Internal and external parasites in Goats

Goats can have internal parasites (inside the intestine and other organs) and external parasites that stay on the outside of the animal.

INTERNAL PARASITES

Worms and flukes

Generally, these parasites cause harm either by absorbing the goat’s food or by feeding on the blood or tissue of the goat. There are different types of worms, some which are easier to see (such as tapeworms) and some which are more difficult to see (such as roundworms). Roundworms (which include wireworms) cause serious losses if not properly controlled. Tapeworms cause a ‘potbelly’ in young animals

Another type of internal parasite is the liver fluke which is found in the goat’s liver. It becomes contaminated when the goat feeds on plants growing near water bodies , marshes and standing water). Liver flukes cause symptoms similar to roundworms.

Wire worm[1],   tapeworm (segments in dung)[2]  and liver fluke[3]

Even if they do not make the goat sick, internal parasites reduce its productivity.  If the goat has heavy infestations, it can lose condition, become anaemic (from loss of excessive amounts of blood), become listless, have a ‘bottle-jaw’, suffer from diarrhoea, and even die.

Some tapeworms form cysts in goats’ brains which lead to mortalities. It is a tapeworm that they pick up from dogs

Figure 4.2 Life cycle of the dog/goat tapeworm – this condition in goats leads to malkop or draaisiekte (see Page 16 section 3.3)

Use of (dewormers)

Goats can be dosed with a variety of dewormers – some only kill one type of worm, while others kill a range. You should try and dose for what particular worms are affecting your goats. Resistance will build up over time so regularly change your dewormer ensuring different active ingredients.

Unless you have a particular type of worm that you are trying to treat, you should swap dewormers regularly (check that they have different active ingredients) to make sure that over time you control the different types. You also need to make sure that the product you are using is safe for goats.

If it is possible, call a Technician to send a dung sample to a laboratory to determine what worms are infecting your goats. You should collect a sample directly from some goats and not from the ground. Keep them in a plastic packet in the fridge until you take them to the lab.

If you plan to slaughter the goat to eat you should also check the withdrawal period of the product (this is the recommended time period from when you dose it to when it is safe to eat the goat or drink the milk). Many medicines also have a withdrawal period.

5-point check for internal parasites

The Five-Point Check is aimed at checking goats or sheep that could be affected by one or more major internal parasites. There are five places on the body that needs to be checked. Those places are the nose, eyes, jaw, tail and the back.

Nose: Discharges from the nose may indicate nasal bot fly (Oestrus ovis).

Eyes: anaemia may be due to wireworm (Haemonchus contortus) and other worm species that cause anaemic conditions such as hookworm.

Jaw: A soft subcutaneous swelling below the jaw is known as the bottle jaw. This is another symptom of worm species that cause anaemia.

Back: Body condition scoring is the assessment of overall condition of the animal. If only a few in the flock show poor condition, this may show worms that suppress the animals’ appetite such as bankrupt worm, brown stomach worm and conical fluke.

Tail: Parasites such as conical fluke and roundworms cause mild or severe diarrhoea. Parasites are known to be major cause of diarrhoea therefore the farmer needs to treat those with visible diarrhoea.

Other observations such as a pot belly, when combined with poor condition or growth rate, is usually an indication of tapeworm infestation.

Other management interventions to control internal parasites

There are other ways to control the worm burden in your goats:

  • Goats pick up worms from the grass when they are grazing (the eggs come out with the faeces and then infect the camp). You can practice rotational grazing so that there is not a build-up of worms in your camps.
  • Fix troughs so that they do not leak as worms can breed in the muddy ground around the trough.
  • Another key measure to control worms is to identify goats which are particularly susceptible to worms and cull them because these goats actually keep infecting other goats in the flock. If you check your goats’ eyes regularly and find that a certain animal often has pale membranes, then you should not just continue to treat it for worms – you should actually sell or slaughter it.

EXTERNAL PARASITES

External parasites affecting goats are mainly ticks and mange mites. Other examples would include mosquitos and flies (especially blowflies). Some external parasites cause skin irritation and tissue damage while others also transmit diseases to the goat.

Ticks

Besides the physical damage caused by ticks, they also transmit a number of diseases. In goats the most serious tick-borne disease is heartwater. Tick borne diseases are specific to a certain type of tick. For example, heartwater is only transmitted by Bont ticks. Ticks can be controlled by insecticides that can be put on in different ways. Spraying is the most common way, or less common is either dipping the goat (in a plunge dip or with a bucket and sponge), applying a pour-on product onto the animal’s back or by injecting it with a registered product (such as an ivermectin).

Remember that dips are poisonous so you should make sure that you use gloves and protective clothing to prevent skin contact as you can actually absorb the dip directly through your skin.

Mange

Mange is inflammation of the skin (causing itchiness) and the loss of hair and is caused by small organisms called mites – they are too small to actually see. The same mites cause sheep scab in sheep. Dips and injectable products are available to control mange..

Fleas

These are small wingless insects that move around different hosts by means of jumping. They have well developed legs that are used for jumping considerable distances. They range between 1 mm to 8 mm in length. Fleas are normally found on dogs and cats. In that way they are passed on to domestic livestock like goats.

Fleas cause rubbing of affected areas, scratching and hair loss. They can be controlled by dipping the goats and treating the affected areas with sprays or powders such as Karbadust.[4]

Lice

There are two recognized types, the biting (red) lice and the sucking (blue) lice. The biting lice feed on dead skin while the sucking lice actually suck blood from the host. Both types cause the animal to itch and in most cases causing the animals to rub against objects.

Lice are normally found on the inside of the legs and around the head and neck and may result in scabby or bleeding areas, loss of hair or a dull coat. Severe cases can cause anaemia.  The goats should be sprayed or dipped with remedies that kill lice (e.g. Zipdip or Deltab Backpack) and the kraal should be treated with an insecticide (they can also be dusted with Karbadust). Infected animals should be separated to prevent the lice spreading to other goats.

Nasal worm

Nasal worms are not proper worms but actually the larvae or bots of a fly. The fly lays its eggs around the nose of goats, the eggs hatch into larvae which travel up the nose into the sinuses in the goats head. Here they cause irritation, inflammation and mucus that runs out of the nose, the goat coughs and sneezes and shakes its head until it eventually gets rid of the bots that then turn into flies again.

 

Fortunately, these nasal worms are easily got rid of, the most effective treatment is to treat with a remedy that contains ivermectin or closantel. Some deworming products can also be used such as Tramisol.

Sometimes the bots cause secondary infection of the sinuses or even infections that eventually spread into the lungs. These infections must be treated with long-acting oxytetracycline products such as Terramycin – at a dosage of 5cc every 3rd day until healed.

Poisonous plants

Animals will usually try to avoid eating poisonous plants, and will usually only be forced to eat them under certain circumstances. This happens when, for example, the veld is overgrazed, due to drought or overstocking of animals, and when the animals are hungry due to inadequate nutrition.  It can also happen when the veld has been burnt, or when animals are introduced into new areas, where they are unfamiliar with which plants are poisonous in that area.

Overgrazing of veld, by overstocking, may cause the invasion and dominance of certain toxic plants such as Deadly nightshade (Solanum sp). Some exotic plants that are planted as garden shrubs are poisonous, for example Lantana, seen in the picture below. Lantana makes animals sensitive to the sun if they eat it (called photosensitivity). Certain plants become poisonous only under certain circumstances. For example prussic acid poisoning happens when certain young, growing plants become dry and wilted. An example of a fodder plant that produces prussic acid when young green foliage wilts is Forage Sorghum.

It is important to familiarize yourself with the poisonous plants which occur in your area, so as to try to prevent animals eating them. Prevention is better than cure, as there are very few cases where treatment is effective, and treatment is often very expensive.  The following steps should be taken as far as possible, to try minimise plant poisonings:

  • Prevent overgrazing. y Prevent overstocking.
  • Monitor animals in planted pastures during danger periods (eg. Hot dry periods where young plants can wilt and become poisonous).
  • Ensure animals are provided with adequate nutrition so that they do not go hungry, by providing supplementary feeding during times when the veld does not provide enough food, for example during wet season and drought periods.
  • Take special precautions especially at the end of wet season, when animals are most hungry and there is the least amount of food available, and the time when many poisonous plants come out.
  • Monitor new animals that are introduced into the area and are unfamiliar with the poisonous plants of that area.

Treatment in general:

  • Dose the animal with activated charcoal, at 2 grams/kg body weight, mixed with water, preferably by stomach tube, or using a 1 or 2 litre plastic coke bottle. Make sure the charcoal does not go down the wind-pipe as this will cause a dosing pneumonia which is often fatal.
  • Inject the animal with multi-B vitamin, to support the liver.
  • Place the animal in a quiet shaded area, and provide plenty of water and feed, and give it time to rest and recover.
  • If the animal is poisoned with a plant causing photosensitivity, ensure it is in a cool, shaded area, and given plenty of water and soft, green feed.
  • Keep the animal very quiet and rested (do not chase the animals or stress them out), as exertion can cause death.

Deaths due to eating plastic

Goats sometimes eat plastic packets that they find lying around. Sometimes it is because they are craving salt and find it in the packets, sometimes it is just because they are hungry. The plastic is not able to pass through the goat’s rumen and in the end the rumen fills up with plastic which limits the amount of food the goat can eat. In the end, it normally leads to the death of the goat. Some people say that providing goats with a mineral lick will reduce the extent to which they eat plastic. Alternatively communities need to try to prevent littering with plastic.

 

 

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