Goats' Common Health Problems

This article will help you to identify and manage some of the more common health problems that can afflict goats. Left undiagnosed or untreated such probems can result in significant economic losses.

The common health problems discussed in this article are;

Gastrointestinal parasites, Capture myopathy, Lice, Pregnancy toxaemia, Ketosis, Respiratory diseases and Clostridial diseases.

This article provides details of the prevailing conditions under which each problem is likely to occur, explains how to diagnose the problem and lists preventative management strategies.

For information on nutritional disorders such as bloat, grain poisoning and vitamin and mineral deficiencies, refer to the article Goat Nutrition. Information on other less common health issues can be found in Goats – less common health issues.

Definitions;

Chronic – a condition which has been affecting an animal for a long time, constantly recurring.

Clinical – the form of a disease where the animal is displaying obvious symptoms.

Acute – severe form of a diseae.

(The information presented here should only be used as a guide. For specific diagnosis, treatment and management advice speak to a veterinarian.)

Gastrointestinal parasites.

Examples:

Brown stomach worm (Ostertagia species), Black scour worm (Trichostrongylus species), Barber’s pole worm (Haemonchus contortus) and largemouth bowel worm (Chabertia species).

Conditions when likely to occur:

• High rainfall regions (>500mm annual rainfall); higher risk above 600mm or on irrigation.

• High stocking rates, especially if the property is running goats and sheep.

• Grazing short pasture.

• Kids are most susceptible after weaning, especially over winter and early spring period when peak larval challenge occurs.

• Does are more prone to worms than males, particularly when they are kidding or under nutritional stress.

• Heat and humidity are ideal conditions for Barber’s pole worm to proliferate. Summer rainfall areas with uniformly warm and wet seasons are particularly prone to Barber’s pole worm.

• Black scour worm and brown stomach worm larvae prefer mild wet seasons.

• Sheep and cattle have a greater immunity to worms than goats.

• Set stocked grazing.

Diagnosis:

  • History of poor performance on pasture (growth rates less than expected given the availability and quality of the pasture on hand).
  • Clinical signs: scouring, weight loss, anaemia, bottle jaw. Scouring – this symptom is not a consistent sign of worms, even with heavy infestations.
  • Autopsy: high total worm counts.
  • Faecal egg counts and larval cultures are valuable tools in diagnosing the level of worm burden.
  • Field trials to assess growth response from drenching can be very useful if you are uncertain of the parasitological and economic benefit. This is particularly relevant in regions where gastrointestinal parasites are generally not considered to be economically important.

Strategic drenching – the timing of drenching to prevent gastrointestinal parasites will vary between regions and with differing local conditions. A sustainable worm control program is about more than drenching. It is important to adopt an integration of ‘chemical’ and ‘non-chemical’ control options.

Preventative management strategies.

Registered products for treating internal parasites in goats:


Note: There are other chemicals used to treat internal parasites in sheep that are often also used in goats (unregistered). However, these chemicals should only be used under the prescription of a veterinarian.

Control strategies include:

Grazing management (eg avoid grazing excessively close to the ground, drench goats on to ‘lowrisk pastures’),

Herd management (does and kids are more prone to worms and should be managed accordingly; resistance increases with age), using bucks and does that are genetically resistant to worms,

Maintaining adequate nutrition, regular Drench testing, and regular Monitoring (worm testing).

Grazing management:

• Graze weaners on pastures with low worm larvae contamination.

• Low risk pastures include:

  • new pasture or fodder crop,
  • pasture grazed by cattle (not sheep) for the last six months,
  • paddocks with a good supply of browse.

• Moderate worm-risk pastures include pasture grazed by mature dry goats.

• High worm-risk pastures include pasture grazed by young wormy goats or kidding does.

Introducing new stock:

• Drench with a product that is suitable for the time of the year and in accordance with your animal health strategy.

• Observe the withholding periods (WHP) and export slaughter intervals (ESI) of all products used. These are available at www.mla.com.au/esi – note: the information on this website will change as more products become available.

• Things to note when using products that are more commonly associated with sheep :

1. Not all drugs or formulations are registered for use in goats. Care should be taken to avoid those not registered, unless the particular circumstances require their use. In this case, the drug should only be used with written approval from a veterinarian.

2. The dose rates as prescribed for sheep are often too low for goats. Dose rates should be based on bodyweight – measured not estimated.

3. The pharmacokinetics of some drugs differ between sheep and goats. Plasma concentrations of levamisole in goats declined rapidly after about 40 minutes, whereas the same concentration in sheep was maintained for up to 300 minutes. New Zealand research has noted that goats excreted oxfendazole, thiabendazole and levamisole more rapidly than sheep.

Worm Control:

WormBoss is a tool that has been developed by the Australian Sheep Industry Cooperative Research Centre (Sheep CRC) and Australian Wool Innovation Ltd (AWI) to assist sheep producers with worm control problems.

The guiding principles of worm control in goats are very similar to those in sheep. Four basic management practices should be observed:

1) Monitor worm populations using worm egg counts to detect infestations early.

2) Conduct drench resistance tests so that you know which drenches are effective on your property.

3) Maximise the use of non-chemical management strategies.

4) If you are unsure of anything seek professional advice.

A list of advisers is included on the WormBoss website www.wormboss.com.au or the WormBoss CD-ROM. The CD is available free of charge from state government offices or rural retail stores such as Landmark. Most of the state departments of agriculture or primary industries will be able to provide recommendations for specific areas.

The use of anthelmintic drenches is necessary for goat health and welfare in most intensive systems. However over-reliance on chemical treatments can lead to chemical resistance, and increases the risk of residue violations. In order to enhance the “healthy meat” image that the goat industry is trying to promote, growers should be aware of the principles of “Integrated Pest Management” and develop non-chemical means of worm control.

All producers should consider the threat that internal parasites pose to their enterprise, and devise a worm control program specific to their conditions. The best way of doing this is to ask an adviser for assistance.

Capture myopathy.

Conditions when likely to occur:

• Occurs in rangeland goats transported over long distances.

• Induced by the stress of capture and changes in the feeding/watering routine.

Diagnosis:

• Muscular degeneration occurs. It is not immediately fatal, but causes death by kidney malfunction later in life.

• Goats that have travelled may die of induced enterotoxaemia, pregnancy toxaemia or transit tetany.

Preventative management strategies:

• Losses may be reduced by vaccinating for clostridial diseases and drenching for parasites two weeks before transport.

• Dietary changes should be as gradual as possible, both before and after transport.

• Reduce the level of stress experienced during transportation.

• Goats should be in good condition when transported.

Lice

Examples:

Biting louse (Bovicola species), sucking louse (Linognathus stenopsis)

Conditions when likely to occur:

• Crowded conditions enable rapid spread.

• Problems mostly arise in cooler months.

• Goats in poorer condition with a long hair-coat and low-quality feed – wellfed goats in good general health will carry very few lice.

• Sucking lice (Linognathus stenopsis) will cross-infect both sheep and goats.

• Biting lice (Bovicola caprae) do not transfer from goats to sheep.

• Bovicola ovis are readily transferred from sheep to goats. They can thrive and reproduce on goats and then be transferred back to sheep.

Diagnosis:

• Clinical signs: animals rubbing against trees etc. Goats shedding fibre. Lice egg casings and dead skin in the fleece.

Registered chemicals for the treatment of lice on sheep:

Note: There are other chemicals used to treat external parasites in sheep that are also often used on goats. These should only be used under the prescription of a veterinarian.

Preventative management strategies:

• Transfer of lice between sheep and goats does become important in relationship to control and eradication of lice from both groups.

• Methods for treatment are similar to sheep ie dipping, spraying, pour-on and strip application.

Care must be taken to use only those products registered for use with goats and to apply them with strict adherence to recommendations and precautions. This is due to the susceptibility of some breeds to the toxic effects of lousicides.

Pregnancy toxaemia

Conditions when likely to occur:

• Pregnancy toxaemia occurs in pregnant does, in the last six weeks of pregnancy, when does are grazing dry, poor-quality pasture. It can affect either over-fat or light does.

• In extensive grazing situations, it may occur if the last third of pregnancy coincides with a late break, followed by cold weather, resulting in little pasture growth.

• Short periods of starvation (yarding and transporting) can result in problems.

• Stress (due to climatic conditions, handling, being chased or management procedures) is also a concern as it can affect feed intake and hormonal balance.

Diagnosis:

• Clinical signs: with pregnancy toxaemia, in the terminal phase, the doe will moan and have labored respiration and sunken eyes. In the paddock, the doe is usually found near shelter, unable to rise and surrounded with mucous-covered droppings, indicating she has not eaten for a few days. This will generally occur two or three days before the doe is due to kid.

• Autopsy: liver is swollen, friable and greasy. Fat in the abdominal cavity has whitish flakes. Necrosis throughout the developing foetus.

Preventative management strategies:

• Pregnancy toxaemia treatment is seldom successful. It is better to avoid getting does too fat during early pregnancy. In the last two months of pregnancy, gradually increase the plane of nutrition by offering better pasture or supplement. Avoid periods of sudden stress during the last two months of pregnancy.

Ketosis

Conditions when likely to occur:

• Ketosis may occur after kidding in overfat does and those not adapted to the concentrate ration, or a change in feed.

• The problem usually appears during the period leading up to peak lactation (six to eight weeks after kidding).

• Short periods of starvation (yarding and transporting) can result in problems.

• Stress (due to climatic conditions, handling, being chased or management procedures) is also a concern as it can affect feed intake and hormonal balance.

Diagnosis:

• In the clinical form, ketosis presents as a decrease in appetite and milk production, rapid loss in condition, hard droppings (which tend to have pointed ends). The doe is moderately depressed and frequently exhibits signs suggestive of abdominal pain. A sweet smell may be detected on the doe’s breath or in the milk.

• Diagnosis can be confirmed by using Acetest tablets in a urine sample.

Preventative management strategies:

The recommendations for preventing ketosis are similar to those for pregnancy toxaemia listed above.

Introduce a production ration about one month before kidding to allow the rumen to adapt. Follow up with a quality roughage diet, up to peak lactation.

Respiratory diseases

Examples:

pneumonia, lungworm, cheesy gland abscesses in the lungs, Mycoplasma, viral infections.

Conditions when likely to occur:

• Dairy breeds appear to suffer from pneumonia more than other breeds.

• Pneumonia is often associated with lungworm, cheesy gland abscess and other bacteria. Alternatively, it may be preceded by a Mycoplasma or viral infection.

• Respiratory diseases can spread rapidly through herds housed in poorly ventilated sheds or where overcrowding occurs.

• Intensive feeding (mainly in feedlot or drought feeding) with dusty feed.

• Lungworm infection is most likely to occur when goats are transported from a dry area to areas of higher rainfall, especially in autumn or winter.

Diagnosis:

• Lungworm can be diagnosed by finding larvae in faecal samples. A drenching program will be necessary.

• Cheesy gland may not show any external evidence. Treatment is usually not successful. Prevention is preferred. Refer article Goats – Vaccinating against diseases.

• Mycoplasma pneumonia in kids can cause coughing, laboured breathing and swollen joints. There is no effective treatment.

• Autopsy: often shows the presence of all the above diseases, and therefore it is difficult to establish the exact cause of death.

• Veterinary advice should be sought for accurate diagnosis.

Preventative management strategies:

• Goats suffering from respiratory diseases should be promptly treated and isolated from healthy goats.

• Provide shelter for goats and if sheds are provided make sure they are well ventilated.

• Faecal examination can be used to monitor lungworm levels. It is important to control lungworm, as infestation will predispose goats to other types of infection.

• Isolate infected goats with discharging cheesy gland abscesses until satisfactorily treated, then cull them.

• Try to reduce the risk of physical injury. In particular, take steps to reduce the risk of head and neck wounds. Damaged or poorly designed head bails, fences with protruding nails, wire or splinters are high-risk items.

• Disinfect shearing equipment after use on infected goats.

• Vaccinate at six to eight weeks with a second dose in four to six weeks, followed by an annual booster dose.

• Mycoplasma pneumonia has no effective treatment. Isolate infected goats and disinfect the premises.

Clostridial diseases

Examples:

The main clostridial diseases that are of concern in goats are tetanus and enterotoxaemia (pulpy kidney). Other clostridial diseases that you may hear about are black leg, black disease, malignant oedema and botulism.

A detailed discussion of clostridial diseases appears in Goats – Vaccinating against diseases.

With all health problems, assess the risk based on the history of problems in the district and, if available, property history. Seek information from local veterinarian, state government officers and local consultants. Intensification of the goat production system is likely to increase the risk of diseases such as gastrointestinal parasitism, clostridial infections and respiratory diseases.