Meloxicam prevents COX-2-mediated post-surgical inflammation but not pain following laparotomy in mice.

BACKGROUND: Inflammation is thought to be a major contributor to post-surgical pain, so non-steroidal anti-inflammatory drugs (NSAIDs) are commonly used analgesics. However, compared to rats, considerably less is known as to how successfully these prevent pain in mice. METHODS: A fluorescent COX-2 selective probe was used for the first time to evaluate the post-surgical anti-inflammatory effects of meloxicam, and automated behaviour analyses (HomeCageScan; HCS), the Mouse Grimace Scale (MGS) and body weight changes to assess its pain-preventative properties. Groups of 8-9 BALB/c mice were subcutaneously injected with saline (0.3 mL) or meloxicam at (1, 5 or 20 mg/kg) 1 h before a 1.5-cm midline laparotomy. The probe or a control dye (2 mg/kg) was injected intravenously 3 h later. Imaging was used to quantify inflammation at 7, 24 and 48 h following surgery. HCS data and MGS scores were respectively obtained from video recordings and photographs before surgery and 24 h later. RESULTS: Post-surgical inflammation was dose dependently reduced by meloxicam; with 5 or 20 mg/kg being most effective compared to saline. However, all mice lost weight, MGS scores increased and behavioural activity was reduced by surgery for at least 24 h with no perceivable beneficial effect of meloxicam on any of these potentially pain-associated changes. CONCLUSIONS: Although meloxicam prevented inflammation, even large doses did not prevent post-laparotomy pain possibly arising due to a range of factors, including, but not limited to inflammation. MGS scoring can be applied by very naïve assessors and so should be effective for cage-side use.

Epidemiological studies of parvovirus infections in calves on endemically infected properties.

Bovine parvovirus serology and virus excretion were monitored in calves located on three endemically infected North Queensland properties. Maternally derived serum antibody to bovine parvovirus was found to have a half-life of 19 days. On all three properties, calves developed intestinal bovine parvovirus infection with seroconversion soon after weaning. This occurred more promptly where the environment was subject to heavier bovine parvovirus contamination due to management practices. The concurrent presence of moderate levels of residual serum antibody had only minor influence on the onset of the infection. On one beef cattle property, onset of intestinal bovine parvovirus infection was associated with an outbreak of post-weaning diarrhoea. Anthelmintic treatment trials indicated that this syndrome was unrelated to helminth burdens, though coccidiosis appeared responsible for occasional subsequent cases of dysentery. It was considered that bovine parvovirus may have significantly contributed to the development of the diarrhoea syndrome, in conjunction with substantial weaning stresses.