PERFORMING COMMON SURGICAL SKILLS - DEHORNING #8645-C

Introduction Some animals are naturally polled, but some animals have their horns removed by mechanical or chemical means. This is called dehorning and it is a common practice among cattle, dairy goat, and show meat goat producers.

Dehorning has also been used on rhinoceroses in Zimbabwe to prevent them from becoming extinct. The dehorning did not negatively affect the rhinos and helped reduce poaching of the animals for their horns. Photo by Gary Stolz courtesy of U. S. Fish and Wildlife Service.

Because of the attractiveness of a properly trained set of horns, some purebred breeders of horned cattle do not dehorn. Photo from IMS.

However, many commercial producers prefer their cattle dehorned or bred for polled stock. Photo from IMS.

Advantages of dehorned cattle over horned cattle include: Dehorned cattle require less feeding, housing, and transporting space; Equipment for handling dehorned cattle requires fewer repairs and lasts longer;

Dehorned cattle have fewer bruises and injuries than horned cattle; Dehorned feeder cattle tend to gain faster, are quieter, and are easier to handle;

Chances of injury to livestock handlers are less with dehorned cattle; and Dehorned cattle usually bring higher prices than do horned cattle.

Age of Animal and Time to Dehorn The animal’s age is an important factor in dehorning cattle and it often determines the method used. Young animals are easier to handle than older animals and handle the after-effects of dehorning better.

Ideally, calves should be dehorned at less than one month of age. Those dehorned at more than two months of age may need at least two weeks to return to their original weight before dehorning.

The best time for dehorning is in the early spring or late fall. Ideally, dehorning should be done when the weather is cool and sunny. When performed properly the first time, the dehorning procedure does not need to be repeated.

Methods of Dehorning Chemical and mechanical dehorning are the two methods used to dehorn. The animal’s age, the size of horns, and the availability of equipment and labor determine which method is used.

Chemical Dehorning Use of chemicals to burn horn buttons and to prevent regrowth is more successful when used on 2- or 3-week old calves.

The most commonly used chemicals for dehorning are: Caustic Soda (sodium hydroxide), and Caustic Potash (potassium hydroxide). Both are available in paste and stick forms.

Apply the caustic substance with caution to prevent injury to yourself and an excessive burning sensation near the animal’s horn base. This method should be used with small, closely supervised herds.

Steps in Chemical Dehorning Step 1: Properly restrain the calf and prepare it for dehorning by clipping a circular band of hair near the base of the small underdeveloped horns or buttons.

Step 2: Wearing rubber gloves, apply a ½ inch band of petrolatum, or petroleum jelly, on the clipped area around the base of the horn. The petrolatum prevents the caustic substance from severely burning the skin and draining into the eyes.

Step 3: If using the caustic stick, wrap paper around one end of the stick and hold the stick by the paper. If using the caustic paste, use a flat piece of wood for the application.

Step 4: After moistening either the stick’s end or the horn button, apply a 1/16 inch thick layer of caustic substance on the horn button. Excessive moisture, either on the stick or horn button, causes the caustic substance to drain.

After applying the caustic substance, keep the calf away from the mother cow until the treated area hardens or dries. This will prevent the caustic substance from burning the cow’s skin and udder.

Do not allow the calf to be exposed to rain for one to two days following chemical dehorning; otherwise, the paste may run into its eyes.

Mechanical Dehorning There are several types of instruments that can be used to perform mechanical dehorning, including: Hot Iron Dehorner, Dehorning Spoon or Tube, Barnes Dehorner, Keystone Dehorner, and Dehorning Saw.

Clean and disinfect instruments used for dehorning before and after each operation. This prevents the introduction and spread of infections and contagious diseases. This is especially important in areas where anaplasmosis is prevalent or suspected.

Wash instruments in cold water to remove blood. Then, soak the clean instruments in a disinfecting solution. Good disinfectants are chlorohexadine or povidol iodine.

The type of dehorner used determines the method of handling the animal. Proper restraining methods, such as placing cattle in a squeeze chute, should be followed.

Hot Iron Dehorner The hot iron type of dehorning is practically bloodless. It works best for calves less than two months of age and with a horn less than one inch long.

There are two kinds of hot iron dehorners: Electrical dehorners – requires electricity to heat the iron; and Dehorning coppers – requires an external heat source (fire) to heat the iron.

Regardless of the type used, select a dehorner large enough to cover the horn button.

Step 1: Heat the irons to the proper temperature. Electrically heated irons maintain a constant temperature throughout the process. Externally heated irons must be continually heated to a dull red color.

Step 2: Properly restrain the animal. Step 3: Place the hot iron dehorner over the horn and hold the iron firmly against the horn base for approximately 15 seconds.

The heat destroys the horn growth cells around the base of the horn. The horn usually sloughs off in 4 to 6 weeks.

Dehorning Spoon and Dehorning Tube A dehorning spoon or dehorning tube is for use on calves less than two months of age with horns less than 1.5 inches long. At this age, the calf’s horns are still appendages and can be scooped out.

The dehorning spoon is for gouging out horns on young calves. With experience, you can do a quick and efficient job with the dehorning spoon.

A dehorning tube should fit over the horn, but also cover a 1/8 inch wide layer of skin around the horn.

Step 1: Properly restrain the animal. Step 2: Place the cutting edge straight down and over the horn. Step 3: Push and twist the dehorning tube until the skin around the horn is cut.

Step 4: Use the cutting edge of the tube to cut under the horn button and remove it.

Barnes-Type Dehorner The Barnes-type dehorner can be used on calves two months of age or older and come in two sizes. The small size is for use on 2- to 8-month old calves. The larger size is for dehorning yearlings or older cattle.

Step 1: Properly restrain the animal in such a manner that enough pressure may be applied to the head to properly use the dehorner. Step 2: Close the dehorner’s handles and fit the knives over the horn base and a narrow ring of skin.

Step 3: Use both hands to spread the handles apart quickly, thus closing the knives and removing the horn.

Keystone Dehorner Most livestock handlers prefer the Keystone dehorner because it is quick, smooth cutting, easy to use, and less painful to the animal.

Step 1: Properly restrain the animal. Step 2: Place the opened blade over the horn base to allow removal of a ½ inch ring of skin with the horn.

Step 3: Quickly close the handles, thus clipping off the horn. The deep cut destroys the modified skin cells from which the horns regrow.

Dehorning Saw Hand-operated or electric dehorning saws are for use on very large horns and for older cattle, if a possibility exists for the Keystone dehorner to crush or sliver the horn.

The electric saw dehorner is similar to a portable electric wood saw. Dehorning with this type of saw is quick, but it is expensive and also difficult to disinfect.

Only cut deep enough to remove a ring of skin to prevent horn regrowth. Administer a local anesthesia (lidocaine, available only by prescription from a veterinarian) before sawing horns, thus eliminating pain to the animal.

Preventing Excessive Bleeding To prevent excessive bleeding in cattle, never dehorn excited or hot animals. Two recommended procedures are commonly used for preventing excessive bleeding caused by mechanical dehorning.

Procedure 1: Use gauze or tissue paper and a commercial blood stopper. Fold the gauze or paper into a pad several layers thick and about 2.5 inches in diameter. After applying the blood stopper, place the pad over the wound and hold the pad in place for a short time.

Do not use a commercial blood stopper on an older animal because the opening at the horn’s base usually extends into the sinuses. The blood stopper may cause a tissue reaction, if it gets into the sinuses.

Procedure 2: Minimize bleeding in a large animal by using forceps to clamp and remove a portion of the main artery on the ventral side, or underside, of the cut. Pull the artery with the forceps until it breaks. The remainder of the artery retracts into the soft tissue, thus stopping the bleeding.

Care of Animals After Dehorning Dehorned animals should be kept in a small pasture or trap during the first week after dehorning. Observe the animals periodically for infection.

Animals tend to become wild-mannered after dehorning. To make them gentler, provide a small amount of feed to them each day while they are in the small pasture.

Newly dehorned animals should not be fed hay, because the hay may get into the sinus cavities and prevent healing of the wounds.