Signs In Cattle Research Articles

The effect of anti-inflammatory agents on the clinical expression of bovine ephemeral fever

The effect of two anti-inflammatory drugs on the development and persistence of clinical signs in cattle experimentally infected with bovine ephemeral fever (BEF) virus was investigated by their administration, either before or after the commencement of fever. A total of 16 cattle was given phenylbutazone sodium (PBZ). The drug prevented fever and other clinical signs in six cattle when given daily during the incubation period, and at 8-h intervals for 5 days when clinical disease might be expected. When treatment with PBZ was deferred until 2–4 h after the commencement o of fever, the rectal temperature returned to normal within 4 h in four of six cattle and the development of other clinical signs was suppressed. Clinical signs of ephemeral fever occurred in four untreated cattle infected at the same time. Viraemia, the development of neutralizing antibodies (at 8–11 days), resistance to subsequent challenge with BEF virus, neutrophilia, lymphopenia and a rise in plasma fibrinogen occurred in all BEF-infected animals whether treated or untreated, despite different clinical appearances. The mean peak of plasma fibrinogen in the untreated cattle was 6.9 g l −1; 3.2 g l −1 when treated 2–4 h after fever developed and 3.8 g l −1 when treated from 18-h post-infection. BEF virus was isolated from leucocytes of each of the cattle, but the frequency of isolation was lower in the treated group. The results indicate that treatment with PBZ blocked the host response which produces the clinical signs and did not have an anti-viral effect. In a similar experiment, a long-acting anti-inflammatory drug, flunixin meglumine, failed to prevent BEF or to modify the clinical signs once they had developed, except for the rectal temperature which returned to normal within 2–4 h of the administration of the drug. The efficacy of this drug was not improved by increasing the dosage to two or three times the recommended level.

Hypersensitivity in cattle after foot -and -mouth disease vaccination: response to hydroxypropylmethylcellulose

Intravenous provocation (IVP) tests demonstrated that hydroxypropylmethylcellulose (MC) was able to elicit anaphylactic signs in cattle vaccinated with foot-and-mouth disease (FMD) vaccine produced at one centre but not with similar vaccine produced at another. The former vaccine also provoked serum reagins which were demonstrated by passive cutaneous anaphylaxis (PCA) tests in goats. Reaginic sera which reacted specifically with MC were used in PCA tests to screen samples taken serially from the vaccine production lines. The reactions observed suggested that a substance with MC or similar specificity was present in the antifoaming agent routinely added to vaccines.

Role of antibody detected by the indirect fluorescent antibody test in the clinical signs of cattle infected with Theileria sergenti

1. Theileria sergenti 実験感染牛では, 抗体価がピークに達した後, 寄生率は低下し, 赤血球容積が増加した. また, 急性貧血で死亡した摘牌牛では, 抗体を検出できなかった. 2. 自然感染発病牛は発病時においても高い抗体価を有し, 回復期にはさらに上昇する傾向があった. 3. 自然感染および実験感染から, 臨床的に回復した牛に対して, 再攻撃した結果, 寄生率の上昇や貧血は認められなかった. 4. 感染耐過牛に副腎皮質ホルモンを投与した結果, 抗体価は変動しなかったが, 赤血球内寄生率は急激に上昇して発症した. 以上の結果から, T. sergenti の免疫機構に, 液性抗体が一定の役割を演じていることは明らかである. しかし再発例にみられたように, 細胞性免疫の関与も無視できない. 本論文の要旨は, 第77回日本獣医学会において報告した.

Toxicity of mould-damaged sweet potatoes (Ipomoea batatas).

THE toxicity for livestock of mouldy sweet potatoes has been recognized for several decades in the United States1 and, especially, Japan2. The few reports available describing toxic manifestations mention pulmonary oedema, emphysema and adenomatosis as characteristic disease signs in cattle involved in natural outbreaks3–5. These disease signs have also been attributed to other moulded feed products, silage and lush pasture grass6. Somewhat similar effects have been observed when large doses of tryptophan were administered to cattle7.