Surgical repair of a full-thickness ear pinna defect in a horse

A 5-year-old gelding used for showing was presented for surgical repair of a full-thickness 15 mm diameter defect in the right pinna, which had occurred as a delayed complication following laser excision of a sarcoid. The defect had resulted in progressive deformity of the ear, and the horse was considered at risk of further injury if the defect became entrapped on a fixed object. Two artificial dermis meshes were inserted to encourage the formation of granulation tissue across the defect, and a commercially available skin expander was implanted adjacent to the site. Eighteen days later, a second surgery was performed to remove the skin expander and to mobilise a local rotational skin flap to close the defect. Both surgeries were performed under standing sedation and local anaesthesia. The site healed well, avoiding further potential trauma to the ear and deformity due to tissue contracture at the site, although some deformation of the lateral aspect of the cartilage remained.     

Use of reversed periosteal flaps in the repair of large nasocutaneous fistulas in two horses

Head injuries occur frequently in horses and a successful outcome after repair depends upon the severity of the initial trauma, the anatomical structures involved and the extent of tissue loss. Often these injuries involve facial bones and enter into the nasal passages or paranasal sinus system. When these injuries occur in conjunction with substantial tissue loss, the resulting defect may be difficult to close and naso/sinocutaneous fistulae can develop. These defects can be challenging and time consuming to repair and an appropriate reconstructive technique must be selected. We describe the use of reverse periosteal flaps as a technique in repairing large nasocutaneous fistulae in 2 horses after previous attempts to close the defects by other means had failed.     

Bilateral skin fold rotation-advancement flaps for the closure of large lumbosacral wounds in three dogs

Three dogs were presented for the management of disease processes resulting in large skin defects over the dorsal lumbosacral region. One had severe dog bite wounds, one had a large burn sustained from a heating pad and one had a large myxosarcoma in the region. In each case, the extent and location of the resulting skin defect were assessed as factors likely to prevent reconstruction using simple tension-relieving techniques alone or in combination with established reconstructive techniques, such as axial pattern flaps or skin stretching devices. Bilateral skin fold rotation-advancement flaps (SFRAFs) based on the flank folds were mobilised dorsally and allowed complete wound closure in two dogs and subtotal closure in the other dog. All wounds healed without major complications and an acceptable cosmetic outcome was achieved in each case. Minor flap debridement was required in two dogs. The use of bilateral SFRAFs is a useful technique alone or in combination with other reconstructive techniques for the closure of large dorsal lumbosacral skin defects when existing techniques are not sufficient. Small flank folds, such as those of obese dogs, may yield unexpectedly large SFRAFs.     

Repair of sinocutaneous fistulae in two horses

Chronic facial defects extending into the sinuses of two mares were repaired using periosteal flaps. Partial osseous bridging was established over the defects following repair. Previous attempts to close the defects with skin alone had failed. A periosteal flap is a simple surgical technique that provides the foundations for successful repair, despite the chronicity of some fistulae.     

Clinical evaluation of random skin flaps based on the subdermal plexus secured with sutures or sutures and cyanoacrylate adhesive for reconstructive surgery in dogs

OBJECTIVE: To evaluate the use of subdermal plexus skin flaps for closing defects after excision of cutaneous and subcutaneous tumors in dogs and to compare outcome of flaps secured with sutures and those secured with butyl-cyanoacrylate and intermittent sutures. STUDY DESIGN: Clinical study. ANIMALS: Fifteen dogs. METHODS: After excision of cutaneous or subcutaneous tumors the skin defect was reconstructed by random flaps based on the subdermal plexus. Flap skin edges were apposed with simple interrupted 4-0 monofilament nylon sutures (group 1; 5 dogs) or nylon sutures alternated with butyl-cyanoacrylate adhesive (group 2; 10 dogs). Flaps were evaluated every 48 hours when bandages were changed, until complete healing. RESULTS: Random flaps based on the subdermal plexus were effectively used to close wound defects; mean flap survival was 89%. Partial flap necrosis occurred in 4 dogs. Wound margins apposed with butyl-cyanoacrylate had thinner and more esthetic scars than sutured margins. CONCLUSION: Random flaps based on the subdermal plexus proved to be versatile for covering limb wounds after excision of cutaneous or subcutaneous tumors. Mean survival rate was comparable to that reported for axial pattern flaps. Butyl-cyanoacrylate adhesive was easy to apply, allowed accurate margin apposition with good cosmetic outcome and reduced sutures needed. CLINICAL RELEVANCE: Cyanoacrylate adhesive should be considered in lieu of suture closure to secure random skin flaps based on the subdermal plexus in dogs.     

Use of rotational periosteal flaps in primary repair of sinofacial fractures in seven horses

ABSTRACT

Case history: Medical records were reviewed of horses (n?=?7) undergoing surgery for fracture of one or more facial bones extending into the paranasal sinuses that was repaired primarily within 24 hours of the time of injury using a rotational periosteal flap, between April 2009 and May 2017. A kick from another horse was the cause of the injury of three horses, and one horse was injured when it collided with a tree. The cause of the injury of three horses was unknown.

Clinical findings and treatment: Fractures were of the right maxillary bone in two horses, the left maxillary bone in two horses, the left frontal and left nasal bones in two horses, and the right frontal bones in one horse. The fracture of all but one horse was accompanied by an open wound. The fracture of all seven horses was reduced, stabilised, and covered with a rotational, periosteal flap. Surgery was carried out while standing in six horses, and while anesthetised in one horse. All horses had a deficit in the fractured facial bones after the fracture was reduced. Four horses had complications following surgery, but all horses were reported to have excellent cosmetic outcomes and had retuned to their previous level of activity, as reported by their owners.

Clinical relevance: Covering a primarily repaired sinofacial fracture of a horse with a rotational periosteal flap resulted in good cosmetic outcomes, and may be especially beneficial if the fracture is accompanied by loss of bone.     

Spongiotic vesicular dermatitis as a cutaneous reaction pattern in seven horses

Over a 6-year period seven adult horses of different breeds and genders developed multifocal, exudative, oozing dermatitis characterized histologically by epidermal spongiotic vesicles and perivascular eosinophilic, neutrophilic and mixed mononuclear inflammation. Three horses were pruritic. Systemic disease was not noted. Two horses had a history of recurrent urticaria (hives) and one horse had nodules or welt-type lesions that progressed to exudative, oozing lesions. Interepithelial immunoglobulin (Ig)G was detected by avidin-biotin complex-peroxidase staining, but the pattern of staining was more consistent with epithelial oedema than specific IgG deposition associated with pemphigus. The exudative oozing lesions developed under circumstances suggesting that dermal oedema progressed to intracellular and intercellular epidermal oedema, which in turn progressed to the spongiotic vesicular epidermal lesions.     

Simultaneous use of bilateral caudal superficial epigastric axial pattern flaps for wound closure in a dog

A neutered male German shorthaired pointer sustained severe bite wounds to the left caudal flank and thigh area. Thorough wound lavage and debridement was performed immediately and also three days after presentation. Daily wound dressing resulted in the production of a mature granulation tissue bed. Prior to wound closure, colour flow Doppler ultrasonography was used to confirm blood flow through the right and left caudal superficial epigastric arteries and veins. Sixteen days after presentation, right and left caudal superficial epigastric axial pattern flaps were simultaneously elevated to cover the defect. The right flap was elevated as an island flap, rotated 120 degrees and used to cover the caudodorsal aspect of the defect. The left flap was elevated and rotated dorsally to cover the cranioventral aspect of the defect. Ninety per cent wound coverage was achieved and flap survival was total. The donor site defect was closed primarily and no dehiscence occurred. Three months postsurgery, the entire defect was closed and limb function was normal.     

Use of skin stretchers to elongate a peninsular thoracodorsal axial pattern flap for antebrachial wound closure in a dog

Objective: To describe preoperative use of skin stretchers to elongate a peninsular thoracodorsal axial pattern flap to close a large antebrachial wound on a dog. Study Design: Case report. Animals: A 21 kg, 7‐year‐old, male intact mixed breed dog. Methods: Two skin stretchers were applied to the site of the thoracodorsal axial pattern flap 4 days before surgery. The elastic cables connecting the adhesive pads were tightened daily to increase the skin available for a peninsular thoracodorsal axial pattern flap, which was created and rotated 180° to cover an antebrachial defect to a level 2 cm proximal to the carpus. Results: The entire flap survived; there was a small amount of incisional separation at the distal margin of the flap that healed without further treatment. Conclusion: Preoperative skin stretching provided additional skin for the axial pattern flap used.     

Use of vacuum-assisted closure for management of a large skin wound in a cat

CASE DESCRIPTION: A 9-month-old domestic shorthair cat was evaluated after being struck by a car. CLINICAL FINDINGS: The cat had a fractured tibia and avulsion of the tail base. Motor and deep pain sensation were absent from the tail. The fractured tibia was repaired 2 days after the trauma. On the third day, the cat developed tachypnea, dyspnea, high serum urea nitrogen and total bilirubin concentrations, epistaxis, persistent hypotension, and oliguria. The cat recovered with supportive care but developed extensive necrosis of the skin on the dorsum by 9 days after the initial trauma. TREATMENT AND OUTCOME: The skin was debrided from the caudal portion of the scapula to the anus and down each pelvic limb to the level of the distal portion of the femur. The tail was amputated. Wet-to-dry bandages were applied to the wound for 3 days. Approximately 50% of the wound underwent delayed primary closure, and the remainder was managed with vacuum-assisted closure. A healthy granulation bed was quickly established. Vacuum-assisted closure was also applied after graft application. Graft acceptance was 100%, and use of the vacuum-assisted closure bandage was not associated with the complications associated with the traditional bandage. CLINICAL RELEVANCE: Vacuum-assisted closure is a useful, easily applicable technique for open and grafted wounds, even when wounds are in challenging anatomic locations.     

Use of negative pressure wound therapy in three horses with open,infected olecranon bursitis

This article describes the clinical use of negative pressure wound therapy (NPWT) in three horses with an open and infected subcutaneous olecranon bursa, in which prior surgical excision followed by primary closure was unsuccessful. The wounds filled in rapidly with granulation tissue and contracted during therapy. All wounds subsequently went on to heal without complications. The use of NPWT was well tolerated in all three horses and facilitated healing in a difficult area.     

Evaluation of arthrocentesis site bacterial flora before and after 4 methods of preparation in horses with and without evidence of skin contamination

OBJECTIVE: To evaluate the effectiveness of four methods of povidone-iodine preparation on skin bacterial flora of arthrocentesis sites, in horses, with and without evidence of skin contamination. STUDY DESIGN: Prospective randomized study. ANIMALS: Twenty-four adult horses. METHODS: Horses were assigned to either the clean or contaminated group based on housing environment and visual evidence of contamination. Using a moist sterile swab, microbial culture samples were obtained from the skin over the distal interphalangeal joints immediately before and after preparation. Each site was aseptically prepared with 1 of 4 povidone-iodine techniques: 10-minutes scrub, 5-minutes scrub, three 30-second scrubs, or commercial one-step iodophor surgical solution. Colony forming units (CFUs) were determined for each sample, 24 hours after inoculation, on blood agar plates. RESULTS: Mean (+/-SD) pre-scrub CFUs/mL was significantly higher in the contaminated group (9588.33+/-1223.65) compared with the clean group (4489.00+/-3842.03) (P<.01). After preparation of the arthrocentesis sites, there were no significant differences in post-scrub CFUs/mL among the 10 minutes (mean clean, 46.00+/-64.36; mean contaminated, 28.67+/-18.04), 5 minutes (mean clean, 84.17+/-109.80; mean contaminated, 40.33+/-44.52), three 30 seconds povidone-iodine scrubs (mean clean, 95.50+/-172.29; mean contaminated, 46.67+/-56.94), or application of a commercial one-step iodophor surgical solution (mean clean, 102.17+/-161.78; mean contaminated 117.67+/-143.78); or between the clean (81.96+/-131.69) and contaminated groups (58.33+/-85.90) (P<.01). CONCLUSIONS: Preparation of the distal interphalangeal joint arthrocentesis site with each of these techniques significantly reduces the bacterial flora to a similar level for arthrocentesis in horses with and without evidence of skin contamination. Clinical Relevance- Aseptic preparation of the skin over the distal interphalangeal joint may be accomplished with any of these techniques.     

Use of local and axial pattern flaps for reconstruction of the hard and soft palate

There are numerous conditions that may result in defects of the hard and soft palate. Reconstruction of these defects may be difficult due to anatomical limitations and limited tissue availability. The majority of palate defects, even when large, may be closed using local and/or axial pattern flaps, while other more advanced techniques such as free tissue transfer and prosthetic implants are required in a smaller number of cases. This article describes the use of local and axial pattern flaps in the reconstruction of the hard and soft palate.     

Treatment of corneal ulceration and bullous keratopathy using a nictitating membrane flap in two horses

Objective

The aim of this study was to describe placement of a nictitating membrane flap as a treatment for corneal ulceration and bullous keratopathy in two horses.

Animals Studied

A 13-year-old American Saddlebred mare presented for severe corneal edema, superficial stromal ulceration, and a central bulla of the left eye. A 4-year-old Trakhener stallion also presented with a large axial bulla of the left eye with concurrent severe corneal edema and a deep stromal ulcer.

Procedure

A complete ophthalmic examination was performed. Samples were obtained for corneal cytology, and both horses were started on aggressive medical therapy. Both underwent general anesthesia for placement of a nictitating membrane flap and a subpalpebral lavage system (SPLS).

Results

Corneal cytology for each horse revealed a mixed bacterial population. Moderate Pseudomonas aeruginosa was cultured from the mare, while Aspergillus species and a few Enterococcus gallinarum were cultured from the stallion. The bullae in both horses resolved at 3 and 4 weeks and vision returned in the affected eye 4.5 and 3 months postoperatively at the last follow-up, respectively.

Conclusion

Aggressive medical management with concurrent placement of a nictitating membrane flap is effective to treat bullous keratopathy in two horses. The described treatments could be used to treat horses that develop severe or progressive bullous corneal lesions.     

Validity of indicators of dehydration in working horses: a longitudinal study of changes in skin tent duration, mucous membrane dryness and drinking behaviour

REASONS FOR PERFORMING STUDY: Dehydration is a serious welfare concern in horses working in developing countries. Identification of a valid and practical indicator of dehydration would enable more rapid treatment and prevention. OBJECTIVES: To examine changes in bodyweight, clinical and blood parameters during rehydration of working horses, identify a 'gold standard' criterion for dehydration and use this to validate a standardised skin tent test, drinking behaviour and mucous membrane dryness as potential field indicators. METHODS: Fifty horses with a positive skin tent test, working in environmental temperatures of 30-44 degrees C in Pakistan, were rested and offered water to drink ad libitum. Bodyweight, clinical and blood parameters, mucous membrane dryness, drinking behaviour and skin tent duration at 6 anatomical locations were measured at 0, 30, 60, 120, 180, 240 and 300 min. RESULTS: Skin tent duration was affected by side of animal (P = 0.008), anatomical location and coat moisture (both P < 0.001). Younger animals had shorter skin tents at all time points (P = 0.007). There was no significant association between plasma osmolality (P(osm)) or water intake and skin tent duration. Horses with a higher P(osm) drank significantly more water (P < 0.001), and had longer (P < 0.001) and more frequent (P = 0.001) drinking bouts. Neither P(osm) nor water intake affected qualitative and semi-quantitative measurements of mucous membrane dryness significantly. CONCLUSIONS AND POTENTIAL RELEVANCE: The standardised skin tent test and measures of mucous membrane dryness investigated in this study were not valid or repeatable indicators of dehydration when compared with P(osm) as a 'gold standard' criterion. The volume of water consumed and the number and duration of drinking bouts were the most reliable guide to hydration status currently available for mature working horses. Offering palatable water to drink ad libitum provides both the diagnosis and the remedy for dehydration in working horses.     

Atypical presentation of caecal perforation in two horses

This case report describes retroperitoneal and subserosal emphysema as the primary indication of a caecal perforation associated with an episode of colic. Feed contamination was not noted on repeated peritoneal fluid samples or within the peritoneal cavity at the time of surgery; however, subserosal and retroperitoneal emphysema at the base of the caecum was identified during surgical exploration, which later corresponded to retroperitoneal caecal perforation at necropsy examination.     

Unusual pathophysiological mechanisms of ptyalism in two horses

This report outlines two cases of ptyalism that were not associated with oral conditions or primary dysphagia. The first, a 9-year-old Thoroughbred gelding, was associated with left-sided peripheral vestibular disease and bone modelling around the left tympanic bulla. The second, a 7-year-old Dutch Warmblood mare, was associated with progressive bilateral laryngeal paralysis and a mediastinal T-cell lymphoma. In Case 1, a neurological pathophysiology was proposed involving altered autonomic innervation of the salivary glands; whilst in Case 2, the mechanism remains unclear but may have involved mechanical compression of the intrathoracic oesophagus or stimulation of afferents within the vagus nerve. This case series highlights rare causes of ptyalism that have not been previously reported in the literature.     

Balloon dilation of oesophageal strictures in two horses

Oesophageal strictures in 2 horses with chronic recurrent oesophageal obstruction or choke was diagnosed by endoscopy and contrast radiography. Balloon dilation of the strictures was performed under endoscopic and fluoroscopic guidance. Follow‐up endoscopic and radiological examinations performed 6 weeks after the procedure showed clear dilation of the strictures. Both horses did not have any recurrence during follow‐up periods of 10 and 12 months.     

Ultrasonographic features of pedunculated lipomas in two horses

Small intestine strangulation by pedunculated lipomas is a common cause of acute colic in horses. However, diagnosis of this condition prior to surgery may be difficult due to the poor specificity of the clinical signs. We describe the ultrasonographic findings of 2 horses presented for acute colic with a diagnosis of strangulating lipoma confirmed in surgery. Lipomas were identified as rounded and well‐defined, homogeneous hyperechoic structures, surrounded by distended small intestine loops and peritoneal fluid. Ultrasonographic identification of lipomas should be attempted during an abdominal scan, especially in horses with evidence of small intestinal ileus and/or obstruction.     

Post‐anesthetic pulmonary edema in two horses

Case 1 A two‐year old, 462 kg Standard bred horse was anesthetized for arthroscopy and castration. During anesthesia, hyperemia of the mucosal membranes and urticaria were noticed. During 5 hours of anesthesia subcutaneous edema of the eyelids and neck region developed. In the recovery box, the orotracheal (OT) tube was left in situ and secured in place with tape. Following initial attempts to stand, the horse became highly agitated and signs consistent with pulmonary edema developed subsequently. Arterial hypoxemia (PaO₂: 3.7 kPa [28 mmHg]) and hypocapnia (PaCO₂: 3.1 kPa [23 mmHg]) were confirmed. Oxygen and furosemide were administered. The horse was assisted to standing with a sling. Therapy continued with bilateral intra‐nasal oxygen insufflation. Ancillary medical therapy included flunixin meglumine, penicillin, gentamycin and dimethylsulfoxide. Following 7 hours of treatment the arterial oxygen tensions began to increase towards normal values. Case 2 An 11‐year old, 528 kg Paint horse was anesthetized for surgery of a submandibular mass. The 4‐hour anesthetic period was unremarkable. The OT tube was left in situ for the recovery. During recovery, the horse was slightly agitated and stood after three attempts. Clinical signs consistent with pulmonary edema and arterial hypoxemia (PaO₂: 5 kPa [37.5 mmHg]) subsequently developed following extubation. Respiratory signs resolved with medical therapy, including unilateral nasal oxygen insufflation, furosemide, flunixin meglumine and dimethylsulfoxide. The diagnosis of pulmonary edema in these horses was made by clinical signs and arterial blood‐gas analysis. While pulmonary radiographs were not taken to confirm the diagnosis, the clinical signs following anesthesia support the diagnosis in both cases. The etiology of pulmonary edema was most likely multifactorial.