Dexmedetomidine constant rate infusion for 24 hours during and after propofol or isoflurane anaesthesia in dogs

OBJECTIVE: To evaluate cardiovascular and respiratory effects and pharmacokinetics of a 24-hour intravenous constant rate infusion (CRI) of dexmedetomidine (DMED) during and after propofol (PRO) or isoflurane (ISO) anaesthesia in dogs. STUDY DESIGN: Prospective, randomized, cross-over study. ANIMALS: Ten healthy adult Beagles. METHODS: Instrumented dogs received a DMED-loading bolus (25 microg m(-2)) at time 0 followed by a 24-hour CRI (25 microg m(-2) hour(-1)), with PRO or ISO induction/maintenance of anaesthesia during the first 2 hours (PRO and ISO treatment groups, respectively). Cardiovascular, respiratory, blood gas, airway gas, serum chemistry variables and DMED plasma concentration data were collected at -15, 5, 15, 30, 45, 60, 90 and 120 minutes. A number of cardiorespiratory and tissue oxygenation variables were calculated from the above data. After the 2-hours of anaesthesia, heart and respiratory rates and electrocardiograms were recorded and DMED plasma concentrations were determined for up to 26 hours. RESULTS: Vasopressor effects and the decrease in heart rate (HR) and cardiac index induced by DMED were greater for PRO than ISO, but were within clinically acceptable ranges. Adequate oxygenation was maintained above the critical O(2) delivery level. The overall incidence of unfavourable arrhythmias was low and tended to vary inversely with HR. Mean DMED plasma concentration ranged from 0.23 to 0.47 ng mL(-1) for both groups during the 24-hour CRI with a mean elimination half-life of approximately 0.46 hour. CONCLUSION AND/CLINICAL RELEVANCE: DMED CRI resulted in typical alpha(2)-agonist induced haemodynamic changes with minimal respiratory effects, and appeared to be an efficacious adjunct during and after PRO or ISO anaesthesia in healthy dogs.     

Comparative short-term efficacy of Oridermyl? auricular ointment and Revolution? selamectin spot-on against feline Otodectes cynotis and its associated secondary otitis externa

The efficacy of Oridermyl^® (acaricidal/antibiotic/antifungal/anti-inflammatory ointment) and Revolution^® (selamectin spot-on) was compared in a blinded randomized study on 24 adult cats with otoacariasis. Twelve cats were treated once daily for 10 d with Oridermyl^® and 12 cats were treated on Day 0 with Revolution^®. Otitis was assessed with cytological counts of mean number of bacteria and yeast on Days 0 and 10, and scored clinically every other day. All auricular secretions were removed for mite count on Day 10. On Day 0, cytological examination confirmed the presence of secondary bacterial (24/24) and fungal (21/24) infections. No live mites were observed otoscopically after Day 4 and in auricular secretions at Day 10 in both groups. On Day 10, secondary infections were resolved for all cats treated with Oridermyl^® but were present in all cats treated with Revolution^®. Improvement in clinical signs of otitis over time was superior in the Oridermyl^® group (P < 0.001).     

The Impact of Egg Ozonation on Hatching Success,Larval Growth,and Survival of Atlantic Cod,Atlantic Salmon,and Rainbow Trout

The direct exposure of fish eggs to ozonated water has generated interest as a means of ensuring pathogen-free eggs without the use of harsh chemicals. However, there are numerous knowledge gaps, including safe contact times, exposure levels, and potential long-term effects on aquaculture species in both freshwater and seawater. The effect of different ozone (O₃) doses (0.5–1.0, 1.5–2.0, and 2.5–3.0 mg of O₃/L for 90 s) on recently fertilized eggs of Atlantic Cod Gadus morhua and eyed eggs of Atlantic Salmon Salmo salar and Rainbow Trout Oncorhynchus mykiss was evaluated in comparison with the effects of two commercial disinfectants: Perosan (0.004 mg/L) and Ovadine (100 mg/L). The impact of ozone application was evaluated based on hatching success, larval nucleic acid concentration, larval growth, and survival. Overall, results indicated that ozonation of Atlantic Cod eggs at a dose less than 3.0 mg/L for 90 s produced no negative effect on the larvae up to 30 d posthatch. Furthermore, ozonation of Atlantic Salmon and Rainbow Trout eggs generated no negative effect on the larvae, based on monitoring until 85% yolk sac re-absorption (16 d posthatch).

Received May 6, 2014; accepted October 24, 2014     

An investigation of Leishmania spp. in Didelphis spp. from urban and peri-urban areas in Bauru (São Paulo, Brazil)

Blood and bone marrow samples were taken from 112 Didelphis spp., collected between March 2005 and February 2006, from urban and peri-urban areas of Bauru, São Paulo State, Brazil, to evaluate the hypothesis that these animals might constitute a reservoir of Leishmania spp. Anti-Leishmania ssp. antibodies were screened in the serum samples using an enzyme-linked immuno-sorbent assay (ELISA) and the polymerase chain reaction (PCR). PCR was performed on fragments of DNA samples from Leishmania spp. using primers 13A and 13B, and showed a positive outcome in 91.6% of the 112 samples tested. Of the 107 samples analyzed by ELISA, 71% were positive. Evidence of epidemiological risk factors such as a circulating parasite and freely moving vectors suggests that Didelphis spp. may participate in the transmission cycle of Leishmania spp. in Bauru.     

Evaluation of an in-office allergy screening test in nonatopic dogs having various intestinal parasites

An in-office allergy screening kit was evaluated in 10 dogs that had no clinical signs of atopy but had various intestinal parasites. All 10 dogs had a positive reaction to the dust mite Dermatophagoïdes farinae, and four dogs had positive reactions to at least one other group of allergens. The kit as presently marketed gives numerous false positive results in parasitized nonatopic dogs.     

Oral administration of yeast, Saccharomyces cerevisiae, enhances the cellular innate immune response of gilthead seabream (Sparus aurata L.)

The effects of including lyophilised whole yeast, Saccharomyces cerevisiae, in the diet on the seabream innate immune response were investigated. Gilthead seabream (Sparus aurata L.) specimens were fed four different diets for 4 weeks: a commercial diet as control and the same diet supplemented with 1, 5 or 10 g/kg yeast. After 1, 2 and 4 weeks, serum complement titres, as a humoral parameter, and phagocytic, respiratory burst, myeloperoxidase and natural cytotoxic activities of head-kidney leucocytes, as cellular parameters, were evaluated. The results showed that yeast supplements enhanced all the latter responses, but not the humoral response. This enhancement was dose-dependent except for the cytotoxic activity that was only stimulated by the lower dose of yeast assayed. As yeast cell walls are able to enhance the seabream cellular innate immune response, these results support the possible use of whole yeast as natural inmunostimulants in common fish diets.     

Audiograms estimated from brainstem tone-evoked potentials in dogs from 10 days to 1.5 months of age

The objective of this study was to build audiograms from thresholds of brainstem tone-evoked potentials in dogs and to evaluate age-related change of the audiogram in puppies. Results were obtained from 9 Beagle puppies 10-47 days of age. Vertex to mastoid brainstem auditory-evoked potentials in response to 5.1-millisecond Hanning-gated sine waves with frequencies octave-spaced from 0.5 to 32 kHz were recorded. Three dogs were examined at 10, 13, 19, 25, and 45 days. Four other dogs were examined at 16 days. Data from 7 dogs between 42 and 47 days of age were pooled to obtain audiogram reference values in 1.5-month-old puppies. The best auditory threshold lowered from above 60 dB sound pressure level (SPL) to values close to 0 dB SPL between 13 and 25 days of age and then stabilized. The audible frequency range widened, including 32 kHz in all tested dogs from the 19th day. In the 7 1.5-month-old puppies, the mean auditory threshold decreased by 11 dB per octave from 0.5 to 2 kHz. The auditory threshold was lowest and held the same value from 2 to 8 kHz. The mean auditory threshold increased by 20 dB per octave from 8 to 32 kHz. Near threshold, click-evoked potentials test only a small part of the audible frequency range in dogs. Use of tone-evoked potentials may become a powerful tool in investigating dogs with possible partial hearing loss, including during the auditory system maturation period.