Thoracic wall and pulmonary trauma in dogs sustaining fractures as a result of motor vehicle accidents

The records of 267 dogs seen at the University of Minnesota Veterinary Teaching Hospital for fractures resulting from motor vehicle accidents were examined to determine the prevalence and types of thoracic wall and pulmonary trauma associated with such cases. Results were analyzed for type and prevalence of thoracic wall and pulmonary injury, and for the prevalence of such injury in dogs with and without extrathoracic injury, in dogs with fractures of single vs multiple bones, in dogs with single fractures of specific bones, in dogs with fractures in the cranial vs the caudal one half of the body, and in dogs with fractures ipsilateral vs contralateral to thoracic injury. The overall prevalence of thoracic wall and pulmonary trauma was 38.9%; pulmonary contusions, pneumothorax, and fractured ribs were the most common injuries. More than 1 type of thoracic wall or pulmonary injury was diagnosed in 57.7% of the cases. Of the dogs with thoracic injury, 24% also had extrathoracic injuries; 16.5% of dogs without thoracic injury had extrathoracic injuries, not including fractures. Of the dogs with fractures of 1 bone, 36.3% had thoracic injuries. Of the dogs with fractures of more than 1 bone, 42.3% had thoracic injuries. The prevalence of thoracic wall and pulmonary trauma was significantly associated with the site of the fracture (cranial vs caudal and ipsilateral vs contralateral); significant association with the specific bone fractured was also seen for some fractures.     

Owner-perceived, weighted quality-of-life assessments in dogs with spinal cord injuries

Objective-To evaluate changes over time in owner-perceived, weighted quality-of-life assessments in dogs with spinal cord injuries and determine whether scores were associated with underlying etiology or with veterinarian-assigned scores for severity of neurologic dysfunction. Design-Cohort study. Animals-100 dogs with spinal cord injury. Procedures-Duration of dysfunction, modified Frankel neurologic injury score, and etiology were recorded. At initial and recheck (4- to 6-week) evaluations, owners were asked to identify 5 areas or activities they believed had the most influence on their dogs' quality of life, assess their dogs' current status in each area, and provide a weighting for the importance of each area; results were used to construct a weighted quality-of-life score. Owners were also asked to provide a quality-of-life score with a visual analog scale (VAS). Results-At initial and recheck evaluations, weighted quality-of-life scores were higher for ambulatory than for nonambulatory dogs. However, scores did not differ among groups when dogs were grouped on the basis of underlying etiology or duration of injury. Dogs with an increase in Frankel score between the initial and recheck evaluations had a significant increase in weighted quality-of-life score, whereas for dogs that did not have any change in Frankel score, initial and recheck weighted quality-of-life scores were not significantly different. Conclusions and Clinical Relevance-Results suggested that owner-assigned, weighted quality-of-life scores for dogs with spinal cord injuries did not vary significantly on the basis of underlying etiology or duration of injury but were higher for ambulatory than for nonambulatory dogs.     

Dog bite wounds in dogs and cats: a retrospective study of 196 cases

The age, type, etc., time of injury, body areas injured, treatment modalities and mortality rates were reviewed in 185 dogs and 11 cats that were bitten by dogs. Male dogs were more frequently bitten than females, and small dogs (< or = 10 kg) were not only the most common victims but also were more likely to suffer multiple injuries. Mortality occurred only in cases with thoracic or abdominal injuries. Exploratory thoracotomy, performed in some of the cases presented with penetrating thoracic injury, did not prove to alter prognosis. Cats are not as frequently bitten as dogs, and are often younger than the mean age of cats in the overall hospital population.     

Acute Oropharyngeal and Esophageal Stick Injury in Forty‐One Dogs

Objective— To report clinical findings, treatment, and outcome in dogs with acute (<7 days) oropharyngeal or esophageal stick injury. Study Design— Retrospective study. Animals— Dogs (n=41) with acute oropharyngeal or esophageal injury. Methods— Dogs had clinical and radiographic examination, and frequently, cervical surgical exploration. The decision to operate was based on radiographic findings of cervical emphysema. Outcome was determined by owner or veterinarian interview. Results— Of 41 dogs, 27 had oropharyngeal injury and 14 had esophageal injury. Five dogs with esophageal injury died. All dogs with radiographic evidence of cervical emphysema (n=34) had ventral median cervical exploration or necropsy; 11 had wood fragment(s) retrieved. In 7 dogs without radiographic signs of cervical emphysema, wounds involving the pharynx or soft palate were treated by local debridement and lavage using an oral approach. Mean follow‐up time was 36.4 months. All wounds healed without complication; however, 1 dog that was not surgically explored had a piece of wood surgically retrieved 3 months later. Conclusions— Radiographic evidence of cervical emphysema is a frequent finding in dogs with acute penetrating oropharyngeal or esophageal injury and indicates trauma to the deeper cervical tissues. Acute penetrating injury of the oropharyngeal region, when treated appropriately, has a better prognosis than acute esophageal penetration. Clinical Relevance— Ventral median cervical surgical exploration is recommended in dogs with acute penetrating injury of the oropharynx or esophagus if there is radiographic evidence of tissue emphysema.     

Comparison of Short‐ and Long‐term Function and Radiographic Osteoarthrosis in Dogs After Postoperative Physical Rehabilitation and Tibial Plateau Leveling Osteotomy or Lateral Fabellar Suture Stabilization

Objectives— To compare short‐ and long‐term functional and radiographic outcome of cranial cruciate ligament (CrCL) injury in dogs treated with postoperative physical rehabilitation and either tibial plateau leveling osteotomy (TPLO) or lateral fabellar suture stabilization (LFS). Study Design— Prospective observational clinical study. Animals— Medium to large breed dogs with naturally occurring CrCL injury (n=65). Methods— Dogs with CrCL injury were treated with either TPLO or LFS and with identical physical rehabilitation regimes postoperatively. Limb peak vertical force (PVF) was measured preoperatively and at 3, 5, and 7 weeks, and 6 months and 24 months postoperatively. Stifles were radiographically assessed for osteoarthrosis (OA) preoperatively and 24 months postoperatively. Results— Thirty‐five dogs had LFS and 30 dogs had TPLO. Radiographic OA scores were significantly increased at 24 months compared with preoperative scores in all dogs. Radiographic OA scores preoperatively and at 24 months were not significantly different between treatment groups. PVF was significantly increased from preoperative to 24 months among both treatment groups but not significantly different between treatment groups preoperatively or at 3, 5, 7 weeks, 6, or 24 months. Conclusion— No significant difference in outcome as determined by ground reaction forces or radiographic OA scores were found between dogs with CrCL injury treated with LFS or TPLO. Clinical Relevance— LFS and TPLO remain good options for stabilizing stifles with CrCL injury with all dogs showing significant functional improvement. This study does not support the superiority of either surgical technique.     

Canine pedal injury resulting from metal landscape edging

Background – This study was performed to document the frequency and severity of limb injuries that occur when dogs come in contact with metal landscape edging. A retrospective study from 1997 to 2007 was performed at Colorado State University veterinary teaching hospital. Sixty dogs were admitted to hospital for traumatic limb injuries resulting from metal landscape edging identified by a computerized medical records search. Key Findings – Most dogs were young, large breed dogs. All 60 dogs suffered traumatic pedal lacerations when contacting metal landscape edging, the majority of which occurred on the forelimbs. Eighty‐five percent required surgical repair. All 60 dogs were discharged from the hospital and 30 were available for long‐term follow‐up. While most dogs healed with a perfect cosmetic outcome, 3 dogs with tendon involvement developed residual digital deformities. Significance – Dogs are at risk of injury when exposed to metal landscape edging. Severity of pedal injury determines treatment protocol and prognosis for recovery.     

Peripheral nerve injury associated with fracture or fracture-dislocation of the pelvis in dogs and cats: 34 cases (1978-1982)

Peripheral nerve injury was associated with fracture or fracture-dislocation of the pelvis in 23 dogs and 11 cats. In most cases, peripheral nerve injury resulted from ilial fracture with craniomedial displacement of bone fragments, or from sacroiliac fracture-dislocation with cranial displacement of the ilium. Sciatic nerve injury was associated with fracture of the acetabulum in 2 dogs. A combination of sensory, voluntary motor, and reflex abnormalities were observed in the ipsilateral extremity of affected animals. Signs of severe pain were noticed in 4 of the dogs and in 1 cat. Eight of the animals died or were euthanatized for reasons not directly related to the severity of peripheral nerve injury. Of the remaining 26 animals, 21 (81%) had good or excellent limb function 16 weeks after peripheral nerve injury was sustained. Limb function was lost or self-mutilation occurred in 4 (15%) of the animals.     

Long-term assessment of pancarpal arthrodesis performed on working dogs in New Zealand

AIM: To determine the outcomes following unilateral pancarpal arthrodesis (PCA) in working dogs in New Zealand, in terms of return to work and ability, as assessed by the owner. METHODS: Working dogs treated using unilateral PCA were identified by searching the medical records of the Massey University Veterinary Teaching Hospital (MUVTH) by diagnosis and breed code. Eight Heading dogs (working Collies) and four New Zealand Huntaways were identified with carpal pathology that had been treated by dorsal-plate application, bone-grafting, and casting. All dogs were actively in work on sheep or cattle farms at the time of injury. Case files and radiographs were retrospectively analysed, and the ability of the dog to work after surgery and owner satisfaction with the outcome were assessed using a questionnaire conducted at a mean follow-up interval of 5 years. RESULTS: Following arthrodesis, 6/12 (50%) dogs could perform duties as before surgery. A further four (33%) dogs could perform most former duties. Ten of the twelve owners were satisfied or very satisfied with resultant mobility and work performance of their dogs. Post-operative complications occurred in 50% of dogs, but in only one case affected the eventual outcome. Eleven owners felt surgical repair was worthwhile in a trained working dog. CONCLUSIONS: Unilateral PCA carries a good prognosis for working dogs in New Zealand to return to work, even on hill-country properties. CLINICAL RELEVANCE: This study may allow veterinarians to provide a more accurate prognosis for working dogs requiring PCA. Working dogs that have sustained severe carpal injury including hyper-extension injury, luxation and fracture, or dogs with crippling carpal osteoarthrosis (OA) can return to work after PCA.     

Motor vehicle accidents in urban dogs: a study of 600 cases.

The records of 600 dogs injured in motor vehicle accidents and admitted as emergencies to the Trauma Emergency Service of the University of Pennsylvania Veterinary Hospital were studied. Young males were the most frequently injured dogs. The motor vehicle accidents resulted in a wide variety of injuries. Superficial wounds were diagnosed as the only manifestation of trauma in 190 (31%) dogs. Among the remaining 410 dogs, skeletal injury was diagnosed in 87% and soft organ injury in 27%. Multiple region injury occurred in 36% of all dogs. Among specific injuries, it was found that the pelvis was the most frequently injured skeletal structure and that the liver was the most frequently injured abdominal organ. Almost all deaths resulted from intrathoracic and intraabdominal injuries, and over 50% of the dogs euthanatized had central nervous system injury. The overall fatality rate, including euthanasias, was 12.5%.     

Spinal-evoked potentials in dogs with acute compressive thoracolumbar spinal cord disease

Spinal evoked potentials (SpEP) were recorded on an electromyograph from electrodes placed percutaneously in the ligamentum flava at the lumbosacral junction and between the 10th and 11th thoracic vertebrae following tibial nerve stimulation in 31 anesthetized dogs with acute compressive spinal cord injuries. The neurologic status of each dog was determined by clinical examination before SpEP recordings, and the neurologic status was monitored for 2 months in dogs that had surgical or conservative treatment. Two months after spinal injury, the response to treatment (outcome) of each dog was evaluated and graded as favorable (ambulatory and urinary continent) or unfavorable (nonambulatory, urinary incontinent, or euthanatized with confirmation of myelomalacia). Onset latencies, conduction velocities, amplitudes and durations of the wave forms, and the ratio of conduction velocity to combined durations of the first positive (P1) and first negative (N1) waves (CV/DPN index) were determined and were compared with reference data from clinically normal (control) dogs. Single SpEP recordings were of value in determining the prognosis for recovery. Significant differences were not found in the L7-S1 recordings between the reference (control) and spinal injury groups. Analysis of data from the T10-11 recordings indicated significant differences between the reference and spinal injury groups and between the favorable and unfavorable outcome groups within the spinal injury group. A CV/DPN index was less than 30 in dogs with unfavorable outcomes and greater than 30 in dogs with favorable outcomes. Stepwise discriminant analysis of data from the spinal injury group predicted outcome correctly in all dogs.     

Treatment of reperfusion injury in dogs with experimentally induced gastric dilatation-volvulus.

In dogs, gastric dilatation-volvulus (GDV) is characterized by cardiogenic shock, with resulting hypoperfusion. Treatment goals include reperfusion of transiently ischemic tissues, which indicates that reperfusion injury may be a factor in the physiopathogenesis of GDV. Recently, we obtained data that indicate that reperfusion injury may be involved in experimentally induced GDV. Using this GDV model, we evaluated mortality in 24 dogs of 4 equal groups, treated with deferoxamine (an iron chelator), dimethylsulfoxide (a free radical scavenger), a combination of the 2 drugs, or isotonic saline solution. All 6 dogs that were given deferoxamine survived; however, 3 dogs of the dimethylsulfoxide-treated group, 2 dogs of the combination-treated group, and 4 dogs of the saline-treated group died. Results of the study indicate that mortality associated with experimentally induced GDV is reduced by appropriate and timely pharmacologic intervention to prevent or attenuate reperfusion injury, and that deferoxamine may be more effective than dimethylsulfoxide.     

Serum cardiac troponin I concentration in dogs with ehrlichiosis

Background: Ehrlichiosis is a multisystemic disease with the potential to cause cardiomyocyte injury in naturally infected dogs.
Hypothesis: Myocardial injury occurs in dogs infected with Ehrlichia canis .
Animals: One-hundred and ninety-four dogs from Brazil with clinical and laboratory abnormalities indicative of ehrlichiosis. Sixteen healthy dogs served as controls.
Methods: Electrocardiogram, echocardiogram, noninvasive blood pressure measurement, and serum cardiac troponin I (cTnI) concentrations were evaluated. Serologic assays and PCR determined the exposure and infection status for E. canis, Anaplasma spp., Babesia canis vogeli, Bartonella spp., Borrelia burgdorferi, Dirofilaria immitis, Ehrlichia chaffeensis, Ehrlichia ewingii, Leishmania chagasi , and spotted-fever group Rickettsia . Dogs were assigned to groups according to PCR status: E. canis infected, infected with other vector-borne organisms, sick dogs lacking PCR evidence for infection, and healthy controls.
Results: E. canis -infected dogs had higher serum cTnI concentrations than controls (median: 0.04 ng/dL; range 0.04–9.12 ng/dL; control median: 0.04 ng/dL; range: 0.04–0.10 ng/dL; P = .012), and acute E. canis infection was associated with myocardial injury (odds ratio [OR]: 2.67, confidence interval [CI] 95%: 1.12–6.40, P = .027). Severity of anemia was correlated with increased risk of cardiomyocyte damage ( r = 0.84, P < .001). Dogs with clinical signs of systemic inflammatory response syndrome (SIRS) were at higher risk for myocardial injury than were other sick dogs (OR: 2.55, CI 95%: 1.31–4.95, P = .005).
Conclusions and Clinical Importance: Acute infection with E. canis is a risk factor for myocardial injury in naturally infected Brazilian dogs. Severity of anemia and SIRS might contribute to the pathophysiology of myocardial damage.     

The incidence of thoracic trauma in dogs with skeletal injury

One hundred dogs with skeletal injury were evaluated for co-existing thoracic abnormalities. Parameters used to assess thoracic trauma were physical examination, thoracic radiographs, electrocardiograms and arterial blood gas PaO₂. Thoracic abnormalities were found in 57 per cent of the dogs. Within this group, 77 per cent had abnormal thoracic radiographs, 44 per cent had abnormal low PaO₂, and 30 per cent had cardiac arrhythmias. No clinical signs suggestive of thoracic injury were found on physical examination in 79 per cent of the dogs with thoracic lesions.     

Cardiac arrhythmias and serum cardiac troponins in Vipera palaestinae envenomation in dogs

BACKGROUND: Vipera palaestinae is responsible for most poisonous envenomations in people and animals in Israel. Cardiac arrhythmias were reported in a retrospective study of V. palaestinae envenomations in dogs. HYPOTHESIS: Cardiac arrhythmias in V. palaestinae-envenomed dogs are associated with myocardial injury reflected by increased serum concentrations of cardiac troponins (cTns). ANIMALS: Forty-eight client-owned dogs envenomed by V. palaestinae. METHODS: Blood sampling (serum biochemistry and cTns, CBC, and coagulation tests) and electrocardiography were performed periodically up to 72 hours postenvenomation. Cardiac rhythm strips were assessed blindly for the presence and type of arrhythmias. RESULTS: Serum cTn-T and cTn-I concentrations were increased in 25% (n = 12) and 65% (n = 31) of the dogs at least once during hospitalization, respectively. Arrhythmias were identified in 29% (n = 14) of the dogs. Dogs with increased cTn-T had a significantly higher occurrence of arrhythmias (58 versus 19%), and higher resting heart rate upon admission and within the following 24 hours. Dogs with increased serum cTn-T concentrations were hospitalized for a significantly (P= .001) longer period compared to those with normal serum cTn-T concentrations. CONCLUSIONS AND CLINICAL RELEVANCE: Dogs envenomed by V. palaestinae appear to sustain some degree of myocardial injury, as reflected by increased serum cTn concentrations and by the occurrence of arrhythmias. The latter should alert clinicians to a potentially ongoing cardiac injury. An increase in cTn-T may be of clinical relevance and indicate a cardiac injury in V. palaestinae envenomations in dogs.     

Cranial cruciate ligament rupture in the dog—a retrospective study comparing surgical techniques

SUMMARY Three surgical techniques, grouped as intra-articular techniques, extra-capsular techniques and fibular head transposition, were used for repair of the cranial cruciate ligament (CCL)-deficient stifle in 113 dogs over a 4 year 4 month period. The clinical outcome of the techniques were compared using information provided by the owners and physical examination. Regardless of surgical technique, 85.7 to 91.0% of dogs showed clinical improvement after surgery. However, less than 50% of dogs became clinically sound on the operated leg and 9.0 to 14.3% of dogs remained persistently lame on the operated leg. No statistical association was found between result after surgery and age, body weight, sex, duration of injury before surgery, association with injury, tibial plateau angle, degree of radiographic osteoarthritis before surgery or the presence of concurrent medial meniscal injury. On physical examination, extra-capsular techniques appeared superior to the fibular head transposition in terms of joint stability and limb function. Concurrent medial meniscal injury necessitating meniscectomy existed in 48.0% of cases. Twenty-two percent of dogs ruptured their contralateral CCL at an average of 14 months after the first.     

Sacroiliac Fracture-Separation in the Dog: A Study of 92 Cases

The case records of 92 consecutive dogs that suffered sacroiliac fracture-separation were examined. Seventy-seven per cent (71 of 92) had unilateral sacroiliac injury and 23% (21 of 92) had bilateral sacroiliac injury. Of the unilateral cases, 93% (66 of 71) of the dogs had associated acetabular, ilial, femoral, or tibial fractures; coxofemoral luxations; or cruciate injuries. Eighty-five per cent (78 of 92) of the dogs had either bilateral sacroiliac injury or unilateral sacroiliac injury and other orthopedic injuries of the opposite limb, thus disabling both hind limbs.
Sixty-five per cent (60 of 92) of the dogs received lag screw fixation of the sacroiliac joint. Of 29 dogs that were re-radiographed on an average of 437 days following fixation, 38% (11 of 29) showed evidence of loosening of the lag screw fixation.a
Screws that were placed in the body of the sacrum in some dogs resulted in the fewest loosened fixations (12%, 2 of 17), compared to other locations of screw placement. The fixation had loosened in 7% (1 of 14) of dogs that had a cumulative screw depth/sacral width of 60% or more, compared with 48% of dogs (10 of 21) where cumulative screw depth was less than 60%. The number of screws per fixation and whether the separation was fully reduced or not did not affect whether the fixation loosened.     

Arthroscopic evaluation of menisci in dogs with cranial cruciate ligament injuries: 100 cases (1999-2000)

OBJECTIVE: To determine prevalence of meniscal injuries by use of arthroscopic examination in dogs with cranial cruciate ligament (CCL) injuries. DESIGN: Retrospective study. ANIMALS: 94 dogs with 100 injured CCLs. PROCEDURE: Records for 94 large dogs (> 20 kg [44 lb]) with 100 naturally occurring CCL injuries that were examined arthroscopically were reviewed. Pathologic findings in the CCL (complete or partial tears), prevalence and type of meniscal injuries, and periarticular osteophytes were recorded. RESULTS: 77% of joints had tears of the lateral meniscus; most were a series of small radial tears of the cranial horn. Fifty-eight percent of joints had tears of the medial meniscus. Positive correlation between complete tears of the CCL and medial meniscal damage was found. No significant relationships were detected between periarticular osteophyte formation and meniscal injury, medial and lateral meniscal injury, or degree of CCL tear and lateral meniscal injury. CONCLUSIONS AND CLINICAL RELEVANCE: There is a strong association between CCL injury and lateral and medial meniscal injuries in dogs. Clinical importance of lateral meniscal lesions is not known; a much higher percentage of dogs had such injuries than has been reported previously, possibly because of use of arthroscopy.     

Oropharyngeal penetrating injuries in 50 dogs: a retrospective study

OBJECTIVES: To summarize the presenting complaints and clinical signs associated with traumatic penetrating injuries to the canine oropharynx. To determine how the site of injury, causative agent, and duration of disease affect the presentation and clinical outcome of treatment. STUDY DESIGN: Retrospective study. SAMPLE POPULATION: 50 client-owned dogs. METHODS: The medical records of 50 dogs with oropharyngeal penetrating injuries referred to Glasgow University Veterinary Hospital (GUVH) between 1979-1999 were reviewed. Data regarding signalment, owners' presenting complaint, history, physical examination, radiographic and endoscopic findings, surgical findings, and outcome were recorded and compared with the GUVH population. Estimates of individual breed-specific odds ratios were calculated. Outcome was evaluated by reexamination 6 weeks after surgery with recurrence of disease recorded as failure. RESULTS: Oropharyngeal injuries occurred most often in medium to large breed dogs. The majority of dogs presented with chronic disease (82%). The common findings on clinical examination were discharging sinus (72%) and swelling (70%). Acute cases typically presented with dysphagia and oral pain. The original site of injury was evident in only 34% of dogs, with the sublingual area the most frequently traumatized. The apparent cause of injury to the oropharynx was most commonly a piece of wood (72%). Other causes were metallic foreign bodies (3 dogs) and bones (2 dogs). In the remaining 9 dogs, the cause was not determined. The clinical signs resolved in all dogs that presented acutely compared with only 62% in dogs with chronic signs. CONCLUSION: Medium to large breed dogs appear to be prone to oropharyngeal injuries caused mainly by wooden foreign bodies. This may be attributable to stick chewing or retrieving behavior in these animals. CLINICAL RELEVANCE: History of trauma, stick retrieval, submandibular/cervical swelling, and discharging sinus are commonly encountered in the presentation of this condition. The sublingual area was the most frequent portal of entry recorded, although in chronic cases the initial site of injury was often unclear. Radiography and endoscopy, while offering definitive diagnosis with positive findings, often provide false negative findings. Aggressive surgical debridement of all sinus tracts is essential in obtaining a successful result, but recovery of a foreign body is not necessarily a determinant of success.     

Pharyngeal stick penetration injuries in the dog

Sixty-five dogs were examined and treated for stick penetration wounds of the pharynx. Dysphagia, pain, pyrexia and local cellulitis were common presenting signs amongst recently injured dogs. Injuries involving the oesophagus resulted in subcutaneous emphysema and dyspnoea associated with pneumomediastinum. Longstanding wounds presented with discharging sinuses of the head, neck or cranial thoracic region. Wooden foreign bodies were recovered from 37 dogs (57 per cent) with subsequent resolution of their clinical signs. No foreign body was retrieved from a further 18 dogs (28 per cent) but their clinical signs resolved after appropriate wound management. Four dogs (6 per cent) died shortly after the injury from major oesophageal tears which allowed mediastinal contamination. Six dogs (9 per cent) had no foreign body recovered at surgery and the discharging sinuses persisthed. The need for vigorous management of the fresh injury in order to preclude the development of chronic complications is emphasised.     

Behavioral evaluation of 65 aggressive dogs following a reported bite event

Peer-reviewed scientific publications on the topic of dog bites are numerous. Montreal was one of the first municipalities in the province of Quebec to require mandatory assessment of aggressive dogs by veterinarians. In 2019, dogs reported as aggressive and considered a potential risk to public safety by city officials were scheduled for a mandatory behavioral assessment by a veterinarian. For the purpose of this study, only aggressive dogs that had bitten (N = 65) were included. The goals were to better describe the aggressive behavior of these dogs (behavioral sequence, type of aggression, and overall reactivity) and perhaps identify new possible risk factors related to severity of injury and dangerousness. The number of signs of increased arousal/reactivity was positively and significantly associated with the injury severity score. Dangerousness increased with size of dogs. Entire males were most dangerous despite absence of recognizable differences in body weight between neutered and unneutered males.