Birth abnormalities in Angora kids

Friday, 18th May 2018

Birth abnormalities in Angora kids

When Angora Kids are born weak or with conformational abnormalities we usually think of the cause as being one of the conditions or diseases causing abortions. Diseases occurring in the first few days of life of the kid may also cause weakness and death so must be kept in mind when considering possible causes of these abnormalities.

Kids from premature births often appear to have laxity/limb deformities which may come right after a few days as long as they are assisted in suckling. These cases often involve twins as space is reduced and unborn kids move less.

Arthrogryposis (limb deformities) are caused by conditions affecting the nervous system which causes the foetus to move less than what it normally would. As a result the limbs become contracted and all the joints are flexed.

Some causes include:

  1. Enzootic abortion

Enzootic abortion (chlamydiosis) is a contagious disease in Angora goats and sheep caused by Chlamydia psittaci. It can result in abortion or the birth of weak kids which may show neurological signs. For more information see the SAMGA website https://www.angoras.co.za/page/abortion-enzootic-abortion#144

  1. Viral infections

Weak kids, early deaths and neurological signs may be seen in good seasons when ewes have been affected by viruses transmitted by mosquitoes such as Rift Valley Fever, Wesselsbron, Abakane and Flavi viruses.

  • Wesselsbron

Congenital CNS malformations with arthrogryposis,

https://www.angoras.co.za/article/wesselsbron-disease#229

  • Rift Valley Fever (RVF)

https://www.angoras.co.za/page/rift_valley_fever#33

 

  • Flavi virus

The kids are born normal in appearance and can suckle but their legs split open.

  • Akabane virus

Can affects the brain and limbs

  1. Live vaccines

If live vaccines are injected in early pregnancy they can cause brain and limb abnormalities. These may include Enzootic Abortion, RVF, Blue toungue vaccine (sheep).

 

 

 

  1. Bacterial enteric infections of the kids

 

  • Colibacilosis is acute and death may occur within 1-3 days in young kids. Kids may show incoordination, recumbency, opisthotonus (head pulled back) and leg paddling movements. Those kids showing signs (usually older 2-4 weeks) may have abdominal pain (reluctant to stand and when lifted may stand with an arched back, bleat and have diarrhoea which may be brownish-grey and blood stained. The diarrhoea has an offensive smell.
  • The Clsotridium perfringens B produces alpha, beta and epsilon toxins. The reason neonates are more susceptible to the Beta toxin is that trypsin is not secreted in sufficient amounts by the kids to inactivate the toxin. It is interesting to note that goats with a high levels of brown stomach worm causes the pH of the abomasum to rise which in effect causes trypsinogen not to be converted to trypsin. The toxins in the intestinal tract cause’s necrosis of the tissue and ulceration leading to increased peristalsis and diarrhoea. Kids die from dehydration, acidosis, toxaemia and shock.

 

  1. Brucella melitensis

 

Brucella melitensis may cause abortions but Kids may also be born alive but usually die soon after

 

  1. Q-fever.

Q-fever may cause abortions (fully developed kids) and peri-natal deaths of kids. See SAMGA website https://www.angoras.co.za/article/q-fevercoxiella-burnetii#230

  1. Border disease

Border disease (Britain) or hairy shaker disease (Australia and New Zealand) is a congenital disorder of lambs characterized by low birth weight and viability, poor conformation, tremor, and an excessively hairy birth coat. Goat kids may also be affected. See SAMGA website https://www.angoras.co.za/article/hairy-shaker-disease-border-disease#271

  1. Nutritional deficiency (energy/protein) especially during late pregnancy may result in small weak lambs being born as well as late abortions. See the article on the importance of nutrition in the late pregnant Angora ewe on the SAMGA website. https://www.angoras.co.za/page/pregnant_and_lactating_ewe#47

Nutritional deficiencies in terms of certain Minerals and Vitamins may lead to weak kids and certain congenital abnormalities.

  • Selenium deficiency. Deficiencies occur in lush pastures, sandy and acid soils with low clay content. High grain diets are low in Se. Deficiencies can be seen in lambs 3-6 weeks old (Stiff lamb disease, White muscle disease) In goats deficiencies can result in poor growth, lower reproduction rates due to reabsorption of fertilised eggs and suppression of sperm activity, early born, weak kids. Many cases of Se deficiency in South Africa seem to have been associated with a high Lucerne diet. This is due to the fact that Lucerne is high in Ca  and S which has a suppressive effect on Se levels.  Antagonists of selenium are calcium, sulphur and iron.
  • Vitamin A. B-carotene deficiencies occur during droughts, when lucerne hay and concentrate diets are fed. The feeding a urea lick, deficiencies in P or Vit E prevents the transformation of B-carotene to Vit A. A high Ca and low Zn diet can also result in Vit A deficiency. Vit A is essential in production of progesterone so deficiencies result in poor expression of oestrus, delayed ovulation and birth defects and negatively affect immune status. Deficiencies can also result in eye disorders, blindness, increased respiratory disease and decreased mohair production.
  • Manganese (Mn) may cause still born kids and skeletal abnormalities to occur. High dietary intakes of Ca such as contained in lucerne reduce Mn absorption.

 

  1. Poisoning

 

  • Dips/Doses.
  1. Albendazole dosed in first month of pregnancy may cause arthrogryposis in kids. The active metabolite, albendazole sulphoxide reaches very high concentrations in the embryo. The embryo is only sensitive to this for a few days during the first trimester.
  2. Rafoxanide and Closantel (Group 4 and in combinations) can potentially cause blindness in Angora goats if overdosed. Trials indicated that kids dose at 4x the therapeutic dose went blind .Kids not affected too badly recovered over 3-4 weeks. Most frequent symptoms of closantel toxicity: Loss of appetite, ataxia (uncoordinated movements), weakness, visual disturbance, blindness

 

  • Prussic acid poisoning may cause arthrogryposis/limb abnormalities in new born kids and stillbirths if occurring in the ewe during pregnancy. In these cases associated with prussic acid, there is usually a concurrent thyroid goiter in the kids/lambs. 

 

  1. Genetics

Familial episodic ataxia (reported in Merino Sheep and Dorpers ) may occur in lambs. Lambs show tremors. Not observed in Angora goats to date.

The cause of Angora kid birth abnormalities are numerous so a good history and veterinary investigation may be required to determine the underlying reason.

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