IMAGING DIAGNOSIS: MAGNETIC RESONANCE IMAGING OF A CERVICAL WOODEN FOREIGN BODY IN A DOG

This article describes the discovery of a chronic cervical wooden foreign body ventral to the left transverse processes of the cranial cervical spine using magnetic resonance imaging (MRI) in a dog that presented with chronic neck pain and lameness. The dog did not exhibit dysphagia or chronic draining tracts, the most common signs of the presumed cause, that of a penetrating oropharyngeal foreign body. The foreign body itself was represented on MR images as an oval straight-edged core within an inflammatory tissue reaction. The wood was slightly hyperintense on T2- and isointense on T1-weighted images relative to muscle. Surrounding this was a more conspicuous contrast-enhancing reactive tissue rim that was hyperintense on all pulse sequences. Adjacent musculature also exhibited diffuse edema and contrast enhancement that extended around the left cervical vertebral transverse processes and local intervertebral nerve roots. The foreign body was found to be a wooden stick upon surgical removal. MRI is an excellent method for visualizing the inflammatory tissue reactions associated with soft-tissue foreign bodies because of its contrast resolution and depiction of anatomy in multiple imaging planes.     

BRONCHOCUTANEOUS FISTULA IN A DOG

A dog with a bronchocutaneous fistula is described. Contrast enhanced computed tomography was useful for diagnosis and treatment of the fistula in this dog.     

RESULTS OF COMPUTED TOMOGRAPHY IN DOGS WITH SUSPECTED WOODEN FOREIGN BODIES

Detection of wooden foreign bodies in dogs can be challenging. A retrospective, cross‐sectional study was done to describe computed tomographic (CT) signs associated with wooden foreign bodies, and to estimate the accuracy of CT for detection of wooden foreign bodies. Patient records and CT images were reviewed for 72 dogs that had a history of suspected stick injury and CT of the affected body part, or possible wooden foreign object reported on CT, and had surgical exploration during the same period of hospitalization. Duration of clinical signs was acute in 48 (67%) dogs and chronic in 24 (33%). Wood was removed from 55 dogs, including a piece of a tree or shrub in 33 (60%) instances, kebab stick in 8 (15%), piece of bamboo garden cane in 2 (4%), cocktail stick in 2 (4%), thorn in 1 (2%), and unidentified wood in the remaining nine instances. Based on review of CT images with knowledge of the surgical findings, sensitivity of CT for wooden foreign bodies was 79% (95% CI 65%–89%), specificity 93% (78%–98%), positive likelihood ratio 11.5 (2.9–44.1), and negative likelihood ratio 0.23 (0.13–0.41). Wooden foreign bodies were predominantly rectangular or linear, with median length 48 mm (range 2–270 mm), median thickness 3 mm (range 1–22 mm), and median attenuation 111 HU (range ?344 to +640 HU). A CT finding of gas in soft tissues was significantly associated with acute cases, whereas suspected foreign material, cavitary lesions, fat stranding, and periosteal reaction on adjacent bones were associated with chronic cases.     

Migrating grass awn within the intraconal part of the retrobulbar space in a dog

A 1.5-year-old MC Cardigan Welsh Corgi was presented for a right oral fistula associated with left tonsil enlargement that responded to medical treatment. A first computed tomography scan was performed and showed no signs of a foreign body. Medical treatment was continued for 2 additional weeks and the dog was free of clinical signs for 3 months. The dog was presented again for a 3-day history of anorexia and marked pain when opening the jaw. The repeat computed tomography scan revealed a migrating foreign body near the optic canal of the right eye, and surgical exploration confirmed that it was trapped within the intraconal part of the retrobulbar space, abutting the optic nerve. The foreign body was surgically removed through an osteotomy of the zygomatic bone. The dog fully recovered with no vision loss. Based on the literature search, this is the first published report describing a migrating grass awn located in the intraconal part of the retrobulbar space, abutting the optic nerve.     

Cutaneopulmonary fistula in a dog caused by migration of a toothpick

A 6-year-old, neutered male, mixed-breed dog was presented for a chronic draining tract and cough. A contrast fistulogram demonstrated a cutaneopulmonary fistula. Excision of the fistulous tract retrieved a migrating foreign body (i.e., a toothpick) within the tract. Clinical signs resolved 2 weeks following surgery. Foreign body migration is a common problem seen in dogs, resulting in many different clinical syndromes. Definitive surgery depends upon complete removal of the foreign body and the diseased tissue. Sinography is an inexpensive, readily available diagnostic tool that can help define a draining tract and confirm a foreign body.     

Identification of a periorbital wooden foreign body as the cause of chronic ocular discharge in a horse

The clinical, diagnostic and therapeutic features of a horse with a wooden foreign body embedded in the deep portion of the right masseter muscle adjacent to the right orbit are presented. The purpose of this report is to describe the clinical presentation, magnetic resonance imaging findings and treatment of a penetrating wooden foreign body in a horse that had no history of trauma or evidence of a puncture wound. This report documents the usefulness of magnetic resonance imaging to detect a wooden foreign body embedded in the soft tissues of a horse with a chronic copious ocular discharge. Two surgical procedures were necessary, which is a frequent complication encountered with wooden foreign bodies.     

Fistulography as an aid in the diagnosis of a nonradiopaque foreign body in a dog

A case of chronic fistula associated with foreign body penetration of the soft tissues was diagnosed in the skull of a dog by fistulography. Radiographic technique and diagnostic features are described and illustrated.     

Gastrocutaneous fistula as a result of migration of a foreign body in a dog

A six-year-old, female Tibetan terrier was referred for investigation of a non-healing wound on the left caudal thorax. A subcutaneous swelling had initially developed on the chest wall, followed by a draining tract from which seropurulent fluid drained for two months. There had been no response to antibiotic treatment. Following radiographic and ultrasonographic examinations, a bone sequestrum from a fractured rib or a foreign body was suspected. Surgical exploration of the wound identified a sinus tract and a wooden foreign body (an ice-lolly stick) was located in subcutaneous tissues. Partial wound dehiscence of the surgical site occurred postoperatively, but healed after 10 days. One month later, fluid began to discharge from the area again. Further surgical exploration confirmed a gastrocutaneous fistula. Dissection of the fistula and surgical closure of the stomach, body wall and skin led to resolution of all signs.     

Ultrasonographic detection of ingested and perforating wooden foreign bodies in four dogs

Four dogs that had ingested wooden foreign bodies were examined. All 4 dogs were young and were examined because of lethargy and a mass involving the left flank that was partially responsive to antimicrobial treatment. Ultrasonography of the flank mass revealed inhomogeneous subcutaneous tissues representing seroma, edema, or reactive tissue. Long, linear, bright interfaces representing the wooden foreign bodies were identified in the stomach of 3 dogs and in the abdominal cavity of 1 dog. The interfaces were associated with uniform shadowing in 3 dogs. Local omental and mesenteric changes suggestive of focal peritonitis were evident in 1 dog. In all 4 dogs, the foreign bodies were removed through an exploratory celiotomy. All dogs recovered without complications.     

Migration of retrobulbar wooden foreign body between diagnostic imaging and surgical extraction in a German shepherd dog

A 2‐year‐old, male castrated German shepherd dog was presented to the University of Tennessee Veterinary Medical Center (UTVMC) with periorbital swelling and conjunctival mucopurulent discharge 2 days following removal of a twig from the medial canthus by the owner. Diagnostic imaging was pursued due to the suspicion of a retrobulbar foreign body (FB). A cylindrical FB approximately 3.0 cm in length and 1.0 cm in diameter with concentric rings, suspected to be wooden material, was identified on computed tomography (CT) imaging. An attempt to remove the FB via a stab incision using ultrasound guidance was unsuccessful, and postmanipulation ultrasound confirmed the FB position was unchanged. An exploratory orbitotomy was performed, using the acquired CT images for guidance in locating the FB; however, the FB was not present at the predicted site. The CT imaging was repeated and showed that the FB had migrated rostrally approximately 3.0 cm, compared to the originally acquired study and its same location during attempted ultrasound‐guided removal. A combination of CT‐guided needle placement and contrast injection was then used with repeat imaging in an attempt to better localize the FB and its soft tissue tract. The dog was taken back into the operating room, and the wooden FB was successfully removed.     

Identification of an intra-cranial intra-axial porcupine quill foreign body with computed tomography in a canine patient

An intra-cranial intra-axial foreign body was diagnosed in a golden retriever dog through the use of computed tomography (CT). Confirmed by necropsy, a porcupine quill had migrated to the patient's left cerebral hemisphere, likely through the oval foramen. This case study demonstrates the efficacy of CT in visualizing a quill in the canine brain.     

FISTULA FORMATION SECONDARY TO A NYLON CABLE BAND IN A DOG

A dog with a 9-month history of a chronic draining tract involving the left flank had previously undergone five surgeries and two drain placements with no permanent resolution of the draining tract. Fistulography and computed tomography were useful in characterizing the draining tract and identifying a suspected foreign body. Surgery was performed and a nylon cable band foreign body was removed.     

Inguinal enterocutaneous fistula in a dog

A two‐year‐old Jack Russell terrier presented with a chronic history of weight loss and the recent development of a discharging wound in the left inguinal region that was confirmed by ultrasound and contrast radiography to be an enterocutaneous fistula. One day following admission the dog displayed signs of abdominal pain and the general condition deteriorated. At exploratory coeliotomy there was evidence of septic peritonitis and a segment of jejunum was found firmly adhered to the left inguinal canal. The affected jejunal segment was excised and an end‐to‐end anastomosis performed. A penrose drain was placed in the inguinal wound which was subsequently managed with open drainage. The inguinal wound healed successfully by second intention and the dog returned to normal body condition. The left testis became atrophic and castration was performed several weeks later. To the authors’ knowledge this is the first veterinary case report of an inguinal enterocutaneous fistula.     

Surgical treatment of a double aortic arch in a dog

An 8-month-old spayed female Labrador retriever dog was evaluated for regurgitation 6 months after surgery for a suspected vascular ring anomaly. The dog had a history of regurgitation and slow development as a puppy. An initial left-sided exploratory thoracotomy was unsuccessful in identifying and treating a vascular ring anomaly. The dog was subsequently presented to the PennVet Emergency Service for regurgitation. Thoracic radiography showed cranial thoracic esophageal dilation and an esophageal foreign body that was then removed endoscopically. Subsequent computed tomographic (CT) angiography revealed a double aortic arch. A left 4th intercostal space thoracotomy was performed. The smaller left aortic arch and a left ligamentum arteriosum were ligated and transected. The dog recovered uneventfully and was healthy at the 1-month follow-up visit. This is the 5th reported successful surgical correction of a double aortic arch in a dog. Computed tomographic angiography was essential in diagnosis and surgical planning.Key clinical message:Although uncommon, double aortic arches can occur and present a diagnostic and surgical challenge when a persistent right aortic arch is suspected. Computed tomographic angiography provides an accurate preoperative diagnosis and allows for surgical planning.     

Exophthalmos due to a wooden foreign body in a dog

An 8-year-old Golden Retriever dog was presented with a 10-month history of right-sided exophthalmos. Radiographs and CT demonstrated a linear density, suggestive of a foreign body, in the region of the ramus of the right mandible. A 7 cm stick, located medial to the right zygomatic arch, was removed during exploratory surgery. The dog recovered with the aid of antibiotics, however was left with a residual facial nerve paralysis.     

Comparison of ultrasound, computed tomography, and magnetic resonance imaging in detection of acute wooden foreign bodies in the canine manus

We evaluated the diagnostic sensitivity of ultrasound, nonenhanced computed tomography (CT) and nonenhanced magnetic resonance (MR) imaging in detecting wooden foreign bodies in the canine manus. Identical wooden splinters were manually inserted into 30 cadaver canine manus, and the limbs were evaluated using ultrasound, CT, and MR imaging by independent observers. All sites were rated as positive or negative for the presence of a foreign body, and observer certainty was scored on a 1-10 scale. Using receiver operating characteristic analysis, CT was the most accurate modality for detection of wooden foreign bodies overall and within each of the three individual regions, followed by ultrasound and MR imaging, respectively. Ultrasound evaluations were most limited in the metacarpal pad, where distal acoustic shadowing from the pad surface hindered evaluation of the tissues in some specimens.     

IMAGING DIAGNOSIS—URETHROVAGINAL FISTULA CAUSED BY A MIGRATING GRASS AWN IN THE VAGINA

A young intact female dog was presented with urinary incontinence. Abdominal ultrasound revealed the presence of hyperechoic linear structures within the cranial vagina suggestive of foreign material. A computed tomography (CT) retrograde vaginourethrogram demonstrated the presence of a fistulous tract between the urethra and vagina. A presumptive diagnosis of urethrovaginal fistula due to migration of foreign material was made. The grass awn was removed with vaginoscopic‐guided retrieval. Fourteen days later, surgical repair of the fistula and an ovariohysterectomy were done. This case report emphasizes the usefulness of CT for diagnosis and precise anatomical localization of genitourinary tract fistulas.     

Bronchoesophageal fistula and transient megaesophagus in a dog

Bronchoesophageal fistula and megaesophagus were diagnosed in a dog. Within 2 days after surgical correction of the bronchoesophageal fistula, peristalsis in the thoracic portion of the esophagus returned to normal and the esophagus resumed its normal size. The cause of the fistula was attributed to damage from a foreign body. The cause of the transient megaesophagus likely was related to the bronchoesophageal fistula.