Scouring (diarrhoea) is common in Angora goats. The first sign of scouring is usually soft wet dags under and around the tail. The most common causes are:
- Johne's disease
- Other infections
- Scouring in hand-reared kids
"Worms" or gastrointestinal nematode parasitism is not just the most common cause of scouring, it's by far and away from the most common disease problem of any kind in Angoras.
Goats and sheep share the same internal parasite worms, but goats seem even more susceptible than sheep. They don't develop age-related immunity as sheep and cattle do, so they remain susceptible throughout their lives, especially if they are stressed for long periods by underfeeding, cold wet weather, or another disease like Johne's disease.
The reason for their susceptibility may be that they have evolved to browse shrubs and not primarily pasture. Browse is generally free of faecal contamination with its worm eggs and larvae, so goats haven't evolved immune systems that can deal effectively with a big worm challenge. Yet as farmers, we tend to force them to graze close to the ground where worm eggs and larvae are most numerous
The stomach worm Haemonchus is a particularly nasty worm that causes scouring and anaemia (because of internal blood loss) in goats in the northern half of the North Island.
- Big worm burdens cause ill-thrift, weight loss, diarrhoea and even anaemia and death.
- Affected kids don't grow well, they scour and have dirty wet daggy fleece under and around their tails.
- They may be thin with a pot belly.
- They may not have a good appetite.
- In severe cases, they may get bottle jaw (swelling under the jaw) because of low protein levels in their blood.
Prevention and control
Anthelmintics can get rid of worms, but it is important to give the correct type of anthelmintic, give the correct dose and drench at appropriate intervals.
There are three types of drench - white, clear and third-generation ivermectin types.
- Only some of the white drenches, including Axilur 10, Bomatak-C, Bomatak-S and Oxfen are licensed for use in goats. Traditionally these have been given at regular intervals of about 4 to 5 weeks throughout the summer and autumn months.
- The clear drenches based on levamisole, eg Nilverm, are not particularly effective in goats. They are not licensed for use in goats and are not recommended. At twice the sheep dose rate, they can cause poisoning.
- The third-generation drenches such as Ivomec Liquid for Sheep and Goats can be given at regular intervals of about 8 weeks throughout summer and autumn.
- There are many other types of pour-on, ruminal bolus and injectable anthelmintics on the market for various livestock species, but not many are licensed for use in goats.
- This is why it is best to consult a vet for advice if planning to use any anthelmintic other than the Ivomec and white drenches mentioned above.
Note that giving too much drench can cause poisoning, especially if it's a clear drench or selenium has been added to it.
- Efficient drenching means giving an anthelmintic that kills 100% of worms and giving it at intervals that ensure that re-infection with worms doesn't build-up to the level when it has damaging effects, e.g. ill-thrift or scouring.
- Read the instructions on the drench container, and give each goat the correct dose for its weight.
- If commercial animal scales are not available, then use bathroom scales.
- Weigh yourself, then pick up a goat and weigh yourself and the goat - the difference is the goat's weight.
- Do this for a representative number of animals to make sure you know the weight of each goat before you drench it
- If the drench is effective, egg counts will be zero in faecal samples taken from the goats 7 to 10 days later.
- Your vet or another professional adviser can arrange for tests of faecal samples to confirm nil egg counts.
- If egg counts are not zero, your drenching was not effective.
- If the drenching was not effective the dose rate may have been wrong or the drenching technique (eg the drench gun) may have been faulty.
- Alternatively, the worms may have been resistant to the drench used, in which case you will need your vet's help to select an effective drench in future.
Drench resistance is a real threat to future worm control in goats.
- About 80% of milking goat herds and 65% of sheep flocks may already have drench-resistant worms on their pasture and in their goats. On some goat farms, resistance to all three drench families has been recorded.
- Drench resistance means that some or all of the worms in the goats are not being removed by the drench used. For example, Nematodirus worms may be resistant to benzimidazole (a white drench).
- Once you have drench-resistant worms in pasture and in livestock on your farm, it is very difficult or impossible to get rid of them, and you must change to an effective drench.
- Delay the onset of drench resistance by avoiding excessive or unnecessary drenching. Try to make the interval between drenches as long as possible, using faecal egg counts to give you confidence. The longer the gap, the lower the risk of selecting resistant worms. Drenching at less than 28-day intervals increases the risk of developing resistance.
- Don't under-dose. If you can't weigh individual goats, base the dose volume on the heaviest animal in the mob. If there is a wide amount of variation in body weight, split onto smaller groups and dose to the heaviest in each group.
The latest thinking with sheep is that it's OK to leave the healthiest animals in a mob undrenched. This helps to maintain a reservoir of 'susceptible' worms in the population to dilute down any resistant worms. This might be appropriate on your goat farm, but before you leave the most robust goats undrenched, talk to your vet about the pros and cons.
Other ways of controlling worms
As well as regular effective drenching, you should use other ways of minimising the number or worm larvae your goats take in with the pasture they eat because this can help reduce the number of drenches needed.
- You can put goats only on "safe" pasture to help keep worm intake down. "Safe pasture" means any pasture grazed only by cattle or non-lactating adult sheep in the previous 3 months. Grazing goats after horses is a good policy too because these species don't share the same worms.
- Long pasture can help control worms because larvae tend to be concentrated at the base of the sward.
- Feeding browse is good because shrub and tree foliage is generally not contaminated by faeces that might contain worm eggs and larvae. The plants should of course be non-toxic! Try willow, poplar, broom or tree lucerne.
- In practice, it's best to use as many of these approaches as you can in a planned worm control programme for the farm.
Prevent the introduction of resistant worms
"Quarantine drench" introduced goats: While there hasn't been nearly as much research on goats as on sheep and the following advice is intended for sheep, it should be relevant for goats too.
- Before adding goats from another source to your herd they should be drenched with a triple combination drench, repeated in about 24 hours.
- Consult a veterinarian about what to use, and be accurate with the dose.
- After quarantine drenching, yard the goats (with hay or browse and water) for 24 hours and then let them out onto a 'wormy' paddock so that any drench-resistant worms are quickly diluted.
If you have had any goats on your farm that lost weight and scoured then died in spite of treatment, they may have had Johne's disease. It's a relatively common disease in sheep and cattle, and it is probably quite common in goats and deer too.
- Johne's disease is a chronic (long-standing) disease of the intestine.
- It causes rapid weight loss, even with good feeding and good management.
- There is usually severe runny diarrhoea that doesn't respond to drenching or the usual scour treatments.
- Affected goats die after a few weeks or months.
- Infection is picked up by kids when they are less than a year old, and it lies dormant before flaring up to cause severe scouring and weight loss.
- Johne's disease is an incurable disease and there is no effective treatment.
- Fortunately, there is a vaccine that can help prevent it.
- The vaccine should be given to kids when they are only a few weeks old.
- Vaccination is currently not an option for cattle and deer because it can cause false-positive reactions to the Tb skin test.
What can you do if you think you have Johne's disease in goats on your farm?
- First, get your vet to confirm or rule out the diagnosis - and definitely check for worms.
- If Johne's is confirmed, cull goats that show unexplained weight loss and or scouring.
- Vaccinate all goats and all kids before they are 2 months old.
- If you are bringing goats onto your farm, introduce only those from farms where no stock has shown signs of Johne's disease in the last few years and/or buy in only vaccinated stock.
- Consider subdividing your farm. If you have an area where there have been no animals with signs of the disease you might be able to use this as a 'safe' area. In the 'infected' area graze only older vaccinated animals.
There are other infectious causes of scouring such as coccidiosis and yersiniosis.
- Coccidiosis is caused by tiny parasites in the small intestine. The signs are severe scouring that is sometimes blood-stained in kids aged from 2 to 12 months old.
- Yersiniosis is a bacterial infection of the small intestine that causes severe watery diarrhoea and sometimes death, and it most often affects young goats during their first winter.
- Stress predisposes to infection because it weakens the immune system.
- Problems can develop in kids just after weaning because of the stresses of separation from their mothers, change of feed type, strange environment, yarding, handling, and sometimes transportation and bad weather as well.
- The diseases can occur in winter triggered by the stresses of cold, wet, windy weather and insufficient feed.
- Shearing can predispose to infection especially if the goats become cold or hungry.
- There are treatments available from your vet. They are most effective if given early soon after the scouring starts. In severe cases, your vet may also give fluid replacement.
- Control of outbreaks requires relieving stresses on the goats, good feeding and good hygiene.
- Prevention requires good management and not grazing young goats in areas where there have been affected goats within the last year or so.
Hand-reared kids are susceptible to scouring especially in the first week or two of life, and the cause can be non-infectious or infectious
- The nutritional causes of kid scours include poor milk or milk substitute quality and sudden changes in feed type.
- Milk or milk substitute that is too concentrated or too hot or cold or given too quickly can cause scouring.
- Milk substitutes should be as close as possible to the real thing, and sheep milk powder is better for kids than calf milk powder.
- The instructions provided on bags of commercial milk powders indicate what concentration, volume and frequency of feeding are best. Follow the instructions carefully.
- Starter meals should be fresh and of good quality. Stale or poor-quality meals can cause scours.
- Avoid feeding silage and chaff to very young animals.
- Infections are more likely to cause scouring if kids have not had enough colostrum in their first few days of life.
- The infectious causes of scours include viruses like rotavirus, tiny one-celled parasites called cryptosporidia, and bacteria such as E coli and Salmonella.
- For very mild diarrhoea, dilute the concentration of the milk offered for a day.
- If the diarrhoea is more marked, replace milk with electrolyte solutions and consult your vet.
- If the diarrhoea is watery or contains mucus or blood, or if the animal shows weakness or a bloated abdomen or pain, or if it refuses to suck or is dehydrated, it is important to consult your vet at once.
- Treatment may involve management changes or antibiotic treatment or both.
- The earlier treatment is begun, the more successful it is likely to be, and early treatment is particularly important when the animal is very young.
- It is important to offer free access to drinking water at all times.
- Kids that have been fed colostrum in the first week of life have a head start. They will be resistant to many of the infections that cause scouring because colostrum is rich in protective antibodies.
- Isolate scouring kids, keep their utensils separate and feed them last to reduce the risk of spreading the infection to other kids.
- Resistance to disease is reduced by stress, so it is important to ensure all hand-reared animals are dry, warm, comfortable and content.
- Feed milk formulation at the concentration, volume and feed frequency indicated on the packaging.
- Good hygiene is vital. Wash all the utensils carefully between animals, and at least once a day soak them in dilute bleach and rinse well.
- Some causes of scours in goats can cause diarrhoea in humans too, especially children. This includes the Yersinia species that cause yersiniosis and some of the infectious causes of kid scours, i.e.rotavirus, E coli, cryptosporidia, and Salmonella species.
- To prevent human infection, make sure you and anyone else in contact with the animals wash your hands afterwards and take all steps to prevent faecal contamination of anything that could go into a human mouth (hands, cigarettes, utensils etc).