The effect of thyroid replacement in dogs with suboptimal thyroid function on owner-directed aggression: A randomized,double-blind,placebo-controlled clinical trial

The efficacy of thyroid hormone replacement therapy (THRT) as treatment for owner-directed aggression in client-owned dogs with borderline low thyroid hormone levels was evaluated by means of a 6-week-long, parallel design, double-blind placebo-controlled study. The designation of “borderline hypothyroid” was made if the dog's free normal thyroxine (T4) value was frankly low or in the bottom 20th percentile of the normal range and either total T4, total triiodothyronine (T3), or free T3 was frankly low or in the bottom 30th percentile of the normal range. The presence of thyroid autoantibodies also qualified a dog for enrollment. Owners recorded the number of aggressive episodes directed toward family members on a daily basis for 8 weeks (2-week baseline phase and 6-week study phase). Twenty-nine dogs completed the study; 14 in a treatment group and 15 in a placebo group. The median number of aggressive episodes per day decreased significantly from baseline in both treated and placebo group dogs in weeks 1-2, 3-4, 5-6, and week 6 (treatment, χ² = 24.8, P < 0.001; placebo, χ² = 20.2, P < 0.001), however the median frequency of aggression was significantly lower in the treatment group (1.21 episodes/day) than in the placebo group (1.71 episodes/day) during week 6 of the study (χ² = 4.047, P = 0.044). Three thyroxine-treated dogs had borderline-low thyroid levels on the final day of the study (day 42). When aggression frequency was compared between the treatment and placebo groups after the removal of 3 thyroxine-treated dogs, the treatment group did not have a significantly lower aggression frequency than the placebo group during week 6 (Kruskal–Wallis statistic: χ² = 3.035, n = 26, P = 0.08). The authors discuss the role of thyroid hormones in the regulation of aggression and other cognitive issues and provide rationale for using THRT in dogs exhibiting owner-directed aggression that also have low normal or baseline thyroid hormone levels.     

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.     

The prevention of undesirable behaviors in dogs: effectiveness of veterinary behaviorists' advice given to puppy owners

The management of puppies is considered of great importance in raising well-behaved adult dogs. This research aimed to assess the effectiveness of advice provided by a veterinary behaviorist regarding puppy-raising practices.Forty-six puppy owners received advice by a veterinary behaviorist concerning puppy raising during the puppy's first visit to a veterinarian. A control group was composed of 43 different dogs whose owners were not counseled by a veterinary behaviorist during the puppy's first veterinary visit. Owners were interviewed about their dog's behaviors at the time of their 1-year booster vaccination visit. The 89 dogs were clinically healthy, between 11 and 18 months old, 53% females and 47% males, of various or mixed breeds.Dogs whose owners received advice displayed less undesirable behaviors than the control group, such as: house soiling (2% vs 23%; χ² = 19.50; P < .01), mounting (26% vs 49%; χ² = 12.11; P < .05), nonstop playing (0% vs 12%; Fisher's exact test P < .05), mouthing of people (11% vs 37%; χ² = 7.15; P < .01), begging for food (17% vs 42%; χ² = 5.31; P < .05), or demanding food from the table (0% vs 12%; Fisher's exact test P < .05). Moreover, the experimental group showed less aggressive behaviors toward unknown people (26% vs 2%; Fisher's exact test P < .01) and dogs (16% vs 2%; Fisher's exact test P < .05).The advice provided was effective in diminishing the incidence of undesirable behaviors in the dogs studied. The positive effect of a behaviorist's advice is remarkable given that the puppies in the experimental group had remained with their mother and littermates for less than 2 months, which is believed to be a high-risk condition for development of behavioral disorders.     

Relationship between management factors and dog behavior in a sample of Argentine Dogos in Italy

Owners' husbandry choices may affect the expression of dogs' behavior. In this study, the relationship management-behavior was explored in 181 Argentine Dogos owned by 94 dog owners who answered 35 Yes/No questions on their dogs' behavior (e.g., obedience, aggression, and fear) and 10 single-choice questions on dogs' husbandry. The association management-behavior was explored with χ². Kennel-living dogs were more aggressive than house-living ones (food protection, P = 0.017; owner-directed aggression, P = 0.050; stranger-directed aggression, P = 0.031; same-sex dog aggression, P = 0.028), whereas the latter were more obedient (P < 0.001), destructive (P = 0.048) and friendly with people (P = 0.002) and dogs (P < 0.001). Physical punishment was associated with food protection (P = 0.023) and owner-directed aggression (P = 0.026). Dog-showing was inversely associated with pulling on the leash (P = 0.007), and fears of environmental stimuli (i.e., traffic, P = 0.001; startling stimuli, P = 0.031; loud noises, P = 0.018). Frequent play sessions were negatively related to fear of startling stimuli (P = 0.039) and positively to obedience (P < 0.001) and friendliness toward strangers (P = 0.004). Short daily walks were associated with fears of environmental stimuli (startling stimuli, P < 0.001; loud noises, P = 0.033), destructiveness (P = 0.054), low concentration (P = 0.025) and poor results in training sessions (P < 0.001). Obedience training was positively associated with obedience (P < 0.001), mounting people (P = 0.003), aggression to handling (P = 0.002) and food removal (P = 0.041). Without establishing cause–effect relationships between management and behavior, this survey highlights husbandry aspects that need careful evaluation because there are associated with undesirable behaviors (e.g., kennel living) and aspects that may reduce problem behaviors (e.g., daily walks, play sessions, dog shows).     

Differences in serotonin serum concentration between aggressive English cocker spaniels and aggressive dogs of other breeds

Aggression is one of the most common behavioral problems in dogs and may have important negative effects on public health, human–animal bond, and animal welfare. There is ample evidence showing a negative correlation between serum serotonin concentration and aggressive behavior in a variety of species, including the domestic dogs. This negative correlation is particularly pronounced in dogs that show impulsive aggression. Data obtained in some previous studies suggest that the English cocker spaniel (ECS) is more likely to show impulsive aggression than other breeds. Therefore, the aim of this study was to analyze possible differences in serum serotonin levels between aggressive ECS and aggressive dogs of other breeds. Nineteen ECSs presented for aggression at the Animal Behavior Service (School of Veterinary Science, Barcelona, Spain) were evaluated and compared with 20 aggressive dogs of other breeds attended at the same center. Serum serotonin levels were measured using an enzyme-linked immunosorbent assay method. Statistical analysis was done using the SPSS 15.0 for Windows. Aggressive ECSs had significantly (P < 0.001) lower levels of serum serotonin than aggressive dogs of other breeds (318.6 ± 67.1 and 852.77 ± 100.58 ng/mL, respectively). Variances were not significantly different between ECSs and other breeds (standard deviation = 449.84 ng/mL vs. 292.47 ng/mL, P > 0.05). This finding may explain why ECSs are more likely to show impulsive aggression than other breeds, and suggests that the ECS could be a good model to study the neurophysiologic mechanisms underlying impulsive aggression.     

Multicenter, randomized controlled trial of pain-related behaviors following routine neutering in dogs

OBJECTIVE: To evaluate the degree of postoperative pain in dogs undergoing elective castration or ovariohysterectomy (OHE); determine whether an association exists between surgeon experience, incision length, or surgery duration and degree of postoperative pain; and determine whether analgesic treatment decreases expression of postoperative pain behaviors. DESIGN: Randomized controlled clinical trial. ANIMALS: 426 client-owned dogs undergoing OHE or castration. PROCEDURES: Dogs underwent OHE or castration performed by an experienced veterinarian or a fourth-year veterinary student. Dogs were randomly assigned to 1 of 4 treatment groups: no perioperative analgesic treatment (n = 44), preoperative administration of morphine (144), preoperative administration of nalbuphine (119), and postoperative administration of ketoprofen (119). Dogs were evaluated while in the hospital before anesthesia and for 4 hours after surgery and once a day at home for 3 days after surgery. RESULTS: Dogs in all 4 groups had significant increases in overall pain scores after surgery, compared with baseline scores. There were significant differences among groups, with control dogs having significantly higher increases in overall pain scores than dogs in the other groups. Factors that did not influence the frequency or severity of pain-related behaviors included breed, individual hospital, anesthetic induction protocol, surgeon experience, and duration of surgery. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that dogs expressed behaviors suggestive of pain following OHE and castration, that analgesic treatment mitigated the expression of pain-related behaviors, and that surgeon experience and surgery duration did not have any effect on expression of pain-related behaviors.     

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.     

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.     

Is breed-specific legislation justified? Study of the results of the temperament test of Lower Saxony

Beginning in July 2000 legislation in Lower Saxony restricted the keeping of bull terriers, American Staffordshire terriers, pit bull terriers, and 11 other breeds. Exemption was possible after attending an especially developed test. The tests analyzed for breed predisposition for excessively aggressive signaling or aggressive behavior in inappropriate situations, differences in behavior between breeds, and factors differentiating biting from nonbiting dogs.The test results of 415 dogs were analyzed. The test consisted of a veterinary examination; a learning test; situations of dog-human, dog-environment, and dog-dog contact; and obedience. Escalation in aggressive behavior was scored using a scale of 1-7. No aggressive behavior (1 on the scale) was shown by 38.07% of the dogs, 61.69% showed aggressive behavior scored as 2 to 5 on the scale, and 0.24% bit without previous threatening signals (6 on the scale).Concerning a score of 1 on the scale, pairwise comparison (chi-square test) showed significant differences between bull terriers and American Staffordshire terriers (P = 0.004), pit bull terriers (P = 0.01), Doberman pinschers (P = 0.003), and rottweilers (P = 0.009). Concerning scores of 2 to 7 on the scale,, no significant differences were found.Ninety-five percent of the animals reacted appropriately in the test situation. Five percent displayed excessive aggressive signaling or aggressive behavior in inappropriate situations. These displays were associated with unusual movements and the dogs' apparent apprehension. Correlation between test results and owners jerking on the leash or misinterpreting their dogs' behavior and dogs trying to elude physical manipulation was found. No significant difference in behavior between breeds was detected.The results show no indication of dangerousness in specific breeds. Justification for specific breed lists in the legislation was not shown.     

Evaluation of 6 ONRAB Ultralite bait flavor matrices delivered to coyotes (Canis latrans): Implications for oral rabies vaccination

The spread of rabies in terrestrial wildlife throughout the United States is primarily controlled through oral rabies vaccination. Relatively low bait acceptance and seroconversion rates by some target species have prompted investigation into an alternative to the RABORAL V-RG bait currently used. In Canada, ONRAB Ultralite baits are used to vaccinate raccoons (Procyon lotor) and striped skunks (Mephitis mephitis). Comparative studies between RABORAL V-RG and ONRAB found higher seroconversion rates among raccoons that ingested ONRAB, suggesting that it may be a suitable alternative. However, ONRAB has not been evaluated in many rabies reservoir species, including coyotes (Canis latrans). Vaccination of coyotes is a critical element in preventing reemergence of canine strain of rabies in the United States. We evaluated flavor preference of ONRAB Ultralite oral rabies vaccine baits by coyotes. Preferences among bait types differed (Friedman χ² = 13.28; df = 5; P = 0.02). Of the 6 bait flavors evaluated, cheese ranked the highest, followed by fish, chicken, sugar-vanilla, egg, and bacon flavors. Pairwise trials among the top 3 flavors (cheese, fish, and chicken) showed no difference (Friedman χ² = 3.00; df = 2; P = 0.22). Our research suggests that among the bait flavors we evaluated, cheese, fish, or chicken-flavored baits may be an appropriate flavor for delivery of ONRAB Ultralite baits to coyotes.     

Aggressive behavior in the English cocker spaniel

A high percentage of aggression problems and a tendency to display noninhibited aggression in the English cocker spaniel (ECS) have been suggested by many authors. The authors of this paper designed a retrospective study to analyze the aggressive behavior of 145 ECSs presented for aggression problems to the Animal Behavior Service at the Barcelona School of Veterinary Medicine's veterinary teaching hospital. Aggressive ECSs were compared with a population of dogs of the same breed presented for a behavior problem other than aggression and with a population of aggressive dogs of other breeds. The most common forms of aggression in the ECS were owner-directed aggression (67.6%), aggression toward unfamiliar people (18.4%), aggression toward unfamiliar dogs (10.1%), and aggression toward family dogs (3.3%).Owner-directed aggression was more common in the ECS than in other breeds, although in similar contexts. In the ECS, the golden coat color was more common in the aggressive dogs than in nonaggressive dogs. ECSs showed impulsive aggression more frequently than aggressive dogs of other breeds. The aim of the study was to analyze cases of aggressive ECSs seen in a referral practice.     

The use of novel stimuli as indicators of aggressive behavior in dogs

To test the predictive value of a doll and an artificial hand, reactions of dogs (n=100) were compared to histories of behavior toward children. Each dog's reaction to the doll and the hand was categorized as normal, fearful, fearfully aggressive, or offensively aggressive. Sixty-five percent (n=37) of the dogs that had a normal or no reaction to the stimuli had a history of being good with children. Eighty-eight percent (n=34) of the dogs that had an aggressive reaction to the doll had a history of aggressive behavior toward a child. Dogs that were fearfully aggressive were significantly more likely to show fearful responses to the doll, and dogs that were either dominant or fearfully aggressive were more likely to exhibit aggression of the same type to the hand. The results of this study indicate that the doll and, to a lesser extent, the hand may be useful components in determining the aggressive tendencies of dogs. The results also point out the major limitations, because the false positives and false negatives are too frequent.     

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.     

Comparison of pain on injection during induction of anaesthesia with alfaxalone and two formulations of propofol in dogs

ObjectiveTo compare the incidence of pain during injection of three intravenous induction agents in dogs.Study designProspective, crossover, randomized, blinded, clinical study.AnimalsThirty dogs requiring anaesthesia for radiotherapy.MethodsDogs were anaesthetized on three occasions at weekly intervals. An IV cephalic catheter was placed, flushed with saline and alfentanil 0.01 mg kg^?1 and atropine 0.02 mg kg^?1 administered. After 30 seconds either: propofol lipid macroemulsion (Drug_P), propofol lipid-free microemulsion (Drug_PC) or alfaxalone (Drug_A) was administered over 60 seconds. Each induction agent was administered once to each dog. Induction was recorded by video and reviewed by an assessor, unaware of treatment. Catheter placement (number of attempts, site, size and recent vein use) were recorded. Behavioural changes associated with pain or excitation, were recorded. Severity of pain on injection was recorded (mild, moderate or severe pain). Incidence of pain was analysed using logistic regression, excitation using McNemar's test (p < 0.05) and association of pain with induction agent and catheter placement using the Akaike Information Criterion (AIC).ResultsNo dogs reacted to saline or Drug_A, thus Drug_A was excluded from analysis. Pain on injection occurred in six dogs (20%) with Drug_PC and one dog (3.3%) with Drug_P. Pain was severe in four dogs with Drug_PC. Drug_P resulted in a trend for reduced risk of pain compared to Drug_PC (p = 0.076, odds ratio [confidence intervals] 0.14 [0.027–0.86]). Both propofol formulations resulted in greater risk of excitation than Drug_A (p = 0.0003, odds ratio 4.5 [1.86–10.90]). Induction agent was associated with pain, whilst catheter placement was not. One dog developed facial oedema and one other dog skin necrosis adjacent to the catheter site following Drug_PC. The study was terminated early due to ethical concerns about the severity of reactions with Drug_PC.Conclusions and Clinical relevanceDrug_PC was associated with clinically relevant moderate to severe pain behaviour whilst Drug_A and Drug_P were not.     

The effect of a pressure wrap (ThunderShirt®) on heart rate and behavior in canines diagnosed with anxiety disorder

The effect of moderate-to-deep pressure on soft tissue has been studied in both humans and nonhuman animals with positive results shown in reducing anxiety and promoting relaxation. Canine anxiety disorders are often treated with medications and behavior modification programming. Pressure wraps are sometimes used to treat canine anxiety, but the effects of this investigation have not been rigorously investigated. The aims of this study were to investigate the use of a pressure wrap (ThunderShirt®; ThunderWorks, Durham, NC) on heart rate and behavior in dogs diagnosed with an anxiety disorder. Subjects were 90 dogs (39 males and 51 females) that were diagnosed with Separation Anxiety or Generalized Anxiety Disorder. Dogs were randomly assigned to 1 of the 3 groups, namely Experimental Group 1 (dogs wore the ThunderShirt® per manufacturer's recommendations), Experimental Group 2 (dogs wore the ThunderShirt® loosely without pressure), and Control Group (dogs had no specific treatment). Average and maximum heart rates were measured at baseline and after 15 minutes alone in the kennel. Dogs were video-recorded and analysis completed for 12 behaviors, namely pacing, panting, yawning, tongue-flicking, drooling, elimination, barking, stress whining, howling, licking, door orientation, and calmness. The results were as follows: Dogs in Experimental Group 1 showed significantly less increase from baseline in average heart rate than the Control Group dogs (P < 0.001) and dogs in Experimental Group 2 (P < 0.001). Dogs in Experimental Group 1did not differ significantly from Control Group dogs in maximum heart rate when all dogs were considered, but did differ significantly from the Control Group (P = 0.04) when only those dogs not currently on anxiety medication were considered. There were no statistically significant differences among groups on behavioral outcomes, except that the dogs in the Control Group were significantly more likely to orient toward the door than the dogs in both Experimental Groups 1 (OR = 7.46, P = 0.01) and 2 (OR = 4.42, P = 0.04). Dogs in the Experimental Group 1 presented a trend of less tongue-flicking (P = 0.06) and yawning (P = 0.07) stress reduction behaviors when compared with the other 2 groups. More research should be conducted with the ThunderShirt® on behavioral outcomes. The ThunderShirt® can be used with behavior modification programming and medication as an adjunct treatment option to assist dogs diagnosed with anxiety disorder to reduce heart rate.     

Effect of age and feeding schedule on diurnal rest/activity rhythms in dogs

Dogs exhibit biorhythms like diurnal sleep/wake and rest/activity behavior patterns with circadian rhythmicity and, similar to other mammalian species, show age-dependent changes in activity rhythms. This study sought to further characterize night/day locomotor activity patterns in adult dogs of various ages, and to examine the effect of feeding frequency (once vs. twice). Three groups (early adults [EA], 1.5-4.5 years; late adults [LA], 7-9 years; senior, 11-14 years) of beagles (N = 48) wore the Actiwatch activity monitoring system for 3 days while housed indoors with 12-hour light/dark schedule. Activity recording devices were used to collect actigraphy data when dogs were on a once- or twice-daily feeding regimen. All dogs demonstrated a circadian activity pattern with high levels of daytime activity and low levels of nighttime activity. The main effect of age differed for both daytime (P < 0.0001) and nighttime (P = 0.002) activity counts. Daytime activity in senior dogs was 17% and 42% lower compared with LA and EA dogs, respectively. With nighttime activity, both LA and seniors had significantly lower counts compared with the EA. Compared to once-daily feeding, twice-daily feeding significantly increased night activity, night/day activity ratio, and activity counts 60 minutes before the light phase across all 3 age-groups. This study provides a comprehensive characterization of age-related changes in locomotor behavior patterns in dogs and uniquely demonstrates that frequency of feeding can influence nighttime activity levels, which is partially associated with level of prelight onset of activity.     

Do dogs use a mirror to find hidden food?

Dog (Canis familiaris) cognition research that examines whether dogs are able to use a mirror as a problem-solving tool is rare. The aim of this study was to explore whether dogs could find food that was visible only via a mirror at the beginning of the experiment. In a laboratory setting, we exposed 44 dogs to a large mirror, attached at a 90° angle to an opaque barrier for 10 minutes. Dogs were allowed complete freedom of movement. For the first minute of the exposure phase, the owner and experimenter stood against a wall, ignoring the dog; afterward, both walked around the room for 9 minutes. The dogs could observe their movements in the mirror. Then, dogs were taught to associate a bowl with food, after which the bowl was surreptitiously placed behind the barrier, and the dogs were positioned so that they could see the reflection of the food in the mirror. Dogs were pseudorandomly assigned to the experimental group (n = 22) as described or a control group (n = 22), which was identical except that the mirror was covered during the testing phase. In the testing phase, dogs that could see the mirror were more likely to find the treat than dogs that could not (P = 0.032). Although fewer dogs in the control condition found the food, those that did were just as likely as those in the mirror condition to locate it within 3 minutes. This suggests that, although dogs' food-searching behavior can be triggered by the mirror's visual cues to locate food, some dogs used other cues that we were unable to control.     

Assessment of neutrophil function in canine cancer patients undergoing chemotherapy and correlation with neutrophil numbers

Decreased neutrophil function following administration of chemotherapy has been reported in dogs with lymphoma. The first objective of our study was to determine if neutrophil oxidative burst and phagocytic activity are affected by chemotherapy 7 to 10 days following initiation of treatment in dogs with lymphoma and non-lymphoma malignancies. The second objective was to determine if there is a correlation between neutrophil numbers and neutrophil function before or after initiation of chemotherapy. Flow cytometric assessment of neutrophil oxidative burst and phagocytosis following stimulation with Escherichia coli was performed in 9 dogs diagnosed with lymphoma and 17 non-lymphoma tumor-bearing dogs pre- and post-chemotherapy, as well as 14 tumor-free control dogs. Spearman rank correlation was performed to determine if blood neutrophil numbers and neutrophil function were significantly correlated. Lymphoma patients showed significantly reduced percentage neutrophil oxidative burst post-chemotherapy compared to healthy controls as well as compared to pre-chemotherapy values (P = 0.0022 and P = 0.0020, respectively). Lymphoma patients also exhibited significantly reduced neutrophil phagocytosis activity post-chemotherapy compared to controls and pre-chemotherapy values (P = 0.0016 and P = 0.014, respectively). Dogs with non-lymphoma malignancies also showed a significant decrease in both percentage oxidative burst and phagocytosis post-chemotherapy compared to pre-chemotherapy values (P = 0.00040 and P = 0.029, respectively). Neutrophil numbers and function were not significantly correlated. The results of the study suggest that chemotherapeutic treatment decreases neutrophil oxidative burst and phagocytic activity 7 to 10 days post-treatment in dogs with various malignancies. Furthermore, neutrophil numbers cannot be used to predict neutrophil function.     

Quantification of plasma DNA as a prognostic indicator in canine lymphoid neoplasia

Dogs have a similar incidence of spontaneous cancers as people, and a noninvasive test to monitor disease status in dogs would be of great value. Humans with cancer often have increased levels of cell‐free circulating DNA in their plasma, which has shown promise for diagnosis, prognosis and detection of residual disease. We hypothesized that dogs with cancer have increased circulating DNA compared with healthy dogs or dogs with non‐neoplastic diseases. Plasma DNA was measured in 40 healthy dogs, 20 dogs with non‐neoplastic diseases and 80 dogs with cancer. The reference interval for plasma DNA in healthy dogs was 1–15 ng mL^?1. Dogs with lymphoma and lymphoid leukaemia had significantly higher concentrations (range: 0–91 ng mL^?1, P < 0.0001). Antigen receptor rearrangement assays suggest that plasma DNA had the same clonality as the primary lymphoid tumours. Dogs with lymphoid neoplasia and plasma DNA >25 ng mL^?1 had shorter remission times than those with < 25 ng mL^?1 (P= 0.0116). In contrast to humans, where increased plasma DNA is seen in many diseases, dogs with nonlymphoid malignancies and non‐neoplastic diseases had plasma DNA concentrations similar to healthy dogs. This study shows that a portion of dogs with lymphoid neoplasia have increased tumour‐derived plasma DNA, which serves as a negative prognostic indicator.     

Efficacy of dog-appeasing pheromone (DAP) for ameliorating separation-related behavioral signs in hospitalized dogs

Dogs hospitalized in veterinary clinics are likely to show signs of separation-induced anxiety from hospitalization. The study assessed the effect of dog-appeasing pheromone (DAP) on 10 typical separation-related behavioral signs in hospitalized dogs. A DAP treated group (n = 24) was compared with a placebo control group (n = 19). There was overall amelioration of the signs without ‘vigilance’ and ‘anorexia’ in the DAP-treated dogs; marked decreases were noted in elimination (P = 0.038), excessive licking (P = 0.005), and pacing (P = 0.017). The results suggest that the use of DAP could decrease separation-induced anxiety, distress, and fear in inpatients, and possibly facilitate recovery in hospitalized dogs.