This is a fairly long article, but there do seem to be rather a lot of significant health problems in dairy goats. Here we discuss some of the main ones, like scouring (including worms and Johne's disease), feet and teeth problems.
Scouring
Diarrhoea or scouring is a sign that something is irritating the lining of the intestine. There are various causes, both infectious and non-infectious. It helps to know the cause if you want to treat the problem effectively and prevent it from spreading to other goats.
Worms
Worms are probably the biggest health problem for goat farmers.
- 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.
- Goats are at risk from the moment they start to eat grass, and growing kids and weak goats are particularly susceptible.
The problem of worm control is complicated in dairy goats by the fact that many anthelmintics remain in the meat and milk for some time after treatment. For this reason, milk from does treated with worm treatments (anthelmintics) shouldn't be used for human consumption until the 'with-holding period' has elapsed.
Clinical signs
To some extent, worms can exist with their hosts causing no problems, but as numbers build up they damage the intestine lining causing fluid and protein loss. The earliest effects, a drop in milk production or a reduction of growth rates can be subtle (subclinical. With increasing worm numbers the signs become more obvious (clinical). The clinical signs of parasitism are ill-thrift, weight loss, diarrhoea and even death.
The stomach worm Haemonchus can be particularly nasty in dairy goats. It causes scouring, anaemia (pale mucous membranes), weakness (because of internal blood loss), and sometimes bottle jaw (swelling under the jaw because of low protein levels in the blood). It occurs in goats in the northern half of the North Island.
Drench resistance
- Drench resistance means that some or all of the worms in the goats are not being removed by the drench used.
- 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.
- To maintain good worm control it is wise to test for drench effectiveness from time to time.
- About 80% of milking goat herds 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.
- 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 for 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.
Controlling worms
- You will never be able to get rid of all the parasitic worms in your goats and pasture, so you should try to keep burdens light to minimise the effect on productivity and health.
- A degree of worm control can be achieved by pasture management, as well as by giving effective worm treatments (anthelmintic drenches) at strategic times.
- You can put goats only on "safe" pasture to help keep worm intake down. "Safe pasture" means hay aftermath or any pasture grazed only by horses or cattle in the previous 3 months.
- Grazing goats after horses is particularly good because these species don't share any types of worm.
- 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.
- Cutting grass from faeces-free areas and carrying it to goats' areas might be laborious but it can help keep worm burdens down (as long as you don't give too much at once and cause digestive problems!).
Prevent the introduction of resistant worms
Take care not to bring in resistant worms in introduced goats.
- Quarantine-drench introduced goats and sheep with triple combination drench.
- Consult a vet 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.
Links
You can read more about the clinical signs of worms, faecal egg counts, efficient drenching, drench types, with-holding times and pasture management as an aid to worm control in Lifestyle File "Worm control in goats" and "Angora goats - health and disease: Scouring".
Scouring in hand-reared kids
Hand-reared kids are susceptible to scouring especially in the first week or two of life, and the cause can be non-infectious (nutritional) or infectious.
You will find more about the causes of scouring in kids, how to prevent it and methods of treating it in the Lifestyle File "Scouring in hand reared animals".
Remember not to neglect personal hygiene if you are treating scouring kids, as some diseases can affect humans too.
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.
- The signs are severe watery diarrhoea and sometimes death, and it most often affects young goats during their first winter.
Problems are particularly likely to develop when goats have been stressed, for example by transportation, yarding, bad weather or a combination of these.
You'll find more on coccidiosis and yersiniosis in the Lifestyle File "Angora goats - health and disease: Scouring".
Johne's disease
If you have had any goats on your farm that lost weight dramatically and perhaps scoured then died in spite of treatment, they may have had Johne's disease. It's a relatively common disease in sheep, cattle and deer, and it is probably quite common in goats too.
- Johne's disease is a chronic (long-standing) disease of the intestine.
- It's an incurable disease and there is no effective treatment
- The main sign is rapid weight loss, even with good feeding and good management.
- Late in the disease, there is sometimes 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 in the womb, or in their first few weeks of life via colostrum or faeces. The younger they are the more susceptible they are.
- The infection progresses very slowly and it may or may not flare up into clinical disease a year or more later.
- Fortunately, there is a vaccine that can help suppress the signs.
- 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. In goats, it can cause false-positive reactions to Johne's blood test and this may be important when selling.
What can you do if you think you have Johne's disease in goats on your farm?
- First, get your vet to help confirm or rule out the diagnosis by doing blood or faecal tests - and definitely check for worms as well.
- Cull goats that test Johne's positive.
- If you are serious about controlling the disease, test all breeding stock every 6 months and cull positives.
- If you don't do diagnostic tests, don't breed any goats that show unexplained weight loss. Separate them until you have an explanation of the signs.
- The only way to help prevent kids from becoming infected is to separate them from their dams at birth and hand-rear them using colostrum and milk from goats that show no signs of the disease. It's not easy!
- Keep down the risk of infection by keeping kids in areas as free of adult faeces as possible and keeping water supplies clean.
- Discuss with your vet the option of vaccinating all goats and all kids.
- If you are bringing goats onto your farm, introduce only those from farms where no ruminants have 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 cattle, sheep, deer or goats 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.
Lameness
Lameness is another big health problem on many goat farms. Part of the reason is that the horn on goats' feet is designed to be worn naturally by rough ground, but on our soft pasture land, the horn tends to overgrow, curling under the toes and trapping dirt that can predispose to bacterial infections like foot rot and foot abscess.
It's important to keep an eye on your goats' feet. As soon as the horn starts to curl under, trim off the excess with sharp horn cutters (these can be purchased from agricultural stores - they're like secateurs but with longer straighter cutting edges). Take care not to cut so deep that you cause bleeding.
You'll find more in Lifestyle File "Feet and foot problems" and "Lameness in livestock. Part 3. Lameness in sheep, goats, cattle and deer".
Teeth problems
Periodontal disease is common in adult dairy goats. The incisors are long and loose and inefficient. The causes are not known and there is no treatment, but removing loose teeth can make it easier for the goat to graze effectively. Even goats with no incisors can maintain good body condition if they are on long soft pasture or fed cut and carried grass and browse or supplementary feed like hay.
Read more about it in Lifestyle File: "Teeth and teeth problems".
Pneumonia
Pneumonia can occur in individual goats or in groups of housed kids, causing laboured breathing or maybe just sudden death. Sometimes there are no obvious signs apart from the loss of appetite and weight loss.
You can read more about it in the Lifestyle File "Pneumonia".
A word of caution when giving medicine like drenches by mouth. Clumsy administration of drench into the lungs instead of down the gullet can cause pneumonia (inhalation pneumonia) and this is usually fatal.
Poisonous plants
Many garden plants and a few natives are toxic, and because of goats browsing habits, plant poisoning is all too common.
When garden prunings are tossed over the fence or the pet goat gets loose in the garden, there is a risk of poisoning. Rhododendron is probably one of the most common causes, and you will find details about treatment in the Lifestyle File "Rhododendron poisoning".
Goats that wander into scrub may be at risk of poisoning by tutu or ngaio.
Caprine arthritis-encephalitis
Caprine arthritis-encephalitis (CAE) is widespread in New Zealand, particularly in dairy goats, but it doesn't always cause obvious health problems. It seems to be more common in dairy goats, possibly because it can spread to kids in pooled colostrum.
The most common sign in adult goats is arthritis, particularly in the knees, which become swollen and painful. An encephalitis form of the disease can occur in kids from 2 to 6 months of age but this is unusual in NZ, as are other forms of the disease that can cause pneumonia or hard udder.
A voluntary accreditation scheme operated for a number of years, but this has now lapsed. Most of the testing that is carried out nowadays is for breeders who wish to control or eradicate the disease from their flocks and for breeders who export goats.
