Influence of intravenous fentanyl or dexmedetomidine infusions, combined with lidocaine and ketamine, on cardiovascular response, sevoflurane requirement and postoperative pain in dogs anesthetized for unilateral mastectomy

OBJECTIVE

To compare the effects of constant rate infusions (CRI) of fentanyl or dexmedetomidine, combined with lidocaine and ketamine, on cardiovascular response during surgery, sevoflurane requirement and postoperative pain in dogs undergoing mastectomy.

STUDY DESIGN

Prospective, randomized, blinded, clinical trial.

ANIMALS

A total of 29 female dogs with mammary tumors.

METHODS

Premedication consisted of intramuscular acepromazine and morphine. General anesthesia was induced with intravenous propofol and maintained with sevoflurane. Dogs were randomized to be administered intravenous DLK [dexmedetomidine 1 μg kg-1 loading dose (LD) and 1 μg kg-1 hour-1; lidocaine 2 mg kg-1 LD and 3 mg kg-1 hour-1; ketamine 1 mg kg-1 LD and 0.6 mg kg-1 hour-1; n = 14] or FLK (fentanyl 5 μg kg-1 LD and 9 μg kg-1 hour-1; same doses of lidocaine and ketamine; n = 15) during anesthesia. Cardiorespiratory variables and end-tidal sevoflurane (Fe'Sevo) were recorded during surgery. The number of dogs administered ephedrine to treat arterial hypotension [mean arterial pressure (MAP) < 60 mmHg] was recorded. Meloxicam was administered to both groups. Postoperative pain and rescue analgesia requirement were assessed for 24 hours using the short form of the Glasgow Composite Measure Pain Scale. Data were compared using a mixed effects model or a Mann-Whitney test.

RESULTS

More dogs required ephedrine in FLK than in DLK (67% versus 7%). Heart rate was not significantly different between groups, whereas lower values of MAP (p ≤ 0.01) and Fe'Sevo (p = 0.018) were observed in FLK than in DLK. Rescue analgesia was administered to 2/15 dogs in FLK and 0/14 dogs in DLK.

CONCLUSIONS AND CLINICAL RELEVANCE

Based on the cardiovascular response during surgery, intraoperative infusions of FLK and DLK provided adequate antinociception. Infusion of DLK provided greater stability of blood pressure. Both protocols resulted in minimal need for additional analgesia within 24 hours postoperatively.

Physical activity measured with an accelerometer in dogs following extracapsular stabilisation to treat cranial cruciate ligament rupture

OBJECTIVES

To quantify the physical activity levels in dogs with cranial cruciate ligament rupture before and after lateral fabellar suture stabilisation surgery.

MATERIALS AND METHODS

Seventeen dogs (mean weight, 12.3±5.1 kg) with unilateral cranial cruciate ligament rupture were fitted with an accelerometer for seven consecutive days at four different time points: before surgery (T0), one (T1), three (T3) and six (T6) months after surgery. The total activity and times spent in sedentary activity, light to moderate activity and vigorous activity were recorded by the accelerometer, and preoperative and postoperative data were compared. At all time points, dogs underwent clinical evaluations (lameness score, stifle pain score and thigh circumference) and their owners were asked to respond to questionnaires to subjectively score the physical activity and quality of life of the dogs.

RESULTS

At the four time points, the dogs spent between 21.2 and 21.4 hours on sedentary behaviour, 2.3 and 2.5 hours performing light to moderate activity, and 13 to 15 minutes performing vigorous activity. There was no increase in physical activity variables or decrease in sedentary behaviour over time. Lameness scores, pain score and dogs' quality of life improved significantly during the postoperative period. At T6, 17 (100%) of 17 dogs presented no lameness, 16 (94%) of 17 dogs presented no stifle pain, 16 (94%) of 17 owners rated the quality of life as very good and excellent, and 16 (100%) of 16 owners reported a total return to normal activity levels.

CLINICAL SIGNIFICANCE

The clinical recovery after extracapsular stabilisation of the stifle joint was not associated with a spontaneous increase in physical activity or a decrease in sedentary behaviour.

Influence of Constant Rate Infusions of Fentanyl Alone or in Combination With Lidocaine and Ketamine on the Response to Surgery and Postoperative Pain in Isoflurane Anesthetized Dogs Undergoing Unilateral Mastectomy: A Randomized Clinical Trial

The aim of this study was to compare the effects of constant rate infusions (CRI) of fentanyl alone or combined with lidocaine and ketamine (FLK), on physiological parameters, isoflurane requirements and the number of postoperative analgesic rescues in dogs undergoing unilateral mastectomy. Twenty-two dogs were premedicated with acepromazine 0.02 mg/kg and morphine 0.5 mg/kg and anesthetized with propofol and isoflurane. Dogs were randomly assigned to 1 of 2 groups: Fentanyl group (fentanyl 5 µg/kg loading dose [LD] and 9 µg/kg/h CRI; n = 11); FLK group (fentanyl [same doses]; lidocaine 2 mg/kg LD and 3 mg/kg/h CRI; ketamine 1.0 mg/kg LD and 0.6 mg/kg/h CRI; = 11). Intraoperative evaluations were performed before the start of surgery and administration of the treatments (T0); three minutes after the LD (T1); during incision and tissue divulsion (T2); during closure of the surgical wound (T3). Meloxicam (0.1 mg/kg) was administered at T3. Blood samples were collected for determination of plasma concentrations of fentanyl, lidocaine and ketamine. Pain scores and the number of postoperative analgesic rescues with morphine (0.5 mg/kg) were evaluated for 24 hours postoperatively using the short form of the Glasgow Composite Measure Pain Scale. Compared to T0, significant decreases in heart rate (from 84 ± 28 to 53 ± 16 bpm in the Fentanyl group and from 93 ± 16 to 63 ± 15 bpm in FLK) and mean arterial pressure (from 61 ± 5 to 49 ± 10 mmHg in Fentanyl and from 59 ± 3 to 38 ± 6 mmHg in FLK) were observed at T1. Arterial hypotension was transient, with normalization of values at T2 and T3. The expired fraction of isoflurane did not differ significantly between the groups. Plasma concentrations of fentanyl, lidocaine and ketamine remained within the therapeutic range. Postoperatively, the number of dogs requiring analgesic rescue was significantly lower in the FLK (0/11, 0%) than in the Fentanyl group (5/11, 45%). In dogs administered morphine and meloxicam as part of the anesthesia protocol, an intraoperative CRI of FLK abolished the requirement for postoperative analgesic rescue for 24 hours in dogs undergoing mastectomy.

Musladin-Lueke Syndrome in a Dog: Case Report

The aim of this study is to report the case of a 4-month-old Beagle dog diagnosed with Musladin-Lueke syndrome. The dog appeared to walk on the digits ("tiptoes") with all limbs during ambulation and rigid extension of the carpus, elbow, tarsus, and knee joints during ambulation. Thickening of the fur and auricular cartilage, reduction in radiocarpal, and tibiotarsal joint amplitude, macrocephaly, and lateralized eyes were noticed on physical examination. Echocardiography showed reduced mobility and altered (tortuous) valve morphology. Bilateral abdominal cryptorchidism was confirmed by ultrasonography. Musladin-Lueke syndrome was the presumptive diagnosis, based on the clinical signs presented. The diagnosis was confirmed after DNA testing performed by serial collection of saliva. This is the first paper that describes unprecedented cardiac and reproductive changes of Musladin-Lueke syndrome in which the dog was followed for 2 years, presenting a good quality of life.

Causes of death in neotropical primates in Rio Grande do Sul State, Southern Brazil

BACKGROUND

Anthropogenic disturbances are the main threats to nonhuman primates conservation, and infectious diseases may also play a key role in primate population decline. This study aimed to determine the main causes of death in neotropical primates.

METHODS

A retrospective study of post-mortem examinations was conducted on 146 neotropical primates between January 2000 and December 2018.

RESULTS

Conclusive diagnoses were obtained in 68.5% of the cases, of which 59 corresponded to non-infectious causes and 41 to infectious diseases. Trauma was the main cause of death (54/100), with anthropogenic stressors caused by blunt force trauma injuries (collision with vehicles) and puncture wound injuries associated with interspecific aggression (dog predation) were the most common factors. Other causes of death included bacterial diseases (27%), followed by parasitic diseases (12%), neoplasms (2%), and viral diseases (2%).

CONCLUSIONS

Free-ranging primates were mostly affected by non-infectious causes, while captive primates were by infectious conditions.

Mucinous Rectal Adenocarcinoma in a Urutu Snake (Bothrops alternatus)

A 15-year-old captive female Urutu snake (Bothrops alternatus) was presented with anorexia, apathy, dehydration, pale mucous membranes and marked enlargement of the caudal third of the coelomic cavity. Radiographs and ultrasonography were suggestive of faecal impaction or neoplasia. Post-mortem findings consisted of solid faecal impaction of the intestines, secondary to obstruction caused by a rectal tumour. Cytological examination of impression smears of the tumour revealed polygonal to round neoplastic cells arranged in clusters in an abundant extracellular mucinous matrix. Histologically, there was transmural growth of neoplastic epithelial cells arranged in small nests or individually and immersed in abundant extracellular mucin lakes. The neoplastic cells were immunopositive for cytokeratin. Clinical and pathological aspects indicated a diagnosis of mucinous rectal adenocarcinoma.

Total intravenous anesthesia in domestic chicken (Gallus gallus domesticus) with propofol alone or in combination with methadone, nalbuphine or fentanyl for ulna osteotomy

OBJECTIVE

To compare the propofol infusion rate and cardiopulmonary effects during total intravenous anesthesia with propofol alone and propofol combined with methadone, fentanyl or nalbuphine in domestic chickens undergoing ulna osteotomy.

STUDY DESIGN

Prospective, randomized, experiment trial.

ANIMALS

A total of 59 healthy Hissex Brown chickens weighing 1.5 ± 0.2 kg.

METHODS

Anesthesia was induced with propofol (9 mg kg^-1) administered intravenously (IV) and maintained with propofol (1.2 mg kg^-1 minute^-1) for 30 minutes. Birds were intubated and supplemented with 100% oxygen through a nonrebreathing circuit under spontaneous ventilation. Thereafter, each animal was randomly assigned to one of four groups: group P, no treatment; group PM, methadone (6 mg kg^-1) intramuscularly (IM); group PN, nalbuphine IM (12.5 mg kg^-1); and group PF, fentanyl IV (30 μg kg^-1 loading dose, 30 μg kg^-1 hour^-1 constant rate infusion). During the osteotomy surgery, the propofol infusion rate was adjusted to avoid movement of birds and provide adequate anesthesia. Pulse rate, invasive blood pressure, respiratory frequency, end-tidal carbon dioxide partial pressure (Pe'CO₂) and hemoglobin oxygen saturation (SpO₂) were recorded.

RESULTS

Data were available from 58 chickens. The mean ± standard deviation propofol infusion rate (mg kg^-1 minute^-1) for the duration of anesthesia was: group P, 0.81 ± 0.15; group PM, 0.66 ± 0.11; group PN, 0.60 ± 0.14; and group PF, 0.80 ± 0.07. Significant differences were P versus PM (p = 0.042), P versus PN (p = 0.002) and PF versus PN (p = 0.004). Pulse rate, blood pressure and SpO₂ remained acceptable for anesthetized birds with minor differences among groups. Values of Pe'CO₂ >60 mmHg (8 kPa) were observed in all groups.

CONCLUSIONS AND CLINICAL RELEVANCE

Methadone and nalbuphine, but not fentanyl, decreased the propofol infusion rate required for anesthesia maintenance, but resulted in no obvious benefit in physiological variables.

Surgical management of long bone fractures in cats using cortical bone allografts preserved in honey

This report describes comminuted fractures in 2 cats repaired by stabilization with cortical bone allografts that had been preserved in honey. Both cats exhibited appropriate post-operative weight-bearing. Preservation of bone in honey is a simple and widely available alternative for bone banking. This is the first report of a bone defect in cats repaired with bone preserved in honey.

Osteitis fibrosa cystica in a domestic young cat

CASE SUMMARY

A 4-month-old cat had bilateral swellings of the mandible, maxilla, humerus and femur, and angular deviations in the axial and appendicular skeleton. The biochemical profile indicated hypercalcemia, hyperphosphatemia and increased parathyroid hormone levels. Because of the poor prognosis, the cat was euthanized. At necropsy, malleable and fragile bones, associated with numerous cystic areas containing yellowish and translucent liquid, were observed. Histologically, the bones showed marked diffuse proliferation of fibrous connective tissue, and large numbers of osteoclasts surrounding numerous cystic structures were also observed within fibrotic areas at the periphery of the trabecular bone. In addition, enlargement of the parathyroid glands, which was associated with increased serum concentrations of calcium, phosphorus and parathyroid hormone, was detected.

RELEVANCE AND NOVEL INFORMATION

The changes observed in this cat are consistent with hyperparathyroidism-associated osteitis fibrosa cystica, which is an unusual presentation in the cat. Hyperparathyroidism, either primary (neoplastic) or secondary (nutritional or renal), is the primary cause of this condition.

Nitric oxide and reactive species are modulated in the polyphenol-induced ductus arteriosus constriction in pregnant sheep

OBJECTIVE

Because we have previously demonstrated the relation between polyphenol-rich foods (PRF) consumption and ductus arteriosus constriction, in this work, pregnant sheep were submitted to oral PRF intake for 14 days to understand how this process occurs. Fetal Doppler echocardiography, oxidative and inflammatory biomarkers and total polyphenol excretion were evaluated.

RESULTS

The high polyphenol intake induced ductus arteriosus constriction by 71.6% increase in systolic (P = 0.001) and 57.8% in diastolic velocities (P = 0.002), and 18.9% decrease in pulsatility index (P = 0.033), along with 1.7-fold increase in total polyphenol excretion, 2.3-fold decrease in inflammatory mediator nitric oxide and following redox status changes (mean ± standard deviation): higher protein carbonyls (1.09 ± 0.09 and 1.49 ± 0.31), catalase (0.69 ± 0.39 and 1.44 ± 0.33) and glutathione peroxidase (37.23 ± 11.19 and 62.96 ± 15.03) in addition to lower lipid damage (17.22 ± 2.05 and 12.53 ± 2.11) and nonprotein thiols (0.11 ± 0.04 and 0.04 ± 0.01) found before and after treatment, respectively. Ductal parameters correlated to NOx , catalase, glutathione peroxidase and protein carbonyl.

CONCLUSION

Our results highlight the need to reduce maternal PRF intake in late pregnancy to prevent fetal duct constriction through NO-mediated vasoconstrictive action of polyphenols.

Detection and characterization of fibropapilloma associated herpesvirus of marine turtles in Rio Grande do Sul, Brazil

Fibropapillomatosis (FP) is a benign tumoral disease that affects sea turtles, hampering movement, sight and feeding, ultimately leading to death. In Brazil, the disease was described for the first time in 1986. Research suggests the involvement of a herpesvirus in association with environmental and genetic factors as causal agents of FP. The objective of the present study was to detect and characterize this herpesvirus in sea turtles living in the coast of state Rio Grande do Sul (RS), Brazil. From October 2008 to July 2010, 14 turtles were observed between the beaches of Torres and Tavares, of which 11 were green turtles (Chelonia mydas) and 3 were loggerhead turtles (Caretta caretta). All turtles were young and mean curved carapace length was 37.71±7.82cm, and varied from 31 to 55cm. Only one green turtle presented a 1cm, papillary, pigmented fibropapilloma. Skin and fibropapilloma samples were analyzed by conventional and real time PCR assays to detect and quantify herpesvirus. All skin samples were negative, though the fibropapilloma specimen was positive in both tests. Viral load was 9,917.04 copies of viral genome per milligram of tissue. The DNA fragment amplified from the fibropapilloma sample was sequenced and allocated in the Atlantic phylogeographic group. This study reports the first molecular characterization of herpesvirus associated with fibropapilloma in turtles from the coast of RS.

Laparoscopic versus open splenectomy in dogs

In the last few years, the use of laparoscopy in veterinary medicine has expanded and consequently so was the need for studies that establish the advantages, disadvantages and possible complications of each procedure. The purpose of the current study was to describe a laparoscopic splenectomy technique and the alterations due to this access, and compare it to the open procedure in dogs. A total of 15 healthy female mongrel dogs were used, with mean weight of 17.4±2.5kg. The animals were distributed into three groups: Group IA of open splenectomy (laparotomy) using double ligation of the vessels of the splenic hilum with poliglicolic acid, Group IB of open splenectomy (laparotomy) with bipolar electrocoagulation of the splenic hilum, and Group II of laparoscopic access with bipolar electrocoagulation of the splenic hilum. Operative time, blood loss, size of incisions, complications during and after surgery were evaluated. Other parameters included pain scores, white blood cell (WBC) counts and postoperative serum concentrations of alanine aminotransferase (ALT), alkaline phosphatase (ALP), creatine kinase (CK), C-reactive protein (CRP), glucose and cortisol. No differences were found in the evaluation of parameters between both open splenectomy techniques employed. Laparoscopic access presented significant differences (p<0,05) when compared with open surgery: Longer operative time, smaller abdominal access, decrease in blood loss, lower concentrations of CRP, higher levels of CK and ALP, and lower scores in the pain scale. Laparoscopic surgery showed fewer complications of the surgical wound. No significant differences were observed between groups in the postoperative temperature, WBC, ALT, cortisol and glucose concentrations. In conclusion, the laparoscopic technique is useful for splenectomy in dogs, being advantageous in terms of blood loss, surgical stress and surgical wounds. However, it expends more operative time and causes transitory increase in hepatic and muscular enzymes.