Evaluation of flunixin meglumine pour-on administration on prostaglandin E2 concentration in inflammatory exudate after induction of inflammation in cattle

The effect of flunixin transdermal pour-on solution (Finadyne® Transdermal; MSD Animal Health) on prostaglandin E₂ (PGE₂) synthesis in bovine inflammatory exudate was evaluated in a tissue cage model of acute inflammation. Twelve calves were randomly allocated to two-treatment groups over two sequences. Three weeks prior to the first period, sterile hollow perforated polyethylene balls were surgically embedded in the subcutis at four distinct sites in each animal. On the first day of each period, an aseptic inflammation was induced by injecting 0.5mL of a 2% carrageenan solution into the lumen of each tissue cage. Treatment with either flunixin transdermal or negative control (NaCl) immediately followed. 0.5mL of exudate was collected prior to challenge, and at 2, 4, 8, 12, 24, 36 and 48h after challenge. Exudate PGE₂ concentrations were analyzed using ultra-high pressure liquid chromatography coupled with tandem mass spectrometry method. Mean PGE₂ concentrations were consistently lower in calves treated with flunixin transdermal than those measured in calves treated with negative control, indicating an inhibitory activity on cyclooxygenase. Inhibition was the highest at 8h after treatment, and differences with the negative control were significant at +8, 24, 36 and 48h. The flunixin transdermal formulation was effective in reducing PGE₂ concentrations in bovine exudate following an induced inflammation. Its anti-inflammatory action started in the first hours after treatment and lasted up to 48h.

First report of closantel treatment failure against Fasciola hepatica in cattle

Control of Fasciola hepatica infection in livestock is based on annual treatment using flukicides such as triclabendazole, albendazole and closantel. However, triclabendazole resistant F. hepatica populations are emerging worldwide and resistance is emerging to albendazole, whereas it has until now never been described for closantel. In Sweden, a topical formulation containing a combination of closantel and ivermectin (Closamectin Pour On) has been registered for use in cattle only since 2011. This study evaluated the efficacy of closantel against F. hepatica in naturally infected beef cattle using both coproantigen and faecal egg count reduction tests. Faecal egg counts (FEC) and coproantigen ELISA examinations were conducted in February 2014 in three beef cattle herds (A, B, C) in south-western Sweden. On each farm, 10 F. hepatica coproantigen-positive and F. hepatica egg-positive animals were allocated after 12-16 weeks of housing into groups and treated topically with a minimum of 20 mg closantel per kg body weight. Faecal samples were collected from selected animals on 0, 7 and 21 day post-treatment (PT). Based on FEC, closantel efficacy 21 days PT was 72% (95% CI: 65-77%) and 97% (95% CI: 95-98%) on farms A and B, respectively. No FEC reduction at all was observed on farm C. In total, 4, 1 and 6 animals remained coproantigen-positive at 21 days PT on farms A, B and C, respectively. Closantel treatment failure was confirmed on two of the farms. As the animals were housed 12-16 weeks before treatment and thereafter during the entire study, failure due to the presence of juvenile flukes was excluded. Although the cause of closantel failure currently remains unclear, development of resistance or/and absorption failure of topical administration should be considered. To our knowledge, this is the first report of closantel treatment failure against F. hepatica in cattle.