Postoperative Complications Associated with Caudectomy in Brachycephalic Dogs with Ingrown Tails

Introduction

Ingrown or “corkscrew” tail is an abnormal inward growth of the tail that is commonly encountered in brachycephalic breeds such as English and French bulldogs, Boston terriers, and pugs. In many cases, an ingrown tail results in either severe intertrigo or skin fold dermatitis, both which are sources of chronic pain and infection. Overlapping of the skin allows for accumulation of surface debris (such as sebum, urine, or feces) and decreases ventilation allowing proliferation of surface bacteria. The most commonly associated bacteria include coagulase-positive Staphylococcus spp., but Streptococcus spp., Pseudomonas, and coliforms have also been cultured, as well as yeasts such as Malassezia and Candida. Chronic irritation and damage to the superficial layers of skin allow surface debris and bacteria to penetrate the deeper layers of skin, leading to inflammatory changes and suppression of local immune function.¹

Complete or partial caudectomy is the treatment of choice for dogs with ingrown tails; however, those surgeries can be challenging in severe cases, and anecdotal reports of complications, such as fecal incontinence, neuroma formation, and infection, often deter owners and veterinarians from seeking surgical assistance. Presently, there is no scientific review of case outcomes following surgical treatment to substantiate those claims. The purpose of this study was to determine type and frequency of complications associated with caudectomy for the treatment of ingrown tails.

Materials and Methods

Animals and Data Collection

Medical records of all dogs with ingrown tails treated with caudectomy from 2000 to 2010 at the University of Georgia Veterinary Teaching Hospital were reviewed. Information collected from the medical records included signalment, history, physical examination findings, surgery performed, and clinical appearance of the surgery site both immediately after surgery and at suture removal. Anesthetic protocol and postoperative pain management was not standardized between patients and was determined at the discretion of the anesthesiologist and surgeon on duty. Occurrence of infection, inflammation, dehiscence, incontinence, pain, nerve damage, or other complications that occurred after surgery were recorded.

Pre- or postoperative inflammation was defined as having three or more of the following signs simultaneously: redness, swelling, pain, heat, and/or serous discharge.² A pre- or postoperative infection was defined as the presence of purulent drainage, an abscess or fistula, or spontaneous dehiscence of one or more wound layers with serous drainage after surgery.^2–4 The presence of either inflammation or infection prior to surgery was recorded, and the surgical wounds were classified as clean, clean-contaminated, contaminated, or dirty.³ Pre-, peri-, and postoperative antibiotic use, as well as other treatments instituted, were also recorded. If there was no follow-up visit in the medical record, the referring veterinarian was contacted by telephone and a standardized questionnaire was used to identify any complications and treatment instituted at suture removal (Table 1). Immediate postoperative complications were defined as those occurring within the same hospital stay as the surgical procedure. Short-term complications were defined as occurring on or before suture removal, and long-term complications were defined as occurring after suture removal. The owners of included dogs were contacted, and complications and satisfaction with surgery were noted using a standardized questionnaire (Table 1).

TABLE 1 Standardized Questionnaire for Referring Veterinarians and Owners

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Response to surgery was graded as excellent, good, or poor. An excellent outcome was defined as incision site healing with no complications, a good outcome was defined as delayed healing of the incision site and/or development of short-term complications, and a poor outcome was defined as either permanent complications or owner dissatisfaction with the outcome. Owners were also asked if resolution of preoperative clinic signs occurred after the surgery and were queried regarding the general well being of the dog at the time of contact.

Results

Animals

Seventeen dogs were included in the study, and data from the immediate postoperative period was recorded for all. Information at the time of suture removal was obtained from 15 referring veterinarians, and information from owners regarding long-term postoperative progress was available for 13 dogs. Mean age at the time of presentation was 3.5 yr ± 1.6 yr. Nine dogs were male (six castrated) and eight were female (five spayed). Mean patient weight was 25.2 kg ± 7.3 kg. Fifteen of the dogs were English bulldogs and two were Boston terriers. At the time of presentation, 12 dogs (70.5%) had pain, inflammation, and/or infection associated with intertriginous dermatitis and an ingrown tail (Table 2). Two dogs (cases 2 and 13) presented for perianal draining tracts and abscesses. One dog (case 9) had undergone a partial caudectomy at another clinic 22 days prior to presentation, but had persistent pain associated with the site and was presented for revision surgery. One dog (case 14) was an intact male with concomitant urethral prolapse. In that case, the ingrown tail and urethral prolapse were surgically corrected during the same anesthetic episode.

TABLE 2 Characteristics and Postoperative Complications of Dogs Treated with Caudectomy for Ingrown Tails

–, not applicable; CM, castrated male; F, female; M, male; SF, spayed female.

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Two of the wounds were classified as clean-contaminated, eight as contaminated, and seven classified as dirty. Infection was present at the site in seven dogs (41%) before surgery, six of which had clinical resolution of the infection immediately following surgery. Four dogs were taking oral antibiotics at the time of presentation. Perioperative antibiotics were used in all dogs and were continued after surgery in 13 dogs (76%) for an average of 13.5 days ± 5.2 days at the discretion of the clinician on the case. Commonly used postoperative antibiotics were amoxicillin/clavulanate acid, clindamycin, metronidazole, and cefpodoxime. Mean duration of hospitalization was 4 days ± 1 day.

Discussion

In the current study, complications associated with caudectomy for the treatment of ingrown tails were described. Complications were identified in 4 of the 17 dogs (23.5%) following surgery. All complications were temporary, and no dog with long-term follow-up available had negative effects from surgery.

English bulldogs represented the majority of dogs in this study. The reason for the increased prevalence of tail malformation in bulldogs is unknown, but may represent an inherited phenotype within the breed. Other vertebral malformations, such as hemivertebra, butterfly vertebra, kyphosis, and scoliosis have been described for certain breeds. An underlying cause for most congenital spinal abnormalities is not known, but a genetic predisposition has been identified in some cases.⁶ Reihart (1950) reported the most commonly affected breeds with kyphosis were also the breeds described for ingrown tails.⁷ A study to determine breed incidence and heritability would be necessary to confirm the occurrence of ingrown tails in bulldogs and other breeds.

The postoperative infection rate for caudectomy in all dogs was 6% (1 of 17), which is within the accepted range for contaminated to dirty surgical sites.^3,4 Vasseur et al. (1988) reported an infection rate of 18% for dirty surgical wounds, which is higher than in the current study, which reports a 14% (1 of 7) infection rate for dirty surgical wounds.³ Of the two dogs who presented for perianal abscess, the dog with postoperative infection (case 2) exhibited more severe clinical signs associated with ingrown tail. That dog had four draining tracts around the anus, the origin of which could not be determined without advanced imaging. The other dog (case 12) had a single draining tact, and rectal palpation revealed that it originated from the distal end of the tail. Follow-up information was not obtained for case 12, but immediate postoperative complications did not occur. Case 2 required additional surgery to alleviate the preoperative infection present at the site. This complication was not unexpected due to the severity of preoperative clinical signs. Case 2 was one of the dogs on preoperative antibiotics who developed a postoperative complication. Of the four dogs on preoperative antibiotics, two developed complications. Postoperative antibiotic usage for each case was at the discretion of the surgeon and was chosen based on preoperative clinical signs, appearance of the site immediately postoperatively, and previous literature of the most common bacteria found at the site.¹ Given the small number of dogs in this series, no conclusions can be drawn between preoperative infection or antibiotic use and postoperative infection.

Fecal incontinence from damage to the pudendal and caudal rectal nerves is a theoretical complication reported in surgical textbooks, and in the authors’ clinical experience, an important reason why owners do not pursue surgical treatment.^1,5 In this study population, there were no cases of fecal incontinence identified following caudectomy. One dog failed to posture to defecate and had subjectively decreased rectal sensation immediately following surgery, but remained continent and maintained anal tone. Another dog was continent immediately following surgery, but had abnormal defecation in the house for the first 3 days at home. The problem resolved on its own without further therapy, and the dog remained continent at the time this report was written. The risk of incontinence with caudectomy appears to be minimal, but temporary changes in defecation habits may be possible. It is unclear if those changes are due to either temporary nerve injury or discomfort related to the surgery, despite postoperative pain management. Fecal incontinence did not occur in this series, but given the regional anatomy and the significant deformity present in some dogs with ingrown tails, care must be taken during the surgical procedure to prevent neurologic damage and resultant complications. Based on this study and its relatively small sample size, clinicians should continue to counsel owners regarding the potential risk of nerve damage during caudectomy.

The owners of one dog reported occasional tail chasing behavior that persisted after the surgery. Compulsive tail chasing is a repetitive behavior that is characterized by either slow to rapid circling with the dog’s attention directed toward the tail or rapid spinning in tight circles with no apparent focus on the tail. When engaged in the behavior, dogs appear dissociated from environment and resistant to any form of interruption. Physical conditions associated with onset and continued elicitation of tail chasing are reported in 20 of 239 dogs with tail chasing behavior, and include first or second estrus cycle, diarrhea, defecation, flatulence, hunger, fatigue, allergies, and tail injury.⁸ It is possible an ingrown tail and the associated chronic irritation could predispose dogs to tail chasing behavior.

Of the other complications reported in the current study, delayed healing of the surgical site occurred in one dog due to suspected tension upon wound closure. Meticulous tissue handling, precise epidermal apposition, and a tension-free closure are imperative for optimal healing of any incision. An optional surgical technique that may be used to decrease tension and cosmetic appearance at the surgical site is described by Pavletic (2010). Briefly, a “T” incision is created caudal to the cranial skin fold at the base of the tail, and dissection of the musculature and disarticulation of the caudal vertebrae performed. The terminal tail segment is grasped with forceps and dorsal traction applied to evert the recessed ventral fold, then a skin incision made at the base of the tail to complete the resection. Absorbable suture is used to close subcutaneous tissue and interrupted skin sutures used for skin closure. The large preserved cranial skin fold forms a prominent peak, giving the semblance of a tail.⁹ Inflammation of the incision occurred in another dog, which may have been a reaction to either the skin sutures or secondary to wound contamination. Antibiotics were used as part of the treatment protocol in both dogs, and both completely resolved. In the dog presented for urethral prolapse, the prolapse was secondary to behavioral issues, not the ingrown tail.

Other complications of caudectomy reported in the literature, including pain, nerve damage, tenesmus, and hematochezia were not observed in the current study.^1,2,10 Sufficient time between surgery and follow-up with owners (150–1,430 days) occurred to exclude any long-term complications associated with the procedure, with the possible exception of amputation neuroma. Dogs with neuromas following tail docking are reported to develop clinical signs such as pain; self-trauma; alopecia; lichenification and hyperpigmentation of the skin; and firm, diffuse thickening of the connective tissue associated with the tail, as long as 1 yr post operatively.¹⁰ Approximately half of the dogs in the current study have follow-up times of < 1 yr. In addition, if neuromas did occur in any dog, they may not be apparent to owners, so a definitive statement cannot be made regarding the occurrence of this complication.

Conclusion

Limitations of the study include a small population size, which may underestimate the reported complications and exclude other complications that may have been seen with a larger sample. Also the lack of hands on follow-up by the surgeon(s) may have resulted in a difference in the type and frequency of postoperative complications reported, as well as the treatment instituted. Despite the above limitations, caudectomy is the recommended treatment of ingrown tails. All of the animals in the study had complete resolution of preoperative clinical signs with minimal complications.