Dehorning (Cornuectomy) - Dr. Brahmbhatt`s Class Handouts

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Dehorning (Cornuectomy)

Disbudding

Pros and Cons of dehorning

 PROS

CONS (dehorning)

Dangerous weapons tetanus

Damage can done by fighting

 sinusitis

Feedlots typically pay less money for horned animals

 myiasis

Can cause damage to the facilities

 Abortion

Death prolonged healing time of the resultant surgical defect regrowth of the horns (scur formation)

 Longitudinal cross-section of a horn, showing extension of the frontal sinus of the skull into the horn. Dehorning, which is performed at the base of the horn, exposes the sinus

Disbudding destroys horn cells

Surgical Removal

 Dehorning is usually performed on a conscious, sedated animal with local anesthesia for control of pain.

Cornual nerve: blocked halfway between the lateral horn base and the lateral canthus of the eye

Infratrochlear: halfway between the medial horn base and the medial canthus of the eye

Needle placement for desensitizing the cornual nerve in the bovine. The cornual nerve follows the temporal ridge to the base of the horn

Anesthesia for dehorning in the goat.

A, Needle placement for desensitizing the cornual branch of the lacrimal nerve.

B, Needle placement for desensitizing the cornual branch of the infratrochlear nerve

Dehorning

 Anesthesia

Feed and water should be withheld for 24 hrs. and 12 hrs., respectively

Xylazine 0.05 mg/lb (20 mg/ml) and butorphanol 0.05 mg/lb mixed together and given IM or IV followed by local block

 Tolazoline (reversal for xylazine) at 2 mg/lb

If general anesthesia is preferred

 ketamine and valium can be added to the below protocol by mixing ketamine and valium together 1:1 and administering 1cc/20lb of the combination IV.

 inhalation anesthesia may be used

Local block

 1 cc of 1% lidocaine or bupivicaine SQ (cornual and infratrochlear)

 lidocaine toxicity (muscular tremors, severe depression, hypotension and occasionally convulsions) avoid using more than 13cc of 2% lidocaine per 100 lb

Dehorning

1.

Surgical preparation

2.

The skin is incised approximately 1.5 cm from the base of the horn (incorporate all germinal or nonhaired epithelium in the horn removal to lessen the likelihood of regrowth or scur formation)

3. Assistant supporting the goat's head

4. Gigli wire is seated under the caudal aspect of the skin incision on one side and the horn is sawed off in a cranial direction

5. Hemostasis can be applied to control hemorrhage from the superficial temporal artery

6. Remove all blood clots and bone chips/dust from the frontal sinuses

7. Bandage (nonadherant dressing (Adaptic®) covered with antibiotic ointment): EOD – week 1; SIW until sinuses’s close

8. Flunixin should be administered for 2-3 days post-operatively and antibiotic administration is at the discretion of the surgeon. Tetanus antitoxin (500 IU) should always be given and a dose of a CD-T bacterin can also be administered to boost immunity.

Chemical Cautery

Example Procedure for Dehorning

1. 10 min before dehorning calves are sedated with xylazine (0.2 mg/kg IM).

2. Hair is clipped around each horn bud, a thin film of caustic paste (2 cm diameter) is rubbed into the scalp until each horn bud is evenly coated, and a ring of petroleum jelly is applied around the paste to prevent spreading.

3. Calves are allowed to rest sternally until recovered from sedation.

(A) Well-healed scabs after caustic paste dehorning

(B) Over-application of caustic paste can damage the calf.

Dehorning “Chiva”

Heat Cautery - Disbudding

This is he fast and almost bloodless method is popular, specially in goat kids (3-7 days)

The tip of the disbudding iron is shaped in an open circle.

When the electric disbudding iron is sufficiently heated, the tip is centered over the horn bud and applied with circular

“rocking” motion with light pressure

 circular tip of the iron should be about ¾ of an inch in diameter

8 to 15 seconds

You will see a “copper-colored" ring around the horn bud if the procedure went as it should

 http://video.google.com/videosearch?q=dehorning+goats&www_google_domain=www.google.com&hl=en

&emb=0&aq=0&oq=dehorning+goat# http://video.google.com/videosearch?q=dehorning+goats&www_google_domain=www.google.com&hl=en

&emb=0&aq=0&oq=dehorning+goat#

References

http://www.sheepandgoat.com/articles/castdoc kdisb.html

http://veterinarycalendar.dvm360.com/avhc/art icle/articleDetail.jsp?id=587158&sk=&date=& pageID=2

Review

ID - Breeds

Terminology http://quizlet.com/3852511/production-animal-finalflash-cards/

TPR of ruminants and PE

Gestation period of ruminants

Restraint

Management procedures: docking, dehorning/debudding, castration

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