D.O Kihurani

Healing of dehorning wounds

Open wound healing following dehorning using a wire saw was observed in 25 cattle aged between 1 and 5 years. Initially, there was a marked thickening of the scab over the wound as a ridge near the skin margin. A pale yellow to pink membrane then developed from the sides of the frontal sinus opening. Granulation tissue formed to fill the frontal sinus opening before healing by epithelization, followed by wound contraction. In some animals a bony horn stump projecting about 2-3 mm above the wound surface appeared which underwent osteosis; the dead bone gradually loosened and fell off during the healing process; histological sections revealed the presence of numerous osteoclasts lining the bone spicules. The presence of the frontal sinus and the stump of the horn processes left after dehorning are factors that make the healing of an open dehorning wound unique compared with other wounds.

Prognosis indicators and economic implications of advanced bovine ocular squamous cell carcinoma after radical surgery

The productive life span of animals is shortened and the carcass devalued by ocular squamous cell carcinoma. This causes remarkable economic losses in the cattle industry, particularly because the disease is most common at the peak of production (Farris and Fraunfelder 1976; Cordy 1978). The carcinoma lesion initially involves the third eyelid, then spreads to the globe (Fox 1963), the eyelids (Spradbrow and Hoffmann 1980), and even the orbital bones (Brier, Kleinschuster, and Corbett 1979). In most cases, squamous cell carcinoma does not involve the orbit, but when it does, the prognosis is extremely guarded (Rebhun 1979). For such cases it is recommended that the animal be destroyed because effective enucleation would be unsuccessful. Occasionally, the lesion spreads to the draining lymph nodes, sinuses and the brain (Brier, Kleinschuster and Corbett 1979). Ocular squamous cell carcinoma is frequently subject to physical trauma and becomes infected and even infested with fly larvae (Spradbrow and Hoffmann 1980). When neglected, the carcinoma becomes ulcerated, infected and discharges foul smelling exudate. Apart from surgical excision, most other available methods of treatment are only effective for early carcinoma lesions (Spradbrow and Hoffman 1980). However, according to Rubin (1984), excisional surgery is most successful in superficial lesions whose margins are clearly distinct and within reach. For advanced extensive carcinoma lesions, a more radical surgery involving removal of most of the ocular and adjacent tissues is advocated (Spradbrow and Hoffmann 1980), and prognosis is even better when radical surgery involves block resection including removal of draining and adjacent lymph nodes such as the parotid (Brier, Kleinschuster, and Corbett 1979). Observation has revealed that most cases are not presented for treatment until the neoplasm is quite advanced and complicated (Fox 1963). In such cases the prognosis is poor even with the most radical surgery. Due to vast economic losses encountered, this paper is intended to point out some factors of advanced ocular carcinoma, as observed in seventeen cows, that may be used in making the prognosis before surgery is attempted. This of course would minimize economic losses from surgery and post-operative complication management of ocular squamous cell carcinoma. This article therefore correlates the clinical manifestation of the carcinoma lesions with the outcome of treatment.

Alpha-2-Adrenoceptor agonists in Veterinary Practice

Since the first a2- adrenoceptor agonist xylazine (Rompun) was synthesized in 1962 in Germany, and subsequent development of others in this group, a2-adrenoceptor agonists have been used for decades for their sedative, analgesic and muscle relaxant properties in laboratory, domestic and wild animal species. Although drugs in this group induce physiologic alterations in many species whose magnitude depends on the dose, rate of administration and concomitantly administered drugs, they have proven to be safe adjunctive agents in augmenting central nervous system depression, analgesia and muscle relaxation in healthy patients. One of the more significant advances in veterinary anesthesiology during the last decade has been the utilization of antagonists for the reversal of injectable anesthetic regimens. Most notable of these is the clinical application of a2-antagonists such as yohimbine, telazoline, midazoxam, and atipamazole for the reversal of the sedative –muscle relaxant action actions induced by xylazine and other a2- adrenoceptor agonists. This advance has made the use of drugs in this group safer and they will continue to play an important role in the evolution and development of reliable synergistic receptor mediated analgesia and anesthesia. This paper looks at the role a2-adrenoceptor agonists have played and continue to play in veterinary practice. The Kenya Veterinarian Vol. 22 2001: pp. 82-90

Computer tomography: a novel diagnostic technique used in horses

In Veterinary Medicine, Computer Tomography (CT scan) is used more often in dogs and cats than in large animals due to their small size and ease of manipulation. This paper, however, illustrates the use of the technique in horses. CT scan was used in the diagnosis of two conditions of the head and limbs, namely alveolar periostitis and Navicular disease. The advantages of the technique are evident in the clarity with which the lesions are seen, as well as the precise identification of the affected tooth or bone. The Kenya Veterinarian Vol. 21 2001: pp. 32-33