The third edition of ‘The Cutting Edge, Basic Veterinary Surgery Techniques’ has been prepared by various veterinary lecturers at the Utrecht University Faculty of Veterinary Medicine, the University of Ghent, and the Royal Veterinary College of the London University. Its goal is to teach students the essential art of surgery without having a specific species in mind. This edition is designed for an open-access web-based platform. Students worldwide will be able to use the information for their benefit while improving their surgical knowledge and skills.
The ‘Cutting Edge 3’ provides veterinary students and new graduates tools to grasp the principles of surgery, along with a discussion of the limitations and complications of surgical procedures. It should not be regarded as a complete reading text for all surgical problems and techniques but merely a basis for the inexperienced surgeon. Other textbooks will be able to provide more advanced techniques.
Previously published work by Dr. Wim Klein, Dr. Marianne Tryfonidou, Dr. Rien van de Velden, Dr. Peter Stolk, Prof Herman Hazewinkel, Prof Astrid Rijkenhuizen, Dr. Ruud Keg, and Prof Ludo Hellebrekers is updated and expanded. We value their expertise and thank them for their previous work. Mr. Joop Fama is thanked for supplying many of the photographic materials used in this book. The ‘Cutting Edge 3’ is an improvement of the Cutting Edge 2 (2006) and is translated initially from the first edition ‘Leren Opereren’ (2005).
We want to acknowledge the help of Dr. Jos Ensink, Dr. Wim Back, Dr. Herman Jonker, and Dr. Stefan Cokelaere for their support of the equine and production animal sections.
Parts of this publication were previously published on Vetvisuals (www.vetvisuals.com), and we would like to thank André Romijn, from Roman House Publishers Ltd and Kathryn Jenner for their support.
Dr. Gert ter Haar is from the Netherlands and studied veterinary medicine at the Faculty of Veterinary Medicine in Utrecht. He graduated in February 1997 with differentiation in Small Animal Medicine and Surgery. After having worked for a few months in private practice, Gert accepted a Clinical Rotating Internship position at the Department of Clinical Sciences of Companion Animals at the Utrecht University, followed by a Residency in Small Animal Surgery from September 1998 – September 2001 in the same Department. In September 2001, he became Assistant Professor in Veterinary Surgery at the university where he trained, dealing mainly with Ear-, Nose- and Throat (ENT) and upper airway diseases. In July 2002, he passed the surgical specialist certifying examination held in Vienna and became a Diplomate of the European College of Veterinary Surgeons. He then became Head of the Department of ENT at the University of Utrecht in February 2003. Also, in 2003 he became the secretary of the International Veterinary Ear, Nose and Throat Association (IVENTA), a specialist association affiliated with the World Small Animal Veterinary Association (WSAVA). His research on hearing in dogs led to his Ph.D. thesis, a 220-page book entitled “Age-related hearing loss in dogs.” in 2009. On the same day, he became President of the IVENTA and the representative of the IVENTA to the WSAVA. He gave over 200 national and international lectures on ENT medicine & surgery, hearing research in dogs, and soft tissue/reconstructive surgery in dogs and cats. He joined the Royal Veterinary College’s surgical team in London, the United Kingdom, in September 2011, where he is working as a senior lecturer in soft tissue surgery and head of the ENT department and ENT, Audiology and Brachycephaly clinics. In 2017, Gert started working in private practice for Anicura in Utrecht, The Netherlands. His current research involves a hearing loss in dogs and cats and brachycephalic obstructive airway syndrome.
Dr. Jolle Kirpensteijn graduated from the Utrecht University Faculty of Veterinary Medicine, Holland in 1988 and finished an internship in small animal medicine and surgery at the University of Georgia in the United States of America in 1989. After his internship, he completed his residency training in small animal surgery and a master’s degree at Kansas State University, USA. The residency was followed by a fellowship in surgical oncology at the Colorado State University Comparative Oncology Unit, USA. In 1993, Jolle returned to Europe to accept a surgical oncology position and soft tissue surgery at Utrecht University. In February of 2005, he was appointed Professor in Surgery at the University of Copenhagen and in August 2008 Professor in Soft Tissue Surgery at Utrecht University. Jolle is a Diplomate of the American and European College of Veterinary Surgeons. Jolle received the title Founding Fellow in Surgical Oncology (2012) and Minimally Invasive Surgery (Small Animal Soft Tissue) (2017) of the American College of Veterinary Surgeons (ACVS). In September 2013, Jolle accepted the Chief Professional Relation Officer position at Hills Pet Nutrition in the USA. Here, he played an integral role as the interface between the company and the profession at large. In 2018, he was promoted to the Chief Professional Veterinary Officer position in the US, where he leads all professional activities in the United States. Jolle has published over 100 peer-reviewed articles, given more than 250 lectures worldwide, and has received the prestigious BSAVA Simon Award in 2007, Hills Voorjaarsdagen Excellence in Healthcare Award in 2009, WSAVA President’s Award, and honorary membership to the Netherlands Association of Companion Animal Medicine (NACAM) in 2017. His main clinical and research interests are professional social media and digital innovations, surgical oncology, and endoscopic & reconstructive surgery. Check out his podcasts at purrpodcast.net and globalveterinarysurgery.net
The World Small Animal Veterinary Association (WSAVA) has elected Thai veterinarian Dr Siraya Chunekamrai as its new President. Dr Chunekamrai is a pioneer of veterinary practice in Thailand where she opened the country’s first equine surgery in 1996. She has a strong interest in self- and professional development and in helping WSAVA member associations in countries where companion animal practice is still emerging to raise standards of care. Dr Ellen van Nierop has been elected as Vice President. A Dutch veterinarian, she practices in Ecuador and is a former Honorary Treasurer of the association.
The WSAVA has also elected two new members of its Executive Board, Dr John de Jong, a past president of the American Veterinary Medical Association, who will serve as Honorary Treasurer, having held the role on an interim basis for several months, and Dr Jim Berry, formerly chair of the WSAVA’s Congress Steering Committee and a past president of the Canadian Veterinary Medical Association. All of those elected will serve a two-year term.
Dr Chunekamrai graduated from Kasetsart University Veterinary School, Bangkok, and studied for her PhD at the New York State College of Veterinary Medicine, Cornell University. She first became involved with the WSAVA in 2008 as President of the Veterinary Practitioners’ Association of Thailand, joining its Executive Board as Honorary Secretary in 2012. She has been Vice President since 2018. Dr Shane Ryan, the WSAVA’s outgoing president will also serve a further two-year term as Past President.
Commenting, she said: “I am humbled and grateful to have been elected as the WSAVA’s first female president, a move that reflects the steps our community has taken to become much more representative of our profession globally.
“Taking on this role in the ‘Pandemic Age’ is challenging but, while disruption is painful, it can highlight new opportunities and it’s inspiring to see our members around the world already making great strides in maintaining their veterinary communities virtually.
“During my presidency, I will be leading efforts to increase our inclusivity and attract more volunteers to support our Committees and other activities. We have already made great progress in transforming ourselves into an ‘offline to online’ association and recently held this year’s Assembly Meeting successfully online.
“While we will reinstate our face-to-face activities as soon as we can do so safely, it’s exciting to see the new ways in which we are already supporting our members virtually and providing leadership, support and education to companion animal veterinarians wherever they are in practice. I’m really looking forward to my presidency and to supporting the rapid growth and development of our amazing global veterinary community. If you’re not involved yet, you should be!”
The WSAVA represents more than 200,000 veterinarians worldwide through its 113 member associations and works to enhance standards of clinical care for companion animals. Its core activities include the development of WSAVA Global Guidelines in key areas of veterinary practice, including pain management, nutrition and vaccination, together with lobbying on important issues affecting companion animal care worldwide.
Surgery, literally meaning “handwork” from its Greek origins, is the art of treating a patient for a medical condition by using manual and/or mechanical methods. In doing so, the surgeon attempts to achieve a particular medical outcome. Surgical skills alone are not enough to achieve the intended outcome, and other factors surrounding both the patient and the owner also play an important role. The well-known expression “the operation was a success, but the patient died” may lead one to believe that surgery is purely the act of performing an operation. This, however, is rather short sighted because many more factors (including ethical and economic) are involved in the surgical process before, during and after the operation, which may last weeks to months after the actual procedure itself (Table 1).
Table 1. Factors influencing surgical outcome
Bodyweight and condition
Personnel (surgery and anaesthesia)
Age, a patient-related factor, is not, as such, a reason to refrain from surgery, but very young and very old patients present special considerations. Young patients have an increased risk of developing hypothermia and hypoglycaemia, whilst geriatric patients may suffer from a subclinical organ dysfunction, which may affect convalescence. Wound healing may be delayed in patients with severe malnutrition and obese patients have a higher risk of complications during and after surgery. Concurrent diseases such as heart disease or renal failure may increase anaesthetic risk and should be identified and managed before surgery.
Surgeon-related factors are based around the skills of the surgeon, the level of training and experience with the procedure that will be performed.
Practice-related factors include the surgical theatre (overpressure ventilation, electrical safety, management of hygiene), the personnel (presence of specialists or technicians qualified in anaesthesia, adequate surgical assistance) and facilities to hospitalize patients requiring prolonged or intensive care.
Client-related factors are the ability of the client to understand the procedure and instructions for appropriate aftercare, and the willingness or ability to pay for the costs of treatment.
1.2 Clinical decision-making
Clinical decision-making in surgery is primarily focused on the question of whether an operation is the best treatment for the disease concerned. The risks and benefits of an operation must be weighed against the risks and benefits of other therapies. Attention should also be paid to treatments that may support or expand the effect of surgery (physiotherapy, radiation therapy, chemotherapy). Ideally, this assessment is based on the proven efficacy of eligible treatments. In veterinary medicine the cost of treatment is an important factor that must also be taken into consideration. A stepwise approach can help to weigh the costs against the expected results at critical stages in the decision-making process. A diagnostic and therapeutic scenario (or check list) is a detailed description of such an approach. In the scenario all steps of the procedure are described in the sequence in which they should be performed. The scenario may be represented graphically in an algorithm or flow sheet.
Diagnostic and therapeutic scenarios are based on evidence from clinical trials and are developed by scientific professional organizations with input from scientists and practicing veterinarians. When a professional organization has published a scenario, it should be binding for all professionals. Disciplinary judges will use the scenario as a standard for professional conduct to which the action of veterinarians is compared.
Unfortunately, evidence-based scenarios are still rare in veterinary medicine. But in the absence of formal scenarios, veterinary surgeons may develop their own algorithms. An example is given in Figure 1, which shows an evidence-based scenario for the diagnosis and treatment of anal sac carcinoma in the dog.
The algorithm starts after an anal sac adenocarcinoma has been diagnosed by fine needle aspiration biopsy. Additional tests are undertaken (chest X-ray or CT, abdominal ultrasound) to stage the disease. A stepwise approach is followed to ensure that each decision is based on a realistic expectation of the results that can be achieved. These are derived (for this example) from two clinical studies that describe survival in 113 and 130 dogs with anal sac carcinoma.1, 2 In these studies, survival was correlated to the clinical stage with median survival times ranging from 2 (stage 4) to 40 months (stage 1). The algorithm illustrates that in advanced stages more treatment modalities are necessary to obtain shorter survival times. The expected survival may help to balance the costs of treatment against the outcome. The algorithm also depicts the sequence in which decisions are made.
Stage 1 is the simplest situation: a small tumour without regional or distant metastasis. Treatment consists of one modality (resection of the tumour) and is expected to produce good long-term results. In stage 2 the tumour is large (> 10 cm2) but there are no regional or distant metastases. If the tumour cannot be removed it may be treated by radiation to reduce the size until it has become resectable. Life expectancy after treatment is less than in stage one, but still acceptable. Stage 3 is characterized by regional metastases from a small or large tumour. If the metastases are resectable, they will be removed; the same applies to the primary tumour. Radiation therapy will be used preoperatively or intra-operatively if the metastases or the tumour are too large for removal or postoperatively. When their size has been reduced sufficiently, the tumour and the metastases are resected. The costs in this scenario increase with the number of treatments, whilst the life expectancy decreases to half of that in stage 2. In stage 4, the disease has spread to distant sites. Life expectancy is short, and treatment is mainly palliative.
The advantage of the algorithm is that it provides insight into the costs and benefits of treatment in various stages of the disease. This helps the veterinarian and the owner to balance these aspects. The algorithm’s limitation is that it displays median survival of a group of patients – individual patients may have a longer or shorter survival. One should be aware of this limitation when using algorithms.
Fig. 1. Diagnostic and therapeutic algorithm for anal sac carcinoma in the dog
An important aspect in the anal sac adenocarcinoma example is the assessment whether the tumour (or the lymph node) is resectable. In general, tumours are resectable if they can be removed with safe margins without causing damage to nearby vital structures (Figure 1). In the anal sac adenocarcinoma example, nearby vital structures are the external anal sphincter and the pudendal nerve. The close proximity of the sphincter to the anal sac excludes resection with wide margins; however, the tumour is resectable if it can be removed with narrow margins without causing severe damage to the sphincter. Vital structures near enlarged lymph nodes may include the rectum and colon, the urinary bladder, prostate and ureters, the aorta and the external and internal iliac arteries.
Figure 2. Removal of a tumor in the anal sac with safe margins
Before asking whether or not the tumor is resectable, the surgeon must assess whether the patient is operable. The American Society of Anesthesiologists has developed a qualification system for the physical status in human patients that is also used in veterinary medicine. Patients are divided into 5 classes:
Table 2. ASA classification of anaesthetic risk[*]
I A normal healthy patient
II A patient with mild systemic disease
III A patient with severe systemic disease
IV A patient with severe systemic disease that is a constant threat to life
V A moribund patient that is not expected to survive without the operation
Patients in category I-IV are usually operable, provided that sufficient knowledge, experience and equipment are available to deal with complications. In group V, there is little choice but this category may be decreased to a lower grade by providing adequate supportive therapy. An example of this is hyperkalemia in a cat with urethral obstruction. If a catheter can be inserted, fluid therapy may move the patient from category V to category IV or III and reduce the risk of cardiac arrest and other problems during surgery and anesthesia.
1.3 Purpose of surgery in animals
Prophylactic surgery: for instance, to prevent neoplastic disease, e.g. ovariectomy (OVE) for mammary gland tumours, excision of actinic dermatitis from the auricle or nasal plane for squamous cell carcinoma (SCC), and castration for cryptorchid testicles.
Therapeutic surgery: in the treatment of e.g. wounds, lesions, inflammation, anatomical changes, tumours
Palliative surgery: to improve but not completely cure the disease that the animal is afflicted with (e.g. debulking surgery)
Diagnostic: e.g. biopsy, operations which reveal a disease (like endoscopic exploratory surgery or an exploratory laparotomy)
Surgery to increase the animal’s utility for certain purposes: e.g. castration, dehorning
Experimental surgery for biomedical research
1.4 Methods for cutting or destroying tissue
Cutting with sharp instruments
Cutting or destroying tissue using high frequency currents: electrosurgery (‘electric knife’) and radiosurgery
Destroying tissue by freezing (and thawing): cryosurgery or cryonecrosis
Destroying tissue by the direct application of hot metal or by chemicals: cauterisation
Localised thermal effect using Light Amplification by Stimulated Emission of Radiation (‘laser’ surgery)
Ultrasonic ablation: e.g. Ultrasonic Surgical Aspirator (CUSA)
Controlled ablation (coblation)
Cutting with radioactive devices (focused radiation therapy including gamma knife)
The latter three devices are rarely available for general veterinary practice due to costs but can be used in specialized (university or private practice) clinics or research facilities. Methods 1-5 will be discussed in length in the upcoming chapters.
1.5 Methods to control intra-operative haemorrhage
Mechanical devices (sutures, clips and ties)
Sealing devices (e.g., the LigaSure, ENSEAL)
Drug carrying devices, e.g. gel foam or biomatrix
The best way to name operations is to use a combination of anatomical terms and Greek suffixes, thereby describing the location and type of operation. Exceptions are operations named after the inventor or surgeon. Examples:
thoracotomy: opening the thorax
gastrotomy: incising the stomach
–stomy (making an opening):
colostomy: making an artificial opening of the colon on the surface of the abdomen
gastroduodenostomy: creating an anastomosis between stomach and duodenum
splenectomy: removing the spleen
ovariohysterectomy: removing the uterus and the ovaries
ovariectomy: removing the ovaries
orchidectomy: removing the testicles (castration)
–plasty (shaping, forming):
episioplasty: reconstruction of the vulva
–centesis (perforating or draining):
paracentesis: penetrating a body cavity for the aspiration of liquid
cystocentesis: penetrating a urinary bladder for the aspiration of liquid
gastropexy: attaching the stomach to the abdominal wall to prevent torsion (volvulus)
colopexy: attaching the colon to the abdominal wall to prevent a rectal prolapse
–rrhaphy (suturing or closing):
inguinal herniorrhaphy: suturing an inguinal hernia
diaphragmatic herniorrhaphy: suturing a diaphragmatic hernia
perineal herniorrhaphy: suturing a perineal hernia
temporary tarsorrhaphy: temporarily suturing upper to lower eyelid
It should be noted that the field of surgery extends beyond the surgical procedure alone. Many other therapeutic modalities are used too, such as wound dressings, pharmacotherapy, radiation- and physiotherapy, etc.
1. Williams LE, Gliatto JM, Dodge RK. (2003) Carcinoma of the apocrine glands of the anal sac in dogs: 113 cases (1985-1995). Journal of the American Veterinary Medical Association, 223(6):825–31
2. Polton GA, Brearley MJ. (2007) Clinical stage, therapy, and prognosis in canine anal sac gland carcinoma. Journal of Veterinary Internal Medicine, 21(2):274-80
Emeritus Professor Michael Day began working with the WSAVA in 2003, holding a range of roles, including membership of the Gastrointestinal Standardization Group and Chair of the Scientific Advisory Committee. He founded the WSAVA’s One Health Committee in 2010 and was Chair of the WSAVA’s Vaccination Guidelines Group from 2009 until March 2020 when ill-health necessitated his stepping down from this and his other WSAVA roles. Emeritus Professor Day was latterly the BSAVA Member Representative for the WSAVA and joined the WSAVA’s Executive Board in 2017. He was elected Honorary Treasurer in 2018.
The inaugural Vice-President of the WSAVA Foundation, Emeritus Professor Day also helped to develop and lead its pioneering African Small Companion Animal Network (AFSCAN) project, which is working to raise standards of companion animal veterinary care in Sub-Saharan Africa. He had recently been awarded the WSAVA’s prestigious Award for Global Meritorious Service.
WSAVA President Shane Ryan said: “We are terribly saddened by the loss of Michael, who served the WSAVA with distinction and dedication for many years. He was a true veterinary leader who made an immense contribution to the WSAVA and the other associations he served. Michael was not only a highly respected colleague but a much-loved friend. We are heart-broken to lose him, and our thoughts are with his wife, our WSAVA colleague Dr Mary Marcondes, his wider family, his friends and colleagues.”
Professor Michael Lappin, Chair of the WSAVA’s One Health Committee, said: “Professor Day was an icon of global veterinary medicine in many fields. His work to found the One Health Committee and the resultant One Health Certificate Course are just two of the ways in which his memory will live on. It was an honor to be his friend and to have him as an inspiration in so many ways, both professionally and personally.”
Dr Jolle Kirpensteijn, WSAVA Past President and Chief Professional Veterinary Officer at Hill’s Pet Nutrition, US, said: “Michael was a friend to the entire global veterinary community and worked tirelessly and humbly to make the world better by championing a One Health approach. His hallmark sense of humor and ability to explain complex concepts touched us all.”
Dr Guillermina Manigot, WSAVA Member Representative for Argentina, added: “Among his many achievements, Professor Day was passionate about the creation of the first set of WSAVA Vaccination Guidelines for Latin America and travelled throughout the region, with members of the Vaccination Guidelines Group, to explain and discuss them with veterinarians. These Guidelines were recently published in Journal of Small Animal Practice and it is now our mission, as Latin American veterinarians, to apply what he taught us for the benefit of our patients and public health. Thank you, Professor Day.”
COVID-19 – An update for WSAVA MembersWeek ending April 3rd, 2020
Our COVID-19 update of March 27 ended with a STOP PRESS note about reports of a cat living in Belgium that was reported to be RT-PCR positive and clinically ill. Following the publication of a manuscript showing cats and ferrets to be theoretically susceptible to infection by SARS-CoV-2 based on in vitro receptor binding, a naturally exposed cat in Belgium was reported (18/03). The cat was living with a family member with COVID-19, was PCR positive for SARS-CoV-2, and had clinical signs of transient vomiting, diarrhea, and respiratory disease. The cat recovered uneventfully and monitoring is on-going to determine whether it develops serum antibodies to the virus. It cannot be determined with certainly that this cat was ill because of SARS-CoV-2.
Data from SARS-CoV-19 experimental infection models in cats, ferrets and other species have started to appear in the literature and a pre-print of a SARS-CoV-2 experimental model currently undergoing peer review has been widely discussed on social media. In this work, SARS-CoV-2 infection was induced in a number of species by inoculation of a high viral dose and some of the animals with primary infection, including cats, were able to pass the virus to other animals housed in close proximity. Clinical signs of disease were recognized in some of the animals.
This type of work helps us to understand the host range of COVID-19, the pathogenesis, and to develop further models for treatment and prevention studies. However, the WSAVA One Health and Scientific Advisory Committees strongly emphasize that these types of studies cannot be directly correlated to what happens in the field. Most importantly, we do not yet know whether the doses of SARS-CoV-2 used to initiate the primary infections of cats, ferrets, and dogs in the experimental studies would be achieved in a natural setting, where an infected owner is the source of infection.
It should also be remembered that public health services around the world monitoring the spread of SARS-CoV-2, have again ended this week steadfastly stating that there is no evidence of transmission from companion animals to people. As recommended in our Advisory, however, individuals who know they have COVID-19 should minimize direct contact with their pets to avoid potential transmission.
The American Veterinary Medical Association (AVMA) and the Center for Disease Control (CDC) released ‘interim recommendations for intake of companion animals from households where humans with COVID-19 are present’ late this week.
The document contains a reminder to house SARS-CoV-2 pets in the home if possible. It also says that bathing is not needed and that healthy exposed pets should be housed with minimal contact with others (pets and people) for 14 days while further information concerning the prevalence and duration of natural infections in cats is gathered.
A webinar on this topic was released on April 2, in which Prof. Mike Lappin represented the WSAVA and Colorado State University with Mr Jim Tedford the President & CEO of The Association for Animal Welfare Advancement and Dr Julie Levy from the University of Florida. Dr Levy is actively involved in the American Association of Shelter Veterinarians which worked closely with the CDC and AVMA on the recommendations.
Watch the webinar here In the United States, more of our regulatory agencies are announcing relaxation of telemedicine restrictions to aid veterinarians in helping companion animals while maintain social distancing for more routine cases. The announcement for Colorado veterinarians came just yesterday. You can read it here: We hope that other states and countries will follow suit.
Read the full announcement here These were the key developments this week so WSAVA would like to end by reminding you that, if you haven’t checked it for a few days, please re-visit the WSAVA’s COVID-19 resource hub as we have added content in new languages this week. With this in mind, WSAVA should, of course, thank their hard-working Translation Committee for its magnificent work to translate content, sometimes overnight, to make it as accessible to as many of our members as possible. We thank you too for all you are doing to continue to care for your patients and reassure their owners. Please keep yourselves and your families safe in these difficult times.
Michael R. Lappin, DVM, PhD, DACVIM (Internal Medicine)The Kenneth W. Smith Professor in Small Animal Clinical Medicine, Colorado State UniversityChairman, WSAVA One Health Committee
Vision Statement: All companion animals worldwide receive veterinary care that ensures their optimal health and welfare Mission Statement: To advance the health and welfare of companion animals worldwide through an educated, committed and collaborative global community of veterinary peers
World Small Animal Veterinary Association, 72 Melville Street, Dundas, Ontario L9H 2A1, Canada