Possible application of oxidative stress parameters for the evaluation of animal welfare in sheltered dogs subjected to different environmental and health conditions

The objective of this study was to establish an additional prognostic parameter to assess animal welfare. We explored the validity of using the thiol antioxidant barrier (SHp) and determination of reactive oxygen metabolites (dROMs) as indicators of stress and welfare in sheltered dogs. The shelter is a stressful environment for a dog because of its unpredictable and uncontrollable nature. The dogs enrolled in the present study belonged to 2 types of animal shelters (shelter 1 and shelter 2) that differed for social and spatial restrictions for the dogs. Animals were tested for leishmaniosis and ehrlichiosis and divided into 4 groups on the basis of their negative (group A and B) or positive (group C and D) status and the shelter they belonged to. The Student t test showed significant differences on SHp concentrations between groups A and B (negative titers; different shelters) (P < 0.0001; t₍₁₀₎ = 11.08), groups C and D (positive titers; different shelters) (P < 0.02; t₍₇₎ = 2.998), and groups A and C (different infection status and same shelter) (P < 0.004; t₍₈₎ = 3.975). Levels of dROMs showed significant differences between groups A and C (different infection status and same shelter) (P < 0.03; t₍₈₎ = 2.552) and groups B and D (different infection status and same shelter) (P < 0.02; t₍₉₎ = 2.817). The high dROMs values recorded in all dogs during the study may be because of the stressful environment of animal shelters, in general. The low SHp concentrations that we found in dogs from shelter 1 may suggest a highly stressful condition related to the poor social environment for interaction. SHp and dROMs may provide useful information about the responsiveness of sheltered dogs subjected to different environmental (social and spatial restrictions, management practices, and diet) and health (negative or positive status for leishmaniosis and ehrlichiosis) conditions and may suggest the possibility of establishing an additional prognostic tool for the assessment of welfare and health in sheltered dogs.     

The effect of volatile anaesthetics on the relative sensitivity of facial and distal thoracic limb muscles to vecuronium in dogs

ObjectiveTo compare n. facialis-m. nasolabialis (nF-mNL) and n. ulnar-mm. carpi flexorii (nU-mCF) sensitivity to vecuronium during halothane or isoflurane anaesthesia.Study designRandomized, prospective, experimental study.AnimalsForty-four client-owned dogs (19 male, 25 female) undergoing surgery; mean age: 5.0 years; mean body mass: 24.7 kg.MethodsThirty minutes after acepromazine (0.05 mg kg^?1) and morphine (0.5 mg kg^?1), anaesthesia was induced with intravenous (IV) thiopental and maintained with either halothane (n = 22) or isoflurane (randomly allocated) in oxygen. The lungs were mechanically ventilated and end-tidal inhaled anaesthetic (Fe’_IAA) maintained at 1.2 × MAC values. Neuromuscular transmission at nF-uNL and nU-mCF was monitored using the train of four count. Vecuronium (50 μg kg^?1 IV) was injected (t = 0) after 15 trains, 50-60 minutes after inhalational anaesthesia began, when Fe’_IAA had been constant for >15 minutes. Times of the disappearance (-) and reappearance (+) of the fourth (T4) and first twitch (T1) were recorded allowing the calculation of: latent (t = 0 to T4-) and manifest onset times (t = 0 to T1-) duration of blockade (T1- to T1+) and drug effect (T4- to T4+) and recovery time (T1+-T4+). Student’s paired t-test was used to compare simultaneous responses at nF-uNL and nU-mCF. An unpaired t-test was used to compare anaesthetic effects.ResultsLatent and manifest onset times were significantly (p < 0.05) briefer, blockade and drug effects were significantly longer and recovery from blockade were significantly slower in the nF-mNL unit in both halothane and isoflurane recipients. Profound block duration and drug action were significantly longer and recovery from blockade were significantly slower in halothane recipients at both nerve-muscle units.Conclusion and clinical relevanceThe nF-mNL was more sensitive than nU-mCF to vecuronium, particularly in halothane-anaesthetized dogs.     

Determination and correlation of anti-Neospora caninum antibodies in dogs and cattle from Mexico

The aim of the present study was to determine and to compare through an indirect enzyme linked immunosorbent assay (ELISA) test, the presence of anti-Neospora caninum antibodies in city and farm dogs, as well as in farm cows, and the relationship among them. The correlation between anti-N. caninum antibodies in farm dogs and cattle was also assessed. The research was conducted in the dairy region of Tizayuca, Hidalgo, Mexico. The frequency of anti-N. caninum antibodies was significantly higher in farm dogs (n = 14) (51%) when compared to those from the city (n = 6) (20%) (P < 0.05), suggesting that farm dogs have a higher risk of exposure to the parasite. There was no significant difference in seropositivity between males (n = 11) (39%) and females (n = 9) (33%) (P > 0.05). The frequency of anti-N. caninum antibodies in farm cattle was significantly higher in farms with dogs (n = 158) (58%) when compared to those with no dogs (n = 43) (35%) (P < 0.05). These results suggest the possible transmission of the parasite from dogs to cattle.     

The post-tetanic count during vecuronium-induced neuromuscular blockade in halothane-anaesthetized dogs

ObjectiveTo evaluate the post‐tetanic count (PTC) for predicting the return of reversible neuromuscular blockade at the n. facialis–m. nasolabialis (nF–mNL) and n. ulnaris–mm. carpi flexorii (nU–mCF) nerve‐muscle units (NMUs) during profound vecuronium neuromuscular blockade in halothane‐anaesthetized dogs.Study designRandomized, prospective, experimental study.AnimalsTwenty‐five dogs (seven male 18 female) undergoing surgery; mean age: 4.8 years; mean body weight 22 kg.MethodsThirty minutes after acepromazine (0.05 mg kg^?1) and morphine (0.5 mg kg^?1) pre‐medication, anaesthesia was induced with intravenous (IV) thiopental and maintained with halothane, N₂O and O₂. The lungs were mechanically ventilated and end‐tidal halothane concentration (Fe′_HAL) maintained at 1.04%. Neuromuscular transmission was monitored using the train‐of‐four count (TOFC) at one nF–mNL and both nU–mCF units. Vecuronium (50 µg kg^?1 IV) was injected after 15 minutes constant Fe′_HAL. When the first twitch (T1) at both nU–mCF units had disappeared (t = 0) one (randomly allocated) ulnar nerve was stimulated every 5 minutes using PTC; TOF stimulation continued at the other sites. The PTC was plotted against the interval between recording time and T1's reappearance at the other NMUs.ResultsAt t = 0, the mean PTC in the contralateral nU–mCF unit was 18 (range 0–20). Mean PTC was a minimum at t = 5, rising to the maximum (20) at 25 minutes. Six dogs were vecuronium‐resistant as monitored by PTC. Excluding data from these revealed a strong negative relationship between ulnar PTC and the time taken for T1's return at the facial (r = ?0.7018; p < 0.00001) and contralateral ulnar (r = ?0.8409; p < 0.00001) NMUs.Conclusion and clinical relevancePost‐tetanic count monitoring beginning >5 minutes after the TOFC at nU–mCF = 0 provided a reliable estimate of T1's return at ulnar and facial NMUs.     

Dogs' features strongly affect people's feelings and behavior toward them

Dogs are a strong appeal for people. The aim of this research was to assess whether different dog features affect people's feelings and behavior toward them. Three puppies (1 Labrador retriever, 1 golden retriever, and 1 Border collie), 7 average adult dogs (3 small, 2 medium, and 2 large), and 2 adult pit bulls (1 black and 1 brown) were involved. They were on the leash with handlers (12 girls) who were instructed to maintain a neutral posture of waiting. People who passed in front of the dog–handler couple were videorecorded and then interviewed through an 8-item questionnaire. Most passersby (81.7%) noticed the dog. Tenderness was higher for the puppies (64.9%) in comparison to the average adult dogs (35.4%) and pit bulls (10.8%) (χ² = 100.442; P = 0.000). Pit bulls left more passersby indifferent (36.3%), followed by the medium-sized dogs (26.5%) and then the small dogs (19.2%) (χ² = 37.268; P = 0.000). Fear was more common at the sight of a pit bull (10.8%), especially when compared with a puppy (2.3%) or a small dog (0.7%) (χ² = 17.723; P = 0.001). More respondents desired to interact with puppies (49.1%) than with pit bulls (22.5%; χ² = 11.133; P = 0.000), and they actually related with young dogs (20.5%) more than with the pit bulls (4.9%). A high statistical difference can be observed for the behavior of participants toward the different categories of dogs (χ² = 43.519; P = 0.000) and their handlers (χ² = 23.854; P = 0.000). In detail, passersby showed more interest toward puppies and interacted more with puppies and large dogs, and their handlers, compared with dogs showing different features.Some factors related to passersby could affect the dog catalysis effect. Women interacted with the handlers more than men did (12.1% vs. 7.3%; χ² = 3.980; P = 0.046), but no difference was observed for the number of interactions with dogs.Passersby handling a dog were more predisposed to interact with the experimental dog (45.6% vs. 7.5%; χ² = 139.606; P = 0.000) and his or her handler (43.5% vs. 5.7%; χ² = 64,526; P = 0.000). Data suggest that puppies and pit bulls are at the 2 extremes of the dog appeal–people axis, with average dogs in the middle.     

Evaluation of auditory evoked potentials to predict depth of anaesthesia during fentanyl/fluanisone−midazolam anaesthesia in rats

Objectives To assess a method for monitoring depth of anaesthesia using components of middle latency auditory evoked potential (AEP) waveforms during anaesthesia with fentanyl/fluanisone and midazolam. Study design Prospective observational study. Animals Five female Wistar rats weighing between 210 and 250 g. Methods Implanted electrodes were used to record AEPs in animals receiving five doses of anaesthetic. Recordings were made at 5 minutes post‐injection (deep anaesthesia; no pedal withdrawal response, PWR) and then at 25 minutes (light anaesthesia; strong PWR). Responses showed five characteristic peaks occurring at 11, 14, 23, 42 and 68 ms that were measured for latency of occurrence and peak amplitude. Results Auditory evoked potential peaks P14, N23 and P42 were increased significantly in latency with successive anaesthetic injections [avg. F(1,4) = 12.53, p < 0.001; avg. F(1,4) = 10.6, p < 0.001; avg. F(1,4) = 3.9, p = 0.02, respectively]. Peak N23 showed a significant reduction in latency during the 20 minute recovery period following both the first and second anaesthetic injections (t(3) = 7.52, p = 0.005; t(4) = 5.17, p = 0.007, respectively). Peak P42 occurred significantly earlier 20 minutes following the second anaesthetic injection (t(4) = 4.75, p = 0.009). The mean overall depth of anaesthesia assessed using PWR scores was significantly correlated with the mean latency of peak N23, such that as the strength of PWR increased, N23 occurred significantly earlier (r = ?0.99, p = 0.01). The amplitude difference between peaks N23 and P42 increased after the second and third drug administrations [avg. F(1,4) = 10.65, p = 0.031 and avg. F(1,4) = 11.24, p = 0.028, respectively]. Conclusion The characteristics of these peaks, and in particular latency of peak N23, may provide a useful tool for assessing depth of anaesthesia produced by this, and possibly other anaesthetic agents.     

Comparison between dexmedetomidine and acepromazine in combination with methadone for premedication in brachycephalic dogs undergoing surgery for brachycephalic obstructive airway syndrome

ObjectiveTo compare dexmedetomidine with acepromazine for premedication combined with methadone in dogs undergoing brachycephalic obstructive airway syndrome (BOAS) surgery.Study designRandomized, blinded clinical study.AnimalsA group of 40 dogs weighing mean (± standard deviation) 10.5 ± 6 kg, aged 2.6 ± 1.9 years.MethodsDogs received either acepromazine 20 μg kg^–1 (group A) or dexmedetomidine 2 μg kg^–1 (group D) intramuscularly with methadone 0.3 mg kg^–1. Anaesthesia was induced with propofol and maintained with sevoflurane. Sedation (0–18), induction (0–6) and recovery (0–5) qualities were scored. Propofol dose, hypotension incidence, mechanical ventilation requirement, extubation time, additional sedation, oxygen supplementation, regurgitation and emergency intubation following premedication or during recovery were recorded. Data were analysed using t tests, Mann-Whitney U or Chi-square tests.ResultsGroup A dogs were less sedated [median (range): 1.5 (0–12)] than group D [5 (1–18)] (p = 0.021) and required more propofol [3.5 (1–7) versus 2.4 (1–8) mg kg^–1; p = 0.018]. Induction scores [group A: 5 (4–5); group D 5 (3–5)] (p = 0.989), recovery scores [group A 5 (4–5); group D 5(3–5)](p = 0.738) and anaesthesia duration [group A:93 (50–170); group D 96 (54–263) minutes] (p = 0.758) were similar between groups. Time to extubation was longer in group A 12.5 (3-35) versus group D 5.5 (0–15) minutes; (p = 0.005). During recovery, two dogs required emergency intubation (p > 0.99) and five dogs required additional sedation (p > 0.99). Oxygen supplementation was required in 16 and 12 dogs in group A and D, respectively (p = 0.167); no dogs in group A and one dog in group D regurgitated (p = 0.311).Conclusions and clinical relevanceDexmedetomidine 2 μg kg^–1 produces more sedation but similar recovery quality to acepromazine 20 μg kg^–1 combined with methadone in dogs undergoing BOAS surgery.     

The effect of breed on age-related changes in behavior and disease prevalence in cognitively normal older community dogs,Canis lupus familiaris

Variation in breed longevity in the dog has led to the inference that large dogs age at a faster rate than small dogs, possibly because of an increased oxidative load. Potential differences in behavioral aging (the rate of age-related decline in cognito-behavioral performance) across breeds represent a significant challenge to veterinarians and scientists. Using data from a large cross-sectional survey of older dog owners, we aimed to identify breed differences in behavioral aging in successfully aged dogs ≥8 years of age. Differences based on longevity (short-lived, <11 years; medium-lived, 11-13 years; and long-lived, >13 years), size (small-sized, <35 cm; medium-sized, 35-55 cm; and large-sized, >55 cm), and breed (pure vs. crossbred) were identified using binary logistic regression. Significant breed differences across longevity group were seen in 2 behavioral responses: dogs drinking >1 L/d (P = 0.001, maximum difference between groups = 16.4%) and dogs showing aggression (P = 0.006, maximum difference between groups = 15.1%). In purebred dogs, 8 responses (P < 0.001-0.008, maximum difference between groups = 8.4%-20%) showed significant differences across size group compared with 1 response, in crossbred dogs (P = 0.008, max difference between groups = 28.4%). Significant differences were observed across longevity group in the prevalence of arthritis (P = 0.014) and across size group in the prevalence of arthritis (P < 0.001) and blindness (P = 0.014). In medium-sized dogs, 2 age × breeding group interactions were seen in ingestive behavior (P = 0.037) and aggression (P = 0.028). In large-sized dogs, 1 age × breeding group interaction was seen in abnormal locomotion (P = 0.025). A consistent direction in the differences identified was not seen across all analyses. In general, these data did not suggest an increased rate of behavioral aging in large, short-lived dogs. It is possible that size-dependent aging affects body systems differently or, alternatively, owner’s management may differ between small and large dogs, resulting in differences in behavior.     

Prevalence of antibodies to Neospora caninum in dogs of rural or urban origin in central New Zealand

AIM: To investigate the seroprevalence of Neospora caninum infection in populations of dogs from dairy farms, sheep/beef farms and urban areas in the central part of New Zealand. It was postulated seroprevalence would be higher for farm dogs than urban dogs if the life-cycle of this parasite involves transmission between dogs and cattle.

METHODS: Serum samples were obtained from dogs that lived on dairy farms (n=161), sheep/beef farms (n=154) and in urban situations (n=150). The relative risk of detecting antibodies to N. caninum using an immunofluorescent antibody test (IFAT) was compared between farm and urban dogs.

RESULTS: The relative risk of having a titre of ≥1:200 to N. caninum was 2.43 (95% CI=1.88-3.14) for dairy-farm dogs and 3.16 (95% CI=2.48–4.02) for sheep/beef-farm dogs, compared with urban dogs. At this titre, which is currently used in New Zealand to indicate seropositivity, seroprevalence of N. caninum infection was 30.7% in urban dogs, 74.5% in dairy-farm dogs and 96.8% in sheep/beef-farm dogs.

CONCLUSION: This observation is consistent with a cycling of this disease between cattle and dogs on farms in New Zealand and with higher exposure of dogs to N. caninum on farms than occurs in urban environments. The prevalence of antibodies in all three groups of dogs tested in this study (dairy-farm dogs, sheep/beef-farm dogs and urban dogs) is higher than has generally been reported elsewhere. New Zealand farm dogs have a higher serological prevalence of N. caninum infection than urban dogs.

CLINICAL RELEVANCE: Management and disease control practices that break the life-cycle of transmission between cattle and dogs should assist in controlling cattle abortion due to N. caninum.     

Evaluation of cerebrospinal fluid lactate and plasma lactate concentrations in anesthetized dogs with and without intracranial disease

The objectives of this study were to establish a reference interval for canine cerebrospinal fluid lactate (CSFL) and to compare CSFL and plasma lactate (PL) concentrations in anesthetized dogs with and without intracranial disease. Using a prospective study, canine blood and cerebrospinal fluid were collected for lactate analysis in 11 dogs with intracranial disease after undergoing magnetic resonance imaging (MRI) (Group ID-MRI), in 10 healthy dogs post-MRI (Group H-MRI), and in 39 healthy dogs after induction of anesthesia (Group H-Sx). Dogs were anesthetized for the procedures using different anesthetic protocols. Neurological scores (NS) and sedation scores (SS) were assessed pre-anesthesia in ID-MRI dogs. The CSFL reference interval [90% confidence interval (CI) for lower and upper limits] was 1.1 (1.0 to 1.2) to 2.0 (2.0 to 2.1) mmol/L. Mean ± SD CSFL concentrations were: ID-MRI, 2.1 ± 0.8; H-MRI, 1.6 ± 0.4; and H-Sx, 1.6 ± 0.2 mmol/L. There was a tendency for higher CSFL in dogs in the ID-MRI group than in those in the H-MRI or H-Sx groups (P = 0.12). There was agreement between CSFL and PL in ID-MRI dogs (P = 0.007), but not in dogs in H-MRI (P = 0.5) or H-Sx (P = 0.2). Of the ID-MRI dogs, those with worse NS had higher CSFL (r² = 0.44). The correlation between CSFL and PL in dogs with intracranial disease and between worse NS and higher CSFL warrants further investigation into the use of CSFL and PL for diagnostic and prognostic purposes.     

Effect of Supplementation With Omega-3 Fatty Acids,Magnesium, and Zinc on Canine Behavioral Disorders: Results of a Pilot Study

Recent discoveries have shown that the chances of a dog developing a behavioral disorder may depend upon a number of factors including nutrition. The current pilot study was designed to provide an assessment of the efficacy of a dietary supplement containing omega-3 fatty acids, magnesium, and zinc on some common behavioral disorders in a population of Iranian domestic dogs. In total, 48 dogs including 6 dogs without any behavior disorder (control group) and 42 dogs with at least 1 common behavioral disorder, namely excessive activity, inappropriate elimination, fearfulness, destructiveness, and aggression toward unfamiliar people and dogs (test group), were given daily oral dose of gelatin capsules of fish oil supplements containing 330 mg eicosapentaenoic acid and 480 mg docosahexaenoic acid. Moreover, all dogs received 12-15 mg/kg of magnesium citrate and 5 mg/kg of zinc sulfate. Data were obtained using a questionnaire that dog owners were invited to fill out 2 times before (Days 0 and 42) and 2 times after the supplement treatment period (Days 84 and 126). The questionnaire asked owners whether their dog had exhibited any of the 6 common behavioral disorders on a 5-point Likert-like scale ranging from 0 (never or very rarely) to 4 (very often). The results showed no significant changes for any of the evaluated behavior disorders scale in the control group. In dogs with behavior disorders, results showed a significant reduction in the median score for the severity of fearfulness (P?=?.0083), destructiveness (P?=?.002), and inappropriate elimination (P < .001). In addition, there were no significant differences in the median score for the severity of excessive activity (P = .162), aggression toward dogs (P = .281), and aggression toward unfamiliar people (P = .09) during the course of the study. Results of the study reported here support the hypothesis that a combination of omega-3 fatty acids, magnesium, and zinc may improve some of the behavioral disorders.     

The effects of medetomidine on the action of vecuronium in dogs anaesthetized with halothane and nitrous oxide

ObjectiveTo quantify the effects of medetomidine on the onset and duration of vecuronium-induced neuromuscular blockade in dogs.Study designRandomized, prospective clinical study.AnimalsTwenty-four, healthy, client-owned dogs of different breeds, aged between 6 months and 10 years and weighing between 5.0 and 40.0 kg undergoing elective surgery.MethodsDogs were randomly allocated to two groups. Pre-anaesthetic medication in group M+ was intramuscular acepromazine (ACP) 25 μg kg⁻¹, morphine 0.5 mg kg⁻¹ and medetomidine 5 μg kg⁻¹. Group M− received ACP and morphine only, at the same dose rate. After induction with thiopental, anaesthesia was maintained with halothane in oxygen and nitrous oxide. End-tidal halothane concentration was maintained at 1.1%. Neuromuscular blockade was produced with intravenous vecuronium (50 μg kg⁻¹) and monitored using a train of four stimulus applied at the ulnar nerve. The times taken for loss and reappearance of the four evoked responses (twitches [T]) were recorded. Normal and nonparametric data were analysed with an independent t-test and Mann-Whitney's U-test, respectively.ResultsThe fourth twitch (T4) disappeared at similar times in each group: 107 ± 19; [72–132] (mean ± SD; [range]) seconds in M+ and 98 ± 17 [72–120] seconds in M− dogs. The first twitch (T1) was lost at 116 ± 15; [96–132] seconds in group M+ and 109 ± 19; [72–132] seconds in M−. The fourth twitch returned significantly earlier in M+ dogs: 20.8 ± 3.8 [14–28] minutes compared with 23.8 ± 2.7 [20–27] minutes (p = 0.032). The duration of drug effect (T4 absent) was significantly shorter (p = 0.027) in M+ (18.9 ± 3.7 minutes) compared with M− dogs (22.2 ± 2.9 minutes). The recovery rate (interval between reappearance of T1 and T4) was significantly more rapid (p = 0.0003) in medetomidine recipients (3.0 ± 1.2 versus 5.2 ± 1.3 minutes).Conclusion and clinical relevance Medetomidine 5 μg kg⁻¹ as pre-anaesthetic medication shortened the duration of effect of vecuronium in halothane-anaesthetized dogs and accelerated recovery, but did not affect the onset time. These changes are of limited clinical significance.     

Effects of pre‐operative administration of medetomidine on plasma insulin and glucose concentrations in healthy dogs and dogs with insulinoma

ObjectiveTo investigate the effect of medetomidine on plasma glucose and insulin concentrations in dogs with insulinoma and in healthy dogs undergoing anesthesia and surgery.AnimalsTwenty–five dogs with insulinoma and 26 healthy dogs.MethodsIn dogs with insulinoma, medetomidine (5 μg kg^?1) was randomly included (n = 12) or omitted (n = 13) from the pre–anesthetic medication protocol, which typically contained an opioid and an anticholinergic. Healthy dogs received medetomidine (5 μg kg^?1; n = 13) or acepromazine (0.04 mg kg^?1; n = 13) plus an opioid (morphine 0.5 mg kg^?1) and an anticholinergic (atropine 0.04 mg kg^?1) as pre–anesthetic medications. Pre–anesthetic medications were given intramuscularly. Plasma glucose and insulin concentrations were measured before (sample 1) and 30 minutes after pre–anesthetic medication (sample 2), and at the end of surgery in dogs with insulinoma or at 2 hours of anesthesia in healthy dogs (sample 3). Glucose requirement to maintain intra–operative normoglycemia in dogs with insulinoma was quantified and compared. Data were analyzed with anova and Bonferroni post–test, t–tests or chi–square tests as appropriate with p < 0.05 considered significant. Data are shown as mean ± SD.ResultsMedetomidine significantly decreased plasma insulin concentrations and increased plasma glucose concentrations in healthy dogs and those with insulinoma. These variables did not change significantly in the dogs not receiving medetomidine. In the dogs with insulinoma, intra–operative glucose administration rate was significantly less in the animals that received medetomidine compared to those that did not.ConclusionsPre–anesthetic administration of medetomidine significantly suppressed insulin secretion and increased plasma glucose concentration in dogs with insulinoma and in healthy dogs undergoing anesthesia and surgery.Clinical relevanceThese findings support the judicious use of medetomidine at low doses as an adjunct to the anesthetic management of dogs with insulinoma.     

A comparison of epidural analgesia provided by bupivacaine alone,bupivacaine + morphine,or bupivacaine + dexmedetomidine for pelvic orthopedic surgery in dogs

ObjectiveTo compare the analgesic efficacy of bupivacaine, bupivacaine + morphine, or bupivacaine + dexmedetomidine administered epidurally in dogs undergoing pelvic limb orthopedic surgery.Study designProspective, randomized, double blinded clinical trial.AnimalsSixty dogs weighing (mean ± SD) 35 ± 15.7 kg, aged 5 ± 3 years.MethodsDogs were assigned to receive a lumbosacral epidural containing bupivacaine (B) 0.5%, 1 mg kg^?1; B, bupivacaine 0.5%, 1 mg kg^?1 + morphine 1%, 0.1 mg kg^?1; B + M, or bupivacaine 0.5%, 1 mg kg^?1 + dexmedetomidine 0.05%, 4 μg kg^?1; B + D. The anesthetic protocol was standardized. The median expired isoflurane concentration (E′Iso) and requirement for additional induction agent preventing purposeful movement were recorded. Pain was scored using visual analog (VAS) and modified University of Melbourne (UMPS) pain scales. Sedation was assessed using a 0–4 scale. All parameters were recorded preoperatively, and at extubation (t = 0), then at 1, 2, 4, 8, 12, 16, and 20–24 hours. Hydromorphone was administered postoperatively to patients with a VAS ≥ 35 and/or UMPS ≥ 9. Time to first voluntary urination and first motor activity were recorded.ResultsPostoperatively, B + D had a lower UMPS pain score than B at t = 1 hour (p = 0.013), but not compared to B + M. The B + D group had a shorter time to urination (p = 0.0131) and a longer time for return of motor function (p = 0.0068). There were no other differences between the treatments.Conclusion and clinical relevanceEpidurally administered B, B + M, or B + D in dogs all provided acceptable analgesia to manage post–operative orthopedic pelvic limb pain. Epidural administration of B + D is an effective alternative to the analgesia provided by B or B + M, but is associated with increased time to return of motor function. The direct neurotoxic effects of epidural dexmedetomidine have not been fully tested.     

Prevalence of Antibodies to Neospora caninum and Toxoplasma gondii in Swedish Dogs

Neospora caninum is a newly described coccidian parasite which has been found in various species such as the dog, cattle, horse, sheep and goat. Morphologically it resembles Toxoplasma gondii with which it is related (Holmdahl et al. 1994), and with which it has earlier been confused. The life cycle of N caninum is only partially known. Tachyzoites and tissue cysts are the only known stages of the parasite, and transplacental transmission is the only known route of infection. Subclini-cally infected dams can transmit the parasite to their fetuses and successive offspring from the same mother might be born infected (Dubey et al. 1990b). Clinical neosporosis is mostly seen in pups or young dogs, and the majority or all pups in a litter are often affected. The disease is characterized by ascending paralysis of the legs, with the hind legs more severely affected than the front legs, paralysis of the jaw, difficulty in swallowing and muscle flaccidity and atrophy (Dubey 1992, Dubey & Lindsay 1993). Fatal infections with N caninum in dogs have been reported from many countries, e.g. Norway (Bjerkäs & Presthus 1988), USA (Dubey et al. 1988), Sweden (Uggla et al. 1989a,b) and the United Kingdom (Dubey et al. 1990a). Serological surveys for antibodies to N. caninum in dogs from Kansas, USA and England have shown a prevalence of 2 and 13%, respectively (Lindsay et al. 1990, Trees et al. 1993).     

ANXITANE® tablets reduce fear of human beings in a laboratory model of anxiety-related behavior

Anxiety and fear are common underlying factors in many canine behavior problems that impair the human–pet bond and often result in abandonment, relinquishment, or euthanasia. A combination of behavioral and pharmacological interventions is used to ameliorate the behavioral signs associated with anxiety-related behaviors in dogs, but there continues to be need for effective interventions. The current study examined the effects of the nutraceutical ANXITANE^® (l-Theanine) chewable tablets on fear of unfamiliar human beings. We first characterized dogs as anxious on the basis of the existence of a fear response to human beings in their home-pen. We then demonstrated that dogs characterized as anxious (N = 10) showed reduced interaction with an unknown human being as compared with normal controls (N = 7). The effect of an administration of ANXITANE^® tablets (N = 5) on these anxious Beagle dogs was compared with placebo (N = 5). Objective behavioral measures of anxiety were obtained using an open-field test, a human interaction test, and an actiwatch protocol that allowed monitoring of activity over 24-hours. The ANXITANE^® tablets-treated dogs showed greater human interaction and approach than the placebo control group, and no side effects related to treatment, including motor stimulant or sedative effects, were seen. The current study suggests that ANXITANE^® tablets are effective for reducing fearful behavior toward unfamiliar human beings in dogs and supports their use for treating anxiety-related behaviors.     

The effect of body condition on propofol requirement in dogs

ObjectiveTo determine if body condition score (BCS) influences the sedative effect of intramuscular (IM) premedication or the dose of intravenous (IV) propofol required to achieve endotracheal intubation in dogs.Study designProspective clinical study.AnimalsForty–six client–owned dogs undergoing general anaesthesia.MethodsDogs were allocated to groups according to their BCS (BCS, 1 [emaciated] to 9 [obese]): Normal–weight Group (NG, n = 25) if BCS 4–5 or Over–weight Group (OG, n = 21) if BCS over 6. Dogs were scored for sedation prior to IM injection of medetomidine (5 μg kg^?1) and butorphanol (0.2 mg kg^?1) and twenty minutes later anaesthesia was induced by a slow infusion of propofol at 1.5 mg kg^?1 minute^?1 until endotracheal intubation could be achieved. The total dose of propofol administered was recorded. Data were tested for normality then analyzed using Student t–tests, Mann–Whitney U tests, chi–square tests or linear regression as appropriate.ResultsMean ( ± SD) propofol requirement in NG was 2.24 ± 0.53 mg kg^?1 and in OG was 1.83 ± 0.36 mg kg^?1. The difference between the groups was statistically significant (p = 0.005). The degree of sedation was not different between the groups (p = 0.7). Post–induction apnoea occurred in 11 of 25 animals in the NG and three of 21 in OG (p = 0.052).ConclusionsOverweight dogs required a lower IV propofol dose per kg of total body mass to allow tracheal intubation than did normal body condition score animals suggesting that IV anaesthetic doses should be calculated according to lean body mass. The lower dose per kg of total body mass may have resulted in less post–induction apnoea in overweight/obese dogs. The effect of IM premedication was not significantly affected by the BCS.Clinical relevanceInduction of general anaesthesia with propofol in overweight dogs may be expected at lower doses than normal–weight animals.     

Evaluating aggressive behavior in dogs: a comparison of 3 tests

This study assessed the consistency with which aggressive behavior occurred across 3 different provocation tests that are currently used in practice to evaluate the behavior and safety of dogs. The aim of this study was not to validate the tests, but to evaluate tests that are not validated but are nevertheless being used in a legal context in Switzerland, by investigating the hypothesis that 3 different approaches, all claiming to correctly evaluate the behavior of dogs, should be expected to show significant agreement. The same 60 dogs were tested in 3 behavioral tests being used in Switzerland at the time of this study in the year 2003 (Test A: Test of the American Staffordshire Terrier Club; Test B: Halterprüfung; Test C: Test of the Canton of Basel-Stadt). “Intraspecific behavior” and “interspecific behavior toward humans” that might relate to potential aggressive behavior were of particular interest.The observed agreement among the 3 tests was compared relative to chance using a κ test. Significant but low levels of agreement were found among the 3 tests for the criterion “intraspecific behavior” (κ = 0.133, P = .014), with the highest correlation between Tests A and B (κ = 0.345, P < .001) and for the criterion “interspecific behavior” (κ = 0.135, P = 0. 014), with Tests A and B (κ = 0.220, P = .005) showing the highest correlation. However, significant absolute values of κ were low in all cases. In a further analysis, dogs evaluated to show no signs of potential aggression in the test situations by all 3 tests were eliminated, and the results of the remaining dogs (“interspecific behavior,” n = 23; “intraspecific behavior,” n = 29) were assessed for disagreement in pairwise combinations using a McNemar chi-square test. No significant levels of disagreement were found for “intraspecific behavior,” however, for “interspecific behavior,” Tests A and B (P = .035), and Tests B and C (P < .001) differed significantly, with no significant difference between Tests A and B (P = 0.11). The inconsistency of the results from different tests suggests test bias at the very least and questions the validity of these tests. Further work examining the validity of each individual test is warranted if they are to be used in a legal context.     

Efficacy of a diet containing caseinate hydrolysate on signs of stress in dogs

The purpose of this randomized, double-blind, placebo-controlled trial was to evaluate the efficacy of a diet containing caseinate hydrolysate (CH) on signs of stress in 2 groups of dogs (defined as Anxious and Nonanxious), using physiological (serum cortisol and lysozyme, N:L ratios and heart rate) and behavioral parameters.From an initial group of 40 female Beagle dogs, ranging in age from 10 months to 4 years (mean = 1.47 years; SD = 0.53) belonging to a dog colony, 32 were selected for this study according to their level of anxiety. A group of 16 Anxious dogs and a group of 16 Nonanxious dogs were identified.A baseline period, aimed to obtain reference values of investigated parameters, preceded the experimental phase. Both groups (Anxious and Nonanxious) were divided into a treatment group, which received the diet containing CH, and a control group which received a placebo diet (PD). Anxious CH and PD groups were balanced for anxiety level. Each dog was evaluated 3 times a day at 4 weeks intervals (T1-T2-T3). Each evaluation lasted 2 days and involved a Reactivity Evaluation Form, a blood sampling, heart rate recording, and a 10-minute behavioral video recording. Results from Reactivity Evaluation Form scores showed that although at T1 Anxious dogs had significantly higher scores (Mann–Whitney test, P < 0.001) compared with Nonanxious dogs, no difference was found between Anxious dogs fed with CH diet and Nonanxious fed with PD or CH diet at T3. Behavioral observations evidenced some signs of improvement in Anxious dog fed with CH diet. Cortisol level significantly decreased in Anxious dogs fed with CH diet (Friedman test, P < 0.05). Individual differences in physiological measures of stress responses may have contributed to the large variability, making interpretation of these measures difficult. These results suggest that CH may be used as a functional ingredient alleviating stress in dogs.     

Urinary corticoid to creatinine ratios using IMMULITE 2000 XPi for diagnosis of canine hypercortisolism

The urinary corticoid to creatinine ratio (UCCR) is one of the most commonly used screening tests for canine hypercortisolism (HC). In this study, a reference interval was established for UCCR using IMMULITE 2000 XPi, the latest chemiluminescence enzyme immunoassay. The diagnostic performance of this method for UCCR in canine HC was also evaluated. The median UCCR was 1.06 × 10⁻⁵ (range: 0.28–2.49) for 58 healthy dogs, and an upper reference limit of 1.98 × 10⁻⁵ (90% confidence interval: 1.76–2.15) was determined. The median UCCR in the 12 dogs with HC (7.38 × 10⁻⁵, range 1.86–29.98) was significantly higher than that in the 16 dogs with mimic-HC (1.59 × 10⁻⁵, range 0.47–3.42, P<0.001). The area under the curve for UCCR to differentiate HC dogs from mimic-HC dogs was 0.971, with a sensitivity of 91.7% and specificity of 100% when the cut-off value was set at 3.77 × 10⁻⁵. The UCCR of 16 paired urine samples collected at home and in hospital showed that the UCCR of samples collected in the hospital was significantly higher than that of samples collected at home (mean difference 3.30 × 10⁻⁵, 95% confidence interval: 0.70–5.90, P=0.001). In summary, we established the upper reference limit for UCCR using IMMULITE 2000 XPi in dogs and confirmed that UCCR is a useful diagnostic test for HC in dogs if urine samples are collected at home.