The effect of epidurally administered dexamethasone with lignocaine for post-operative analgesia in dogs undergoing ovariohysterectomy. A dose-response study

Abstract Purpose: To evaluate the postoperative analgesic and adverse effects of three doses of dexamethasone, administered epidurally in combination with lignocaine, in dogs undergoing ovariohysterectomy (OVH). Methods: Twenty-four female dogs undergoing ovariohysterectomy were pre-medicated with acepromazine and general anaesthesia was induced and maintained with propofol. Animals were randomly allocated into four groups of six. The control group was given lignocaine 2% (LI) and the treatment groups were given lignocaine with either 2 mg dexamethasone (LIDEX2), 4 mg dexamethasone (LIDEX4) or 8 mg dexamethasone (LIDEX8) administered at the lumbosacral epidural space. Duration of postoperative analgesia, first analgesic rescue, motor blockade, heart rate, blood pressure, respiratory rate, and rectal temperature were evaluated. Results: The duration of postoperative analgesia was 19.5 (SD 6) hours for LIDEX8 (p=0.001), 10 (SD 2) hours for LIDEX4 (p=0.002), 4 (SD 2) hours for LIDEX2 (p=0.074) treatments compared with values for the LI control treatment 2.2 (SD 1.6) hours. All treatments had significant cardiovascular and respiratory alterations but they were within acceptable range in these clinically healthy female dogs. Conclusion: Dexamethasone added to epidural lignocaine significantly extends the postoperative analgesia after ovariohysterectomy in female dogs.

Comparison between two different experimental models of osteoarthritis in rabbits. Intra-articular collagenase injection and anterior cruciate ligament transection

ABSTRACT PURPOSE: To compare two different experimental models of osteoarthritis in rabbits: intra-articular collagenase injection and anterior cruciate ligament transection. METHODS: Ten adult rabbits were randomly divided in two groups: COLL (collagenase group) and ACLT (anterior cruciate ligament transection). The COLL group was treated with 0.5 ml collagenase solution (2mg collagenase/0.5 ml sterile PBS), and the ACTL group was subjected to anterior cruciate ligament. After six and twelve weeks, respectively, the animals in the COLL and ACTL groups were euthanized. The gross appearance and histological examinations conducted in the cartilage articular surface was blindly scored according to the criteria developed by Yoshimi et al. (1994) and Mankin et al. (1971), respectively. RESULTS: The gross morphologic observation, macroscopic score and histological examinations have demonstrated that the ACTL group presented the highest scores, and lesions more severe than those in the COLL group. CONCLUSIONS: Both methods, anterior cruciate ligament transection and collagenase, applied to the stifle joint of the rabbits have effectively induced degenerative changes in the cartilage tissue, through statistically significant analysis (p≤0.05). The ACTL method has presented more severe lesions.

Effects of epidural nalbuphine on intraoperative isoflurane and postoperative analgesic requirements in dogs

To measure the change in the minimum alveolar concentration of isoflurane (EtISO) associated with epidural nalbuphine and the postoperative analgesic requirements in dogs after ovariohysterectomy. METHODS: Twenty four healthy female dogs were randomly assigned to receive saline or nalbuphine at 0.3 or 0.6 mg/kg (n=8 for each group) administered via lumbosacral epidural catheter introduced cranially into the epidural canal. Changes in heart and respiratory rates and arterial blood pressure during surgery were recorded along with the corresponding EtISO. Immediately after tracheal extubation, analgesia, sedation, heart rate, respiratory rate, and arterial blood pressure were measured at predetermined intervals and every 60 min thereafter until the first rescue analgesic. RESULTS: A significant decrease in EtISO was associated with epidural nalbuphine at 0.3 mg/kg (26.3%) and 0.6 mg/kg (38.4%) but not with saline in ovariohysterectomized dogs. In the postoperative period, VAS and Colorado analgesic scores were lower for the dogs that received the higher nalbuphine dose, which only required supplemental analgesia 10 h following its administration, compared with dogs that received the lower dose. CONCLUSION: Epidural nalbuphine significantly reduces the intra-operative isoflurane requirement and provides prolonged postoperative analgesia after ovariohysterectomy in dogs.

Comparative study between fibrin glue and platelet rich plasma in dogs skin grafts / Estudo comparativo entre a cola de fibrina e o plasma rico em plaquetas em enxertos cutâneos em cães

PURPOSE: Compare fibrin glue (Tissucol®) and platelet-rich plasma in full-thickness mesh skin grafts in dogs. METHODS: Eighteen dogs were used, divided into two groups: fibrin glue (FG) and platelet-rich plasma (PRP). In all the animals, a full-thickness 3x3 cm mesh skin graft was implanted. In the left limb, the biomaterial was place between the graft and the receptor bed, according to the group, while the right limb served as the control group. All the animals were evaluated clinically every 48 hours until the 14th day, using the variables of exudation, coloration, edema and cosmetic appearance. Three animals were evaluated histologically, on the third, seventh and tenth postoperative days, using the variables of fibroblasts, collagen, granulation tissue, microscopic integration-adherence and acute inflammation. RESULTS: Clinical evaluations showed that the group CF showed better scores for all variables compared to PRP group. On the histological evaluations PRP group had a higher presence of fibroblasts in the seventh and fourteenth days. CONCLUSION: The fibrin glue group was clinically superior to the platelet-rich group when used on full-thickness skin grafts in dogs.

OBJETIVO: Comparar a cola de fibrina (Tissucol®) e o plasma rico em plaquetas em enxertos cutâneos de espessura completa em malha em cães. MÉTODOS: Foram utilizados 18 cães, distribuídos em dois grupos, cola de fibrina (CF) e plasma rico em plaquetas (PRP). Em todos os animais foi realizado um enxerto cutâneo de 3x3 cm, em malha de espessura completa. No membro esquerdo foi colocado o biomaterial entre o enxerto e o leito receptor, cada qual em seu grupo, o membro direito serviu como grupo controle. Todos os animais foram avaliados clinicamente a cada 48 horas até o décimo quarto dia, através das variáveis: exsudação, coloração, edema e aspecto cosmético; histologicamente em três animais, no terceiro, sétimo e décimo quarto dia de pós-operatório através das variáveis: fibroblastos, colágeno, tecido de granulação, integração-aderência microscópica e inflamação aguda. RESULTADOS: Avaliações clínicas demonstraram que o grupo CF apresentou melhor escores em todas variáveis quando comparado com o grupo PRP. Nas avaliações histológicas o grupo PRP apresentou maior presença de fibroblastos ao sétimo e décimo quarto dia. CONCLUSÃO: A cola de fibrina foi clinicamente superior ao grupo plasma rico em plaquetas quando usados em enxertos cutâneos de espessura completa em cães.