Cardiac performance in conscious healthy dogs during dobutamine infusion

The aim of this study was to determine the cardiac performance of conscious healthy dogs during stimulation with dobutamine. Eight healthy unsedated beagle dogs were used. Cardiac output was measured by the thermodilution technique and blood pressures by extravascular pressure transducers. Dobutamine challenge at a dosage ranging from 275 to 50 pg kg⁻¹ min⁻¹ -1 induced a significant rise in cardiac power index ( ), cardiac index ( ), stroke index ( ) and heart rate ( ) and a significant decrease in pulmonary vascular resistance ( ) and systemic vascular resistance ( ). The highest CPI was 2·05 times greater than its basal resting value. The CI was primarily responsible for this increase in . The si and HR contributed approximately 55 per cent and 45 per cent respectively of the maximal increase in .     

Oncocytoma in the mandibular salivary gland of a cat

A cat was referred for investigation of a soft tissue mass caudal to the left mandible. Initial investigations suggested a malignant salivary gland tumour, and the mass was removed by extracapsular resection of the mandibular gland. Histopathology showed an oncocytoma within the salivary gland. An oncocytoma is a neoplastic transformation of oncocytes. Oncocytes are cells with a small nucleus and intense eosinophilic granular cytoplasm due to numerous mitochondria, which proliferate during ageing in exocrine and endocrine glandular tissues. Physiological proliferation occurs next to oncocytosis, oncocytoma, and oncocytic carcinoma. This is the first report of an oncocytoma in a feline mandibular salivary gland, and the first report of long-term survival after surgical removal.     

Long‐term Effects of Pyrethrin and Cyfluthrin,a Type II Synthetic Pyrethroid,Insecticide Applications on Bull Reproductive Parameters

The objectives of this study were to determine effects of cyfluthrin and pyrethrin spray products, used in combination with cyfluthrin topical and ear tag applications, on bull reproductive parameters over 18 weeks. Angus or Angus x Simmental bulls were randomly assigned to one of three treatment groups: (i) no exposure to pyrethrins/cyfluthrin (CONT; n = 10), (ii) cyfluthrin ear tag and topical applications (ET; n = 10), or (iii) cyfluthrin ear tag, topical, premise spray and pyrethrin fog spray applications (ET+S; n = 8). Bull body weight was measured every 3 week, and body condition score and scrotal circumference were recorded on weeks 0, 9 and 18. Semen and serum were collected every 3 weeks for sperm evaluation and testosterone measurement, respectively. There was a treatment × week interaction (p < 0.01) for sperm with primary defects; bulls in CONT group had a greater (p = 0.01) percentage of sperm with primary defects than bulls treated with insecticides at week 18. Overall and progressive sperm motility, normal sperm morphology, secondary sperm defects and serum testosterone concentrations changed (p < 0.01) over time in all bulls; however, treatment did not affect (p ≥ 0.13) any of these parameters. There were also no treatment effects (p ≥ 0.08) on bull body weight, body condition score or scrotal circumference. The use of pyrethrin‐ and cyfluthrin‐based insecticides, regardless of application, did not negatively affect reproductive parameters in beef bulls when administered over 18 weeks.     

Rhinitis/Bronchopneumonia syndrome in Irish Wolfhounds

This study describes the clinical, immunologic, genetic, and pathologic features of Irish Wolfhounds with rhinitis/bronchopneumonia syndrome. The dogs examined were from Belgium, The Netherlands, UK, Canada, Germany, and Switzerland. Signs included transient to persistent mucoid or mucopurulent rhinorrhea, cough, and respiratory dyspnea. Radiographic, rhinoscopic, and bronchoscopic findings were variable. Analysis of ciliary ultrastructure was performed in 5 affected dogs, but no characteristic primary ciliary defects (primary ciliary dyskinesia) were detected. Serum and bronchoalveolar lavage fluid (BALF) concentrations of IgA, IgG, and IgM were determined in some affected dogs and clinically normal Irish Wolfhounds. Serum IgA concentration was below the reference range in 5 of 8 affected dogs tested, whereas BALF IgA concentration was above the normal range in 2 affected adult dogs. The CD4 to CD8 lymphocyte subset ratio (CD4:CD8) in peripheral blood was tested in 3 affected dogs and was within the normal range. BALF CD4:CD8 was tested in 1 affected dog and was higher than the normal range. Decreased neutrophil phagocytosis was observed in 1 of the 4 dogs tested. Analysis of pedigrees of the Belgian, Canadian, German, and Swiss dogs revealed common ancestry, suggesting a heritable syndrome.     

Studies on mammary blood flow during experimentalE. Coli endotoxin mastitis

The effect of intramammary (i.mam.) infusion ofEscherichia coli lipopolysaccharides (LPS) upon mammary blood flow (MBF) was studied in lactating goats using the electromagnetic flow technique. After i.mam. LPS administration mastitis, accompanied by a significant increase in MBF, occurred. This phenomenon showed two conspicuous peaks which occurred 11/2h and 8–10h after LPS administration. Other symptoms were: fever, increased heart rate, swelling and pain of the gland, increased chloride (MCl^?) and total cell count (TC) in milk. Since there was a marked coincidence between the increment stage of fever and the break-down of MBF peak I, studies were performed to evaluate the possible role of fever in this typical biphasis MBF pattern.

1. Mastitis was induced in one gland (homolateral) and MBF was recorded in the other (heterolateral) gland. During homolateral mastitis, clinical aspects, MCl^? and TC in the heterolateral gland were normal. For MBF, however, 3 types of responses could be distinguished. In 66% of the experiments (expts) there was a delayed MBF peak which coincided with MBF peak II of the homolateral mastitis gland. Furthermore, in 10% of these cases, a 1st MBF peak occurred simultaneously with MBF peak I of the homolateral gland. After tying off the vasoanastomoses between both udder halves, only the heterolateral MBF peak II persisted. In 33% no heterolateral peaks were present and in most cases a MBF decrease was observed between the 3rd and the 6th hours.
2. Large doses of prostaglandin E₂ (PGE₂) were infused intracerebroventricularly (i.c.v.) in normal, conscious lactating goats. In 58% of expts fever started quickly after infusion accompanied by a decrease in MBF. However, as soon as fever was established, MBF returned to normal and even rose above pre-infusion values.
3. The i.c.v. PGE₂ infusion was preceded (30 min) by i.mam. injection of LPS. In most expts fever appeared earlier than during mastitis control expts. Although symptoms of mastitis were observed, MBF peak I was lacking.
4. The antipyretic effects of 3 non-steroidal anti-inflammatory drugs (N.S.A.I.D.) on the biphasic MBF pattern during LPS mastitis were tested: Suprofen, Indomethacine and Flurbiprofen abolished fever, muscular shivers, myosis and tachycardia but had only little effect on the MBF pattern during LPS mastitis. MBF peak II was partially suppressed by these drugs, but most significantly by Flurbiprofen, which also delayed the appearance of MBF peak I. The latter is probably the consequence of its anti-inflammatory properties. None of these drugs could prevent the breakdown of MBF peak I.

It might be concluded that local mechanisms underlie the genesis of MBF peak I, but that in MBF peak II both systemic (e.g. fever) and local mechanisms are involved. The increment stage of fever may be responsible only to some extent for the breakdown of MBF peak I. Other factors than fever per se must be involved.     

利用Q/I测定评价一些耕作土壤的钾素状况

供试土壤按粘土矿物组成分为4组.第1组(土壤7)和第2组(土壤1,2和6)以蛭石和伊利石矿物占优势,具有较高的阳离子代换量.该类土壤,尤其是第1组土壤,具有较高的缓冲钾位势变化的能力和有效钾库;但钾的有效性却较低.相反,以高岭石为主、阳离子代换量较低的第4组土壤(土壤3,8,9和10),其钾位缓冲力和有效钾库均较低;但钾的有效性却较高.而以伊利石为主、高岭石为次的第3组土壤(土壤4和5),其钾素状况则介于上述两者之间.