has a good chance of full recovery.

Also read: The difference between antibiotics and vaccines

Treatment will not be successful if the disease is only identified when there is already a thick yellow excretion from the nose, the animal is breathing with its mouth open, or it is already lying down because it cannot breathe in air.

It is not always possible for the animal owner to recognise the specific disease affecting an animal or group of animals. To ensure that he can get effective help, it is essential that he describes the disease fully when speaking to the vet.

Small-scale farmers generally don’t have access to an emergency clinical service provided by a veterinarian or can’t afford to use it. But they can at least have a telephonic consultation with a vet, via a landline or cellular phone.

How to take an animal’s temperature

  • Use a rectal thermometer.
  • Make sure the thermometer is clean and shake it down.
  • Hold the animal still and slide the thermometer into the rectum, about 2 finger widths deep.
  • Hold it there for 2 minutes, then remove it.
  • Clean it with a piece of toilet paper and read the temperature.
  • Wash and dry the thermometer and place it in its protective container.

Also read: Use your eyes to assess cattle condition

  • This article was written by Dr. Danie Odendaal and first appeared in Farming SA.

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