Guidelines for Recognition, Assessment and Treatment of Pain

The perfusion index as a method of assessing epidural anaesthesia efficacy in healthy dogs

Introduction

Perfusion index (PI) is used as assessment of epidural anaesthesia efficacy in human medicine, but its usefulness in dogs is unknown. The aim of this study was to evaluate the usefulness of PI in determining epidural anaesthesia effectiveness.

Material and Methods

This is prospective cross-over experimental study. Five healthy adult beagle dogs were anaesthetised and an epidural catheter was inserted in the lumbosacral area and adjusted so that the end of the catheter was placed at the fourth lumbar vertebra. Single-port catheters were used in the control group and multiple-port catheters were used in the treatment group. A PI probe was placed on a hind leg, and the catheter placement was confirmed via computed tomography. The treatment group received a bolus dose of lidocaine, and the control group received saline, via epidural catheter. The PI value was recorded every 5 min until 30 min after lidocaine injection.

Results

The PIs of the hind limbs were not significantly different over time, nor were they between the control and lidocaine-injected groups at any point in time.

Conclusion

The PI is not useful in determining the efficacy of epidural anaesthesia in dogs under general anaesthesia. In the future, finding a reliable method to evaluate the success of regional anaesthesia, even in patients under general anaesthesia, will be necessary.

Assessing the Analgesic Efficacy of Lumbosacral Epidural Morphine in Cats Undergoing Ovariohysterectomy: A Comparative Study of Two Doses

Opioids are administered epidurally (PV) to provide trans- and postoperative analgesia. Twenty healthy female cats aged between 6 and 24 months and weighing between 2 and 3.7 kg, undergoing elective ovariohysterectomy (OVH), were induced with propofol (8 mg/kg), followed by continuous infusion (0.1-0.4 mg/kg/min). Three groups were defined: CG (0.1 mL/kg of iodinated contrast, n = 6), G0.1 (0.1 mg/kg of morphine, n = 7), and G0.2 (0.2 mg/kg of morphine, n = 7) per VP. All received 0.1 mL/kg of iodinated contrast per VP and injection water to obtain a total of 0.3 mL/kg. Heart rate (HR), systolic blood pressure (SBP), temperature, expired CO2, oxygen saturation, and number of rescue analgesics were monitored. Postoperatively, a multidimensional scale was used to assess acute pain in cats for 12 h. The mean HR and SBP in the CG were higher at the time of maximum noxious stimulation and required fentanyl in all groups. Postoperatively, 83%, 28%, and 7% of the animals in CG, G0.1, and G0.2, respectively, received rescue analgesia. In cats undergoing OVH, epidural morphine at doses of 0.1 and 0.2 mg/kg did not prevent the need for intraoperative rescue analgesia but reduced the postoperative analgesic needed.

Evaluation of preoperative rectus sheath block with bupivacaine for analgesia in cats undergoing ovariohysterectomy: a cadaveric and randomized clinical study

OBJECTIVE

Phase 1: to determine the feasibility of desensitizing ventral branches of spinal nerves within the rectus sheath using an ultrasound-guided rectus sheath block (USRSB). Phase 2: to determine the effect of preoperative USRSB on intraoperative responses to surgical stimulation and postoperative pain.

STUDY DESIGN

Cadaveric study and prospective, randomized, blinded, parallel-arm clinical trial.

ANIMALS

A group of five cat cadavers and 37 shelter-owned cats undergoing ovariohysterectomy.

METHODS

Phase 1: anatomical dissection was performed on one uninjected cadaver. Abdominal walls were dissected in four cadavers (eight hemiabdomens) following bilateral USRSB using 1:1 new methylene blue and 0.5% bupivacaine (0.8 mL kg-1 total). Phase 2: preoperative bilateral USRSB was performed with 0.8 mL kg-1 of 0.25% bupivacaine (RSB) or equivalent volume of 0.9% saline (CONTROL). Intraoperative systolic arterial blood pressure (SAP), heart rate (HR), respiratory rate (fR) and vaporizer setting (vap%) were recorded before skin incision, during celiotomy and abdominal wall closure. In recovery, cats were administered robenacoxib (2 mg kg-1; CONTROL) or 0.9% saline (0.1 mL kg-1; RSB) subcutaneously. Postoperative pain was evaluated for 6 hours using the Glasgow Composite Measure Pain Scale.

RESULTS

Phase 1: spinal nerves T9-L3 were identified within the rectus sheath, and stained in 0%, 40%, 63%, 75%, 100%, 88%, 50% and 13% of hemiabdomens, respectively. Phase 2: 37 cats were included (RSB, n = 17; CONTROL, n = 20). Intraoperatively, SAP, HR and fR were not significantly different between groups. Vap% was significantly lower in RSB during celiotomy (p = 0.036) and closure (p = 0.044). Postoperatively, RSB cats were 5.3 times (95% CI 1.8-8.3) more likely to require rescue analgesia than CONTROL cats.

CONCLUSIONS AND CLINICAL RELEVANCE

During surgery, USRSB with bupivacaine offered minor benefits and provided markedly less postoperative analgesia than robenacoxib, indicating that relying on USRSB provides insufficient postoperative analgesia for ovariohysterectomy in cats.

Tropane Alkaloid Isolated from Erythroxylum bezerrae Exhibits Neuropharmacological Potential in an Adult Zebrafish (Danio rerio) Model

This study carried out to investigate the anti-inflammatory and antinociceptive effect of tropane alkaloid (EB7) isolated from E. bezerrae. It evaluated the toxicity and possible involvement of ion channels in the antinociceptive effect of EB7, as well as its anti-inflammatory effect in adult zebrafish (Zfa). Docking studies with EB7 and COX-1 and 2 were also performed. The tested doses of EB7 (4, 20 and 40 mg/kg) did not show any toxic effect on Zfa during the 96h of analysis (LD50>40 mg/kg). They did not produce any alteration in the locomotor behavior of the animals. Furthermore, EB7 showed promising pharmacological effects as it prevented the nociceptive behavior induced by hypertonic saline, capsaicin, formalin and acid saline. EB7 had its analgesic effect blocked by amiloride involving the neuromodulation of ASICs in Zfa. In evaluating the anti-inflammatory activity, the edema induced by κ-carrageenan 3.5 % was reduced by the dose of 40 mg/kg of EB7 observed after the fourth hour of analysis, indicating an effect similar to that of ibuprofen. Molecular docking results indicated that EB7 exhibited better affinity energy when compared to ibuprofen control against the two evaluated targets binding at different sites in the cocrystallized COX-1 and 2 inhibitors.

The Role of the Thalamus in Nociception: Important but Forgotten

Pain is a complex response to noxious stimuli. Upon detection of the nociceptive stimulus by first-order neurons or nociceptors, an action potential ascends to the spinal dorsal horn, a crucial site for synapsing with second-order neurons. These second-order neurons carry the nociceptive stimulus to supraspinal regions, notably the thalamus. Although extensive research has focused on spinal-level nociceptive mechanisms (e.g., neurotransmitters, receptors, and glial cells), the thalamus is still poorly elucidated. The role of the thalamus in relaying sensory and motor responses to the cortex is well known. However, a comprehensive understanding of the mechanisms in the synapse between the second-order and third-order neurons that transmit this impulse to the somatosensory cortex, where the response is processed and interpreted as pain, is still lacking. Thus, this review investigated the thalamus's role in transmitting nociceptive impulses. Current evidence indicates the involvement of the neurotransmitters glutamate and serotonin, along with NMDA, P2X4, TLR4, FGR, and NLRP3 receptors, as well as signaling pathways including ERK, P38, NF-κB, cytokines, and glial cells at nociceptive synapses within the thalamus.

Comparison of Butorphanol, Methadone, and Pethidine in Combination with Alfaxalone for Premedication in Isoflurane-Anesthetized Cats Undergoing Ovariectomy

The aim of this study was to compare three different anesthetic protocols administered intramuscularly (IM) in cats undergoing elective ovariectomy, while evaluating the quality of sedation, antinociceptive, isoflurane-sparing effect, and analgesia in the intra-operative and post-operative phases. A total of 71 female cats were sedated IM with alfaxalone (3 mg/kg) combined with either butorphanol (0.3 mg/kg), methadone (0.3 mg/kg), or pethidine (5 mg/kg). During surgery, vital parameters were constantly monitored; at the end of the procedure, the quality of recovery was assessed through a specific form and each cat was scored for perceived pain using the UNESP-Botucatu scale for 5 days, and rescue analgesia was provided with buprenorphine IM when indicated. Moreover, differences between two different post-operative resting regimens (hospital kennels vs. home) were also assessed. A significant difference emerged for the amount of IM dexmedetomidine required to achieve an adequate level of sedation for intravenous catheterization, highlighting a greater need in the pethidine group (p = 0.021). There was no significant difference between opioid groups for the requirement of intra-operative rescue analgesia, and the clinical parameters were kept within physiological ranges regardless of the opioid used in premedication. Lastly, differences between the UNESP-Botucatu scores were detected from day 3 to day 5 post-operatively, with lower scores in cats with home resting regimens compared to the hospitalized animals, likely due to the presence of an unfamiliar condition and the absence of a cat-friendly environment.

Real-time and video-recorded pain assessment in beef cattle: clinical application and reliability in young, adult bulls undergoing surgical castration

Bovine pain assessment relies on validated behavioral scales related to normal and pain-related behaviors. This study investigated the reliability and applicability of real-time and video-recorded pain assessment, and their agreement, in young, adult bulls undergoing surgical castration. Ten Nelore and nine Angus bulls underwent general anesthesia and surgical castration. Three-minute real-time observations and simultaneous videos were recorded at - 48 h (M0), before sedation, under fasting (M1), after surgery, 3 h after sternal recumbency (M2), after rescue analgesia (M3) and at 24 h (M4). Animals received morphine (after M2), dipyrone (after M3), and flunixin meglumine after surgical castration (M4). Two trained evaluators assessed real-time (n = 95) and video-recorded time-points (n = 95) using the Unesp-Botucatu Cattle Pain Scale (UCAPS). Both assessment methods inferred 'very good' reliability (≥ 0.81) with minimal bias, however, video-recorded assessment (4.33 ± 2.84) demonstrated slightly higher scores compared to real-time (3.08 ± 2.84). The results from this study suggest that UCAPS can be used in real-time or video-recorded to assess pain and guide analgesic therapy in cattle.

Use of Gabapentin or Alprazolam in Cats during Postoperative, Short-Term Hospitalization

This prospective, randomized study aimed to assess the anxiolytic efficacy of gabapentin or alprazolam in cats during short-term postoperative hospitalization. Sixty cats were randomly assigned to three groups (gabapentin-treated [100 mg per cat], alprazolam-treated [0.125 mg per cat], or placebo-treated), with treatments administered twice daily for two days. Stress levels were evaluated using Cat Stress Scores, serum cortisol, and glucose concentrations. Pain scores, food consumption, and adverse effects such as sedation were also monitored. Fifty-five cats completed the study. Both medications demonstrated similar reductions in stress levels. Cats receiving gabapentin had lower pain scores, while those receiving alprazolam exhibited significantly increased food intake on the first postoperative day. However, both medications resulted in comparable levels of sedation. In the context of postoperative hospitalization, pharmacological intervention with anxiolytics could be effective in reducing stress levels. Despite potential side effects, gabapentin and alprazolam may contribute to an improved quality of short-term hospitalization for cats.

Assessment of potential maladaptive pain in dogs with elbow osteoarthritis using a von Frey aesthesiometer

BACKGROUND

This study aimed to investigate the possible presence of maladaptive pain in the thoracic limbs of dogs with elbow osteoarthritis (OA) using an electronic von Frey aesthesiometer (eVFA).

METHODS

Twenty-eight client- and staff-owned dogs (OA, n = 14; controls, n = 14) were enrolled in the study. Every dog underwent a full orthopaedic examination, and then five von Frey measurements were obtained from each carpal pad of each dog. A maximum test threshold of 400 g was set and approved by an ethics committee.

RESULTS

eVFA thresholds were significantly lower (p < 0.001) in dogs with OA (median 248 g, range 128-369 g) than in control dogs (median 390 g, range 371-400 g). In the OA group, the sensory threshold was significantly lower (p = 0.048) in the more severely affected limb than the less severely affected limb.

LIMITATION

The low maximum threshold required for ethical approval may influence the variability in the control group.

CONCLUSIONS

Dogs with elbow OA had significantly lower sensory thresholds than control dogs, which is compatible with the presence of maladaptive pain, potentially due to central sensitisation. Further research is required to evaluate the potential use of the eVFA for monitoring clinical progression and treatment response in dogs with elbow OA.

Erector spinae plane block in dogs undergoing hemilaminectomy: A prospective randomized clinical trial

OBJECTIVE

To compare the perioperative cumulative opioid consumption and the incidence of cardiovascular complications in dogs undergoing hemilaminectomy in which either an erector spinae plane (ESP) block or systemic opioids were administered.

STUDY DESIGN

Prospective randomized clinical trial.

ANIMALS

A total of 60 client-owned dogs.

METHODS

Dogs were randomized to one of three groups: an ESP block (group ESP), a constant rate infusion of fentanyl (group FNT, positive control) or a single dose of methadone as premedication (group MTD, negative control). Intraoperative nociceptive response was treated with fentanyl [1 μg kg-1, intravenously (IV)] boli. Before closure of the surgical site, morphine (0.1 mg kg-1) was applied to the dura mater. The cumulative dose of opioids was recorded and compared between groups. The incidence of intraoperative bradycardia and/or hypotension and the time to extubation were compared between groups. The short form of the Glasgow Composite Pain Scale (SF-GCPS) was used to score nociception before anaesthetic induction and 1, 2, 6, 12,18 and 24 hours postoperatively. Methadone 0.2 mg kg-1 was administered IV if the SF-GCPS score was ≥ 5.

RESULTS

Group MTD required more intraoperative rescue analgesia than groups ESP (p = 0.008) and FNT (p = 0.001). The total cumulative intraoperative dose of fentanyl was higher in groups FNT (p < 0.0001) and MTD (p = 0.002) than in group ESP. The incidence of cardiovascular complications was similar between groups. Extubation time was longer in group MTD (p = 0.03). Postoperatively, the time to first rescue analgesia was longer in group ESP than in group MTD (p = 0.03). The cumulative postoperative opioid consumption and pain scores were similar between groups.

CONCLUSIONS AND CLINICAL RELEVANCE

The ESP block resulted in a reduced intraoperative opioid consumption compared with the control positive and negative groups.

Effect of meloxicam or robenacoxib administration timing on renal function and postoperative analgesia in cats undergoing ovariohysterectomy: A randomized, blinded, controlled clinical trial

We evaluated the effect of administration timing of meloxicam and robenacoxib on renal function, platelet cyclo-oxygenase and perioperative analgesia in 60 cats undergoing ovariohysterectomy, in a prospective randomized blinded controlled study. Twelve cats were randomly allocated to one subcutaneous treatment group: meloxicam (0.2 mg/kg) or robenacoxib (2 mg/kg) at admission (MA, RA), at induction (MI, RI) and robenacoxib at the end of surgery (RE). All cats received the same anaesthesia protocol. Plasma renin activity (PRA), plasma creatinine, drug concentrations and serum thromboxane (TxB2) were measured sequentially. Anaesthesia significantly increased PRA, as activity at end of the surgery was higher than 2 h later (mean ± SD: 26.6 ± 2.8 versus 10.0 ± 3.9 ng/mL/h). PRA remained higher at 2 h post-surgery in admission groups compared to induction groups (p = .01). Serum TxB2 was lower with meloxicam than robenacoxib (p = .001), and was lower in the MA than each robenacoxib group at catheter placement. Admission groups (16/24 from RA and MA groups) received earlier rescue analgesia than other groups (p = .033). In conclusion, the renin-angiotensin system was activated during anaesthesia despite cyclo-oxygenase inhibition, possibly due to hypotension or surgical stimulation. There was no effect of drug or timing on the markers of renal function but one cat receiving meloxicam at induction had suspected IRIS grade II acute kidney injury.

Pharmacokinetics of a continuous intravenous infusion of hydromorphone in healthy dogs

Introduction

Dosing recommendations for hydromorphone intravenous constant rate infusion (IV CRI) are derived from simulations following IV bolus administration. While this extrapolated dose regimen has been described clinically, pharmacokinetics (PK) of hydromorphone infusions in dogs are not yet described. The study objective was to describe the PK of hydromorphone in healthy dogs receiving an IV bolus followed by an IV CRI for 48 h.

Methods

A prospective, experimental study was performed involving the administration of hydromorphone (0.1 mg/kg IV bolus then IV CRI 0.01 mg/kg/h over a 48 h period) to 6 healthy Beagle dogs. Blood samples were collected at 16 time points between 0 and 58 h relative to the initial bolus. Plasma hydromorphone concentrations were analyzed by high pressure liquid chromatography with tandem mass spectrometry detection. Pharmacokinetic parameter estimates were obtained with compartmental methods using commercially available software.

Results

A two-compartment model with first order elimination was used. At the end of the infusion, median (range) plasma hydromorphone concentrations were 6.8 (5.5-19.6) ng/mL. The median total body clearance was 30.4 (19.8-36.7) mL/min/kg; volume of distribution at steady state was 4.5 (3.2-7.8) L/kg; and terminal elimination half-life was 11.2 (7.6-24.3) h.

Conclusion

Hydromorphone (0.1 mg/kg IV bolus then IV CRI of 0.01 mg/kg/h) maintained steady-state plasma concentrations above the minimum human analgesic target in healthy Beagle dogs with minimal side effects. Further studies are needed to determine the effective plasma concentrations of hydromorphone in painful dogs.

An investigation into how accurately UK rabbit owners identify pain in their pet rabbits

BACKGROUND

Rabbits are popular family pets. They are prey species and so have evolved to hide signs of illness and pain. Recent research has developed robust pain scales for use in a clinical setting, but to date none has examined rabbit owners' ability to recognise pain in their animals. This study investigated how owners identify pain in their pet rabbits and their ability to correctly identify different levels of pain, in order to determine any need for owner education in this area.

METHODS

Owners were recruited via Facebook and a two-part online survey was distributed. Part one collected data on demographics, owners' knowledge of pain signs and beliefs about pain in rabbits. Part two asked respondents to pain score eight videos of rabbits in different levels of pain for comparison to pain scores made by three experts. We used a simplified version of the Bristol Rabbit Pain Score (BRPS) which involved a single 0 to 3 scale. We explored the number of pain signs each respondent could list, the total score given to the videos, and their deviation from the experts' scores.

RESULTS

A total of 500 respondents completed part one of the survey and 345 additionally completed Part two. Respondents were on average able to state five signs of pain (range 0-12), but females stated significantly more (p = 0.018), as did those who worked with rabbits (p = 0.004) and those with experience of their rabbit having an operation (p = 0.01). Overall, 98.6% of respondents thought rabbits felt pain as much or more that dogs and cats. In Part two, respondents more frequently agreed with the experts when identifying rabbits in no pain (88.8%) and severe pain (65.2%), but there was lower agreement when identifying mild (28.4%) and moderate pain (43.2%). Respondents overall rated pain lower than experts with an average total pain score of 11.9 compared to 18 given by the experts.

CONCLUSIONS

Most rabbit owners are able to list numerous pain signs and are generally able to identify pain-free rabbits and those in severe pain. Owners' ability to differentiate between mild and moderate pain is more limited and could benefit from training in the subtler signs of pain. Veterinary professionals are well placed to educate owners about signs of pain in rabbits and should be aware of areas where owners' knowledge can be improved.

A blinded, randomized and controlled multicenter field study investigating the safety and efficacy of long-term use of enflicoxib in the treatment of naturally occurring osteoarthritis in client-owned dogs

Background

Enflicoxib is a COX-2 selective NSAID shown to be efficacious and safe in the treatment of pain and inflammation associated with canine osteoarthritis (OA) in clinical studies of 6 weeks duration.

Objective

This prospective, multisite, blinded, randomized, placebo-controlled, parallel-group field study aimed to confirm the safety and efficacy of enflicoxib in long-term canine OA treatments.

Animals

A total of 109 client owned dogs with clinical and radiographic signs of OA for at least 3 weeks were enrolled with 78 dogs completing all study visits.

Methods

Dogs were randomized at a 3:1 ratio to receive enflicoxib (n = 83) or placebo (n = 26) once weekly during 6 months. Dogs underwent veterinary assessments from Day 0 to Day 189 using a clinical sum score (CSS). Efficacy was also assessed by the owners using the Canine Brief Pain Inventory (CBPI). Safety was assessed clinically and by repeated blood and urine sample analysis. The efficacy outcome measure was the treatment response according to the CSS and secondarily the treatment response according to the CBPI. The primary safety outcome was the incidence of adverse events (AEs) and secondarily the evolution of the clinical pathology parameters.

Results

Percentages of CSS responders for enflicoxib were 71.6; 74.6 and 71.6% on Days 44, 135 and 189 respectively, always showing statistically significant differences (p < 0.05) vs. placebo (41.7, 33.3, and 20.8% respectively). Treatment response according to owner assessments followed the same pattern, achieving significant differences compared to placebo after 2 weeks of treatment. The incidence and type of AEs were as described in previous enflicoxib studies of shorter duration and as for other NSAIDs, with no tendency to increase over time. No relevant changes in hematology, biochemistry or urine parameters were observed.

Conclusions and clinical relevance

Enflicoxib safety and efficacy profile is maintained after a long-term treatment, which together with its weekly administration, makes it a good alternative for the chronic treatment of dogs with naturally occurring OA.

Development and Preliminary Validation of an Equine Brief Pain Inventory for Owner Assessment of Chronic Pain Due to Osteoarthritis in Horses

An owner-completed questionnaire was designed to monitor the level of chronic pain and impact on quality of life in horses with osteoarthritis (OA). A standardized approach to develop and validate subjective-state scales for clinical use was followed. Scale items were generated through literature review, focus group meetings, and expert panel evaluation. The draft tool was tested for reading level and language ambiguity and piloted in 25 owners/caregivers of horses with osteoarthritis, with factor analysis performed on responses. The resulting revised questionnaire is currently undergoing validation in a larger sample population of 60 OA and 20 sound control horses. In the pilot group, 21 people (84%) found the questionnaire easy to complete and 22 people (88%) found it useful. It could be completed within 5 min by all participants. Readability scores (Flesch Reading Ease Score, Flesch-Kincaid grade level, SMOG index) indicated an English language reading level comparable to that of 6th to 7th grade in the U.S. system (age 11-12 years). Cronbach's alpha of all items in the tool was 0.957, indicating excellent inter-item correlation. Interim analysis for 23 OA horses from the sample population showed good test-retest reliability and higher scores compared to 5 control horses. Full validation must be completed for the instrument to be used in clinical practice.

Evaluation of lidocaine administration into the ovarian pedicle for the control of intraoperative and early postoperative pain during ovariohysterectomy in dogs

OBJECTIVE

To evaluate effects of lidocaine 2% administration into the ovarian pedicle on intraoperative nociception and early postoperative pain in dogs undergoing ovariohysterectomy.

STUDY DESIGN

Prospective, randomized, blinded clinical study.

ANIMALS

A total of 20 healthy adult female dogs of different breeds.

METHODS

Dogs were premedicated with acepromazine (0.02 mg kg-1) and morphine (0.5 mg kg-1) intramuscularly, anesthesia induced with propofol and maintained with isoflurane. Dogs were randomly assigned to be administered 2 mL of saline (group S) or lidocaine 2% (group L) into the mesovarium (1 mL each side). Heart rate (HR) and noninvasive systemic arterial pressure were recorded before surgery (T0), before (T1) and during ligation of the right ovarian pedicle (T2), before (T3) and during ligation of the left ovarian pedicle (T4). Rescue treatment (propofol) was administered if HR or systolic arterial pressure (SAP) increased by 20% compared with the previous time point. Pain, assessed with the Glasgow Composite Measure Pain Scale-Short Form (CMPS-SF) was recorded before premedication (baseline) and after extubation. Administration of postoperative rescue analgesia was recorded.

RESULTS

In group S, HR was higher at T2 than T1 (112 ± 18 versus 89 ± 21 beats minute-1, p = 0.001) There were no significant differences between treatments at any time. SAP was higher at T2 than T1 in group S (110 ± 12 versus 100 ± 10 mmHg, p = 0.031). SAP was higher in group S than group L at T3 (113 ± 12 and 91 ± 10 mmHg, respectively, p = 0.001). No dogs required propofol intraoperatively. All dogs required postoperative rescue analgesia. Compared with baseline, CMPS-SF increased 60 minutes after extubation (group S; p = 0.019, group L; p = 0.043).

CONCLUSIONS AND CLINICAL RELEVANCE

Administration of lidocaine 2% into the mesovarium did not reduce intraoperative nociception and did not improve postoperative analgesia.

Comparison of Two Surgical Techniques Based on the Semitendinosus Myocutaneous Flap in Cats

The objective of this experimental study was to compare the semitendinosus (ST) to the split-semitendinosus (SST) myocutaneous flap in covering distal limb skin defects in cats. Twenty-eight purpose-bred laboratory DSH cats were used and allocated into two groups (ST-group (A); n = 14, SST-group (B); n = 14). ST flaps, based on the distal muscle pedicle, and SST flaps, after longitudinal division of the muscle based on both muscle pedicles, were tested over skin defects created on the medial distal tibia. Clinical assessment, planimetry, CT-angiography (CTA) and histological examination were compared between groups. Days to complete flap healing between ST and SST-flaps (30.36 ± 9.1, 32.29 ± 5.44, respectively) and final total flap areas (68.36% ± 27.18, 51.83% ± 22.48, respectively) revealed no significant differences. On CTAs, the caliber of the distal caudal femoral vein on day 10 was statistically significant higher (p < 0.001) for group A and a significantly higher caliber of the distal caudal femoral artery on day 30 for group B (p = 0.021). Histology revealed statistically higher degeneration at 6 months (p = 0.047) for group A, and statistically higher fibrosis at 12 months (p = 0.019) for group B. Both ST and SST flaps had similar healing times and provided coverage of skin tibial defects in cats.

Attitudes to acute pain and the use of pain assessment scales among Spanish small animal veterinarians

Evaluation of acute pain in dogs and cats is the basis for an appropriate treatment and improved well-being. The difficulties involved in pain assessment pose a challenge for veterinarians, and recent findings indicate that the most effective tools available-validated pain assessment scales-may not be widely utilized.

Objectives

This study aimed to characterize the level of concern among Spanish veterinarians regarding acute pain in companion animals. Additionally, it sought to determine whether this concern correlates with the utilization of optimal assessment tools.

Methods

A survey was conducted to explore Spanish veterinarians' attitudes toward pain and its assessment. The survey was distributed through two most prominent small animal veterinary associations, the Spanish association for veterinary anesthesia and analgesia, as well as key industry players committed to proactive pain management. Descriptive analysis of the collected data was performed using Excel and SPSS.

Results

A total of 292 veterinarians participated in the study. A high level of concern regarding pain in dogs and cats was determined where 44% of surveyed veterinarians assessed pain in all patients. Despite an awareness of validated pain scales, only 28% used them. The preferred scales were the Glasgow CMPS for dogs (94%) and the Feline Grimace Scale for cats (93%). Among respondents who do not use these validated tools, there was a considerable interest in incorporating these scales into practice (85%) and considered lack of training was the most relevant issue (32%). Other challenges to scale utilization were identified, including constraints related to time, staffing, and the need to establish a habit.

Conclusions and relevance

Spanish small animal veterinarians demonstrated a strong awareness to pain in their patients and employed various methods for pain assessment. However, a limited use of validated tools was identified and likely attributed to challenges such as a lack of established routine, time constraints, insufficient personnel, and, notably, a knowledge gap among veterinarians who do not employ pain assessment scales. The most commonly used scales were the Glasgow CMPS for dogs and the FGS for cats. Overall, these results suggest a window of opportunity for the implementation of training programs in small animal pain assessment at a national level.

Thai veterinarians' perceptions of cannabidiol products for dogs with osteoarthritis: a qualitative interview study

Introduction

The global popularity of cannabidiol (CBD) led to its approval for human use in Thailand and potential use in animals. Many studies revealed CBD's efficacy in treating chronic osteoarthritis (OA) in dogs. To facilitate tailored CBD product development for canine OA and ensure market success, this study explores Thai veterinarians' perception of CBD for canine OA.

Methods

In-depth interviews were conducted with experienced veterinarians who treated OA in ≥25% of their canine patients. Interview questions covered treatment, CBD perception, and adoption. Interviews were held from January to March 2023.

Results

Eleven out of twenty invited veterinarians participated in the study. Though all favored non-steroidal anti-inflammatory drugs (NSAIDs) for OA in dogs, concerns about adverse reactions, including ulcers and renal failure, emerged. CBD was widely known and was perceived positively for pain, inflammation, cancer, and epilepsy. However, half distinguished CBD from marijuana and tetrahydrocannabinol (THC). Ten expressed willingness to prescribe CBD for OA upon robust clinical evidence. Worries centered on product consistency and impurities. Many suggested CBD should be under veterinarians' supervision at first, but this can be relaxing once safety and efficacy are established. CBD products should be chewable tablets, oils, or gelatin capsules with flavors like beef, liver, pork, fish, or seafood.

Conclusion

Though CBD benefits were recognized, knowledge gaps among the participants persisted, warranting robust CBD safety, efficacy, and quality evidence to ensure Thai market success. Comprehensive education, including continuing education for those in practice and incorporating CBD-related topics into the Schools of Veterinary's curriculum, is recommended.

Instrument shank-assisted ovariohysterectomy: a randomized clinical trial of surgical and pain alleviation efficiency of a single-person modified technique

Objectives

To evaluate a modified ovariohysterectomy (OHE) technique performed by a single person and compare it with the conventional method based on time efficiency, trauma, and postoperative pain.

Methods

In a prospective, randomized, experimental study, 18 healthy, large, deep-chested, mixed-breed intact female dogs were randomly allocated to conventional (n = 9) and instrument shank-assisted (n = 9) groups. On the basis of video recordings, the various surgical step durations were analyzed: total surgery time (TST), pedicle intervention time (PIT), suspensory release time (SRT), shanking time (ShT), clamping time (ClpT), ligating time (LigT), and closure time (CT). The Glasgow composite pain scale short-form (GCMPS-SF), university of Melbourne pain scale (UMPS), and Visual Analogue Scales (VAS) were used to measure pain. C-reactive protein (CRP) fluctuation was also investigated. These evaluations were completed before and 6, 24, 48, and 72 h postoperatively.

Results

Instrument shank-assisted OHE was less time-consuming than conventional OHE (p = 0.005), improved PIT by 30.7% (6.44 min for both pedicles, p = 0.014), and correlated strongly with TST (ρ = 0.862, p = 0.003 and ρ = 0.955, p = 0.000, respectively). The two method's surgical step durations were also TST = 47.40 ± 9.9 vs. 34.70 ± 6.7 min, PIT = 20.96 ± 5.78 vs. 14.52 ± 3.73 min, SRT = 78.97 ± 69.10 vs. ShT = 20.39 ± 8.18 s (p = 0.035), ClpT = 50.66 ± 45.04 vs. 63.55 ± 37.15 s (p = 0.662), LigT = 12.82 ± 3.37 vs. 8.02 ± 3.11 min (p = 0.005), and CT = 16.40 ± 4.5 vs. 11.60 ± 2.5 min (p = 0.013), respectively. While both techniques inflicted pain on the animals, the novel approach resulted in a reduction of pain at T6 (GCMPS-SF, p = 0.015 and VAS, p = 0.002), T24 (UMPS, p = 0.003), and T48 (GCMPS-SF, p = 0.015 and UMPS, p = 0.050). Both methods exhibited a peak in CRP level after 24 h, which subsequently returned to baseline after 48 h. However, the shank-assisted method demonstrated a significantly lower reduction in CRP level at the 48-h compared to the other group (p = 0.032).

Conclusion

Instrument shank-assisted technique permitted ovarian removal without an assistant, less damage to animals and reducing its time when compared to a conventional technique, and resulting in an alternative that causes less surgical stress and fatigue. Further research with a larger population size is required to determine the serum CRP levels as an alternative pain biomarker.

Healing Effect of a Nano-Functionalized Medical-Grade Honey for the Treatment of Infected Wounds

Based on the qualities of Ulmo honey (Eucryphia cordifolia), a medical-grade honey (Ulmoplus®) has been developed. Relevant to this, the use of copper represents an emerging therapy for the treatment of wounds. Therefore, the aim of this study was to see how this medical-grade honey with copper nanoparticles (CuNPs) helped to heal infected or non-infected wounds. Twenty-four guinea pigs (Cavia porcellus) were divided into four groups for phase 1 (without and with infection, U + F1 and U + F2), and two groups for phase 2 (selected formulation, without and with infection, U + F2NI and U + F2I). Bacteriological and histopathological studies, collagen fibers content evaluation, and stereological analysis were performed. The selected formulation displayed the same antibacterial potency as Ulmoplus®, indicating that this medical-grade honey by itself can be used as an antibacterial agent. However, the evaluation of collagen content demonstrated a significant increase in fibroblast and type III collagen fibers for infected and uninfected groups, which correlated with the histopathological study. Therefore, it is correct to affirm that adding CuNPs to Ulmoplus® improved the maturation of collagen fibers. Finally, polymorphonuclear cells presented similar values between experimental groups, which would indicate that the formulation under study was able to regulate the inflammatory process despite their infectious condition.

Healing Effect of a Nano-Functionalized Medical-Grade Honey for the Treatment of Infected Wounds

Based on the qualities of Ulmo honey (Eucryphia cordifolia), a medical-grade honey (Ulmoplus®) has been developed. Relevant to this, the use of copper represents an emerging therapy for the treatment of wounds. Therefore, the aim of this study was to see how this medical-grade honey with copper nanoparticles (CuNPs) helped to heal infected or non-infected wounds. Twenty-four guinea pigs (Cavia porcellus) were divided into four groups for phase 1 (without and with infection, U + F1 and U + F2), and two groups for phase 2 (selected formulation, without and with infection, U + F2NI and U + F2I). Bacteriological and histopathological studies, collagen fibers content evaluation, and stereological analysis were performed. The selected formulation displayed the same antibacterial potency as Ulmoplus®, indicating that this medical-grade honey by itself can be used as an antibacterial agent. However, the evaluation of collagen content demonstrated a significant increase in fibroblast and type III collagen fibers for infected and uninfected groups, which correlated with the histopathological study. Therefore, it is correct to affirm that adding CuNPs to Ulmoplus® improved the maturation of collagen fibers. Finally, polymorphonuclear cells presented similar values between experimental groups, which would indicate that the formulation under study was able to regulate the inflammatory process despite their infectious condition.

Current attitudes and self-rated abilities of Bosnia and Herzegovina veterinarians toward pain recognition and quantification in domestic animals

In previous years interest has grown in investigating the attitudes and capabilities of veterinarians regarding the recognition, quantification and treatment of animal pain throughout different parts of the world and encompassing various species. This is the first report exploring the attitudes and self-rated abilities of veterinarians in Bosnia and Herzegovina (B&H) concerning recognition and quantification of pain in domestic animals. A study questionnaire was made available to 535 general practice veterinarians throughout B&H and 73 (14%) responded in full. The questionnaire contained polar, multiple choice, ordinal and interval scale questions and consisted of sections asking about demographic data, attitudes to pain recognition and quantification, use and availability of analgesics, estimates of pain intensity during specific surgical procedures, and the perceived need for pain assessment and continuing education programmes for analgesia. Half of the respondents considered the recognition and quantification of pain to be difficult while 89% did not make use of pain assessment scales. Of the respondents, (33/73; 45%) felt a certain level of pain to be advantageous since it reduces the activity of the healing animal, whereas 52% (38/73) did not agreed with this concept. Cost was a consideration when deciding whether or not to use analgesics for 58% (42/73) of the respondents with the most commonly used types being NSAIDs (72/73;99%) and opioids (60/73; 82%). Practitioners in B&H displayed awareness of the importance of pain assessment and management however a significant proportion were unaware of pain scales and relied upon physiological indicators of pain.

Gabapentin: Clinical Use and Pharmacokinetics in Dogs, Cats, and Horses

Gabapentin is an anticonvulsant drug, which presents an established clinical efficacy in human patients for the management of refractory partial seizures, secondarily generalized tonic-clonic seizures, and for the control of chronic neuropathic pain. Gabapentin was synthesized as a structural analogue of the inhibitory neurotransmitter GABA, with GABA-mimetic effects, able to cross the blood-brain barrier. In veterinary medicine, is extra-label used in combination with other treatments to control seizures when other drugs are no longer effective or become toxic or for neuropathic pain treatment and anxiety. This review aimed to clarify gabapentin use and pharmacokinetic aspects to promote conscious use in dogs, cats, and horses. In dogs, gabapentin was beneficial in the treatment of epilepsy, as well as chronic, neuropathic, and post-operative pain, as well as anxiety. In cats, it showed efficacy in post-ovariohysterectomy-related pain and in anxiety management. In horses, gabapentin has been administered as an analgesic for chronic pain management. In conclusion, when used in combination with other drugs, gabapentin can be considered an interesting therapeutic option for the treatment of neuropathic diseases and analgesia in postoperative and chronic pain. However, despite its beneficial use in different clinical settings, further trials and pharmacokinetic studies are needed for the definition of an effective dosage regimen through proper pharmacokinetic/pharmacodynamic correlation in dogs, cats, and horses.

Blinded, randomized, placebo-controlled study of the efficacy of bupivacaine liposomal suspension using static bodyweight distribution and subjective pain scoring in dogs after tibial plateau leveling osteotomy surgery

OBJECTIVE

To compare the analgesic effect of surgical wound infiltration with liposomal bupivacaine (LB) to saline placebo in dogs after tibial plateau leveling osteotomy (TPLO).

STUDY DESIGN

Blinded, randomized, placebo-controlled clinical prospective study.

ANIMALS

Fifteen client-owned dogs receiving LB and 17 dogs receiving an equivalent volume of saline placebo, all with confirmed unilateral cranial cruciate ligament insufficiency.

METHODS

Preoperatively and up to 48 h after surgery, Glasgow Composite Measure Short Form (CMPS-SF) pain scores were assigned and using a weight distribution platform, static bodyweight distribution (%BW_dist ) to the operated limb was measured. Postoperatively, dogs also received carprofen 2.2 mg/kg subcutaneously every 12 h. Rescue analgesia was provided. Treatment success was defined as not requiring rescue analgesia over the 48-h postoperative period.

RESULTS

There was no difference between treatment success, postoperative opioid consumption, CMPS-SF pain scores, or %BW_dist in dogs that received surgical wound infiltration with LB compared with those receiving saline placebo, following TPLO. There was no linear correlation between CMPS-SF pain scores and %BW_dist .

CONCLUSION

For the population of dogs that underwent TPLO and received postoperative carprofen at our institution, LB did not provide an analgesic effect discernable by success/failure analysis, CMPS-SF pain scores, or %BW_dist measurement using a weight distribution platform, compared with saline placebo.

CLINICAL SIGNIFICANCE

LB may not provide detectable analgesia during the first 48 h for dogs recovering from TPLO and receiving only postoperative carprofen.

Evaluation of the Analgesic Efficacy of Undiluted Intraperitoneal and Incisional Ropivacaine for Postoperative Analgesia in Dogs after Major Abdominal Surgery

Recommendations for intraperitoneal (IP) and incisional (INC) administration of local anaesthetics after visceral surgery exist, but evidence is scarce. This prospective, randomized, blinded, controlled, clinical trial compared postoperative pain in dogs undergoing major abdominal surgery. Sixteen client-owned dogs were anaesthetized with a standardized balanced protocol including opioids and received either 2 mg/kg ropivacaine IP (0.27 mL/kg) and a 1 mg/kg INC splash (0.13 mL/kg) or equal volumes of saline. Influence of the treatment on heart rate (HR) and postoperative pain was assessed using the Short Form of the Glasgow Composite Pain Scale (GCPS-SF), a dynamic interactive visual analogue scale (DIVAS) and mechanical nociceptive threshold testing (MNT). Data was tested with mixed ordinal regression and log linear mixed models for 0.5, 1, 2, 3, 4, 6, 8, 10 and 12 h after extubation. Rescue analgesia was given to 3/8 dogs after ropivacaine and 0/8 dogs after saline. GCPS-SF and MNT were not different between groups. DIVAS was slightly higher after ropivacaine (odds increased by 5.44 (confidence interval (CI) 1.17-9.96, p = 0.012)), and HR after ropivacaine was 0.76 * that after saline (CI 0.61-0.96, p = 0.02) with no effect of time (p = 0.1). Undiluted ropivacaine IP and INC was not beneficial for postoperative analgesia.

Multimodal Approach to Pain Management in Veterinary Rehabilitation

Pain recognition, assessment, and management is a primary focus and an integral part of veterinary rehabilitation. Evidence-based pain mitigation protocols will use both pharmacologic tools and nonpharmacologic methods to create a customized, safe, and effective treatment plan. A multimodal, patient-centered approach will allow for the best outcomes for pain relief and improved quality of life.

Tramadol Administered Intravenously Either as a Bolus or a Slow Injection in Pain Management of Romifidine-Sedated Calves Undergoing Umbilical Hernia Repair

Umbilical hernias in calves occur with relative frequency. Most abdominal surgeries can be performed in cattle using standing sedation and local blocks. Romifidine is widely used in calves, alone or in combination with opioids. Tramadol administered as an intravenous slow injection provided better analgesia than an IV bolus in cows. The aim of the present study was to compare the response to surgical stimulus, and sedative effects of tramadol administered intravenously either as a bolus or a slow injection in romifidinesedated calves. Twenty Frisian calves undergoing umbilical hernia repair received romifidine (0.08 mg/kg IM; time 0) followed by tramadol (1 mg/kg IV) 5 min later either as a bolus (n = 10, B group) or a slow injection over 10 min (n = 10, SI group). Surgical area was infiltrated with lidocaine (4 mg/kg). Heart rate (HR), respiratory rate (RR), systolic, dyastolic and mean arterial pressure (SAP, DAP, MAP), sedation scores and response to surgical stimulus were recorded for up to 55 min. After the calves recovered a standing position, postoperative pain scores were assessed for up to 50 min. Sedation scores were significantly higher in the SI group than in the B group at 55 min (p < 0.05). HR, RR, SAP and response to surgical stimulus were significantly higher in the B group than in the SI group (p < 0.05). No significant differences were recorded in postoperative pain scores between groups (p > 0.05). Romifidine IM followed by intravenous tramadol, as a bolus or slow injection and local infiltration with lidocaine provided adequate sedation and analgesia in calves undergoing umbilical hernia repair.

Use of a semitendinosus myocutaneous flap for the coverage of hindlimb full-thickness skin defects in cats

BACKGROUND

The management of feline hindlimb full-thickness skin defects is challenging. On the other hand, the use of a semitendinosus (ST) myocutaneous flap for their coverage has not been reported.

OBJECTIVES

To describe the ST flap and compare it with second intention healing for managing hindlimb full-thickness skin defects.

METHODS

In 12 purpose-bred laboratory domestic short-haired cats, two wounds were made on each tibia. The wounds in group A (n = 12) were covered with ST flaps, and those in group B (n = 12) were left to heal by second intention. In both groups, clinical assessment scoring and planimetry were performed between one-30 d postoperatively. Computed tomography-angiography (CTA) was performed on days zero, 10, and 30, and histological examinations were performed on days zero and 14 and at 6 and 12 mon postoperatively.

RESULTS

Statistically significant differences in the clinical assessment scores were observed between groups A and B on days 14 (p = 0.046) and 21 (p = 0.016). On the other hand, the time for complete healing was similar in the two groups. CTA revealed significant differences in the muscle width (day 0 compared to days 10 and 30 [p = 0.001, p = 0.026, respectively], and days 10 to 30 [p = 0.022]), ST muscle density, and the caliber of the distal caudal femoral artery and vein (day 0 compared to day 10 [p < 0.001], and days 10 to 30 [p < 0.001]). Histologically significant differences in inflammation, degeneration, edema, neovascularization, and fibrosis were observed on day 14 compared to zero and 6 mon, but no differences were found between the time interval of 6 and 12 mon.

CONCLUSIONS

An ST flap can be used effectively to manage hindlimb full-thickness skin defects.

Acupuncture in Zoological Companion Animals

Over the past years, the concept of pain management in veterinary medicine has evolved and led to the establishment of a new concept of multimodal approach to pain management, as the current standard of care. The use of multimodal analgesia combining pharmacologic and nonpharmacologic techniques not only helps optimize the quality and efficacy of analgesia but also may prevent the development of chronic or persistent pain. During the past decade, acupuncture has become more popular and evolved into one of the most used forms of integrative medicine interventions and nonpharmacologic therapeutic options for pain management in humans and animals in North America and Europe. There is ample evidence from basic and clinical research for acupuncture is effective in the treatment of acute and chronic pain by influencing neural networks of the nervous system. While in the modern days' veterinary acupuncture has been predominantly used in horses and dogs, its popularity in zoologic companion animals (ZCA) has increased in recent years as an adjunct therapy for treating musculoskeletal, neurologic, and gastrointestinal disorders due to its minimal invasiveness and low risk of adverse events. The integrative use of acupuncture has become even more important with the increasingly limited use of opiates in veterinary medicine due to the opiate crisis. The purpose of this article aims to provide guidance for using acupuncture for pain management in ZCA in clinical practice, based on available information and recommendations from experienced veterinary acupuncturists.

Pain Recognition and Assessment in Birds

The recognition and assessment of pain in avian species are crucial tools in providing adequate supportive care in clinical, laboratory, zoologic, rehabilitation, and companion animal settings. With birds being a highly diverse class of species, there is still much to be determined regarding how to create specific criteria to recognize and assess pain in these animals. This article provides a clinical review on the physiology of pain in birds, observed behavioral and physiologic alterations with pain, how different sources and degrees of pain can alter behaviors observed, and how this information can be applied in a clinical setting.

Treatment of Pain in Birds

This article provides an overview of the current understanding of evidence-based clinical analgesic use in birds. The field of avian analgesia has dramatically expanded during the last 20 years, affording more options for alleviating both acute and chronic pain. These options include opioids, nonsteroidal anti-inflammatory drugs, local anesthetics, and/or other drugs like gabapentin, amantadine, and cannabinoids, acting at different points in the nociceptive system thereby helping to provide greater pain relief while reducing the risk of adverse effects when combined.

The use of pain scales in small animal veterinary practices in the USA

OBJECTIVES

Pain assessment in veterinary medicine is challenging. Uncertainty in the ability to recognise pain in animals contributes to suboptimal analgesia. Pain scales have been developed to aid in pain recognition. It is unknown if such scales are routinely utilised in veterinary practices.

MATERIALS AND METHODS

A survey using RedCap software was emailed to veterinarians and veterinary technicians working in practices across the USA. This study aimed to investigate whether pain scoring was routinely performed and reasons to use or not use pain scales. One hundred and forty-four participants were required to estimate prevalence (95% confidence level, 5% precision) with hypothesised prevalence of approximately 10%.

RESULTS

One hundred and forty-seven participants completed the survey. Seventy (47.6%) responded that pain scoring was performed in their practices, 24 (16.3%), reported "sometimes" and 53 (36.1%) reported pain scores were not performed. Reasons for not pain scoring included no training (51.9%) and busy caseload (48.1%). Disadvantages of pain scales were unreliability (16/82; 20%), duration required for completion (14/82; 17%) and vocalisation (14/82; 17%).

CLINICAL SIGNIFICANCE

Almost 50% of the small animal practices surveyed reported the use of pain scales as part of their routine workflow. However, many practices still do not consistently utilise pain scales to assess pain in dogs and cats. Perceived unreliability and lack of compliance were reasons for this result. Improvement of training and proper pain scale introduction and implementation in small animal practices in the USA appears to be required.

Impact of Lidocaine on Pain-Related Grooming in Cuttlefish

Nociception is the neural process of encoding noxious stimuli and is typically accompanied by a reflex withdrawal response away from the potentially injurious stimulus. Studies on nociception in cephalopods have so far focused on octopus and squid, with no investigations to our knowledge on cuttlefish. Yet, these are an important species both in scientific and commercial use. Therefore, the present study demonstrated that a standard pain stimulus, acetic acid, induced grooming behaviour directed towards the injection site in cuttlefish and that the injection of lidocaine reduces grooming behaviours in acetic-acid-injected cuttlefish. Wound-directed behaviour demonstrates that the animal is aware of the damage; thus, when subjecting these animals to any painful treatments in the laboratory, researchers should consider alleviating pain by the administration of pain-relieving drugs.

The Effects of Sedation with Dexmedetomidine-Butorphanol and Anesthesia with Propofol-Isoflurane on Feline Grimace Scale© Scores

This study aimed to evaluate the effects of sedation and anesthesia on Feline Grimace Scale© (FGS) scores. Twelve healthy cats were included in a prospective, blinded and randomized, cross-over study with a 14 day wash-out. Saline or dexmedetomidine-butorphanol (Dex-But) was administered intramuscularly before an anesthetic induction with propofol and maintenance with isoflurane. Saline or atipamezole (Dex-But) was administered at the end of the general anesthesia. Video-filming/image capturing was performed before and up to 24 h post-anesthesia. A total of 125 images were evaluated by four raters blinded to the treatment groups using the FGS (ear position/orbital tightening/muzzle tension/whiskers change/head position; action units (AU); scores 0−2 for each AU). The effects of the sedation/anesthesia were analyzed (p < 0.05). The total FGS and each AU scores were significantly higher with Dex-But than with saline 20 min post-sedation. In the saline group, the total FGS, orbital tightening, and whiskers and head position scores were significantly higher than baseline at 0.5 h post-anesthesia. In the Dex-But group, the total FGS and each AU scores were significantly higher after sedation, whereas the orbital tightening scores were significantly higher at 0.5 h post-anesthesia when compared with the baseline. None of the other comparisons between or within the groups was significantly different. The sedation with dexmedetomidine-butorphanol and anesthesia with propofol-isoflurane changed the FGS scores on a short-term basis; consequently, they may bias acute pain assessment.

An Anatomical, Sonographic, and Computed Tomography Study of the Transversus Abdominis Plane Block in Cat Cadavers

This study compared the distribution of a bupivacaine-iopamidol-dye solution following ultrasound-guided in-plane TAP injection using a 1-point (TAP-L) or 2-point (TAP-SL) approach in cat cadavers. Two cadavers were used to study the TAP sonoanatomy while eight cadavers were enrolled in a randomized, prospective, blinded investigation. Each cat randomly received a TAP-L with 0.5 mL/kg in one hemiabdomen and a TAP-SL with 0.25 mL/kg/point in the contralateral hemiabdomen. After injection, computed tomography and dissection were performed to assess contrast distribution and number of stained target nerves. TAP-SL resulted in a wider contrast spread (mm) compared with TAP-L (87 ± 7 versus 71 ± 9; p = 0.002). The prevalence of nerve staining was higher using TAP-SL than TAP-L (p = 0.001). The ventral branches of T10, T11, T12, T13, L1 and L2 were stained in 2/8, 2/8, 5/8, 7/8, 4/8 and 1/8, and in 7/8, 7/8, 8/8, 8/8, 8/8 and 1/8 using TAP-L and TAP-SL approaches, respectively. Computed tomography and dissection identified minimal injectate intraperitoneally or within the falciform ligament fat following 1 TAP-L and 2 TAP-SL. Ultrasound-guided TAP-SL provided better injectate distribution around the thoracolumbar spinal nerve branches than TAP-L.

Nociception-Induced Changes in Electroencephalographic Activity and FOS Protein Expression in Piglets Undergoing Castration under Isoflurane Anaesthesia

The objective of this study was to investigate the electroencephalographic reaction pattern and FOS protein expression in male piglets undergoing surgical castration under light isoflurane anaesthesia with or without local anaesthesia. The experiment was conducted under isoflurane anaesthesia to exclude the effect of the affective components of pain on the measurements. Changes in the oscillatory activity of the cerebral cortex over a 90 s period after noxious stimulation or simulated interventions were analysed. FOS expression was determined postmortem by performing immunohistochemistry in the dorsal horn of the spinal cord. The analysis of the response to an interdigital pinch revealed a biphasic reaction pattern in the electroencephalogram (EEG) that similarly was observed for the surgical stimuli during the castration procedure in the group without analgesia. This EEG response was attenuated or altered by the application of local anaesthetics. Immunohistochemical staining for FOS indicated a lower expression in the handling and in three local anaesthetic groups than in the animals castrated without pain relief. The findings indicate that EEG and FOS expression may serve as indicators for nociception in piglets under light isoflurane anaesthesia. A lower activation of nociceptive pathways occurs during castration after the application of local anaesthetics. However, EEG and FOS analyses should be combined with additional parameters to assess nociception, e.g., haemodynamic monitoring.

Comparative clinical and morphometric investigations of cervical stenosis of the spinal canal in humans and dogs

Acquired stenosis of the spinal canal is a common problem in human and animal pathology. It is defined as a pathological condition that mainly develops as degeneration of the spine with cervical myelopathy development, which is a characteristic manifestation of this pathology. Pain both in the neck and upper back is the leading syndrome of this pathology. 65 human patients aged 20–65 years and 19 dogs weighing more than 20 kg were examined with the aim of comparative clinical and morphometric analysis of stenosis of the spinal canal. The age of the dogs was maximally converted to the age of a person. Computed tomography using the Pavlov-Torg index and the reserve space evaluation supplemented diagnosis of stenosis of the spinal canal. The mass proportion of stenotic changes of the spinal canal against the background of the degenerative-dystrophic process was 21 in males (n = 25) 84.0%, females – 28 persons (n = 40) 70.0%. Pain syndrome was the main complaint in all patients. Cervicalgia prevailed in 60 (92.3%), pain in the upper back was registered in 32 (49.2%) patients. The intensity of pain syndrome was equal to 3.1 ± 0.4 points. Motor deficiency in the form of paresis, mainly of the distal parts of the hands, was registered in 48 patients (73.8%), pyramidal symptoms were noted in the legs in 32 (49.2%) patients, pelvic reservoir dysfunction (7.0–10.8%), and sensory disorders were also found (24.0–36.9%). Such manifestations of cervical myelopathy progressed slowly. Pyramidal symptoms were more frequent and more pronounced in men. According to the computed tomography scan, degenerative changes of the spine were maximal at the level of the C6 vertebra with the maximum clinical correlation (neurological deficit, pain syndrome, etc.). In the course of the research, probable stenosis of the spinal canal was found in people on computed tomography images. In the 19 dogs observed weighing 20 kg or more the presence of pain syndrome was evaluated in all the animals (100.0%) as well as behaviour change (100.0%). During the examination, gait disorder was detected (18.0–94.7%); reaction to palpation of the neck area (15.0–78.9%); the habitus of animals experiencing pain, especially during neck movements (14.0–73.7%), body tension (12.0–63.1%), etc. Bony outgrowths of the edges of the vertebrae and intervertebral joints were found in almost all dogs of 18 (94.7%) large breeds compared to others. Narrowing of the intervertebral openings, deformation and sclerotic changes of the locking plates, thickening of the yellow and elongated ligaments occurred three to four times more in large breeds compared to dogs weighing less than 20 kg, and were absent in cats. Stenosis of the spinal canal was detected in 15 (78.9%) dogs. Therefore, acquired stenosis of the spinal canal probably develops after degenerative-dystrophic changes in the neck in 87.7% of people and in 78.9% of dogs with clinical manifestations of cervical myelopathy and with persistent pain syndrome (equal to 3.1 ± 0.3 points in humans and 2.6 ± 0.4 points in animals according to visual analog scale). This kind of pathological process in the investigated groups developed mainly at the level of the C6 vertebra. Similar clinical and morphometric indexes were obtained in humans (87.7%). It was found that the maximum similarity of pathological processes with stenosis of the spinal canal formation was characteristic in dogs of exclusively large breeds. Therefore, we consider it promising to study the development mechanisms of stenosis of the spinal canal and peculiarities primarily in young generations of humans and animals, to implement modern non-invasive neuroimaging methods, in particular for animals with investigation of morphometric indexes. This will prevent the occurrence of most comorbid syndromes, including chronic pain, neurological deficits as well as help find new opportunities for correction of stenosis of the spinal canal, to suppress the aging processes not only of the muscle-skeletal system but also of the body as a whole. The importance of this work, we suppose, lies in the further identification of adequate models in animals of different breeds and weight categories with stenosis of the spinal canal pathology in which it develops significantly faster, for extrapolation to humans to predict the development of pathological events.

Psychometric properties of the Brazilian version of the Canine Brief Pain Inventory (CBPI) for dogs with clinical signs of osteoarthritis and preliminary evidence of its clinical utility

ABSTRACT This study aimed to determine the psychometric properties and clinical use of the Brazilian version of the Canine Brief Pain Inventory (CBPI) in dogs with hip dysplasia (HD). Forty-three dogs with HD and 16 clinically normal dogs were enrolled. The HD dogs were treated daily with 4.4mg/kg carprofen (GT = 21) or placebo (GP = 19), for four weeks. Owners completed the CBPI at two weeks (W-2) and immediately before the start of the treatment (W0), two (W2) and four (W4) weeks during treatment, and two weeks (W6) after the end of treatment. The internal structure was accessed, and the Cronbach’s alpha coefficient was 0.97, indicating the high internal consistency of the instrument. Principal Component Analysis (PCA) suggested the retention of one component, which accounted for 78% of the variability. The ROC curve analysis concluded that the score 3 has an excellent performance to discriminate between normal and possible HD dogs (AUC of 0.973). There was no difference between dogs treated with carprofen versus placebo. The instrument in Portuguese showed construct and criterion validity and reliability to be used in dogs with HD.

Pharmacokinetics of Bupivacaine Following Administration by an Ultrasound-Guided Transversus Abdominis Plane Block in Cats Undergoing Ovariohysterectomy

Bupivacaine is commonly used for peripheral nerve block in veterinary medicine. This study described the pharmacokinetics of two doses of bupivacaine following administration by an ultrasound-guided transversus abdominis plane (TAP) block in cats undergoing ovariohysterectomy. Twelve healthy female adult cats were included in a randomized, prospective, blinded clinical trial. Anaesthetic protocol included acepromazine–buprenorphine–propofol–isoflurane–meloxicam. Each cat received 1 mL/kg of bupivacaine 0.2% or 0.25% (BUPI-2 and BUPI-2.5, respectively) via bilateral two-point TAP block before surgery (n = 6/group). Plasma concentrations of bupivacaine were detected using liquid chromatography-mass spectrometry. A one-compartment model and non-compartmental analysis described the pharmacokinetic parameters. Bupivacaine was detected up to 480 min (335 ± 76 in BUPI-2 and 485 ± 198 ng/mL in BUPI-2.5). For BUPI-2 and BUPI-2.5, maximum plasma concentrations were 1166 ± 511 and 1810 ± 536 ng/mL at 33 ± 14 and 47 ± 22 min, clearance was 5.3 ± 1.8 and 4.9 ± 1.5 mL/min/kg, and elimination half-life were 253 ± 55 and 217 ± 52 min, respectively. The two doses of bupivacaine via TAP block produced concentrations below toxic levels in cats. A dose of 2.5 mg/kg bupivacaine was safe to be administered using this block in healthy cats.

Evaluation of clinical efficacy of undenatured type II collagen supplementation compared to cimicoxib and their association in dogs affected by natural occurring osteoarthritis

The aim of the study was to evaluate the clinical efficacy of 30 days treatment of undenatured type II collagen(UC-II®), compared to cimicoxib and to their combination, in osteoarthritic dogs. Client-owned dogs were enrolled in a clinical, randomized, controlled and prospective study. Posture, lameness, pain, range of motion and x-ray of affected joint(s) were evaluated and scored based on severity (CLINICAL score). The Liverpool Osteoarthritis in Dogs survey was used to score the owner evaluation of dog's mobility (LOAD score and MOBILITY score). Osteoarthritis (OA) stage was defined through the Canine Osteoarthritis Staging tool (COAST). After diagnosis (T0), all patients were randomly assigned to different treatment groups: C group = cimicoxib 2 mg/kg/day orally OS, F group = UC-II® 1 tablet per day OS; C + F group = cimicoxib-UC-II® at the same previous dosages; CTR group = dogs who didn't received any treatment. All treatments were administered for 30 days. Seventy-six dogs completed the study. LOAD score was recorded significant lower after treatment for each group, with a reduction in percentage of 29.5% for C, 31.4% for F, 21.1% for C + F. LOAD score was lower in C(P = 0.04), F(P = 0.001) and C + F(P = 0.009) group at T30 than CTR group. MOBILITY and CLINICAL scores were significantly lower in all groups at T30, when compared to T0. MOBILITY score was lower than CTR in C(P = 0.02) and F(P = 0.01); CLINICAL score was lower in C + F(P = 0.016). The present findings prove that the treatment with UC-II®, cimicoxib and their combination provide significant reduction in clinical signs associated with OA.

Chronic cerebral hypoperfusion and blood-brain barrier disruption in uninjured brain areas of rhesus monkeys subjected to transient ischemic stroke

Blood-brain barrier (BBB) disruption is a pivotal pathophysiological process in ischemic stroke. Although temporal changes in BBB permeability during the acute phase have been widely studied, little is known about the chronic phase of cerebrovascular changes that may have a large impact on the long-term outcome. Therefore, this study was aimed to measure cerebral vascular abnormalities using CT perfusion in nine rhesus monkeys subjected to transient middle cerebral artery occlusion (tMCAO) for ≥1 year (MCAO-1Y+). The level of cerebral perfusion demonstrated by mean transit time was significantly higher in the ipsilateral caudate nucleus, white matter, thalamus, hippocampus, and contralateral thalamus in MCAO-1Y+ compared with the other nine age-matched control monkeys. The increase in BBB permeability measured through the permeability surface was found in the same ten regions of interest ipsilaterally and contralaterally. We also found decreased levels of Aβ 42/40 ratio in the cerebrospinal fluid (CSF), suggesting a potential link between post-MCAO cognitive decline and Aβ metabolism. Overall, we demonstrated significant cerebral hypoperfusion, BBB disruption, and CSF Aβ decrease during the rehabilitation stage of ischemic stroke in a non-human primate model. Future studies are needed to elucidate the cause-effect relationship between cerebrovascular disruptions and long-term neurological deficits.

Dental Pain in Cats: A Prospective 6-Month Study

Dental pathology is among the most ubiquitous diseases in cats of all ages. Dental pain is yet to be fully understood in cats and therefore its presence is often missed. To better understand feline dental disease as a pain trigger during routine examination and whether disease severity correlates to the degree of pain, a 6-month prospective study in a cats’ only veterinary hospital in Portugal was conducted. Sixty-four cats that randomly presented for different clinical procedures were evaluated. Dental and periodontal abnormalities (primary dental parameters, PDP), as well as clinical signs related to dental pain (secondary dental parameters, SDP), were assessed. All cats underwent an oral cavity examination, upon which, the Feline Acute Pain Scale from Colorado State University Veterinary Teaching Hospital (CPS), was used in order to assess pain. Six PDP (periodontal disease, gingival index, calculus index, tooth resorption, tooth fracture and missing teeth) and five SDP (mouth discomfort, halitosis, hypersalivation, difficulty in holding food and several attempts at prehension of food), were compared with CPS pain scores. All SDP were significantly associated to higher CPS pain scores (p < 0.05). The number of missing teeth was significantly associated to higher CPS pain scores (p < 0.0001). A trend was observed between higher CPS pain scores and tooth resorption (p = 0.08). This study concluded that cats with dental disease feel pain during clinical examination and the pain increases as the severity of the disease progresses.

Evidence-Based Complementary and Alternative Orthopedic Veterinary Medicine

The use of complementary and alternative veterinary medicine (CAVM) continues to become more widespread, especially for the management of chronic pain conditions such as canine osteoarthritis. Many patients have comorbidities that preclude traditional medical options, have not adequately responded to conventional therapies, or have owners interested in pursuing a complementary approach. Evidence-based CAVM can serve as a safe and effective adjunct to manage chronic pain conditions. There is growing evidence in the veterinary literature for the use of acupuncture and some herbal supplements in the multimodal management of canine osteoarthritis. The majority of evidence supporting chiropractic is limited to equine and human literature.

Observational study of the clinical value of the Canine Osteoarthritis Staging Tool

The aim of this multi-centred, cohort, prospective, observational study was to evaluate the clinical application of the canine osteoarthritis staging tool (COAST), in dogs affected by osteoarthritis (OA). In all dogs, a COAST stage was obtained based on the Liverpool Osteoarthritis in Dogs (LOAD) score and a complete orthopaedic and radiographic examination. The severity of OA (COAST stage) was scored as 1 (preclinical), 2 (mild), 3 (moderate), and 4 (severe). These scores were compared with the overall subjective opinion of experienced orthopedic surgeons who examined the dogs (Clinical Opinion). Data were analysed with descriptive statistic, multiple regression analysis, chi-square and Bland-Altman tests (P < 0.05). In total, 362 evaluations were performed in 202 dogs. Clinical Opinion had a greater proportion of stage 1 and 2 cases compared to COAST (P < 0.0001). The proportion of stage 4 cases was higher in COAST compared to Clinical Opinion (P < 0.0001). The proportions of Stage 3 cases were similar in the two evaluation systems. COAST had a strong correlation (r = 0.79; P < 0.01) with Clinical Opinion. Overall, the two evaluation systems exhibited strong agreement (mean bias 0.51). Stages 1 and 2 had weaker agreement (mean bias 1.04 and 0.75, respectively), than stage 3 and stage 4 (mean bias 0.46 and 0.0, respectively).

The Effect of Different Opioids on Acid-Base Balance and Blood Gas Analysis in Hospitalized Dogs

Pain management is central to veterinary practice, contributing to successful case outcomes and enhancement of the veterinarian-client-patient relationship. Analgesic drugs represent one of the pillars of the multimodal approach to acute and chronic pain management. In dogs, the most used opioids are methadone, buprenorphine and tramadol. Several episodes of hypoglycemia in people treated with tramadol and methadone have recently been described. The aim of this work is to evaluate the changes in the glycemic and acid-base balance induced by tramadol, methadone and buprenorphine in hospitalized dogs. A retrospective review of the medical records of dogs hospitalized for both medical and surgical reasons was performed. During 2018-2020, a total of 876 canine patients were treated with opioids, including 228 with tramadol, 273 with methadone and 375 with buprenorphine. Of all these dogs, only a small percentage met the inclusion criteria presented in the initial design. All the hospitalized animals were monitored daily through clinical examination and blood sampling. Blood samples were obtained before opioid administration (T0), and 24 h (T1) and 48 h (T2) after °pioid administration. The following parameters were evaluated: blood gas value (pH, pCO₂), acid-base state (cHCO₃), oxymetric values (ctHb, haematocrit), electrolyte values (K+, Na+, iCa, Cl-) and metabolic values (glucose, lactate, anion GAP K+c). The glycemic value in enrolled dogs showed a decrease over time, regardless of the type of opioid used, but remained within the physiological range. The highest average glycemic drop was recorded for methadone, between T0 and T1, followed by tramadol between T1 and T2, while buprenorphine recorded the highest overall glycemic drop between T0-T2 when compared to the other two opioids. Female dogs showed the greatest drop in glycemic value. Lactate concentration always presented values beyond the physiological range at an early stage, which then normalized quickly. Measurement of electrolyte concentrations showed a consistent increase in the values of iCa, Na and Cl. In hospitalized dogs treated with opioids monitoring of gas analytic parameters is important and more attention should be paid to patients hospitalized with certain metabolic and endocrine diseases.