Sheep Prod - CVV thru Metabolic Acidosis

What is Cache Valley Virus (CVV)?

A mosquito-transmitted virus that can cause reproductive problems and severe birth defects in lambs.

How is Cache Valley Virus transmitted?

By mosquitoes.

What reproductive problems can Cache Valley Virus cause?

Infertility, abortion, dystocia, stillbirth, premature birth, and mummified fetuses.

What types of birth defects can Cache Valley Virus cause?

Severe deformities involving the joints, spine, brain, nervous system, and muscles.

What are some physical abnormalities seen in lambs affected by CVV?

Fused joints, curved or twisted spines, underdeveloped muscles, and enlarged skulls.

What usually happens to lambs severely affected by Cache Valley Virus?

They are usually stillborn; if born alive, they are often very weak and die soon after birth.

Are all lambs in multiple births usually affected by CVV?

Yes, all lambs in multiple births are usually affected.

What happens if a ewe is infected with CVV less than 28 days into gestation?

Abortion often occurs.

What happens if a ewe is bitten by an infected mosquito after 45 days of gestation?

Usually, there are no adverse effects.

What happens if a ewe is infected with CVV between 28 and 45 days of gestation?

Fetuses often develop arthrogryposis and hydranencephaly (A-H syndrome), causing congenital abnormalities.

Do infected ewes usually show symptoms of Cache Valley Virus?

No, infected ewes generally show no symptoms.

Is the Cache Valley Virus still viable at the time of birth?

No, the virus is not viable at the time of birth.

Do infected ewes generally develop immunity to CVV?

Yes, infected ewes generally develop immunity.

Is Cache Valley Virus contagious from sheep to sheep?

No, the virus is not contagious.

When and where was Cache Valley Virus first discovered in the U.S.?

It was first discovered in Cache Valley, Utah, in 1956.

Is there a known vaccine for Cache Valley Virus?

No, there are no known vaccines.

How can Cache Valley Virus be controlled?

By controlling disease-carrying mosquitoes.

What are some ways to reduce mosquito exposure to ewes?

Breed after frost, breed in barns with fans, haul manure, and spray for mosquitoes.

What is Early Dilation Syndrome (EDS)?

A reproductive problem that is separate from Ringwomb.

Which ewes are primarily affected by Early Dilation Syndrome?

Yearling ewe lambs and virgin 2-year-old ewes.

Does Early Dilation Syndrome commonly occur in older ewes?

No.

When does Early Dilation Syndrome typically occur?

About 2–3 weeks before the due date.

What is a sign of Early Dilation Syndrome involving the mammary gland?

Very little mammary development or the ewe may appear to "bag up" overnight.

What is happening to the fetus during Early Dilation Syndrome?

The ewe is aborting a rotten fetus.

What may be seen protruding from the vulva during Early Dilation Syndrome?

Fetal membranes.

What condition are the lambs in during EDS?

The lambs are dead or macerated.

What is found during a vaginal examination of a ewe with EDS?

The cervix is not dilated or is only dilated enough for 1–2 fingers and is very firm.

How can the cervix be manually dilated in Early Dilation Syndrome?

Make a cone with the hand and gently expand it to dilate the cervix.

Is Early Dilation Syndrome genetic?

No.

Will ewes with Early Dilation Syndrome generally have problems during later lambings?

Generally, no.

What is Ringwomb?

Failure of the ewe's cervix to dilate sufficiently during parturition to allow delivery of the lambs.

What type of ewes generally experience Ringwomb?

Multiparous ewes carrying multiple fetuses.

Is Ringwomb the same problem as Early Dilation Syndrome?

No, they are separate issues.

What does Ringwomb involve?

The cervix fails to dilate sufficiently during labor.

What is believed to cause Ringwomb?

Failure of the cervix to respond to hormones responsible for parturition or abnormal secretion of those hormones.

What does Ringwomb NOT result from according to the slides?

Infection, abnormal presentation, premature delivery, or mineral/nutritional deficiencies.

When does Ringwomb usually occur?

On the due date, although pregnancy may be prolonged up to 14 days.

What is a sign of Ringwomb?

Fetal membranes protruding from the vulva with no signs of labor.

Do ewes with Ringwomb always show normal labor symptoms?

No, they may not show normal labor symptoms.

What may happen to udder development with Ringwomb?

Udder development may be poor or slow.

What does the cervix feel like during Ringwomb?

It is closed or may only allow 1–2 fingers.

How can the cervix be manually dilated during Ringwomb?

Insert the hand in a cone shape and gently expand the hand to dilate the cervix.

What may be necessary if the cervix cannot be adequately dilated?

A C-section.

What happens if a ewe with Ringwomb is left to deliver without correction?

The cervix may close again in 2–3 hours, resulting in death of the lambs.

Can most ewes breed again after experiencing Ringwomb?

Yes, most ewes will breed back and not experience Ringwomb again.

What does the slide recommend regarding ewes with Ringwomb?

Cull them.

What does the slide question about the cause of Ringwomb?

Whether it may have a genetic/familial component.

What are the three names used for Milk Fever?

Milk Fever, Hypocalcemia, and Parturient Paresis.

What is Milk Fever/Hypocalcemia/Parturient Paresis?

A condition affecting pregnant females or newly fresh females.

What causes Milk Fever?

Inadequate intake of calcium.

What other problem can contribute to Milk Fever?

The inability to mobilize calcium reserves before or after freshening.

What conditions can have symptoms similar to Milk Fever?

Toxemia can have many similar symptoms.

How does an animal with Milk Fever respond to calcium therapy?

It should respond to calcium therapy.

How can calcium be administered for Milk Fever?

It can be given subcutaneously or intravenously if the animal does not respond.

What problem can occur with subcutaneous calcium injections?

The injection site is sensitive to abscesses.

When should calcium be given intravenously?

If the animal does not respond to subcutaneous calcium.

What should be considered if an animal does not respond to calcium therapy?

Assume toxemia and drench/consider inducing.

What is metabolic acidosis also called in the slides?

Grain overload.

What type of sheep are commonly affected by metabolic acidosis?

Sheep fed diets containing a high percentage of grain, especially feedlot lambs.

What causes metabolic acidosis?

Ingestion of toxic amounts of highly fermentable carbohydrates.

How quickly can changes begin after grain overload?

Within 2–6 hours.

What bacteria rapidly increase after grain overload?

Gram-positive bacteria, especially Streptococcus bovis.

What do the increased bacteria produce?

Large amounts of lactic acid.

What happens to rumen pH during metabolic acidosis?

Rumen pH falls below 5.

What happens to rumen microflora during metabolic acidosis?

The low pH destroys rumen microflora, including organisms that use lactate.

What happens to rumen motility during metabolic acidosis?

Rumen motility is impaired.

What happens when lactobacilli use the carbohydrate?

They produce excessive amounts of lactic acid.

How does lactic acid affect the blood?

Lactic acid is absorbed into the blood, causing lactic acidosis and acidemia.

What are possible results of severe metabolic acidosis?

Dehydration, cardiovascular collapse, renal failure, muscular weakness, shock, and death.

What are common symptoms of metabolic acidosis?

The animal lays down, is listless, goes off feed, has shallow and rapid respiration, and may have diarrhea.

What does diarrhea associated with metabolic acidosis look and smell like?

It may be yellow or tan with a sweet/sour odor.

What is one treatment listed for metabolic acidosis?

Drench with 1 pint of water containing 2 tablespoons of baking soda.

What other treatments are listed for metabolic acidosis?

Pepto-Bismol or activated charcoal, penicillin, Banamine, IV fluids, and rumen microorganisms such as Probios or a rumen transfusion.