World Veterinarian Quiz 36

 

ANATOMY OF HORN

⇒ The cornual process of the frontal bone encloses the horn and corium of horn completely envelops the horn core and fuses with its periosteum.

⇒ The frontal sinus is continuous with horn. It is also known as flint bone.

⇒ Horn corium covers the horn core, it secrete horn shell.

⇒ Blood supply: The cornual branch of the superficial temporal artery and its satellite vein supplies horn.

⇒ Nerve supply: The cornual branch of the lacrimal nerve supplies horn. Lacrimal nerve is the branch of ophthalmic nerve, which in turn is the branch of trigeminal (fifth cranial nerve) nerve.

⇒ Interior of horn: Consists of irregular space, which is continuation of the frontal sinus.

⇒ Buffalo’s horn: Horns of buffalo are massive, angular and well developed with wider base compared to cattle. The thickness of horn increases towards apex until it becomes solid. The corium is traversed by numerous blood vessels.

SURGICAL AFFECTIONS OF HORN

1. Horn cancer

2. Fracture of the horn

3. Avulsion of horn

4. Fissure of the horn and horn core

1. HORN CANCER

⇒ Horn cancer has been defined as any granulomatous or eczematous condition at the base of the horn. Pathologically, it is regarded as typical squamous cell carcinoma with the formation of epithelial pears with keratinized area in the center. 

⇒ Bovine horn cancer, a squamous cell carcinoma of the horn mucosa is the most predominant cancerous condition affecting cattle in India.

⇒ The horn cancer is predominantly reported in bullocks, less in cows and rarely in bulls.

Etiology

⇒ The exact etiology of horn cancer is not known but following conditions are considered to predispose the animal for horn cancer viz,

⇒ Hormonal imbalance - As the disease is occasionally seen in bulls but more common in bullocks, it indicates the role of reproductive hormonal imbalance in horn cancer.

⇒ Injury to the horn inflicted by any mechanical means.

⇒ Chronic irritation at the base by flies and worms.

⇒ Initiation due to coal tar used for making the horn black.

⇒ Trauma due to chronic irritation (Rope or leather string causing a gall at the base of the horn).

⇒Solar radiation.

⇒ Painting of horn and tying of rope closely to horn might have caused horn cancer.

Stages and clinical signs of horn cancer

⇒ Different stages of horn cancer according to internal or external appearance i.e. before and after amputation of horn.

Stage - I:

⇨ Animals showed frequent shaking of head

⇨ Rubbing of horn on some object and striking it with legs

⇨ Slight bloody or slimy discharge from nostril or affected horn

⇨ Lacrimation and slightly bending of the horn.

⇨ After amputation the mucous membrane of the sinus near the base of the horn showed polyploid growth.

Stage - II:

⇨ Affected animals kept head a little lower or inclined towards the affected side indicated pain.

⇨ There is thick slimy nasal discharge of the affected side.

⇨ Affected horns bent and on percussion dull sound was noticed.

⇨ After amputation of horn, polyploidy bodies might also be found free in the sinus.

Stage – III:

⇨ During the third stage of the disease symptoms are aggravated.

⇨ Bent horn, soft swelling at base with or without wound

⇨ Automatically sloughing of horn is noticed.

⇨ Highly vascular, friable, foul smelling cauliflower like neoplastic growth is seen at the base of horn.

⇨ Affected animals show prolong sickness become weak, anemic, cachectic and finally die.

2. FRACTURE OF THE HORN

Etiology

⇨ External violence.  Usually oblique fracture and broken surface will be irregular.

Classification

⇨ Complete fracture: fracture of the horn through its full thickness.

⇨ Incomplete fractures: Only a part of horn is fractured.

⇨ Fracture near the tip of horn.

⇨ Fracture at the middle of horn.

⇨ Fracture at the base of horn. 

Clinical Signs

⇨ Broken horn

⇨ Bleeding from the open wound and from the affected side nostril.

Surgical Management 

⇨ Treatment option depends on the type of fracture 

⇨ For incomplete fractures or fracture at the tip of horn immobilization using plaster of paris, bamboo splint, metal splint is recommended.

⇨ For fractures at middle third or lower third of horn stabilization is not possible. So amputation is the only choice.

Complications

⇨ Empyema (pus) in frontal sinus.

3. AVULSION OF HORN

⇨ Separation of horny covering from the bony core.

Etiology

⇨ Direct violence such as by fighting or by blow or striking the head against a hard object.

⇨ Repeated injury by the yoke in the working bullocks causes chronic inflammation of the keratigenous membrane which leads to loosening of the sheath of the horn followed by detachment when stucking it against a fixed object.

Clinical signs

⇨ There is profuse bleeding.

⇨ Exposure of the horn core.

⇨ Maggot wound if not treated in time.

Management

⇨ Perform cornual nerve block.

⇨ Clean and disinfect the exposed horn core and cover it with bandage soaked in tincture benzoin.

⇨ Pour tincture benzoin solution directly over the bandage (Don’t remove the bandage).

⇨ Fly repellent creams should be applied to prevent maggot infestation.

Post-operative care

⇨ Antibiotics and analgesics in prescribed doses for five days.

4. FISSURE OF THE HORN AND HORN CORE

⇨ A fissure may form in the horn or horn core only or in both as a result of direct injury and appear as its parallel to its long axis. Symptoms include inflammation in affected part and when there is a fissure, blood may ooze. If it gets infected, it may become suppurative.

Management

⇨ Apply ice packs, astringent and antiseptic lotion. If the pus is present cut the horn and dress it aseptically.

Diagnosis

⇨ History and clinical signs like gradual bending of horn, foul smelling nasal discharge, growth at the base of the horn,

⇨ Percussion of the affected horn produces dull sound when compared to the resonant sound of unaffected horn.

⇨ Exfoliative cytology.

⇨ Fluorescent antibody technique.

⇨ Radiological examination.

Surgical Management (Flap method)

Restraint	:	Either in standing position or in lateral recumbency with affected horn on the upper side.
Anesthesia	:	Cornual nerve block along with sedation (Furious animal).
Site of incision	:	All around the base of horn at the level of corium.
Surgical procedures	:
⇨ First give skin incision on the frontal crest and then on nutchal crest. ⇨ Join the skin incision by circular incision around the base of the horn. ⇨ The skin is undermined sharply to prepare the dorsal and ventral flap. ⇨ Locate and ligate the cornual artery. ⇨ The horn is amputed as near to frontal bone as possible using Gigli wire saw/hexo blade/chisel. ⇨ Control the hemorrhage. ⇨ The horn core is trimmed with chisel and hammer if required to appose the skin flaps. ⇨ The wound is cleaned and the skin flaps are sutured together either with simple interrupted or vertical mattress sutures using non-absorbable suture material.  ⇨flush the frontal sinus with water again flush with normal saline

Post-operative care

⇨ Application of fly repellent surrounding the operative area.

⇨ Antibiotics, NSAID, antihistaminic for 5-7 days.

⇨ Daily antiseptic dressing of the suture line.

⇨ Fly repellent

⇨ Tie animal away from hard surfaces.

⇨ Suture removal on 12^th postoperative day.

Advice/Instruction to animal owner

⇨ Animal should be keep away from tree to avoid scratching and self-mutilation of surgical wound.