Efficacy of tramadol for postoperative pain management in dogs: systematic review and meta-analysis

Perioperative Pain Management for Mastectomy in Dogs: A Narrative Review

Mammary tumours are the most common neoplasia in adult female dogs. Mastectomy leads to moderate to severe pain. Effective pain management is crucial in veterinary medicine. This review outlines analgesic techniques for managing perioperative pain in dogs undergoing mastectomy. A literature search on dog mastectomy analgesia was conducted from January 2001 to January 2025. Pre-emptive meloxicam reduces postoperative cardiovascular changes without affecting renal function. When combined with gabapentin, it lowers the need for rescue analgesic opioids, similar to robenacoxib. With regard to tramadol, it offers contrasting analgesia in the studies considered when used alone, while its effect appears enhanced when used in combination with meloxicam/dipyrone. However, methadone provides superior pain control, especially when given preoperatively or intraoperatively. The combination of ketamine, lidocaine, and maropitant enhances pain management, while fentanyl, alone or with lidocaine and ketamine, is effective for intraoperative pain control. Local infiltration with lidocaine/bupivacaine provides effective pain control, and devices like Comfont-in® or WSC facilitate this process. Tumescent anaesthesia using lidocaine/ropivacaine allows for extensive infiltration of the mammary gland. Epidural analgesia, paravertebral blocks, and TAP blocks are beneficial in multimodal protocols. Transdermal patches containing fentanyl/buprenorphine offer prolonged analgesia, while electroacupuncture can help reduce the need for rescue analgesics. Multimodal analgesic protocols are crucial for effective pain management in dog mastectomy surgeries, minimising the need for rescue opioids.

Perioperative pain management in dogs and cats: Attitudes and practices among Thai veterinarians

OBJECTIVE

To assess attitudes of Thai veterinarians towards perioperative pain management in dogs and cats, and explore associations between demographic characteristics and use of analgesics and pain assessment.

STUDY DESIGN

Paper-based survey distributed in person during various small animal practitioner conferences in 2022.

METHODS

The questionnaire encompassed six sections: demographic information, use of analgesic techniques, postoperative pain evaluation, pain indicators, general opinions and confidence in managing postoperative pain in dogs and cats. Chi-square test, logistic regression model and Mann-Whitney U or Kruskal-Wallis tests were used for data analysis; p < 0.05 was considered significant.

RESULTS

A total of 390 completed questionnaires were collected, with one discarded owing to potential erroneous responses. The most widely used analgesics were alpha-2 adrenergic receptor agonists (84%), postoperative non-steroidal anti-inflammatory drugs (NSAIDs; 83.5%) and preoperative opioids (74.3%). Carprofen (87.3%) and tolfenamic acid (80.9%) were the most frequently administered NSAIDs, while tramadol (86%) and morphine (71%) were the most widely used opioids. Preoperative and postoperative opioid administration were less common among males than females, with odds ratios (ORs) of 0.53 and 0.56, respectively (both p = 0.009). Veterinarians who graduated after 2014 were less likely to prescribe preoperative NSAIDs than those who graduated before 2009 (OR = 0.25; p < 0.001). Epidural anesthesia, nerve blocks and pre- and postincisional blocks were more frequently used by referral center veterinarians than those working in non-referral clinics (ORs = 30.5, 14.7, 4.29 and 8.85, respectively; all p < 0.001) and by veterinarians holding advanced degrees beyond the Doctor of Veterinary Medicine (DVM) compared with those with a DVM degree (OR = 6.25, 4.83, 2.25 and 5.75, respectively; all p < 0.001).

CONCLUSIONS AND CLINICAL RELEVANCE

This study reveals variations in perioperative pain management practices in dogs and cats among veterinarians, influenced by sex, graduation year, education and workplace.

Evidence-based veterinary medicine-potential, practice, and pitfalls

Understanding and incorporating evidence-based veterinary medicine (EBVM) into clinical practice and research continues to pose a challenge for our profession despite over 2 decades of increasing awareness of this concept. Reasons for this include a lack of understanding of its importance to the practice of medicine, veterinary literature that often fails to adhere to evidence-based standards, inadequate attention to teaching EBVM at the university level, and the inherent reluctance of clinicians to alter historical practice styles. For many practitioners, EBVM continues to be an abstract concept they believe requires advanced training in statistics and epidemiology resulting in them relying on less robust sources for clinical guidance. This unfortunately results in suboptimal care for our patients and delayed medical advancements for our profession. As part of the 20th anniversary of the founding of the Evidence-Based Veterinary Medicine Association (EBVMA), we are refocusing our efforts to highlight the need for dedicated teaching of EBVM at the university level, for rigorous adherence to established research reporting guidelines, for expansion of EBVM infrastructure, and for the provision of easily accessible tools that permit clinicians to incorporate EBVM into their daily practice. As the quality of veterinary literature improves, so too will development of more effective clinical practice guidelines that ultimately can be widely adopted if they are flexible enough to support the triadic relationship between veterinarians, our clients and our patients. Ultimately, EBVM is not an end unto itself, but rather a means to improve the quality of care we provide our patients.

Evaluation of the effect of cannabidiol administration with and without nonsteroidal anti-inflammatory drugs in dogs with mobility disorders: a prospective, double-blind, crossover, placebo-controlled study

Introduction

With rapidly growing interest in the use of cannabidiol (CBD) in the management of pain and other conditions, more information is needed on the safety and efficacy of this supplement, particularly its co-administration with commonly used pharmaceuticals such as non-steroidal anti-inflammatory drugs (NSAIDs). This study sought to assess the effect of CBD in dogs with mobility impairments, as well as evaluate the clinical tolerance of CBD used together with NSAIDs.

Materials and methods

Forty-two client-owned dogs with diagnosed mobility impairments were enrolled in this prospective, double-blind, crossover, placebo-controlled study. Baseline data were collected for 10-14 days followed by random allocation to either placebo or CBD oil for 45 days with a 30-day washout period in between. CBD was dosed at 5 mg/kg orally every 12 h with masked placebo administered at equal volume. Outcome measures included objective gait analysis, accelerometry, and clinical metrology instruments. CBD plasma levels and serum biochemistry were also collected along with hepatic ultrasound if warranted.

Results

Thirty-eight dogs finished the study with thirty-nine included for at least partial analysis. Compared to baseline, dogs receiving CBD showed evidence of improved outcomes based on blinded veterinary assessments and accelerometer data. Compared to placebo, dogs receiving CBD showed some evidence of improved outcomes on CBPI, CSOM, and blinded veterinary assessments, but not for objective outcome measures. There was evidence of increased ALP when CBD was co-administered with NSAIDs compared to CBD administration alone. Additionally, there was evidence of ALT elevations with CBD and NSAID co-administration, but this elevation did not show evidence of an increase over CBD use alone.

Discussion

These results suggest a potential therapeutic benefit in the administration of CBD for the management of mobility impairments, but greater ALP elevations were seen when administered with NSAIDs. While the sample size of dogs that received further hepatic work-up for liver enzyme elevations is small, chosen diagnostics varied, and liver biopsies were not performed, there did not appear to be clinically apparent liver damage. Further research is needed to better understand the efficacy of CBD in a larger population of dogs and patient tolerance and safety when administered with NSAIDs or other medications long term.

Pain Management in Animals with Oncological Disease: Opioids as Influencers of Immune and Tumor Cellular Balance

Advancements in understanding pain physiopathology have historically challenged animals' absence of pain senses. Studies have demonstrated that animals have comparable neural pain pathways, suggesting that cats and dogs likely experience pain similarly to humans. Understanding brain circuits for effective pain control has been crucial to adjusting pain management to the patient's individual responses and current condition. The refinement of analgesic strategies is necessary to better cater to the patient's demands. Cancer pain management searches to ascertain analgesic protocols that enhance patient well-being by minimizing or abolishing pain and reducing its impact on the immune system and cancer cells. Due to their ability to reduce nerve sensitivity, opioids are the mainstay for managing moderate and severe acute pain; however, despite their association with tumor progression, specific opioid agents have immune-protective properties and are considered safe alternatives to analgesia for cancer patients.

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.

Improving access to melarsomine therapy: treating canine heartworm infection in a high-volume, outpatient community clinic setting

BACKGROUND

Models that provide high-quality veterinary care for more affordable prices are emerging, but not well documented outside of wellness and preventative care. Effective treatment guidelines for heartworm disease have been developed by the American Heartworm Society; however, not all owners are able to access treatment due to the high costs associated with sick and emergency care services.

METHODS

To increase access to high-quality adulticidal treatment of canine heartworm disease, we developed and implemented a technician-leveraged heartworm treatment protocol for high-volume, outpatient community clinic settings based on the American Heartworm Society guidelines. Modifications were few and included limited pre-treatment blood work, pre-injection sedation, post-injection pain medication, and a reduced exercise restriction period. We monitored retention rates for 556 dogs throughout treatment, evaluated treatment success (defined as no antigen detection 9 months post treatment) for patients that returned for post-treatment antigen testing, and reported on adverse reactions and therapy adherence throughout treatment.

RESULTS

Of the patients that began adulticide therapy, 539/556 (97%) successfully completed the three-injection series. No microfilariae were detected in 99% (428/433) of those who returned for post-injection microfilaria testing. Among those that returned for or reported the results of post-injection antigen testing, no antigen was detected for 99% (245/248) and no microfilariae were detected for 99.5% (200/201). During the course of treatment, 483/539 (90%) of patients experienced at least one adverse reaction, with the most frequently reported types being behavioral and injection site reactions. 25/539 (4.6%) of owners sought additional medical care for adverse reactions at some point during the treatment course. The overall mortality rate was 1.3% (7/556).

CONCLUSIONS

This study represents the first evaluation of a heartworm treatment protocol optimized for implementation in a high-volume, outpatient community clinic setting. Our findings align with those previously reported in private practice or tertiary referral centers, illustrating that through the inclusion of pre-treatment blood work, employing short-acting or reversible sedatives, ensuring proper analgesia, minimizing the use of ancillary diagnostics, reducing the duration of in-clinic monitoring while focusing on outpatient care, and maximizing technician involvement, we can deliver effective and safe melarsomine therapy at a more affordable cost to pet owners.

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 (%BWdist ) 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 %BWdist 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 %BWdist .

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 %BWdist 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.

Pelvic limb anesthesia and analgesia in dogs undergoing tibial plateau leveling osteotomy (TPLO): A survey of board-certified anesthesiologists

OBJECTIVE

To report the locoregional anesthesia and analgesia preferences of veterinary anesthesiologists for use in dogs undergoing a TPLO and determine any association with specialty college, time from board-certification, or employment sector.

STUDY DESIGN

Cross sectional study.

SAMPLE POPULATION

Diplomates of the American (ACVAA) and European (ECVAA) Colleges of Veterinary Anesthesia and Analgesia.

METHODS

An electronic survey was distributed to diplomates and responses were used to determine associations between preferred methods.

RESULTS

The survey response rate was 28% (141/500) with 69% (97/141) of ACVAA diplomates and 31% of diplomates with ECVAA (44/141) certification. Peripheral nerve block (PNB) was preferred by 79% (111/141) of all diplomates, lumbosacral epidural (LE) by 21% (29/141), and peri-incisional infiltration (PI) by <1% (1/141). There was no association (p = .283) with specialty college. There was an association (p < .001) with time from board-certification with increased preference for LE when >10-years from certification and PI preferred by only those board-certified >20-years ago. There was an association with employment sector (p = .003) with more academic diplomates preferring LE. Anesthesiologists reported that treatment decisions were affected by various factors including time pressure and surgeon influence.

CONCLUSION

Diplomates of ACVAA and ECVAA prefer PNB as the locoregional method of pelvic limb anesthesia in dogs undergoing TPLO. A greater percentage of newer and private practice diplomates prefer PNB while a larger percentage of senior and academic diplomates prefer LE. Decision making is multifactorial and includes perceived time pressure and surgeon influence.

CLINICAL SIGNIFICANCE

Veterinary anesthesiologists prefer and frequently use PNB in dogs undergoing TPLO and surgeon influence may affect their chosen treatment.

Comparative growth dynamics of bacterial and fungal contaminants in bupivacaine liposomal injectable suspension, bupivacaine 0.5%, and propofol

OBJECTIVE

To determine whether bupivacaine liposomal injectable suspension (BLIS) supports microbial growth when artificially inoculated and to evaluate liposomal stability in the face of this extrinsic contamination as evidenced by changes in free bupivacaine concentrations.

STUDY DESIGN

A randomized, prospective in vitro study in which three vials of each BLIS, bupivacaine 0.5%, and propofol were individually inoculated with known concentrations of Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Candida albicans (n = 36) to quantify bacterial and fungal growth was conducted. Over 120 hours, aliquots from contaminated vials were withdrawn, plated, and incubated to determine microbial concentrations. High-pressure liquid chromatography (HPLC) was used to evaluate free bupivacaine concentrations over time in BLIS. Data were analyzed using a mixed effects model with multiple comparisons.

SAMPLE POPULATION

Twelve vials of each BLIS, bupivacaine 0.5%, and propofol.

RESULTS

BLIS did not support significant growth of Staphylococcus aureus or Candida albicans at any time. BLIS supported significant growth of Escherichia coli and Pseudomonas aeruginosa beginning at the 24 hour time point. Bupivacaine 0.5% did not support significant growth of any organisms. Propofol supported significant growth of all organisms. Free bupivacaine concentrations changed minimally over time.

CONCLUSION

Bacterial and fungal contaminant growth in artificially inoculated BLIS is organism dependent. BLIS supports significant growth of Escherichia coli and Pseudomonas aeruginosa. Extra-label handling of BLIS should only be undertaken with caution and with adherence to strict aseptic technique.

Treatment of Pain in Rats, Mice, and Prairie Dogs

Recent myomorph and scuiromorph rodent analgesia studies are reviewed and evaluated for potential clinical application. Differences between laboratory animal studies and clinical use in diseased animals are discussed. Analgesia classes reviewed include local anesthetics, nonsteroidal anti-inflammatories, acetaminophen, opioids, and adjuvants such as anticonvulsants. Routes of administration including sustained-release mechanisms are discussed, as are reversal agents. Drug interactions are reviewed in the context of beneficial multimodal analgesia as well as potential adverse effects. Dosage recommendations for clinical patients are explored.

Clinical features and management of snake bites in 70 dogs in Korea

BACKGROUND

Snakebites remain a devastating and life-threatening environmental hazard. While the management of snakebites has been well described in humans, few clinical data and guidelines exist for dogs, especially in Korea.

OBJECTIVES

This retrospective study evaluated the clinical features of 70 dogs with snakebite wounds in Korea.

METHODS

The medical records of 72 dogs that presented to three animal hospitals from June 2008 to July 2021 were reviewed; among these, 70 dogs that met the inclusion criteria were enrolled. Their signalment, history, clinical signs, physical examination, blood analysis, treatment, and prognosis were also evaluated.

RESULTS

Of 70 dog owners, 35 (50%) witnessed the bite, with a mean time between bite and hospital presentation of 9.7 ± 4.1 h in 58 dogs. Blood smears were evaluated in 45 dogs, of which 28 (62%) showed echinocytosis. Anemia and acute kidney injury were found in 21 (29%) and 2 dogs (3%), respectively. A total of 37 dogs (53%) were hospitalized, 5 (7%) of which died.

CONCLUSIONS

The most significant finding was the high prevalence of echinocytosis. The data from this retrospective study could inform the management of dogs bitten by snakes in Korea.

Intensity of perioperative analgesia but not pre-treatment pain is predictive of survival in dogs undergoing amputation plus chemotherapy for extremity osteosarcoma

The purpose of this bi‐institutional retrospective study was to determine whether, in dogs treated with limb amputation and adjunctive chemotherapy for osteosarcoma, oncologic outcomes are impacted by either: (1) baseline cancer pain severity, or (2) the approaches used for perioperative pain management. Data were extracted from the medical records of 284 dogs that underwent both limb amputation and chemotherapy (carboplatin and/or doxorubicin) between 1997 and 2017 for localized (non‐metastatic) osteosarcoma of the appendicular skeleton. Kaplan–Meier survival curves and Cox proportional hazard (PH) models were used to determine the impact that retrospectively scored baseline pain levels (high vs. low) and various analgesic and local anaesthetic treatments had on both metastasis‐free survival and all‐cause mortality. For the entire population, the median disease free interval and median overall survival times were 253 and 284 days, respectively. Baseline pain was rated as “low” in 84 dogs, and “high” in 190 dogs; pain severity had no detectable effect on either metastasis‐free survival or all‐cause mortality. When accounting for the potential influences of known prognostic factors, dogs treated with what was characterized as a high‐intensity perioperative analgesic plan (including both a non‐steroidal anti‐inflammatory drug [NSAID] and a bupivacaine‐eluting soaker catheter placed at the amputation site) had a higher probability of survival than dogs treated with a low‐intensity perioperative analgesic plan (neither an NSAID, nor a soaker catheter); the median overall survival times were 252 and 378 days, respectively (hazard ratio: 2.922; p = .020).

Comparative Multimodal Palliative efficacy of gabapentin and tramadol By Using Two Pain Scoring Systems in Cats Undergoing Ovariohysterectomy

The analgesic efficacy of the gabapentin-tramadol combination was compared with meloxicam-tramadol and tramadol perioperative analgesic regimens in cats brought to the clinic for ovariohysterectomy. Thirty adult cats belonging to comparable demographics (age, body weight), were enrolled into a randomized, blinded study after due consent from their owners into four treatment groups. A Gabapentin-Tramadol group (GT-group, n = 10), Meloxicam-Tramadol group (MT-group, n = 10), and a Tramadol group (T-group, n = 10) were formed. Gabapentin capsules at 50 mg were administered orally 2 hours before surgery while the rest received a placebo dose. Tramadol (2 mg/kg, IM) and meloxicam at (0.2 mg/kg, SC) were injected immediately prior to anesthetic premedication. Anesthetic protocol involved premedication with ketamine and xylazine, while anesthesia was induced using propofol. Inhalant isoflurane anesthesia was used to maintain a surgical plane. GT group scored lower on IVAS as well as CPS than MT group, and T group for up to 8 hours after surgery. The mechanical nociceptive threshold remained higher (98±0) for up to 12 hours postoperatively a nd serum cortisol concentrations remained significantly lower during the 24hr period. The addition of gabapentin to the tramadol regimen significantly improved analgesia and mechanical nociceptive threshold than when used on its own.

Evaluation of prescribing practices for gabapentin as an analgesic among veterinary professionals

OBJECTIVE

To describe the prescribing practices for gabapentin as an analgesic within the veterinary community.

STUDY DESIGN

Anonymous online voluntary survey.

POPULATION

A total of 718 veterinarians within the United States and Canada, including general practitioners and diplomates of the American Colleges of Veterinary Anesthesia and Analgesia, Emergency and Critical Care, Surgery and Internal Medicine.

METHODS

An anonymous online survey was used to gather information about individual prescribing practices for gabapentin including frequency of use, reasons for prescribing and procedures for authorizing refill requests. Questions specific to gabapentin covered mechanisms of action, perceptions of efficacy and the potential for abuse in people. Dunn's test for multiple comparisons and pairwise Mann-Whitney U test were used to evaluate relationships between veterinary specialty and survey responses.

RESULTS

A total of 718 veterinarians responded to the survey, 528 (73.5%) answered all questions of the survey to completion. Frequency of prescribing was high with 365/529 (69.0%) of respondents prescribing gabapentin as an analgesic on a daily or weekly basis. Surgeons and general practitioners used gabapentin significantly more frequently than other groups, with surgeons more likely to prescribe gabapentin for postoperative pain. The most common reason [254/517 (49.1%)] survey respondents prescribed gabapentin as an analgesic was because administration of a non-steroidal anti-inflammatory medication was contraindicated for that animal. The majority of survey respondents [362/527 (68.7%)] considered the abuse potential of gabapentin to be low in people.

CONCLUSIONS AND CLINICAL RELEVANCE

Veterinary prescribing practices for gabapentin closely mirrored that of human physicians, with gabapentin being prescribed frequently and for uses largely unrelated to its labeled indication. The perception of the potential for abuse of gabapentin is low within the veterinary community.