Comparison of the sedative effects of medetomidine administered intranasally, by atomization or drops, and intramuscular injection in dogs.

OBJECTIVE: To compare the sedative effects of intranasal atomization (INA) of medetomidine with intranasal drops (IND) and intramuscular (IM) injection in healthy dogs. STUDY DESIGN: Prospective, blinded, randomized study. ANIMALS: A group of 18 mixed-breed shelter-owned dogs weighing 27 ± 4.3 kg (mean ± standard deviation). METHODS: The dogs were randomly assigned to equal groups of six dogs for administration of medetomidine (40 µg kg-1) by INA, IND and IM routes. Ease of administration was evaluated using a resistance scale. Composite sedation score (CSS), heart rate (HR) and respiratory frequency (fR) were measured immediately before (T0, baseline) and after drug administration at time points 15, 45, 75 and 120 minutes. The time of onset of sedation was recorded. Ease of administration and onset of sedation were analysed by the Kruskal-Wallis and post hoc Dunn's tests. Repeated measures analysis of anova and least significant difference tests were used to analyse CSS, HR and fR over time. Tukey's post hoc test was used for time point comparisons among groups. Significance was set at p < 0.05. RESULTS: No differences were detected among groups for ease of administration (p = 0.346). CSS increased in all groups from baseline values. Onset of sedation in IM was 6.3 ± 2.0 minutes, in INA was 7.2 ± 2.5 minutes and in IND was 20.7 ± 5.4 minutes. CSS in IND was lower than in the other groups at T15 and lower than in INA at T45. CSS was not different between IM and INA. HR and fR decreased in all groups compared with respective baseline values. HR in IND was lower than in IM at T45-T120. CONCLUSIONS AND CLINICAL RELEVANCE: INA medetomidine (40 µg kg-1) can be an alternative and noninvasive route to IM injections for sedating healthy dogs. IND resulted in a slow onset of sedation.

Comparison of intranasal and intramuscular ketamine-midazolam combination in cats.

OBJECTIVE: The aim of the present study was to compare intranasal (INS) and intramuscular (IM) routes of administration of a ketamine-midazolam combination in cats. STUDY DESIGN: Randomized block design. ANIMALS: Twelve healthy mixed breed cats (six males and six females). METHODS: The drug combination was ketamine (14 mg kg(-1) ) and midazolam (0.5 mg kg(-1) ). In the IM group, drugs were injected into quadratus femoris muscle; in the INS. group, the combination dropped equally into the two nostrils. Pulse and respiratory rates, peripheral haemoglobin oxygen saturation (SpO2 ) and rectal temperature were monitored before and at intervals after drug administration. Time to onset and duration of sedation and, during recovery to head up, sternal recumbency and recovery were recorded. RESULTS: There were no significant differences between the groups in any time measured except for recovery to sternal recumbency, where time was lower in the INS than in the IM (p = 0.034). Respiratory rate was greater in the INS than in the IM group (p = 0.029), but there was no difference between groups in other physiological parameters. In both groups SpO2 was low before and fell further during sedation. CONCLUSIONS: The results substantiated that INS ketamine-midazolam can produce effective sedation in cats. CLINICAL RELEVANCE: Intranasal (INS) administration of ketamine-midazolam is atraumatic, and its use may avoid the pain of injection of ketamine combinations when this drug is used to induce sedation in cats.

A comparison of bone reconstruction following application of bone matrix gelatin and autogenous bone grafts to alveolar defects: an animal study.

The aim of this study was to compare the quantity and quality of osseous healing of bone matrix gelatin (BMG) with autogenous bone graft (ABG) in cat models. Osseous defects (5 x 5mm) were made through upper alveolar bone distal to the canines in the left and right quadrants (maxilla) in each of twelve Persian male cats and filled randomly with BMG and ABG. The repair response was examined on days 14, 28, and 56 after surgery (n=4 per bone substitute per time point). Qualitative histological and quantitative histometric analysis including percentage of new formed bone fill (BF) and density were done. The inter-treatment comparison of mean levels of BF at specific time points showed consistently greater levels within BMG treated defects and reached significance on days 14, 28, and 56 (P<0.05). Regarding bone density (BD), there was no significant difference between BMG and ABG on days 14 and 28 (P>0.05). On day 56, BD was significantly higher within BMG group (P<0.05). Intra-treatment evaluation of bone formation in each group showed that BD significantly increased during treatment (P<0.05), and BF in BMG group reached significance at every time point but in ABG group only increase from day 28 to 56 reached significance (P<0. 05). Our results support the use of BMG to treat bone defects. Clinicians might expect better clinical outcomes without the possibility of side effects and morbidity associated with the harvest of autogenous bone.

Oculocardiac reflex induced by zygomatic arch fracture in a crossbreed dog.

A 3-year-old crossbreed male dog was presented with a history of blunt facial trauma. Skull radiographs showed right zygomatic arch fracture. An electrocardiogram revealed bradycardia, first-degree atrioventricular block and QT prolongation. Standard biochemical profile including electrolytes was normal. Atropine response test (0.04 mg/kg intravenously) restored normal sinus rhythm at a rate of 140 bpm with normal QT and PR intervals. This observation is consistent with oculocardiac reflex secondary to zygomatic arch fracture.