March 22, 2009

Angora (Mohair) Goat Basics: Diseases PART 1

Agriculture, animal husbandry, goats, Angora, Mohair, health, diseases, lameness, sudden death

By Dr Marjorie Orr


Lameness - overview
  • Practically every goat farmer has to deal with lame goats at some time or other.
  • It’s a common problem, particularly on wet land and when the horn on the feet becomes overgrown.
  • The most common causes of lameness are foot scald, foot rot, foot abscess and arthritis.
  • In young kids, joint ill can cause lameness.

Foot scald
  • Foot scald (interdigital dermatitis) is a bacterial infection that is very painful.
  • Foot scald tends to develop suddenly when conditions underfoot are wet and there are a lot of animals in a small area.
  • It commonly occurs the morning after a shower in mild weather and when the grass is long.
  • It is a very painful condition and it causes affected goats to go down on their knees to take the weight off their feet.
  • You might see several goats on their knees the morning after a shower in mild weather and when the grass is long.
  • The skin between the toes is either red and swollen, or blanched and white.
  • Affected feet aren’t smelly like foot rot.
  • With mild infections, goats can recover spontaneously if they are moved to drier pasture.
  • Standing affected goats in a foot bath containing 10% zinc sulphate as described below is an effective treatment.
Footrot
  • Footrot is caused by another type of bacterium, and the infection is between the horn and the sensitive growing tissue that lies beneath it.
  • The horn tends to separate from the underlying tissue with the gap becoming filled by dirt and smelly exudate.
  • Footrot is particularly likely when the horn is overgrown.
  • Overgrown horn tends to curl under the foot, trapping mud and predisposing to infection.
  • In goats with long-standing footrot, the infection can track into the foot, causing painful abscesses and sometimes arthritis causing swelling above the foot.
  • To treat foot rot, first cut back any overgrown horn as described below.
  • Put the goats through a footbath containing 10% zinc sulphate as described below.
  • Stand the goats in the footbath for at least 5 minutes and preferably 10 minutes.
  • Repeat the footbaths at regular intervals to keep infection at bay.

Foot abscesses
  • Foot abscesses develop when foot rot is untreated or when any infection tracks deep into the foot and causes pus to form in or around a joint.
  • There may be an obvious swelling and/or the affected toe may be hot and very painful.
  • The abscesses are caused by bacterial infection, and they make animals very lame indeed.
  • Get veterinary help right away because affected animals need treatment.
  • Your vet may pare the foot to try to release the pus, but generally this is not possible, and a long course of antibiotic treatment is the only treatment option.
Preventing foot problems
  • The outer weight-bearing part of each toe is made of thick strong horn. The inner non-weight-bearing parts of the sole are made of thinner horn.
  • Normally the outer horn grows slowly, like our finger and toenails, and it is usually worn down at the rate it grows at by natural wear.
  • If conditions underfoot are soft, the horn grows faster than the rate of wear.
  • The horn on the two toes can get so long it curls under the foot or it may grow forward until the toes cross.
  • This is a recipe for foot problems and excess horn should be trimmed.
  • To help prevent foot infections put the goats through a foot bath regularly.

Trimming feet
  • Don’t trim off so much horn that you draw blood. Trim off only excess dead horn, using a clean sharp pair of clippers.
  • If you draw blood when you trim feet, you may well cause painful infections to develop.
  • Foot trimming equipment needs to be kept sharp and very clean, with regular disinfection.

Foot baths
  • To prevent foot infections and to treat early cases, put the goats through a foot bath.
  • 10% zinc sulphate is best for the foot-bath.
  • 10% copper sulphate or 4% formalin have been used in the past but they are more hazardous for operators, animals and the environment.
  • Stand the goats in the foot-bath for at least 5 minutes, then on a hard surface like concrete for a while for the feet to dry before returning to the paddock.
Lameness with swollen joint(s)
  • There are many causes of arthritis, including injuries that can leave the injured joint permanently enlarged.
  • However a lot of arthritis is caused by bacterial infections.
  • Bacteria get to the foot joints in the blood or by tracking from nearby infections.
  • In very young goats the infection can spread in the blood from the navel at birth (joint ill).
  • In older goats the infection can spread from nearby foot rot.

Joint ill
  • In very young (unweaned) goat kids, bacterial infections can cause lameness with swollen joints (a condition called “joint ill”).
  • Joint ill can affect one or more joints in the legs.
  • The affected joints become swollen, hot and very sore.
  • The bacteria that cause the disease enter the body through the cord soon after birth, so the problem occurs most often in kids born in unhygienic conditions and it develops within days of birth.
  • To prevent joint ill keep the birthing areas clean and dip navels in dilute iodine immediately after birth.
  • If swollen joints develop, consult a vet immediately as treatment requires antibiotics by injection and only early cases respond well to treatment.

Dealing with on-going lameness problems
If there is a persistent problem with lameness in goats on your farm, you should consult a vet so that together you can devise a programme of foot trimming, foot bathing and culling to combat it.

Sudden death – overview
There are many potential causes of sudden death. Here are some of the diseases that can kill goats quickly.

Pneumonia
  • Pneumonia in goats is fairly common as a cause of death. Goats may be found dead with blood-stained froth at the nostrils, or they may first seem short of breath and slow to keep up with the mob when driven.
  • Pneumonia is often triggered by transportation or a spell of wet cold weather after shearing.
  • It doesn’t seem to be very infectious because usually only one or two goats are affected at one time.

White muscle disease
  • White muscle disease is caused by a deficiency of selenium and or vitamin E and it is the most common trace element problem in goats.
  • A common form of the disease involves the heart muscle and this can cause breathing difficulties and sometimes sudden death.
  • Affected goats usually range in age from newborn to 3 months old.
  • Selenium and vitamin E deficiencies can also cause lesions in skeletal muscles, and kids then have difficulty suckling and walking.
  • In growing goats, selenium/vitamin E deficiency causes unthriftiness.
  • White muscle disease in goats can occur even in areas where selenium responsiveness is not seen in sheep and cattle.

Selenium poisoning
  • Deaths occasionally occur because selenium supplementation has been too generous!
  • Only two or three times the recommended dose can kill a goat.
  • This happens most often when supplements are provided in several ways (in prills on pasture, in selenised drench and in salt licks).

Pulpy kidney disease
  • Pulpy kidney disease or enterotoxaemia is not common in goats. It’s probably over-diagnosed, but it does occur.
  • As with sheep, the signs are usually sudden death often in recently weaned goats, but goats of any age can be affected.
  • It may follow the feeding of green lush pasture or goats gorging on concentrate feed.
  • As with sheep, goats can be given a vaccination course as kids, then does can be given an annual pre-kidding booster.

As well as these diseases there are paddock accidents that can kill goats quickly. Horns can get caught in fences, even electric fences, feet and legs can get caught up in gates and yards, and any goat taking on a larger buck head to head risks fatal spinal cord injury or a broken neck. More good reasons for regular monitoring and good facilities.

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