Infestation in the dog by the paralysis tick, Ixodes holocyclus — 5. Treatment

In this study the value of drugs administered with hyperimmune serum in the treatment of advanced disease produced by Ixodes holocyclus was compared under controlled conditions. All control dogs died rapidly whereas one dog survived and 3 dogs died after receiving hyperimmune serum alone. When promethazine hydrochloride was administered with hyperimmune serum 2 dogs recovered rapidly while the remaining 2 died. Administration of dexamethasone and hyperimmune serum allowed 3 dogs to survive while administration of phenoxybenzamine hydrochloride in conjunction with hyperimmune serum allowed rapid recovery of all 4 dogs. Phenoxybenzamine hydrochloride, an alpha-adrenergic blocking drug, was chosen because of its potential to attenuate the arterial hypertension previously reported (Ilkiw et al 1988). The survival of all dogs together with the rapid return to normality indicated that this drug was beneficial in the treatment of dogs with advanced signs of tick paralysis.     

Effect of Tamoxifen Citrate on Canine Immobilization (Disuse) Osteoporosis

The effect of tamoxifen citrate on bone mass in immobilization osteoporosis was studied in 11 growing dogs. Immobilization osteoporosis was induced by fiberglass cast immobilization of the right hindlimb for 28 days, while the left hindlimb served as a nonimmobilized control. Six dogs received tamoxifen citrate (1.5 mg/kg per os) once daily for 28 days; five dogs received no treatment. All dogs were euthanatized on day 28 and bone samples were collected. Bone mineral content of the distal tibial metaphysis of casted and uncasted limbs was measured by single photon absorptiometry. Immobilization resulted in a significant reduction in bone mass in the casted limb of untreated and tamoxifen-treated dogs. However, tamoxifen-treated dogs had less severe immobilization osteoporosis than untreated dogs. The calculated bone mass sparing effect of tamoxifen was 24.4%. Because of the complexity of pathologic bone remodeling, use of a single therapeutic agent may not be the optimal means of preventing bone loss associated with immobilization.     

Case Study: Chronic Erysipelas of the Sow – a Subclinical Manifestation of Reproductive Problems

Systemic infections with Erysipelothrix rhusiopathiae are usually associated with skin lesions, vegetative endocarditis and arthritis, but they can also cause reproductive symptoms such as abortion, increased stillbirths, and smaller litter size. In a large Hungarian breeding unit that had ceased to vaccinate the sows against erysipelas, an increased incidence of pre- and post-partal vulval discharge, increased weaning-to-oestrus intervals, decreased farrowing rates, and reductions in total number of pigets born and live-born litter size were reported. Anterior vaginal swabs were obtained from 64 sows shortly before parturition and they all yielded heavy growths of E. rhusiopathiae . A vaccination programme with a killed vaccine was reinstated and subsequently the incidence of vulval discharge and weaning-to-oestrus intervals were decreased and total born and live-born litter size were increased. In the absence of a control group definitive conclusions can not be made regarding the effect of vaccination against E. rhusiopathiae on sow fertility. However, it is not unreasonable to suggest that the aetiology of the reduced sow fertility in the present herd did involve E. rhusiopathiae and that appropriate vaccinations subsequently protected the sows from the disease.     

Comparison of the Fenwick can and Schuiling centrifuge methods for the extraction of potato cyst nematodes from soil1

An evaluation of the efficacy of the Schuiling centrifuge and traditional Fenwick can methods of extracting Globodera cysts from infested field soils confirmed the accuracy of the Schuiling centrifuge extraction method. Experience has shown that samples with a high organic matter content may reduce extraction efficiency. Improvements in the mechanical and electrical construction of the present Schuiling apparatus are needed, but once they have been made the choice of extraction method in large-scale statutory and advisory programmes need only depend on considerations such as convenience of use and cost-effectiveness.     

Sickness, mortality and the buller steer syndrome in a western Canadian feedlot

Objective To determine if an association existed between sickness, mortality and bullers in a western Canadian feedlot.
Design A retrospective epidemiological study.
Animals 78,445 male cattle that entered a 24,000-head feedlot in western Canada from 1991 to 1993.
Procedure Animal health records for bullers were collected and analysed to see if they were at greater risk of sickness and mortality than other steers, and to see if pens with a high prevalence of bullers also had a high prevalence of sickness and mortality.
Results The prevalence of bullers increased with increasing age of cattle on arrival at the feedlot (R = 0.36; P < 0.001). Sickness and mortality decreased with increasing age of cattle on arrival. However, sickness and mortality in bullers relative to other steers actually increased with increasing age on arrival suggesting an interaction existed between sickness and bullers. Bullers were significantly (P < 0.05) more likely to get sick and to die than other steers. In all cases, there was a strong temporal association between sickness and bullers, with sickness and bullers mostly occurring within the first 30 days of the feeding period. On average, pens of cattle with a high prevalence of bullers did not have a correspondingly high prevalence of sickness or mortality.
Conclusion This study suggests that sickness is an effect modifier of dominance behaviour and therefore bullers in feedlot steers. Bullers should always be checked for signs of sickness and treated accordingly. Further research is needed to investigate the effects of sickness on dominance behaviour in pens of feedlot cattle.     

Complexing agents as herbicide additives

In not experiments with Agropyron repens, Stellaria media and dwarf bean (Phaseolus vulgaris), several acids which are complexing agents enhanced the effects of glyphosate and dichlorprop. Both herbicides were activated by orthophosphoric citric, tartaric, lactic, oxalic and glycollic acids. Other acids which are not complexing agents had little or no effect. Sodium or ammonium salts often acted like the parent acids. Glyphosate activity was increased by EDTA while dichlorprop effects were enhanced by FDTA, NTA and polyphosphates. It is suggested that activation was due to interactions with calcium or other metallic ions, which would otherwise immobilize the herbicides. In field experiments, orthophosphoric or oxalic acids increased the effects of glyphosate on Agrophron bud viability. Ammonium sulphate had a similar effect. However, in contrast to glasshouse experiments, most three-way mixtures of an acid, ammonium sulphate glyphosate wer antagonistic. Les agents complexants en tant qu adjuvants pour les herbicides Dans des experiences en pots avec Agropyron repens, Stellariamedia et des haricots (Phaseolus vulgaris), plusieurs acides qui sont des agents complexants out augmenté l'activitié du glyphosate et du dichlorprop. Ces deux herbicides ont été activés par les acides orthophosphorique, citrique, tartrique, lactique, oxalique et glycollique. D'autres acides, qui ne sont pas des agents complexants, n'ont eu que peu ou pasd'effet. Les sels de sodium ou d'ammonium présentent souvent la méme activité que les acides don't ils dérivent. L'activite du glyphosate a été accrue par l'EDTA, cependant que les effets du dichloprop ont augmenté avec l'EDTA, le NTA et les polyphosphates. II est suggéré que cette activation était due aux interactions avec le calcium ou d'autres ions métalliques qui pourraient, par ailleurs, immobiliser les herbicides. Dans des expériences au champ, les acides orthophosphorique ou oxalique ont augmenté les effets du glyphosate sur la viabilité des bourgeons d'Agropyron. Le sulfate d'ammonium a eu en effet similaire. Toutefois, en opposition avec les expériences en serre, la plupart des mélanges ternaries d'un acide, de sulfate d'ammonium et de glyphosate se sont révélés antagonists. Komplxbildner als Additive für Herbizide In Gefässversuchen mit Agropyron repens, Stellaria media und Phasealus vulgaris wurde die Wirkung von Glyphosat und Diehlorprop durch komplexbildende Säuren verstärkt. Beide Herbizide wurden a tiviert durch: ortho-Phosphor. Zitronen, Wein, Milch-, Oxal- und Glykolsäure. Andere Säuren, die micht komplexbildend sind, wirkten nur schwach oder gar nicht. Natrium-oder Ammoniumsalze wirkten häufig wie die entsprechenden Säuren. Die Aktivität von Glyphosat wurde durch EDTA verstärkt, während die Wirkung von Dichlorprop durch EDTA, NTA und durch Polyphosphate verbessert wurde. Es wird vermutet, dass die bessere Wirkung in Interaklionen mit Kalzium oder anderern Metallionen zu suchen ist, die sonst die Herbizide immobilisieren. In Feldversuchen wurde durch ortho-Phosphorsäure und Oxalsäure die Wirkung von Glyphosat auf die Lebensfähigkeit von Agropyron-Knospen erhöht. Ammoniumsulfat wirkte ähnlich Im Gegensatz zu Versuchen im Gewächshaus wirkien aber die meisten Dreikomponenten Mischungen von Säure. Ammoniumsulfat und Glyphosat, antagonistisch     

AGROPYRON REPENS (L.) BEAUV.—SOME EFFECTS OF RHIZOME FRAGMENTATION, RHIZOME BURIAL AND DEFOLIATION

Summary. A factorial experiment with couch grass ( Agropyron repens (L.) Beauv.) grown in boxes examined the effects of rhizome fragmentation, planting depth and shoot removal on the survival of rhizome pieces, new rhizome growth and rhizome carbohydrate reserves.
Burial to 4 in. depth in sandy loam soil led to the death of 54% of 1 in. long rhizome pieces and 28% of 3 in. pieces. With all the segment lengths tested deeper planting decreased the proportion of buds which produced shoots.
Shoot removal every 14 days decreased the dry weight and carbohydrate content of the planted rhizomes and prevented new rhizome growth. Segments 1 or 3 in. long lost their carbohydrate reserves more quickly than 9 in. pieces. Rhizomes planted at 4 in. depth contained less carbohydrate after establishment than shallow-planted material, and produced less new rhizome growth.
IS Agropyron repens (L.) Beauv.–Quelques effets de la fragmentation et de l'enfouissement du rhizome et de la defoliation