Comparison between the Effect of Lidocaine or Ropivacaine Hematoma Block and of Different Timings of Administration on Post-Operative Pain in Dogs Undergoing Osteosynthesis of Long-Bone Fractures.

OBJECTIVE: We aimed to compare the efficacy of intra-operative lidocaine hematoma block (HB) to ropivacaine HB and to compare the efficacy of different timings of ropivacaine HB in controlling post-operative pain in dogs undergoing the osteosynthesis of long-bone fractures. STUDY DESIGN: We conducted a randomized, blinded, prospective clinical study. ANIMALS: Forty-eight dogs with long-bone fractures were included and were randomly allocated to four groups: lidocaine (L), ropivacaine (Rmid), ropivacaine pre- (Rpre) and ropivacaine post- (Rpost) groups. METHODS: The dogs in group L (n = 14) and in group Rmid (n = 11) received a lidocaine or ropivacaine HB, respectively, after fracture reduction and before osteosynthesis material placement. Rpre dogs (n = 11) received ropivacaine HB before fracture reduction, and Rpost dogs (n = 12) received ropivacaine HB after osteosynthesis material placement. Eight post-operative pain assessments were performed using the University of Melbourne Pain Scale (UMPS) and an algometer. Rescue analgesia was administered based on UMPS scoring. For data analysis, the Shapiro-Wilk test of normality, chi-square, Student t test and Split Plot analysis were used. The level of significance was set at α = 0.05. RESULTS: Rescue analgesia was administered to one dog in group L, one in group Rmid and one in group Rpost, with no significant differences detected. Compared to group Rmid, group L dogs exhibited significantly higher mean mechanical pain thresholds (p = 0.049) and lower mean UMPS scores (p = 0.001). Group Rpost dogs had statistically significantly higher mean pain thresholds compared to group Rmid (p = 0.009). CLINICAL IMPLICATIONS: When performed after fracture reduction and before osteosynthesis material placement, lidocaine HB seems to be more effective than ropivacaine HB in controlling post-operative pain in dogs undergoing osteosynthesis of long-bone fractures. The administration of ropivacaine HB after osteosynthesis material placement seems to be more effective than administration after fracture reduction and before osteosynthesis material placement or administration before fracture reduction in controlling post-operative pain in dogs undergoing osteosynthesis of long-bone fractures.

A Retrospective Study on Canine and Feline Mortality during Anaesthesia at a University Clinic in Greece.

This retrospective cohort study investigated the mortality rate during anaesthesia and possible contributing factors in canine and feline population in an academic institution in Greece. Data on 1187 dogs and 250 cats which underwent general anaesthesia from 1 January 2018 to 31 December 2019 at the Veterinary Faculty of the Aristotle University of Thessaloniki were analysed regarding cardiac arrest and mortality. In dogs, the rate of cardiac arrest was 1.1% and the rate of death was 0.6%. In cats, these rates were 2.8% and 0.8%, respectively. The mortality rate in healthy/mild disease (ASA I-II) dogs was 0.1% and in cats was 0.5%. Sick (ASA III-V) dogs exhibited a death rate of 2.6%, while sick cats had a rate of 2.2%. In dogs, ASA status had a positive association with cardiac arrest and mortality, with sick dogs being 23 times more likely to suffer cardiac arrest and 24.5 times more likely to die than healthy/mild disease ones. Other factors associated with cardiac arrest and mortality were the anaesthetic protocol and the use of inotropes. In cats, premedication and inotropic support were related to cardiac arrest and death. Feline anaesthesia involves higher risk, and requires greater vigilance in peri-anaesthetic management than dogs.

Effect of Classical Music on Depth of Sedation and Induction Propofol Requirements in Dogs.

The main objective of this prospective, randomized, blind, cross-over experimental study was to evaluate the effect of classical music on the depth of sedation and propofol requirements for the induction of anaesthesia in dogs. Twenty dogs were involved, and each was subjected to three different treatments with a 3-month gap: Chopin music, Mozart music, and no music, via loudspeakers. The dogs were premedicated with acepromazine and butorphanol by intramuscular injection, and anaesthesia was induced using propofol intravenously. To compare the depth of sedation and propofol requirements for the induction of anaesthesia among the different treatments, we utilized non-parametric tests (Kruskal-Wallis test) for the depth of sedation due to a slight deviation from the normal distribution and parametric (ANOVA) for propofol requirements. When exposed to music (Chopin or Mozart), dogs exhibited deeper sedation and required less propofol for their intubation compared to the no-music treatment (p < 0.05). Exposure to classical music had a positive impact on the level of sedation, and more profound central nervous system depression seemed to contribute to approximately 20% lower propofol dose requirements for tracheal intubation. Therefore, classical music during the preoperative period appeared to exert a beneficial effect, at least when applying the specific pre-anaesthetic medications used in the present study.

Effect of gonadectomy on pain assessment in dogs undergoing orthopaedic stifle surgery.

OBJECTIVE: To compare pain perception between gonadectomized and intact dogs. STUDY DESIGN: Blinded, prospective, cohort study. ANIMALS: A group of 74 client-owned dogs. METHODS: Dogs were divided into four groups: group 1-female/neutered (F/N), group 2-female/intact (F/I), group 3-male/neutered (M/N) and group 4-male/intact (M/I). Premedication consisted of intramuscularly administered acepromazine (0.05 mg kg-1) and morphine (0.2 mg kg-1), and subcutaneously administered carprofen (4 mg kg-1). Anaesthesia was induced with propofol (1 mg kg-1 intravenously and supplementary doses to effect) and maintained with isoflurane in 100% oxygen. Intraoperative analgesia was achieved with fentanyl infusion (0.1 µg kg-1 minute-1). Pain assessments [using the University of Melbourne Pain Scale (UMPS) and an algometer at the incision site (IS), parallel to the incision site (NIS), and on the contralateral healthy limb] were performed preoperatively, and at 1, 2, 4, 6, 9 and 20 hours after extubation. The time-standardised area under the curve (AUCst) for measurements was calculated and compared by performing a one-way multivariate analysis of variance (manova). Statistical significance was set at p < 0.05. RESULTS: Postoperatively, F/N exhibited higher pain than F/I, with estimated marginal means (95% confidence intervals) AUCstISGroup1 909 (672-1146) versus AUCstISGroup2 1385 (1094-1675) (p = 0.014), AUCstNISGroup1 1122 (823-1420) versus AUCstNISGroup2 1668 (1302-2033) (p = 0.024) and AUCstUMPSGroup1 5.30 (4.58-6.02) versus AUCstUMPSGroup2 4.1 (3.2-5.0) (p = 0.041). Similarly, M/N showed higher pain than M/I with AUCstISGroup3 686 (384-987) versus AUCstISGroup4 1107 (871-1345) (p = 0.031) and AUCstNISGroup3 856 (476-1235) versus AUCstNISGroup4 1407 (1109-1706) (p = 0.026), and AUCstUMPSGroup3 6.0 (5.1-6.9) versus AUCstUMPSGroup4 4.4 (3.7-5.2) (p = 0.008). CONCLUSIONS AND CLINICAL RELEVANCE: Gonadectomy affects pain sensitivity in dogs undergoing stifle surgery. Neutering status should be taken into consideration when planning individualized anaesthetic/analgesic protocols.

Effect of anaesthesia on cell-mediated immunity in dogs undergoing mastectomy for mammary cancer.

OBJECTIVE: To investigate if anaesthesia for canine cancer mastectomy further influences host cell-mediated immunity (CMI) promoting cancer progression. STUDY DESIGN: A randomized, controlled, blinded clinical study. ANIMALS: A total of 20 bitches with malignant mammary tumours of clinical stage II or III undergoing the same type of mastectomy (regional mastectomy). METHODS: Dogs were randomly allocated to one of two anaesthetic groups (10 per group). The anaesthetic protocol of group A used minimally immunosuppressive drugs (tramadol, robenacoxib, propofol), whereas that of group B (control) used more immunosuppressive drugs (morphine, fentanyl, thiopental, isoflurane). For each animal, measurements of white blood cells (WBCs), neutrophils and lymphocytes, and flow cytometric assessment of T cells (CD3+), helper T cells (CD4+), cytotoxic T cells (CD8+) and CD5low+ T cells were performed prior to anaesthesia (day 0) and on days 3 and 10 postsurgery. Data were analysed using a General Linear Model for repeated measures and presented as mean ± standard deviation, p ≤ 0.05. RESULTS: In all animals, on day 3, WBCs and neutrophils were significantly increased (p < 0.0005), while flow cytometry revealed significantly decreased relative percentages of T cells (CD3+) (p = 0.003) and their subpopulations CD4+ (p = 0.006), CD8+ (p = 0.029) and CD5low+ (p = 0.031). Specifically, on day 3, the cytotoxic T cells (CD8+) were significantly decreased (p = 0.05) only in group B, whereas the CD4+ (p = 0.006) and CD5low+ (p = 0.008) T cells in group A. The only significant difference between groups was found preoperatively in the CD4+/CD8+ ratio, which was higher in group A (p = 0.006). CONCLUSIONS AND CLINICAL RELEVANCE: In dogs with mammary cancer undergoing regional mastectomy, a significant decrease in components of CMI was observed on day 3 postsurgery in both anaesthetic groups. Some indication, however, for better preserved cellular immunity by less immunosuppressive anaesthetic/analgesic drugs was detected, rendering their use advisable.

Effect of major versus minor mastectomy on host immunity in canine mammary cancer.

Surgical procedures can affect host immunity proportionally to the extent of surgical trauma. In cancer cases, surgery-induced immunosuppression can potentially promote tumour metastasis. The aim of this study was to investigate, in bitches with malignant mammary tumours, whether major surgery (total unilateral mastectomy or bilateral regional mastectomy) has a more negative effect than minor surgery (unilateral regional mastectomy) on components of host immunity. Twenty bitches with mammary cancer of clinical stage II or III were allocated to group A (minor surgery) or group B (major surgery) of 10 animals each receiving the same anaesthetic protocol for mastectomy. Immune cell measurements in blood [number of leukocytes, neutrophils, lymphocytes and platelets, and relative percentages of T-lymphocytes (CD3+) and their CD4+, CD8+ and CD5low+ subpopulations] were performed before anaesthesia (day 0) and on days 3 and 10 post-mastectomy. On day 3, leukocytes, neutrophils and platelets numbers were higher (p = 0.016, 0.032 and 0.017, respectively) in group B than in group A. For all 20 bitches, T-lymphocytes and the CD4+, CD5low+ T-cells were significantly decreased on day 3, but no significant differences were noted between groups. Minor mastectomy seemed to preserve innate immunity better than major mastectomy, but cellular immunity was rather equally affected.

Factors Affecting Intraoperative Gastro-Oesophageal Reflux in Dogs and Cats.

In animals, gastro-oesophageal reflux (GOR) may occur during anaesthesia, and it can lead to severe consequences such as oesophagitis and oesophageal stricture. This systematic review investigates the effect of fasting duration and anaesthetic and nonanaesthetic drugs on GOR in dogs and cats during general anaesthesia. Fifteen clinical studies met the inclusion criteria in this systematic review. In thirteen studies the population was dogs, while in two studies the population was cats. In the meta-analysis, seven studies were included. Four studies on the effect of fasting duration on GOR in dogs were included in the meta-analysis. In total, 191 dogs had a fasting duration less than 5 h, while 311 dogs had a fasting duration more than 5 h. The heterogeneity of the studies was high and statistically significant (p = 0.0002, I2 = 85%), but the overall effect was statistically nonsignificant (p = 0.82, odds ratio = 0.81, 95% CI 0.15, 4.26), in favour of the low fasting duration (<5 h). Concerning the effect of antacids on GOR, three studies were included in the meta-analysis. The heterogeneity of the studies was low and nonsignificant (p = 0.13, I2 = 52%) and the overall effect was statistically nonsignificant (p = 0.24). The low number of studies and the diverse factors affecting the incidence of reflux prevented us from reaching valuable conclusions on the risk factors for GOR.

Use of propofol to induce food consumption by anorectic dogs following ovariohysterectomy.

OBJECTIVE: To determine whether IV propofol administration at a dose of 2 mg/kg (0.9 mg/lb) could induce food consumption by anorectic female dogs following elective ovariohysterectomy. ANIMALS: 51 healthy female dogs that failed to eat voluntarily when food was offered 6 hours after ovariohysterectomy. PROCEDURES: In a randomized, blinded, controlled clinical trial, dogs received propofol (2 mg/kg; n = 31) or an equivalent volume of saline (0.9% NaCl) solution (20) IV 6 hours after ovariohysterectomy. Afterward, food was offered to the dogs and food consumption was reassessed. Pain, sedation, and stress were scored before and immediately after treatment. RESULTS: 27 of the 31 (87%) dogs in the propofol group consumed food immediately after administration of the assigned treatment, whereas only 1 of 20 (5%) dogs in the placebo group did. No difference in pain, sedation, or stress scores was identified between the 2 groups. Sedation scores for dogs in the propofol group increased immediately after propofol administration. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that food consumption following elective surgical procedures can be effectively induced in anorectic female dogs by IV administration of propofol at a dose of 2 mg/kg.

The Role of Magnesium in the Management of Acute and Long-Term Symptoms Caused by Tetanus in Two Dogs.

Tetanus in dogs is a relatively uncommon neurological disease caused by the sporogenic bacillus Clostridium tetani. This disease is associated with prolonged hospitalization and mortality rates from 8%-50%. A 2-year-old, neutered male King Charles Spaniel and an approximately 8-months-old female Mongrel dog presented to Companion Animal Clinic with symptoms of muscle rigidity and generalized stiffness. A tentative diagnosis of generalized tetanus was made in both dogs. Treatment consisted of IV fluids, antibiotics (metronidazole), human tetanus antitoxin, analgesics and supportive care. Muscle relaxation was provided by midazolam. Acetylpromazine meleate was added to the treatment of the second dog to better control excitability. Each dog received magnesium therapy on the 10th and 3rd days, respectively; which was provided per os to the first dog and constant rate infusion (4 mg/kg/h) to the second dog. The addition of magnesium helped to increase muscle relaxation and increased the time interval between acetylpromazine administration. On the tenth day, magnesium sulfate was discontinued from the second dog and magnesium aspartate (12 mg/kg), twice a day, per os was administered in both animals. Further muscle relaxation was noted in both dogs with a substantial reduction of tetanus symptoms. Both dogs were discharged from Intensive Care Unit on the 14th and 13th day respectively with sole treatment of magnesium aspartate (12 mg/kg) orally, twice a day. Magnesium aspartate was continued for 14 days and 12 days respectively. Both dogs had progressive reduction of muscle rigidity and the first dog recovered completely. The second dog presented again with muscle rigidity and increased spinal reflexes after the discontinuation of magnesium aspartate, thus therapy with magnesium aspartate was started again and symptoms subsided after the second oral dose of magnesium. Therapy was continued for two more weeks during which muscle rigidity subsided and then was stopped. At that time, tetanus symptoms did not relapse and the dog was considered fully recovered. According to the findings of this case series, magnesium therapy may provide further muscle relaxation during the standard therapeutic protocol of tetanus in dogs. In addition, long term symptoms of the disease were adequately managed with the administration of magnesium aspartate, orally.

Evaluation of blood T-lymphocyte subpopulations involved in host cellular immunity in dogs with mammary cancer.

Cancer-bearing patients are often immunosuppressed. In dogs with mammary or other cancers, various alterations in blood cell populations involved in host cellular immunity have been reported; among these cell populations some T-lymphocyte subsets play an important role against cancer. The purpose of the present study was to investigate any alterations in circulating T-lymphocyte subpopulations involved in cellular immunity in bitches with mammary cancer, in comparison to age-matched healthy intact bitches. Twenty eight dogs with mammary cancer and 14 control dogs were included in this study. Twelve out of the 28 bitches had mammary cancer of clinical stage II and 16/28 of stage III. Histological examination revealed that 23/28 animals had carcinomas, 3/28 sarcomas and 2/28 carcinosarcomas. White blood cell, neutrophil and lymphocyte absolute numbers were measured by complete blood count. Furthermore, blood T-lymphocyte population (CD3+) and the subpopulations CD4+, CD8+ and CD5low+ were assessed by flow cytometry. White blood cell and neutrophil but not lymphocyte absolute numbers were higher (P=0.003 and P=0.001, respectively) in cancer patients than controls. Flow cytometric analysis revealed that the relative percentage of T-lymphocytes (CD3+) and of CD4+, CD8+ subpopulations was lower (the CD4+/CD8+ ratio was higher), whereas the percentage of CD5low+ T-cells was higher, in dogs with cancer compared to controls; however, a statistically significant difference was found only in the case of CD8+ T-cells (P=0.014), whereas in the case of the CD4+/CD8+ ratio the difference almost reached statistical significance (P=0.059). Based on these findings, it can be suggested that, although the absolute number of blood lymphocytes is unchanged, the relative percentages of T-lymphocyte subpopulations involved in host cell-mediated immunity are altered, but only cytotoxic CD8+ T-cells are significantly suppressed, in dogs with mammary cancer of clinical stage II or III compared to age-matched healthy controls.

Vaginal rupture and evisceration in a dog.

A 1.5-year-old German Shepherd mixed breed dog was admitted with mild haemorrhage from the vulva and a perineal mass of 24-hour duration, which had been first observed immediately after parturition. Parturition had occurred at low ambient temperature, and only one puppy survived out of the seven oversized fetuses. The dog was in poor body condition, dehydrated, hypothermic, depressed, non-ambulatory and in a state of shock. Intestinal loops, the urinary bladder and the uterine horns and body were protruding from the vulva. A true vaginal prolapse was also observed. The abdominal viscera were flushed with warm sterile saline solution, protected and maintained wet. The laboratory findings included moderate anaemia, leukocytosis, hypoalbuminaemia, azotaemia and elevated liver enzyme activities. Stabilisation of the dog's general condition was attempted before surgery. Antimicrobial and analgesic drugs were also administered. After exploratory laparotomy the protruding organs, which were in good condition, were reduced. A recent rupture in the vaginal wall, approximately 6 cm long, was observed. Ovariohysterectomy and partial vaginectomy were performed. The preoperative course of therapy was continued, but the bitch died 12 hours later. The probable cause of vaginal rupture and evisceration in this bitch was tenesmus and/or trauma due to the oversized fetuses.

Use of a temporary incontinent end-on colostomy in a cat for the management of rectocutaneous fistulas associated with atresia ani.

A 2 1/2-month-old cat was evaluated for the presence of multiple draining tracts ventral to the tail of 8 days duration. Clinical and radiographic examination revealed that the cat had rectocutaneous fistulas and type II atresia ani. The cat underwent a temporary end-on colostomy for faecal diversion. Sixty days after surgery and after the fistulas resolved the animal underwent a second surgery for colostomy closure and anal reconstruction. Two years after surgery the cat was reported to be in good health with no faecal incontinence.