ABSTRACT As a result of the large increase in brachycephalic dog breed ownership , veterinary professionals have had greater involvement in their care , especially in relation to caesarean sections . As discussed in Part 1 of this series ( VNJ , November 2022 ), veterinary professionals should encourage preoperative testing to minimise breeding for extreme conformation traits . This second part of the series focuses on perioperative care of the pregnant brachycephalic bitch , from admission for surgery through to recovery , as well as appropriate communication with breeders / owners throughout .
Keywords brachycephalic , nursing , c-section , caesarean , breeding
Introduction
Elective caesarean sections ( c-sections ) are often indicated in high-risk brachycephalic dog breeds . Despite the need for surgical intervention in these breeds , recent studies have shown that c-sections do not have a high impact on fertility [ 1 ] . This could explain why many breeders opt for surgical interventions . Preoperative discussions and information provided by veterinary professionals can help to minimise the breeding of unsuitable bitches , but not all pregnant brachycephalic bitches are seen prior to surgery so this is not always achievable .
Admitting the patient
Brachycephalic dog breeders may consider c-sections a routine procedure , due to their high prevalence , but they must be treated as a high-risk anaesthetic when gaining informed consent . This is mainly because the brachycephalic anatomy affects oxygen delivery to the tissues . In the author ' s experience , pregnant brachycephalic bitches can benefit from being administered an omeprazole tablet the night before surgery . This should be confirmed at the time of admission . If it has not been given , an injection of omeprazole can be administered at the practice at least 4 hours preoperatively . This is to minimise the risk of regurgitation and gastroesophageal reflux [ 2 ] .
Once the consent form has been completed and the patient has been weighed , they can be preoperatively assessed . Pre-anaesthetic checklists , such as those produced by the Association of Veterinary Anaesthetists ( AVA ), are recommended , to identify risks and prepare accordingly . The American Society of Anaesthesiologists ( ASA ) physical status scale is another useful rescource . Most brachycephalic patients are classed as ASA Grade 2 , as there is a mild systemic disease caused by conformation that does not limit their normal function . However , brachycephalic patients that are unable to function normally due to this systemic disease and their morphology are classed as ASA Grade 3 , meaning they are at moderate risk of mortality under general anaesthesia [ 3 ] .
If possible , it is good practice to place an intravenous catheter in the brachycephalic patient once admitted , but this can be delayed if the patient is stressed . The use of a eutectic mixture of local anaesthetics ( EMLA ) topical cream 30 – 45 min prior to placement , and placing a catheter in the saphenous vein , may be less stressful .
Premedication and induction
Careful consideration of drug choices is crucial for pregnant brachycephalic bitches . Although opioids administered preoperatively reduce the amount of induction or inhalation agent that is given , they will travel through the placenta to the foetuses [ 4 ] , so they should be avoided if possible . It should be noted that maropitant is used off-licence in pregnant and lactating bitches . However , it is recommended that maropitant ( 1 mg / kg ) be administered subcutaneously 30 min before administering opioids , to limit aspiration and regurgitation in brachycephalic patients [ 5 ] .
Preoxygenation at 100 ml / kg / min should be given for at least 3 – 5 min via an oxygen mask . This replaces the functional residual capacity ( FRC ) of oxygen in the lungs , increasing it from 21 % to 100 %, resulting in slower oxygen desaturation [ 6 ] . If tolerated , it is beneficial to start clipping the surgical site at this stage to reduce anaesthetic time .
Once the patient is preoxygenated , the veterinary surgeon ( VS ) can induce anaesthesia with intravenous propofol or alfaxalone . If opting for propofol , it should be noted that , although it is rapidly metabolised , it can cause cardiopulmonary depression in puppies , whereas use of alfaxalone as an induction agent results in higher puppy vigour and improved appearance , pulse , grimace , activity and respiration ( Apgar ) scores [ 7 ] .
Immediately after induction , an endotracheal tube should be placed and appropriately inflated to minimise the risk of regurgitation . The use of a laryngoscope provides better visualisation when intubating these patients due to their elongated soft palates . Tube size is usually smaller in brachycephalic breeds as they have a narrowed trachea . Intubating them increases tracheal height and width by 10 %, improving respiration [ 8 ] .
Once the patient is intubated and attached to a suitable circuit , an eye lubricant should be applied . This is particularly important in brachycephalic breeds as they are predisposed to corneal ulcerative disease [ 9 ] . Veterinary nurses ( VNs ) may also administer 1 – 2 drops of a nasal decongestant on induction of anaesthesia , or just before if tolerated by the patient . The surgical
28 Veterinary Nursing Journal