Atresia ani in the dog: a retrospective study

Congenital anomalies of the rectum and anus are rare in dogs. The most frequently reported anomaly is atresia ani. Four types of atresia ani have been reported, including congenital anal stenosis (Type I); imperforate anus alone (Type II) or combined with more cranial termination of the rectum as a blind pouch (Type III); and discontinuity of the proximal rectum with normal anal and terminal rectal development (Type IV). An increased incidence was found in females and in several breeds, including miniature or toy poodles and Boston terriers. Surgical repair is the treatment of choice, but postoperative complications can occur, including fecal incontinence and colonic atony secondary to prolonged preoperative distension.     

Rectovaginal fistula with atresia ani in three kittens.

Rectovaginal fistula with atresia ani was diagnosed in 3 kittens. Physical abnormalities included abdominal distension, bulging of the perineum, and lack of an anal opening. Vaginography was helpful in determining the type of malformation present in 2 cases. In each kitten attempts were made to surgically correct the anatomic malformations. Various post-operative complications such as fecal incontinence, would dehiscence, constipation, and excessive scar tissue formation occurred and are discussed.     

Complete diphallia, imperforate ani (type 2 atresia ani), and an accessory scrotum in a 5-day-old calf.

A 5-day-old Angus calf was submitted to the necropsy service at the University of Kentucky Livestock Disease Diagnostic Center. At birth, the calf was noted to have 2 scrota. Five days post-calving the calf developed severe tenesmus and an umbilical infection. Clinical examination revealed atresia ani. At necropsy, complete diphallus, imperforate ani (type 2 atresia ani), and remnants of 2 scrota were identified. This report describes the gross pathologic appearance of a rare case of complete diphallia, imperforate ani (type 2 atresia ani), and an accessory scrotum in a 5-day-old calf.     

Surgical Repair and Management of Congenital Intestinal Atresia in 68 Calves

Objective— To determine outcome and survival rate after surgical treatment of intestinal atresia, gender predilection, and effect of rectal palpation on the cause of atresia coli in calves.
Study Design— Prospective clinical study.
Animals— Newborn calves (n=68).
Methods— Data collected were husbandry system, anamneses, physical examination findings, surgical treatments, and postoperative results. Calves with atresia ani, and with atresia coli et recti had anal reconstruction and right flank colostomy, respectively. In midflank colostomized calves, the inner muscular layers were dissected to form a valve-like stoma.
Results— Of 68 calves with intestinal atresia, 37 were treated surgically. Anal reconstruction was performed in 21 calves with atresia ani with a long-term survival rate of at least 6 months with good condition. Colostomy was performed in 14 calves with atresia coli and 1 with atresia coli et recti; survival rate was 73%. The case morbidity rate for intestinal atresia was 13.8% and for atresia coli, 5.7% in the hospital population. No gender predilection for occurrence of atresia ani and atresia coli was identified. Palpation per rectum for early pregnancy diagnosis did not predispose to atresia coli.
Conclusion— Surgical treatment of atresia ani through circular anal skin removal has a good prognosis for survival. Colostomy is not an acceptable treatment from the calf's perspective because of the resulting poor condition but the high survival rate is important to allow continued milk production of the dam.
Clinical Relevance— Early diagnosis, supportive treatment, and surgical correction are important in management of atresia coli.     

Incomplete caudal duplication in a puppy: gross and radiological observations

Caudal duplication is a rare type of conjoined twinning. The aim of this case report is to describe a case of caudal duplication in a male crossbreed puppy. The puppy was macroscopically and radiographically examined after death. External features included a supernumerary limb projecting from the perineum, complete lack of tail, anal atresia, double penis and absence of scrotal sacs. Internal examination showed anomalies involving the intestine and the urinary system. At x-ray examination, the supernumerary limb showed features similar to that of the normal right hindlimb but showed absence of fibula and tibia and presence of three metatarsi and phalanges. The authors discuss the pathogenic mechanisms of this condition, infrequently reported in veterinary practice, pointing out the importance of embryonic duplications commonly associated with dystocia.     

Rectovaginal fistula with anal atresia in 5 dogs

Five dogs with rectovaginal fistula and atresia ani that had been treated by surgical correction of the malformations were studied retrospectively. Ages at presentation varied from 1 to 3 months and weight from 350 g to 7.5 kg. The histories included voiding of feces through the vulva, with or without tenesmus, usually observed after weaning. Atresia ani, presence of feces in the vaginal canal, abdominal distention, and discomfort on abdominal palpation were observed during clinical examination. Also, 3 dogs had partial tail agenesis. In all dogs, the rectovaginal fistula was isolated and transected, the vulvar and rectal defects were closed separately, and the atresia ani was repaired. Normal defecation was restored, but 1 dog had fecal incontinence that subsequently resolved. One dog died 2.5 months postoperatively, and follow-up was done on the others for periods ranging from 1.6 year to 7.7 years. Surgical correction in dogs with rectovaginal fistula and atresia ani may result in a favorable outcome, if it is done early.     

Intestinal atresia in calves: 22 cases (1978-1988)

A retrospective study of 22 calves afflicted with intestinal atresia was performed to determine typical signs of disease, treatment, and survival rate. All 22 calves, except 2 heifers with atresia ani and rectovaginal fistula, were examined when they were between 1 and 10 days old because of depression, anorexia, abdominal distention, and lack of feces. All calves had been observed to stand and suckle shortly after birth. Survival rate was influenced by the atretic segment affected: 0% (0/2 surgically treated) for atresia jejunal; 42% (5/12 examined) or 71% (5/7 recovering from general anesthesia) for atresia coli; and 63% (5/8 examined) or 71% (5/7 surgically treated) for atresia ani. Survival appeared to depend principally on early recognition, anatomic site affected, and successful surgical establishment of a patent intestinal tract.     

Persistent Cloaca, Fused Kidneys, Female Pseudohermaphroditism and Skeletal Anomalies in a Simmental Calf

A 5-day-old Simmental calf was referred to our department for atresia ani and postural abnormalities caused by skeletal deformities. The calf had a short and deviated tail and a bowed hind limb. The calf appeared like a male because of the prepuce and penis located just near the teats and the absence of female external genitalia. During the necropsy, a horseshoe kidney, single ureter that originated from the kidney, and bilateral uterine horns with one ovary each were detected. The ureter, blind-ended large intestine, and bilateral uterine horns were connected to a dilated cloaca having two sacs, which were filled with a yellowish brown viscous fluid admixed with meconium and urine. Skeletal deformities found included scoliosis, partial synostosis of vertebrae, deviation of rudimentary sacrum and coccygeal vertebrae, and narrowed pelvic cavity. This is the first report of an anomalous combination including urogenital, large intestinal, and skeletal deformities in cattle.     

Atresia ani and urethrorectal fistula in a kitten

A case of urethrorectal fistula associated with atresia ani in a seven-week-old male kitten is described. The main clinical sign was tenesmus. The diagnosis was confirmed by positive contrast radiography and post mortem examination.     

Preservation of the fistula for reconstruction of the anal canal and the anus in atresia ani and rectovestibular fistula in 2 dogs

OBJECTIVE: To report a technique for correction of atresia ani and rectovestibular fistula with fistula preservation, and outcome in 2 dogs. STUDY DESIGN: Case report. ANIMALS: Two intact female puppies. METHODS: The fistula was approached by episiotomy. A vertical median perineal incision was made starting dorsal to the anal region and extended to surround the fistula. The rectum and vagina were separated, and the end of the fistula was sutured to the skin. RESULTS: Early postoperative complications included constipation, fecal incontinence, and perineal soiling, but long-term outcome was good in both dogs. CONCLUSION: With careful dissection, the fistula and internal anal sphincter can be preserved and used in the surgical reconstruction of the anal canal and anus. CLINICAL RELEVANCE: Preservation of the fistula may provide an internal sphincter that contributes to a better functional result during correction of atresia ani. A surgical approach that combines episiotomy and perineal incision for separation of the vagina and rectum, and preserves the fistula may decrease the risk of dehiscence.     

Treatment of atresia ani type I by balloon dilatation in 5 kittens and one puppy

Atresia ani is the most common anorectal anomaly in small animals. In the present study, an anal stricture (atresia ani type I) in five 3 to 8 weeks old kittens and one 4 month old puppy was treated by balloon dilation. In 4 kittens and the puppy the stricture was eliminated permanently and without complications by a single intervention. Only the smallest kitten with the most severe stenosis developed a rectal fistula as a complication of repeated balloon dilation, which necessitated surgical correction. Balloon dilation proved to be an efficient therapeutic method for anal atresia type I, and can be recommended as the treatment of choice.     

PERINATAL LAMB MORTALITY IN WESTERN AUSTRALIA 7. Congenital Defects

Four hundred and one malformed lambs were examined during a 3-year investigation into the causes of perinatal lamb mortality. Frequence of involvement of the various body systems was: musculo-skeletal 55.4%, digestive 12.7%, cardiovascular 9.7%, uro-genital 7.1%, nervous 6.0%, special senses 3.5%, integument 3.2%, and endocrine 1.5%. A third of the defects (32.9%) involved more than one body system. There was a sex difference of 3 males: 2 females. The common defects in the lambs autopsied in order of frequence were: agnathia, atresia ani, cardiac defects, arthrogryposis, micrognathia, scrotal bifurcation, embryonic duplications, hernias, meningocele, and perosomus elumbis. Agnathia, atresia ani and persistent umbilical haemorrhage appeared to be hereditary. There was no relationship between congenital defects and the time of lambing and phytoestrogens.     

Arterial supply of the penis in agoutis (Dasyprocta prymnolpha, Wagler, 1831)

The arterial vascularization of agoutis’ penis (Dasyprocta prymnolopha) were analysed using ten male adults from ‘Núcleo de Estudos e Preservação de Animais Silvestres da Universidade Federal do Piauí’ (FUFPI/IBAMA n° 02/99). Among the total number of specimens, six animals had natural death and were members of the research collection of the Laboratory of Anatomy, and four were killed after anaesthesia. Stained bi‐centrifugated‐Cis‐I‐4 latex was injected in arterial vessels responsible for penis vascularization throughout the abdominal portion of aorta. The samples were fixed in 10% formaldehyde solution and arteries were dissected. The penile artery is originated as a branch of internal pudendal artery. At the level of ischiatic arch, the penile artery project two branches, the penile dorsal and the deep arteries; those arteries irrigates the penile dorsal surface and the corpus cavernosum penis. The penile dorsal arteries have an independent course up to the glans penis. Based on the conditions of this work a remarkable similarity regarding the distribution of vessels destined to the agouti penis when compared to other domestic, wild and lagomorph rodents as rabbits.     

Preputial reconstruction in a dog

A 2-year-old dog was examined after a 22-month history of intermittent drying and chafing of the distal portion of the penis after traumatic loss of the cranial portion of the prepuce and fracture of the os penis at 8 weeks of age. A multiple-staged surgical procedure was performed to reconstruct the prepuce, including free buccal mucosal grafting and transfer of a peripreputial bipedicle subdermal plexus flap. Preputial reconstruction provided mucosal and cutaneous coverage of the penis.     

Penile vascular system of the dog. An injection-corrosion and histological study

The vascular architecture of the dog penis was studied by resin casts and histological preparations. Morphological evidence was found for penile engorgement. The crus and the bulb were compressed by the ischiocavernosus and the bulbospongiosus muscles, respectively, indicating that these muscles act as a booster pump. The distal part of the bulb was also strangulated by the external anal sphincter, indicating that this muscle prevents blood in the corpus spongiosum penis from going back into the bulb. The common trunk of the dorsal vein of the penis was significantly occluded by the ischiourethralis muscle. The internal pudendal vein was also throttled by the levator ani, the coccygeus, and the internal obturator muscles. The extremely narrow diameter of each vein draining the erectile body was insufficient to drain the increased blood flow and, therefore, formed a sluice channel. It is inferred that these muscle activities and sluice channels facilitate the erection of the penis.     

Resection of a premaxilla and rostral portion of the maxilla in a horse

A 5‐year‐old, 520 kg Standardbred mare was admitted for an osteosarcoma of the right premaxilla. Two horizontal incisions of the labial mucosa and lingual surface were made 1 cm around the ulceration from the canine tooth to the premaxillary symphysis. The premaxilla and rostral portion of the maxilla were transected 1 cm caudal to the canine tooth with an oscillating saw. The maxillary symphysis was transected using an oscillating saw and a hammer. The wound was closed by primary intention and healed without complication. The cosmetic appearance of the mare was good. The mare was able to prehend hay and grain and grazed without difficulty and the tongue did not protrude. The neoplasm had not recurred 18 months after the surgery. A premaxilla and rostral portion of the adjacent maxilla can be resected to treat horses for a unilateral lesion of the premaxilla but care must be taken to avoid the palatine and incisive arteries which lie within the interincisive canal.     

Preputial damage and lateral penile displacement during castration in a degu

CASE DESCRIPTION: A 2-month-old male degu was treated for preputial damage and lateral penile displacement that occurred during attempted castration. CLINICAL FINDINGS: Bruising and swelling of the prepuce and severe edema to the left of the prepuce were evident. The penis could not be extruded from the prepuce. Radiography revealed a large bladder. Contrast medium injected into the prepuce filled the peripreputial subcutaneous tissues. TREATMENT AND OUTCOME: During surgical exploration through a peripreputial approach, the penis was found to be completely separated from the prepuce and located in the adjacent subcutaneous tissue. The penis was repositioned in the prepuce and anchored with a suture at its base. The following day, the preputial orifice was crusted over, urine was leaking from the incision, and the penis could not be extruded from the prepuce. The anchoring suture was removed, and the tip of the penis was sutured to the preputial orifice so that the penis protruded slightly from the prepuce. Urination was normal after the second surgery. Two years later, the preputial orifice remained adhered to the distal portion of the penis and the exposed penile tissue was healthy. CLINICAL RELEVANCE: Penile displacement from the prepuce is an unusual complication of castration in degus. The surgical technique used in this animal may be an effective means of repair. Permanent exposure of the tip of the penis may be well-tolerated in degus.     

Chromosomal evaluation of a ewe lamb with atresia ani vaginalis

Chromosomes of a ewe lamb born with atresia ani vaginalis were examined after a 72-hour culture of peripheral whole blood. The 2n number of chromosomes was 54,XX, with no apparent deviation from normality. Pedigree analysis of the ewe lamb indicated that her sire and dam were only slightly related (Rsd = 0.59%); therefore, the amount of inbreeding of the lamb was small (Fx = 0.30%).     

Effect of Oxytocin,IBMX and dbcAMP on Rabbit Ovarian Follicles

Oxytocin (OT) and protein kinase A (PKA), a possible intracellular mediator of hormone action in the ovary, can be potent activators of ovarian functions and fertility. Nevertheless, action of OT on ovarian follicle atresia has not been studied yet. Only single administration of PKA activators [3‐isobutyl‐1‐methyl‐xanthine (IBMX) and dibutyryl cyclic adenosine monophosphate (dbcAMP)] on ovarian follicle atresia was studied previously. The aim of this study was to examine the effect of OT (single treatment per one reproductive cycle, multiple treatments for three cycles), IBMX and dbcAMP (multiple treatments) on folliculogenesis and follicular atresia in rabbit. The ovarian cycle in control females was induced only by gonadotropins. Experimental females received co‐administration of gonadotropins with OT, IBMX or dbcAMP (at 50 μg/female). All females were artificially inseminated. Single‐treated females were euthanized after 18–19 h. Multiple‐treated females were euthanized after the third reproductive cycle. Histological sections of the ovaries were prepared and evaluated by a light microscopy. The follicles were divided into four classes according to the structure of granulosa and theca cells as follows: none or small atresia, cystic atresia, obliterative atresia and atresia associated with luteinization. The ovaries from the control and experimental females, treated during one reproductive cycle or three cycles, were compared. Single OT co‐administration increased proportion of follicles with atresia associated with luteinization, but not other types of atresia. No influence of multiple OT co‐administration on follicular atresia was recorded. Multiple IBMX and dbcAMP co‐administration decreased the proportion of atretic follicles and increased the proportion of healthy follicles without atresia.