Dean A. Hendrickson

Dean A. Hendrickson
Colorado State University | CSU · Department of Clinical Sciences

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152
Publications
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Publications

Publications (152)
Article
Background: The frequency of surgical site infection (SSI) following orthopaedic implant placement in horses has been reported but not compared with respect to specific antibiotic protocols administered. Objectives: To determine factors associated with SSI in horses undergoing proximal interphalangeal joint (PIPJ) arthrodesis including periopera...
Chapter
Due to benefits such as decreased pain, reduced tissue damage, and quicker return to performance, laparoscopic and thoracoscopic procedures are increasing in popularity. In the horse, these may be done under standing sedation or general anesthesia. The chapter summarizes the effects on cardiovascular parameters, oxygenation, ventilation, and intrac...
Chapter
Surgical procedures most commonly performed in marine mammals include wound management, dental extraction and excision of oral tumors, cataract removal, fracture repair, and upper gastrointestinal and respiratory endoscopy. Both minimally invasive surgery (MIS) and laparotomy have also been successfully performed in marine mammals. There are severa...
Chapter
Surgical procedures in megavertebrate mammal species (elephant, rhinoceros, and hippopotamus) have historically been uncommon. With the advent of new laparoscopic equipment, improved anesthetic techniques, and logistical enhancements that allow patient positioning, abdominal surgical procedures can now be safely utilized in these species. This chap...
Article
Injection of the equine navicular bursa can be technically challenging, and inadvertent penetration of other synovial structures is common using previously described techniques. When injecting the navicular bursa, inadvertent penetration of other synovial structures and hoof configuration can affect success rate, especially when performed by inexpe...
Article
Antibiotics have been injected intra‐articularly by equine veterinarians for decades, either prophylactically when other drugs are administered for osteoarthritis or therapeutically to treat septic arthritis. This route of administration has also more recently gained attention in human orthopaedic clinical practice, particularly as an alternative t...
Article
Background: Frequency of synovial sepsis in horses following intrasynovial injection has been reported, but not compared with respect to environment in which the injection was performed. Objectives: To describe occurrence of synovial sepsis following intrasynovial injections performed in ambulatory versus hospital settings. Study design: Retro...
Article
Full-text available
Septic arthritis causes significant morbidity and mortality in veterinary and human clinical practice and is increasingly complicated by multidrug-resistant infections. Intra-articular (IA) antibiotic administration achieves high local drug concentrations but is considered off-label usage, and appropriate doses have not been defined. Using an equin...
Chapter
Laparoscopy is a minimally invasive procedure used in the evaluation and treatment of a large variety of medical conditions in the horse. Laparoscopy allows the objective visual assessment of the ovaries, uterine body and horns, and broad ligament. Examples of how laparoscopy can be used in the area of equine reproduction include ovary evaluation a...
Chapter
Suture serves as a fundamental part of veterinary surgery and is mainly used for tissue apposition of a wound/incision and vessel ligation for hemostasis. Briefly, suture material is classified by degradation behavior (absorbable vs. nonabsorbable), composition (natural vs. synthetic), and structure (monofilament vs. multifilament). The list of com...
Chapter
A few of the benefits of laparoscopic surgery include reduced postoperative pain, faster onset of postoperative activity and improved wound healing resulting in less wound infections. Complications can occur with open or laparoscopic surgery. Although many clinicians, surgeons and clients tend to think of laparoscopic surgery as minor surgery, it i...
Chapter
A surgical complication is dependent on the surgical skill of the surgeon, the facilities and equipment available and the condition of the patient. A combination of variables encompassing all involved pathways, and even variables related to other body systems susceptible to stress‐related consequences such as the reproductive system, should be incl...
Article
Objective To compare efficacy and safety of a continuous rate infusion of detomidine hydrochloride and romifidine hydrochloride for standing elective bilateral laparoscopic ovariectomy in mares. Study Design Blinded, randomized prospective clinical study. Animals Eighteen healthy mares presenting for elective bilateral ovariectomy Methods Mares...
Article
Full-text available
Background: Prophylactic perioperative antimicrobial protocols in equine synovial endoscopy have been described but not compared with respect to post-operative outcomes and complications. Increasing antimicrobial resistance in equine practice and interest in promoting judicious use of antimicrobials has prompted reevaluation of drug selection and...
Article
Full-text available
There is risk of dropping an amputated ovary within the abdomen during standing laparoscopic ovariectomies in mares. If the ovary can no longer be directly visualized with the laparoscope, the procedure is then converted to a flank laparotomy for manual retrieval of the ovary which negates the minimally invasive nature of the laparoscopic procedure...
Article
Full-text available
The objective of this study was to compare the biomechanical properties in a single cycle axial loading test and the types of failures in two constructs (3-hole 4.5 mm dynamic compression plate and 7-hole 5.5 mm Y locking compression plate) in equine proximal interphalangeal joint arthrodesis. One limb in each pair was randomly assigned to PIJ arth...
Article
Veterinary medical education is a relatively small community with limited numbers of institutions, people, and resources widely dispersed geographically. The problems faced, however, are large-and not very different from the problems faced by (human) medical education. As part of an effort to share resources and build a community of practice around...
Article
Hiatal hernia with focal megaoesophagus was diagnosed in a 10‐year‐old Friesian stallion presenting to the referral hospital for further investigation of recurrent oesophageal obstruction. Oesophageal endoscopy revealed dilation of the distal oesophagus with alterations in the mucosa characteristic of gastric mucosa in the distal oesophagus. In add...
Article
Despite its fundamental importance, the educational mission of most schools of veterinary medicine receives far less recognition and support than the missions of research and discovery. This disparity is evident in promotion and tenure processes. Despite the frequent assertion that education is every college's core mission, there is a broad consens...
Article
Determining if ovariectomy will abolish unwanted behaviors can be challenging in mares without ultrasonographic ovarian abnormalities and/or endocrine values not consistent with a granulosa cell tumor. The objective of the study was to identify mares that have a positive improvement in unwanted behaviors after elective standing laparoscopic ovariec...
Article
Objective: To evaluate the efficacy of stents to distribute pressure when incorporated into tension-relieving sutures. Study design: An in vitro study and case report. Animal: One common bottlenose dolphin (Tursiops truncates). Methods: Three novel silicone stents, a traditional stent, and a control were tested in vitro by using a suture sim...
Article
Case description: A 6-year-old Quarter Horse gelding used for barrel racing was evaluated for acute onset of non-weight-bearing lameness of the left hind limb following strenuous exercise. Clinical findings: Nuclear scintigraphic imaging revealed focal increased radiopharmaceutical uptake centrally within the left talus. Subsequent standard radi...
Article
Competencies can guide outcomes assessment in veterinary medical education by providing a core set of specific abilities expected of new veterinary graduates. A competency-guided evaluation of Colorado State University's (CSU) equine veterinary curriculum was undertaken via an alumni survey. Published competencies for equine veterinary graduates we...
Article
Objective: To compare pain-related responses in mares receiving topical or injected anesthesia of the ovarian pedicle prior to standing unilateral laparoscopic ovariectomy. Study design: Prospective randomized, blinded, placebo-controlled study. Animals: Fifteen healthy research mares. Methods: Mares were restrained in stocks and administere...
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Full-text available
Vaginoscopy using a 10-mm, 30° forward viewing rigid endoscope was used to evaluate the caudal reproductive tract of four subadult southern white rhinoceros (Ceratotherium simum simum). A vertical vaginal septum was documented in all four animals, including a primiparous cow that gave birth to a stillborn calf 14 months before vaginoscopy. Vaginosc...
Article
Surgical intervention on cetaceans is rarely performed due to challenges including general anesthesia and post-operative wound healing. This report describes the evaluation and treatment of an adult female bottlenose dolphin (Tursiops truncatus) with the US Navy Marine Mammal Program, with a chronic ventral cervical abscess caused by Candida glabra...
Article
Objective To describe a standing left paralumbar fossa approach combined with mesocolon fenestration for bilateral equine ovariectomy. Study design Prospective experimental clinical study. Animals Four healthy client‐owned mares and 1 client‐owned Molly mule. Methods Mares were restrained in standing stocks and sedated with an α2‐agonist continu...
Article
Full-text available
The objective of this study was to investigate the effect of playing video games on the performance of basic laparoscopic skills. The study was an experimental pre-test-post-test comparison group design. Fifty-two students (31 from the Western University of Health Sciences College of Veterinary Medicine and 21 from the Colorado State University Col...
Article
The cause of transient post-operative pain in a subset of horses undergoing laparoscopy is unclear. The objective of this study was to evaluate if residual pneumoperitoneum is associated with transient post-operative pain in mares undergoing ovariectomy. Thirty-eight mares undergoing routine standing laparoscopic ovariectomy were randomly allocated...
Article
Objective: To determine the temperature of a vessel sealer and divider device during unilateral paralumbar laparoscopic ovariectomy in standing, sedated mares. Study design: Prospective study. Animals: Fifteen healthy research mares. Methods: Healthy mares with normal ovarian palpation and ultrasonographic appearance were enrolled. Horses we...
Article
Full-text available
Anesthesia and surgery in cetaceans have inherent risks and have rarely been utilized as viable treatment options. This report represents the first known multidisciplinary team approach to emergency laparotomy in a compromised, 22-yr-old, female Pacific white-sided dolphin (Lagenorhynchus obliquidens). The inciting clinical signs and ancillary diag...
Article
Objective: To develop a novel technique for left paralumbar laparoscopic bilateral ovariectomy in standing, sedated mares. Study design: Prospective descriptive clinical study. Animals: Twelve client-owned mares. Methods: Healthy mares with normal ovarian palpation and ultrasonographic appearance were enrolled. Horses were restrained in stan...
Article
Objectives: 1) To identify factors associated with short-term survival and time to death after hospital discharge in horses with nephrosplenic entrapment (NSE). 2) To compare the frequency of recurrent colic episodes in horses with and without laparoscopic closure of the nephrosplenic space. Study design: Historical cohort with a nested case con...
Conference Paper
Full-text available
An adult female Pacific white sided dolphin (Lagenorhynchus obliquidens) presented with an abrupt change in demeanor Sunday, May 24, 2015. She was inappetant and unresponsive to trainers, with no observed defecations. She did not respond to oral fluids or antibiotics and within 3 days had developed peritoneal effusion and severe, progressive fluid...
Article
As the use of social media websites continues to grow among adults 18-34 years old, it is necessary to examine the consequences of online disclosure to the veterinary admissions processes, and to consider the effects on the professional integrity of veterinary schools and on the e-professionalism of DVM graduates. Prior research has shown that empl...
Article
Full-text available
Case description: An 18-year-old Paint stallion (horse 1) and a 17-year-old Morgan gelding (horse 2) were evaluated because of an acute onset of severe unilateral forelimb lameness. Clinical findings: Both horses were unable to bear weight on the affected forelimb and had a dropped elbow appearance. Radial nerve paralysis, triceps myopathy, and...
Article
This report describes a method for removal of large granulosa cell tumours through small paralumbar incisions using laparoscopic dissection of the mesovarium and subsequent removal of the ovary in a sterile retrieval bag via morcellation. Morcellation allows division of the granulosa cell tumour and subsequent reduction of incision size required fo...
Article
In March 2009, a 25-yr-old captive female African elephant (Loxodonta africana) underwent an exploratory laparoscopy after several weeks of diarrhea, submandibular and ventral edema, and swelling on medial and lateral aspects of all feet. Although there have been recent advances in laparoscopic vasectomies in free-ranging African elephants in South...
Article
The advantages of performing standing male urogenital surgeries are numerous when compared with performing the same surgery in the anesthetized animal. Some traditional standing male urogenital surgeries, such as castrations, may be faster and cheaper to perform. Laparoscopic standing male urogenital surgeries may allow for improved visualization o...
Article
Equine standing surgery and laparoscopy are becoming increasingly important aspects of equine surgery. Laparoscopic advancements lag behind the human medical field, mainly due to decreased access to appropriate training and instrumentation. It is nearly impossible to cover the topic of equine standing surgery without discussing advances in laparosc...
Article
Objective To describe a surgical technique for, and outcome after, laparoscopic vasectomy of free-ranging elephants. Study DesignCase series. AnimalsAfrican elephants (Loxodonta africana; n = 14). Methods Male elephants (12–35 years old) were anesthetized with etorphine and supported in a sling in a modified standing position, and positive pressure...
Article
Full-text available
Several small, enclosed reserves in southern Africa are experiencing significant elephant population growth, which has resulted in associated environmental damage and changes in biodiversity. Although several techniques exist to control elephant populations, e.g., culling, relocation, and immunocontraception, the technique of laparoscopic vasectomy...
Article
Full-text available
Significant advances in veterinary diagnostic and surgical techniques have been made over the past several decades. Many of these advances, however, have not reached the field of marine mammal medicine. A number of limitations exist: risks of anesthesia, anatomical challenges, difficulties with wound closure, environmental constraints, equipment li...
Article
Topical application of prostaglandin E2 (PGE2) gel to the surface of the uterine tubes via a laparoscopic procedure improved embryo recovery rates or pregnancy rates in 28 subfertile mares suspected of uterine tubal pathology. Gelatinous masses may occlude the lumen of the uterine tube and prevent sperm from reaching the site of fertilization or pr...
Article
Introduction Anesthesia, Positioning, and Surgical Preparation Instrumentation Surgery Postoperative Management Conclusion Bibliography
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Introduction Anesthesia, Positioning, and Surgical Preparation Surgery Postoperative Management Conclusion References
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Introduction Standing Surgery Dorsally Recumbent Surgery Postoperative Management Conclusion References
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Introduction Anesthesia, Positioning, and Surgical Preparation Surgery Instrumentation Postoperative Management Conclusion References
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Introduction Anesthesia, Positioning, and Surgical Preparation Instrumentation Surgery Postoperative Management Conclusion References
Article
To determine the effect of unilateral laparoscopic cryptorchidectomy and removal of the descended testis on peritoneal fluid values, and to compare effect between 2 methods for cryptorchid testis vessel hemostasis. Randomized clinical study. Stallions (n = 10) with unilateral abdominal cryptorchid testis. During standing laparoscopic cryptorchidect...
Article
Full-text available
Minimally invasive surgery in the human was first identified in mid 900's. The procedure as is more commonly practiced now was first reported in 1912. There have been many advances and new techniques developed in the past 100 years. Equine laparoscopy, was first reported in the 1970's, and similarly has undergone much transformation in the last 40...
Article
A 7-year-old mixed-breed stallion was admitted because of colic. Entrapment of the left colon in the renosplenic space was diagnosed via rectal palpation and ultrasonographic examination, despite a renosplenic space ablation 6.5 years earlier. The renosplenic entrapment was corrected with a combination of phenylephrine administration, rolling, and...
Article
To characterize pulmonary gas exchange and arterial lactate in horses with gastrointestinal disease undergoing anesthesia, compared with elective surgical horses, and to correlate these variables with postoperative complications and mortality. Prospective clinical study. Horses undergoing emergency laparotomy for acute intestinal disease (n = 50) a...
Article
To compare the biomechanical characteristics of 2 arthrodesis techniques for the equine proximal interphalangeal joint (PIP) using either a 3-hole 4.5 mm locking compression plate (LCP) or 3-hole 4.5 mm narrow dynamic compression plate (DCP), both with 2 transarticular 5.5 mm cortex screws. Experimental. Cadaveric adult equine forelimbs (*n=6 pairs...
Article
The objective of this study was to isolate bacteria on the skin of the proximal to distal equine limb to guide the practitioner in the selection of prophylactic antimicrobial protocols. This prospective study involved 20 client-owned horses that were admitted to the Veterinary Teaching Hospital for routine elective surgery. Each horse spent between...
Article
To compare the presence or absence of pain, pain-related behavioral responses, and hormonal responses to noxious stimuli during standing laparoscopic ovariectomy in mares sedated with continuous intravenous (IV) detomidine infusion and caudal epidural detomidine. A double blind prospective study. Mares (n=12) Mares were divided into 2 treatment gro...
Article
Unlabelled: Summary Reasons for performing study: Medial meniscal injuries and subchondral cystic lesions (SCL) are known to occur independently within the medial femorotibial (MFT) joint in horses. However, there are no reports of a potential clinical relationship between these 2 types of lesions. Objectives: To: 1) document the concurrent pres...
Article
Description-An 11-year-old Quarter Horse stallion was admitted for intermittent hemospermia of 4 years' duration. A linear vertical defect had been detected endoscopically following multiple episodes of hemospermia on the caudodorsal convex surface of the urethra at the level of the ischial arch. When sexual rest alone did not result in complete he...
Article
Rupture of the urinary bladder, although relatively common in foals, is an infrequent occurrence in adult stallions. Standing laparoscopic repair of a ruptured urinary bladder offers significant advantages over other treatment options, and to date, there are no reports describing this technique in treating adult stallions. This case study details t...
Conference Paper
Introduction: Proximal interphalangeal joint (PIJ) osteoarthritis is a common cause of lameness in horses and often requires surgical intervention. The severity of periarticular bone proliferation can make disarticulation of the joint difficult during a standard PIJ arthrodesis. The purpose of this study was to assess the frequency of occurrence of...
Article
Full-text available
The objective of this study was to evaluate duodenocecostomy in horses performed through a ventral midline laparotomy and report its influence on body weight, glucose absorption, serum components, and characteristics of jejunum, cecum, and large colon histology. Four horses were submitted to the duodenocecostomy technique through a ventral midline...
Article
This article describes surgical complications associated with laparoscopy, how to avoid them, how to recognize them if they do happen, and how to deal with them in the most expedient method possible. Complications of sedation, anesthesia, positioning, the general surgical approach, and complications associated with specific surgical procedures are...
Article
The purpose of this study was to determine the analgesic efficacy of bupivacaine, morphine, or saline (control) when injected epidurally into the lumbosacral epidural space in goats after abdominal surgery. Goats received either bupivacaine (0.5%; 1.5 mg/kg in 0.9% sodium chloride solution), 0.9% sodium chloride solution (0.2 mL/kg), or preservativ...
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Full-text available
Objective—To describe a technique for laparoscopic colopexy in horses. Study Design—Description of a technique to perform laparoscopic colopexy in horses. Animals—Six healthy adult horses between 3 and 23 years of age and weighing between 440 and 636 kg. Methods—Horses were positioned in dorsal recumbency, and the abdomen was insufflated to an intr...
Article
Full-text available
To compare efficacy and safety of paste formulations of firocoxib and phenylbutazone in horses with naturally occurring osteoarthritis. Randomized controlled clinical trial. 253 client-owned horses with naturally occurring osteoarthritis. Horses were treated with firocoxib (0.1 mg/kg [0.045 mg/lb], PO, q 24 h) or phenylbutazone (4.4 mg/kg [2 mg/lb]...
Article
The best plan is a surgical procedure that is well thought out ahead of time. Organization and prioritization of the surgical steps from beginning to end are essential. Once the procedure has started, adequate visualization and identification of all structures before dissection saves time and produces a better outcome. Rapid or mishandled tissue of...
Article
There are no published results of subchondral cystic lesions (SCLs) in the medial femoral condyle (MFC) treated with arthroscopic injection of corticosteroids into the lining of the cyst. 1) To determine the success rate for treatment of SCLs in the MFC with arthroscopic injection of the fibrous tissue of the cyst with corticosteroids. 2) To identi...
Article
Because laparoscopic surgery eliminates the side effects of general anesthesia, the success and therefore the use of laparoscopic surgery continues to broaden. Laparoscopic ovariectomy, once only used to treat medical problems such as granulosa cell tumors, is now being expanded to treat behavioral problems in mares. Thirty-five mares with behavior...
Article
To compare pain responses in stallions undergoing standing laparoscopic cryptorchidectomy following intratesticular or mesorchial infiltration of lidocaine. Clinical trial. 20 stallions with 1 or 2 undescended testes. Standing horses were administered a nonsteroidal anti-inflammatory drug and a caudal epidural injection of detomidine hydrochloride...
Article
Laparoscopic surgery has become commonplace in the field of equine urogenital surgery. As with most surgical procedures, the limiting factors in developing new surgical techniques are limited to the patient size and demeanor, the skills of the surgeon, and the available equipment. Some of the greatest benefits of laparoscopic surgery in the horse i...