T.A. Ngatia

Microscopic changes in infected bovine teats

Two hundred and fifty-two teats from the udder quarters of 68 dairy cows were studied by bacteriological examination of quarter milk samples and microscopic examination of the teats. Of 252 quarters, 169 teats showed inflammatory changes, while 83 were of normal appearance. The inflammatory changes consisted of either neutrophil infiltrations, mononuclear cell infiltrations and fibrosis, or a combination of these changes. The reaction was restricted to the teat cisterns and/or Fürstenbergs rosettes, but very rarely also in the teat canal. In 136 of 169 cases, the inflammatory reaction was associated with bacteria in the milk, while in 33 cases no bacteria could be recovered from milk, in spite of inflammatory changes in the teat structures. Only 36 of 83 of normal teats were bacteriologically positive.

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.

Pneumonia in goats following administration of live and heat-killed Pasteurella haemolytica

Six of 7 and 3 of 4 goats inoculated with live and heat-killed P. haemolytica (biotype-T), respectively, had pneumonia at necropsy. Clinically, the pneumonia was only detected in 8 of 9 goats with diseased lungs. One goat died of a fibrinous pneumonia which was associated with a profuse growth of both P. haemolytica (biotype-T) and P. multocida and a limited growth of Escherichia coli from the lungs. In the remaining 8 goats with lung lesions, the pneumonia was of the proliferative type, with only some showing the exudative feature. Five of these goats (including 3 controls) had bacteriologically sterile lung lesions, while the other 3 yielded P. haemolytica (biotype-T) and in one of them, chlamydia were also isolated. P. haemolytica (biotype-T) and P. multocida were isolated from 1 of 2 goats with normal lungs.

Nasal bacterial flora of clinically normal goats

An enclosed swab assembly was employed to collect nasal mucus from 45 clinically normal goats. Eleven bacterial species were isolated from their nasal cavities. Pasteurella haemolytica and Pasteurella multocida were the most important isolates.

Epidemiological, Clinical and Pathological findings of Oedema Disease of Swine in Kenya

The main epidemiological findings that were associated with oedema disease of swine were recent weaning (8-14 days), mixing of piglets from different litters, change of feed and ad libitum feeding with concentrates after weaning and high fatality rate (70%-100%) even with treatment. The consistent clinical history was sudden death of healthy piglets after weaning. The clinical manifestation was combination of the following; anorexia, staggering gait, oedema of the eyelids, dropping edematous ears, hoarse sound, tremors, paralysis and recumbency. Marked dyspnea and bluish red discoloration in some cases. The main microscopic findings were subcutaneous oedema of the head, submucosa of the stomach wall, mesentery of the spiral colon and the brain and the meninges characterized by cloudy appearance, lung congestion, edema, consolidation and collapse and excessive fluid in the serous cavities. In animals that had died suddenly there were no gross lesions at necropsy. Microscopically the main lesions in all the animals were edema in the predilection sites, interstitial pneumonia of varying degrees of severity and non-suppurative ventricular encephalitis. The histopathological lesions in the lung and the brain tissues were suggestive of a viral involvement in addition to normal E. coli toxemia. Consequently it was concluded that the etiopathogenesis of these cases of oedema disease of swine could have also involved a virus in addition to the normal E.coli toxaemia. The Kenya Veterinarian Vol. 22 2001: pp. 79-81

Arteriosclerosis and related lesions in rabbits

Eleven female rabbits, mainly of the NZW breed, aged between 1 and 3.5 years, were examined post mortem. All had originated over the years 1982 to 1987 from the same rabbitry where they had been fed on pellets from the same manufacturer. Apart from one rabbit, all had a history of progressive loss of bodily condition and six of them had also been infertile. Grossly, most of them were emaciated and their arteries were hardened. In some, hepatopathy, nephropathy and pulmonary emphysema were evident. In one case, mummified foetuses were recovered from the abdominal cavity. Microscopically, degenerative changes and calcification were found in the walls of arteries, kidneys, lungs, hearts and ovaries.