Resistance to synthetic pyrethroids in South Australian populations of sheep lice (Bovicola ovis)

SUMMARY Lice were collected from 71 flocks detected as Infested at market Inspection in 1990 and 1991, from 16 flocks where resistance was suspected and from 31 flocks from Kangaroo Island. Susceptibility to cypermethrin was measured by a treated surface technique and survival of lice at 5 ppm or greater was taken as an indication of resistance. The prevalence of resistance was 34% in louse populations from the market inspection sample, 50% in flocks in which resistance was suspected and 68% in flocks from Kangaroo Island. Most resistance factors were in the range 1 to 20 although one louse population with a resistance factor of 91 was found on Kangaroo Island.     

Effects of local anaesthesia of 4 to 8 hours duration on the acute cortisol response to scoop dehorning in calves

Objective To determine the effect of a long-acting local anaesthetic on the plasma cortisol response in calves dehorned using a scoop.
Design A physiological study with controls.
Procedure Seventy female calves, 3 to 4 months old, were divided into seven groups and dehorned by scoop with or without a long acting local anaesthetic (bupivacaine) which provides local anaesthesia for 3 to 4 h. In some treatment groups the local anaesthetic was given a second time, after 4 h, to give 8 h of anaesthesia. Blood samples were taken before and for 9 h after treatment and plasma cortisol concentrations were measured.
Results Scoop dehorning caused a marked rise in plasma cortisol concentration, which returned to pre-dehorning values after 7 h. The cortisol concentrations of calves given bupiva-caine were similar to those of control animals for 4 h after dehorning, but then a significant and protracted rise occurred, with concentrations returning to pretreatment values at about 9 h after dehorning. In calves given a second treatment of bupivacaine 4 h after dehorning, the plasma cortisol concentration remained similar to control values for 8 h after dehorning but then increased sharply.
Conclusions During its period of activity long-acting local anaesthetic prevented the rise usually seen after scoop dehorning in plasma cortisol concentrations; by inference it also alleviated the pain-induced distress caused by this procedure. However, when its effects had worn off the plasma cortisol values rose sharply indicating that animals still experienced pain-induced distress despite local anaesthetic being administered.     

Surgical management of suspected congenital luxation of the radial head in three dogs

Abstract

CASE HISTORIES: Three dogs, aged between 11 and 20 weeks, were presented with unilateral forelimb lameness, with an associated bony prominence on the lateral elbow.

CLINICAL FINDINGS AND DIAGNOSIS: Radiographs revealed a caudolateral luxation of the radial head in all cases, consistent with a diagnosis of suspected congenital luxation of the radial head. Surgical reduction and stabilisation involved open reduction of the radial head, and in two cases the use of a trans articular pin.

CLINICAL RELEVANCE: Congenital luxation of the radial head is an uncommon condition that has conflicting reports in the literature regarding its cause, heritability, breed predisposition, treatment and prognosis. The three cases here occurred in young dogs of English Bull Terrier, Jack Russell Terrier, and Staffordshire Bull Terrier breeds. Surgical reduction and stabilisation provided successful outcomes, in all cases. Only six cases of congenital luxation of the radial head managed surgically have previously been reported in the literature.     

Efficiency of inspection procedures for the detection of tuberculous lesions in cattle

The sensitivity of the abattoir inspection procedure introduced for Australian export beef in 1976 was compared to a detailed necropsy procedure for the detection of tuberculous lesions in cattle. In a sample of cattle that were reactors to the tuberculin test, abattoir inspection failed to detect an estimated 47% of cattle with lesions. The detailed necropsy examination of cattle with lesions of tuberculosis identified 21 sites of infection compared with 13 to 18 in cattle examined by routine meat inspection procedures. Of the lesions detected during detailed necropsy, 15.9% did not involve the thoracic cavity or the medial retropharyngeal lymph nodes. The failure to detect lesions during abattoir inspection has its greatest significance in an animal with a single lesion. If the 245 cattle found with single lesions during detailed necropsy had been examined by abattoir inspection using the 1976 or the 1986 procedures, 0.8 and 8.9%, respectively, of these animals would not have been detected because the diseased tissues would not have been examined. If meat inspection is to provide an effective means of monitoring the level of bovine tuberculosis during the final stages of eradication, a procedure no less sensitive than that introduced in 1976 should be used.     

Results of a survey of attitudes of dairy veterinarians in New Zealand regarding painful procedures and conditions in cattle

AIMS: To quantify the range of attitudes and perceptions of cattle practitioners to painful procedures and conditions in cattle, to identify some of the demographic factors affecting those attitudes and perceptions, and to compare results from veterinarians based in New Zealand with those from the United Kingdom (UK) and Europe.

METHODS: A questionnaire, based on one used for similar surveys in Europe, was sent to all 455 members of the Society of Dairy Cattle Veterinarians (DCV) of the New Zealand Veterinary Association. This questionnaire included a section on demographic data, e.g. gender, year of graduation, and preveterinary school background, and a section which asked the respondents to rate on a scale of 1 to 10 how painful they thought 24 procedures and conditions would be without any analgesia.

RESULTS: A total of 166 questionnaires were returned, a response rate of 37%. From the range of procedures and conditions outlined in the questionnaire, those perceived as most painful were claw amputation, then Caesarean section, followed by surgery for left-displaced abomasum (LDA). The two least painful were mastitis with milk clots only, and the effect on a calf of dystocia.

There were significant differences between the pain scores assigned by men and women and by respondents who had graduated in different decades. Female respondents and more recent graduates tended to give a higher pain score for most conditions. These effects remained, even after the potential interaction between age and gender had been assessed. The effect on pain score of either background or time spent treating cattle was much less marked than the effect of age and gender.

Overall, the results were very similar to results from similar surveys undertaken in the UK and Europe.

CONCLUSIONS: The responses to this survey indicate that, as in the UK and Europe, dairy cattle practitioners in New Zealand have a wide range of attitudes to pain in cattle. The estimates of the severity of pain were subjective, but such a survey allows the majority opinion of a considerable number of informed assessors to be quantified.

CLINCAL RELEVANCE: The wide range of results suggests that more needs to be done to disseminate up-to-date knowl- edge of pain in cattle to veterinarians to ensure they provide appropriate levels of analgesia. In particular, the baseline data from this study can be used by practitioners to identify whether they are underestimating pain in cattle and, if they are, to assess whether they are using analgesia appropriately. Additionally, this dataset provides an informed and independent assessment of the pain associated with husbandry procedures, and could be used to better guide legislation concerning pain control of such procedures.     

Systemic Concentrations of Endogenous and Exogenous FSH in Anoestrous Ewes Superstimulated with Folltropin®-V

The synchronization of follicular waves with medroxyprogesterone acetate (MAP) and oestradiol‐17β (E₂‐17β) prior to ovarian superstimilation in anoestrous ewes reduces the variability in superovulatory responses by an unknown mechanism. Follicle stimulating hormone (FSH) is a primary promoter of antral follicular development, but the relevance of circulating FSH concentrations to the superovulation performance in ewes has not been examined. Eighteen anoestrous Rideau Arcott ewes (May–June) were superovulated with Folltropin^®‐V (porcine FSH), with (n = 8; treated ewes) or without (n = 10; control ewes) a single i.m. dose of 350 μg of E₂‐17β, given on the sixth day of a 14‐day treatment with MAP‐releasing intravaginal sponges (60 mg). The superovulatory treatment, begun 6 days after E₂‐17β injection, consisted of six i.m. applications of Folltropin^®‐V given twice daily (at 08:00 and 16:00 h), followed by an i.m. injection of GnRH (50 μg). Blood samples collected every 8 h throughout the 3‐day treatment, were analysed by radioimmunoassays for concentrations of ovine and porcine FSH, using species‐specific standards and primary antibodies. Serum concentrations of oFSH were greater (p < 0.05) in the controls compared to treated ewes at 40, 64 and 72 h and the variability in mean oFSH concentrations was greater (p < 0.05) in control ewes at 40, 48, 64 and 72 h after the 1^st Folltropin^®‐V injection. There were no differences (p > 0.05) between the two groups in serum concentrations of pFSH. Significant correlations were recorded between the number of corpora lutea (CL) and oFSH concentrations at 8 h (r = 0.72, p < 0.05), 16 h (r=0.63, p < 0.05) and 64 h (r = 0.84, p < 0.01) after the 1^st Folltropin^®‐V injection. The total number of recovered embryos was positively correlated to oFSH concentrations at 56 h (r = 0.69, p < 0.05). We concluded that changes in endogenous FSH concentrations during ovarian superstimulation with pFSH might contribute to the variability in superovulatory responses in ewes.