{'fraction_non_alphanumeric': 0.03274375091360912, 'fraction_numerical': 0.02346148223943868, 'mean_word_length': 5.070541259982254, 'pattern_counts': {'":': 0, '<': 4, '<?xml version=': 0, '>': 1, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 1, 'zh_pornsignals.json': 0}}
Outcome and complications in goats treated by perineal urethrostomy for obstructive urolithiasis: 25 cases (2010‐2017)

Background Obstructive urolithiasis commonly affects male goats. Perineal urethrostomy (PU) can be a permanent treatment option but is generally considered undesirable because of the risk of stricture of the urethral stoma. Limited information exists regarding long‐term outcome and complications in goats undergoing PU for treatment of obstructive urolithiasis. Objectives To determine short‐term and long‐term outcome and complications in goats undergoing PU for treatment of obstructive urolithiasis. Animals Twenty‐five client‐owned goats. Methods Multi‐institutional retrospective case series. Results Of the 25 goats, 13 (52%) were alive at the time of follow‐up. Mean time from surgery to follow‐up was 34 months (range, 4‐65). Nine goats (36%) died between discharge and follow‐up with a mean survival time of 46 days (range, 5‐120). Cause of death in 7 of 9 (78%) goats was related to urolithiasis. Goats treated by use of a modified proximal perineal urethrostomy (MPPU) were significantly more likely to survive at least 150 days postoperatively (P < .01). The most common postoperative complications were hemorrhage (10/25 [40%]) and surgical site infection (3/25 [12%]). Hemorrhage was significantly associated with MPPU (P < .0001). Stricture of the surgical stoma occurred in 7 of 22 (32%) discharged goats. Mean time to stricture was 65 days (range, 10‐240). Conclusions and Clinical Importance Perineal urethrostomy can provide effective long‐term resolution of obstructive urolithiasis in goats. Re‐obstruction or stricture seems most likely within the 1st 2 months after surgery. MPPU may provide better long‐term results but should be approached cautiously because it can be associated with life‐threatening hemorrhage.


| INTRODUCTION
Obstructive urolithiasis is a common condition in male goats. With the increasing popularity of goats as pets, veterinarians frequently are faced with the challenge of providing a treatment option for obstructed goats that maximizes the long-term survival and comfort of the animal. Determining the most appropriate method of treatment requires careful consideration of many factors, and no single approach is best in all cases. 1 Perineal urethrostomy (PU) provides a permanent alternative mode of urinary egress but generally is considered an unattractive long-term solution for goats because of complications including stricture of the urethral stoma, urine scalding, and cystitis. [2][3][4] Treatment of obstructive urolithiasis in goats frequently requires multiple surgical interventions for many reasons including displacement of the cystostomy tube from the urinary bladder, re-obstruction, and persistent urethral obstruction. 5 In cases where other surgical or medical treatment options have failed, PU can provide resolution of urinary obstruction. Other indications for PU include animals with Abbreviations: MPPU, modified proximal perineal urethrostomy; PU, perineal urethrostomy. evidence of urethral rupture, urethral stricture, or urethral obstruction with multiple stones that are not conducive to dissolution with urine acidification. Limited long-term follow-up information is available regarding complications and outcome of goats treated by PU for obstructive urolithiasis. 2,4,6 Reported survival in goats 1 year after PU is highly variable and ranges from 3 of 18 to 9 of 10 animals. 2,4,6 The purpose of our study was to determine long-term survival (>1 year) and complications in goats treated by PU. We hypothesized that PU can provide an effective surgical option for long-term recovery for goats with obstructive urolithiasis.

| Criteria for case selection
Medical records of all goats admitted to 4 veterinary medical teaching hospitals between January 2010 and July 2017 were reviewed. Goats that underwent PU for treatment of obstructive urolithiasis and owners of which could be contacted for follow-up were included.

| Medical records review
The following information was gathered from the medical records: signalment, body weight, admission date, duration of hospitalization, dietary history, onset of clinical signs of urinary obstruction before presentation, previous treatment for urinary obstruction, surgical procedure, perioperative complications, and date and cause of death.

| Follow-up information
Follow-up information was obtained by telephone interview with owners. Owners were asked if the goat had experienced any complications related to the PU including stricture, urine scalding, cystitis, re-obstruction, and infection. If the goat had experienced stricture, information was obtained regarding the time to development of the stricture relative to the PU, any treatment sought, and the outcome of such treatment. If the goat died, they were asked for details regarding death to determine if it was related to urolithiasis.

| Statistical analysis
Descriptive statistics were calculated for the data. The Shapiro-Wilk test showed the data to be non-normally distributed and thus median (range) is reported. A Fisher's exact test was used to examine the association between PU surgical approach (modified proximal perineal urethrostomy [MPPU] versus traditional high or low PU) and complications and survival.

| Animals
Twenty-five goats underwent PU and met the inclusion criteria for the study. The cases came from 4 university hospitals: Kansas State University (n = 4), University of Missouri (n = 6), Oklahoma State University (n = 9), and Texas A&M University (n = 6). One goat, from the University of Missouri, was lost to follow-up and excluded.
The median age of the goats was 20 months (range, 3 months to 11 years). The median weight of the goats was 46 kg (range, 11-110 kg).

| History
Of the goats, 20 of 25 had received ≥1 previous treatments for obstructive urolithiasis. Previous treatments included urine acidification with PO ammonium chloride (3), urethral process amputation For these 9 goats, the mean time between admission and PU surgery was 13 days (range, 2-33 days). Of the 21 goats for which dietary information was available, 15 (71%) were fed some form of grain or concentrate, 4 (19%) received alfalfa hay as a portion of the diet, and 7 (33%) were fed exclusively grass hay or pasture grass.

| Treatment
Three different PU surgical approaches were used. Eleven goats (11/25 [44%]) were treated by MPPU. 6 The remaining 14 goats were treated using a high or low PU with the urethral mucosa spatulated to the skin in 7 (7/28 [28%]) and the stump of the transected penis sutured to the skin without any spatulation of the urethral mucosa in the remaining 7 (7/25 [28%]). 7,8 The MPPU approach was used at 3 institutions. All 4 institutions reported performing at least 1 high or low PU with spatulation of the urethral mucosa, whereas 2 institutions used a high or low approach without any spatulation of the urethral mucosa. The median duration of hospitalization was 8 days (range, 0-41 days). Three goats died before discharge from the hospital. Of the goats that survived to discharge, 12 (12/22 [55%]) goats were released with instructions to be given either ammonium chloride (AniMed ACH Products, Inc, Winchester, Kentucky) or a rumen fermentation enhancer (AniMed ACH Products, Inc) to promote urine acidification.

| Postoperative complications
The most common postoperative complications were hemorrhage  Table 1). Hemorrhage was significantly associated with MPPU (P < .0001). Hemorrhage was reported in 8 of 11 (73%) goats that had MPPU performed and was severe enough to require blood transfusion in 2 of the goats. Three goats (3/25 [12%]) did not survive to discharge. Two goats were euthanized at 1 and 5 days postoperatively because of re-obstruction of the proximal urethra. One goat died 10 days postoperatively from anesthetic complications during a 2nd procedure to investigate surgical site hemorrhage.

| Long-term outcome and complications
Among the 22 goats that survived to discharge, the most commonly reported complication was stricture of the surgical stoma (7/22 [32%]). The mean time to stricture of the stoma was 65 days (range, 10-240 days). Goats that had MPPU were significantly more likely to live at least 150 days without stricture of the urethral stoma (P < .01).
Four of the 5 goats in which re-obstruction was reported were successfully treated by retrograde urethral catheterization and lavage to dislodge hard, spherical, non-dissolvable stones obstructing the proximal urethra. Of the 7 goats with urethral stricture, 6 were treated. The stricture was successfully relieved in 2 goats using balloon dilatation with 1 goat requiring 3 separate treatments at approximately 1-month intervals; 2 goats underwent revision of the PU at a more proximal location but 1 of the revised stomas formed a stricture 18 days later; 1 goat was successfully treated by catheterization of the urethral stoma; 1 goat underwent bladder marsupialization; and 1 goat was treated with ammonium chloride but continued to strain and died after hemorrhaging at the surgical site.

| DISCUSSION
We found that although the risk of complications associated with PU is high, it can be a viable long-term treatment for obstructive urolithiasis in goats, particularly those in which other treatments have failed. Two previous studies investigating the long-term outcome of sheep and goats treated by PU concluded that the procedure does not provide a favorable long-term solution in small ruminants with obstructive urolithiasis. 2,4 In 1 of the studies, 3 of 18 (17%) animals discharged were alive 1 year postoperatively. 2 In contrast, the longterm outcome in the other study was better with 4 of 8 (50%) animals still alive at the time of follow-up at least 1 year later with a mean survival time of 34 months. 4 Another previous study reported favorable long-term results using a modified surgical approach with the urethrostomy site still patent after 1 year in 9 of 10 goats. 6 In our study, goats were treated using similar surgical techniques to those described in the previously reported studies. We hypothesized that PU can provide an effective surgical option for long-term recovery in goats with obstructive urolithiasis. Our findings support this hypothesis with 10 of 22 (45%) discharged goats surviving at least 1 year postoperatively with a mean survival of 37.5 months, and 13 of survived at least 1 year postoperatively. 9 The goats in that study also experienced multiple complications including ascending cystitis (2/4), abscess formation (1/4), and stricture of the stoma (1/4). 9 In our study, approximately one-third of the goats that were dis- surgical intervention because of tube displacement, persistent or recurrent obstruction, and urethral rupture. 5 Owners considering PU should be warned that there is a risk additional procedures will be required to maintain patency of the urethral opening.
The propensity of goats to experience stricture after PU has led veterinarians to seek new surgical techniques. Multiple surgical approaches for PU are described in small ruminants. 1,2,4,6,8,10 The more commonly described technique involves making the approach near the level of the ischial arch and either spatulating the urethral mucosa to the skin or simply suturing the transected penile stump to the skin. 2,4,8 Although this technique is similar to that used in 14 of the goats described here, the other 11 goats had MPPU performed. 6 The MPPU is technically challenging and carries a high risk of hemorrhage but has the advantage of providing a surgical stoma less prone to stricture. 6 It seems likely that in our study, MPPU was selected more frequently for pet goats because longevity was a primary concern. In our study, 8 of 11 (73%) goats that underwent MPPU experienced some hemorrhage, with 2 requiring blood transfusion. However, the risk may be justifiable because the goats treated using the modified approach went a mean of 112 days without stricture compared with a mean of 29 days for the goats treated by 1 of the other 2 approaches.
Dietary changes and urine acidification are used to help prevent re-obstruction in goats with urolithiasis. 3 In our study, 18 of 25 (72%) goats were fed some form of grain, alfalfa hay, or treats, which may have predisposed them to development of obstructive urolithiasis.
However, no information about postoperative dietary changes was collected. Although 12 of 22 discharged goats were prescribed a urine acidifying agent, most (11/14 for which the calculus type was identified) were reported to have calcium carbonate stones, which do not respond to urine acidification. One study recommended that, whenever possible, a cystostomy followed by dietary management is a more effective long-term management strategy than PU in small ruminants. 4 Unfortunately, cystostomy or dietary management was reported to be previously unsuccessful treatments in nearly half of the goats in our study, possibly because the obstructing uroliths were of a composition that was refractory to medical dissolution.
The mineral composition of uroliths is a critical consideration for the management of obstructive urolithiasis in goats. 11

CONFLICT OF INTEREST DECLARATION
Authors declare no conflict of interest.

OFF-LABEL ANTIMICROBIAL DECLARATION
Authors declare no off-label use of antimicrobials.

INSTITUTIONAL ANIMAL CARE AND USE COMMITTEE (IACUC) OR OTHER APPROVAL DECLARATION
Authors declare no IACUC or other approval was needed.

HUMAN ETHICS APPROVAL DECLARATION
Authors declare human ethics approval was not needed for this study.