A lag-screw technique for bridging of the medial aspect of the distal tibial physis in horses

A lag-screw technique for transphyseal bridging of the medial aspect of the distal tibial physis in foals with tarsal valgus deformities and results of the technique in 11 foals (6 with bilateral tarsal valgus deformities and 5 with unilateral tarsal valgus deformities) are described. Briefly, horses were anesthetized, and a single stab incision was made through the skin to the underlying bone over the most distal aspect of the medial malleolus. A 20-gauge needle was placed in the incision to guide screw placement, and a lag screw was inserted parallel to the medial cortex of the tibia under radiographic guidance. Screws were removed when the tarsal valgus deformity was clinically assessed to have improved by at least 80%. Clinically, all horses had evidence of a tarsal valgus deformity of > 7 degrees prior to surgery. Mean age at the time of lag-screw implanation was 220 days (range, 116 to 364 days). Mean time the implant was in place was 62 days (range, 39 to 89 days). The tarsal valgus deformity resolved in all 11 horses with excellent cosmetic results.     

The use of an absorbable bone screw as a transphyseal bridge for the correction of fetlock varus deviations in six foals

This report describes and evaluates the use of a single‐positional absorbable screw (Smart Screw) ¹ as a temporary transphyseal bridge of the lateral aspect of the distal metacarpus in 6 foals with fetlock varus deformities. Using radiographic and visual assessments, an improvement in the severity of the deviation was identified in all cases. There were no complications encountered during screw placement or post operatively. The use of absorbable screws in the treatment of angular limb deformities in foals has potential and offers several advantages over the use of traditional stainless steel implants.     

Vertebral distraction-fusion for cervical spondylopathy using a screw and double washer technique

A technique using two interbody washers and a transvertebral screw was utilised to distract the cervical vertebrae and so decompress the spinal cord in 17 dobermann pinschers and three great danes with cervical spondylopathy. Neurological dysfunction was graded (1 to 5) according to the degree of hindlimb ataxia. Myelography showed evidence of spinal cord compression at C6-7 in all dogs and at C5-6 in six dogs. Twenty-three compressive lesions were reduced when traction was applied to the cervical spine. Seventeen dogs improved following surgery and of these 10 improved by two or more grades. Follow-up radiographic studies indicated resorption of end-plate bone and eventual fusion of the vertebral bodies. Displacement of the screw into the vertebral canal, remodelling of the vertebral canal, fracture of C6 ventral spinous process and breakage of the screw were implant associated complications. The distraction-fusion technique with modifications appears to be an effective procedure for the management of cervical spondylopathy in dogs in which the compressive lesion is soft tissue in nature.     

Management of disc-associated wobbler syndrome with a partial slot fenestration and position screw technique

A previously unpublished surgical technique for the management of disc-associated wobbler syndrome is described. A series of 17 middle-aged dobermanns (mean age 7·4 years) with this condition were managed by a technique of partial slot fenestration and position screw fixation of the affected disc space (C6/7 in all cases). One patient was lost to follow-up and, of the remaining 16 cases, 13 improved following surgery (81 per cent). The three failures were a consequence of incorrect placement of one of the screws. Careful evaluation of immediate postoperative radiographs allows this problem to be identified; the screw can then be correctly repositioned with an immediate return to surgery.     

Vertebral stabilisation for cervical spondylopathy using a screw and washer technique

A transvertebral screw and interbody washer technique was used to stabilise the vertebrae and maintain the intervertebral space in 34 adult dobermann pinschers with cervical spondylopathy. The long term success of the procedure was 50 per cent. Pre-operatively three dogs were considered mildly ataxic, 16 moderately ataxic, 13 severely ataxic and two non-ambulatory. Thirty dogs had radiographic changes of calcified disc, vertebral malalignment or narrow intervertebral disc space and all dogs had myelographic abnormalities in the caudal cervical spine. Vertebral malalignment and narrow intervertebral space correlated closely with myelographic cord compression. However, compressive lesions were not identified in 11 cases on plain films. Follow-up was available on 30 dogs of which 25 showed neurological improvement. This was temporary in 10 cases which were destroyed two weeks to three years following surgery.     

Standing placement of transphyseal screw in the distal radius in 8 Thoroughbred yearlings

This retrospective study describes placement of distal radial transphyseal screws in Thoroughbred yearlings with carpal varus deformities while standing, and identifes short- and long-term complications following the procedure. Data gathered from 2009 to 2013 identified 8 yearlings that met the inclusion criteria. Horses were sedated intravenously and a single 4.5-mm cortical screw was placed in the distal lateral radial physis following application of local anesthetic and surgical preparation of a pre-placed hole. All horses were evaluated weekly after surgery and screw removal was performed standing and under sedation when correction of the angular limb deformity was achieved. The mean time for screw removal was 46 days. No short- or long-term complications were identified. Findings indicate that placing a single transphyseal screw in the lateral aspect of the distal radial physis with the horse standing is a viable option to treat varus angular limb deformity of the carpus in horses.     

Active tension‐extension splints: A novel technique for management of congenital flexural deformities affecting the distal limb in the foal

A variety of methods are described for managing distal limb flexural deformities in the foal, including intravenous oxytetracycline and splint or cast use. This case series describes a novel technique that creates an ‘active tension‐extension splint’ by wiring the toe into a custom‐made fibreglass splint and therefore into active extension. A dorsal fibreglass splint is made by halving a cast that is set around the affected leg with padding underneath it, so that it is sculpted to a more appropriate anatomical shape. Cerclage wire is placed through the toe and the dorsal aspect of the splint, then tightened to pull the limb into active extension. Foals with distal limb flexural deformities that were treated in this way were followed up by examination of hospital records and telephone questionnaire. Records were examined for 13 foals treated between 2004 and 2010. One foal developed septic osteitis of the distal phalanx due to suspected laminar penetration; other post operative complications seen were bandage sores and minor cosmetic scarring. Out of 10 foals where follow‐up by questionnaire was available, 8 had complete resolution of their deformity following active tension‐extension splinting, one required inferior check ligament desmotomy for complete correction and one had carpal flexural deformities that did not resolve. All that survived to adulthood are sound and have achieved their intended purpose. This previously unpublished technique using a wire through the toe to create an active tension‐extension splint has a high success rate for correction of congenital flexural deformities affecting the distal interphalangeal and metacarpo‐/metatarsophalangeal joints in the foal. The majority of post operative complications are minor and easily managed. This is a simple technique that can improve the management of neonatal distal limb deformities both in a hospital situation and for equine practitioners in the field.     

Single transphyseal screws for the correction of moderate to severe angular limb deformities in 28 Thoroughbred foals

This study reports on the effective use of a single transphyseal screw for the treatment of moderate to severe angular limb deformities (ALDs) of the fetlocks and carpi of 28 young Thoroughbred foals. The objective was to evaluate the surgical management of foals with moderate to severe ALDs treated with single transphyseal screws. Evaluation of medical records of 28 Thoroughbred foals treated with single transphyseal screws placed across the distal radial, metacarpal and metatarsal physes was undertaken. The angle of joint deviation was measured prior to implantation and at removal of the implants, and the degree of improvement was calculated. A total of 39 screws were placed: 24 in the distal metacarpus or metatarsus and 15 in the distal radial physis. Varus or valgus deformities in the fetlock improved by 4–5° over a period of 15–30 days. Varus or valgus deformities in the carpi improved by 8–11° in 11–56 days. One case failed to improve adequately due to implant infection. Single transphyseal screws were effective in treating moderate to severe varus and valgus ALD of the fetlocks and carpi in young Thoroughbred foals. Further investigation into their use in the distal radius in young foals is needed. While single transphyseal screws are almost exclusively used by some clinics in the distal metatarsal and metacarpal physes, many clinicians do not use them in the distal radial physis of young foals due to fear of over‐correction, physitis and metaphyseal collapse. This was not observed in any of our cases.     

Surgical repair of rib fractures in 14 neonatal foals: case selection, surgical technique and results

Reasons for performing study: Fractured ribs are encountered quite frequently in newborn Thoroughbred foals, often with fatal outcome. Surgical repair of fractures therefore requires consideration as a means of reducing mortality. Objectives: To evaluate the repair of rib fractures using internal fixation techniques in foals at 2 different equine hospitals following similar diagnostics and case selection. Methods: The records of 14 foals that underwent internal fixation of fracture ribs were reviewed. Subject details, clinical presentation, diagnosis, surgical technique, post operative care and complications were recorded. Follow-up information was obtained in 7 foals. Results: The fractured ribs were reduced and stabilised using reconstruction plate(s), self-tapping cortical screws and cerclage wire in 12 cases, Steinmann pins and cerclage wires in 1 case and both techniques in 1 case. Not every rib was reduced on each case. Surgical reduction was performed on an average of 2 ribs, range 1-3 ribs in each foal. At the time of writing, 4 foals had been sold, one age 2 years was in training and 2 others died from unrelated causes. Conclusions: Our data support the use of surgical stabilisation utilising reconstruction plates, self-tapping cortical screws and cerclage wire for selected cases of thoracic trauma in neonatal foals. The use of Steinmann pins may be suboptimal due to cyclic failure, implant migration and the potential for iatrogenic internal thoracic trauma. Potential relevance: Foals with existing extensive internal thoracic trauma resulting from rib fracture(s), or the potential for such trauma, previously considered to have a guarded to poor prognosis for survival, may be successfully managed with internal fixation of selected fracture sites.     

Periosteal transection and stripping for treatment of angular limb deformities in foals: clinical observations

Correction was attempted in 27 foals (41 limbs) with angular deformities at the carpal region (35 limbs), metatarsophalangeal region (5 limbs) and distal end of the tibia (1 limb) by hemicircumferential transection of the periosteum (HCTP) and periosteal stripping (PS). Successful outcome was determined by straight limbs and soundness, which was achieved in 81.5% of the cases, with 60% of the horses in performance training. Follow-up evaluation for all foals was completed at various times after physiologic closure of the physes. In none of the limbs was the deformity overcorrected. Owners of foals with carpal region deviations corrected by means of HCTP and PS were satisfied with the result. The cosmetic appearance of the surgical site was excellent. The HCTP and PS adequately corrected greater degrees of carpal region deformity and greater degrees of deformity in older foals than previously reported with this or other surgical techniques.     

Effect of plasma transfusion on neutrophil function in healthy and septic foals

OBJECTIVE: To evaluate the effect of plasma transfusion on phagocytosis and oxidative burst activity of peripheral blood neutrophils from healthy and septic equine neonates with sub-optimal passive transfer of maternal immunity. ANIMALS: Nine healthy and seven septic foals with suboptimal passive transfer of maternal immunity (serum IgG < 8 g/L) presented to participating veterinary hospitals for plasma transfusion, and seven healthy foals less than 7 days of age and with circulating IgG concentrations > or = 8 g/L. PROCEDURE: Foals with serum IgG concentrations < 8 g/L were assessed as healthy or septic. Sepsis was recognised by positive bacterial cultures and/or sepsis scores of > or = 11. All foals received between 1 and 3 L of plasma to boost circulating IgG concentrations to > or = 8 g/L. Serum IgG concentrations were determined before and following transfusion by glutaraldehyde coagulation test and confirmed by single radial immunodiffusion assays. Neutrophil phagocytosis and oxidative burst activity were determined before plasma transfusion and at 0 h, 12 h, 24 h, 48 h and 5 d following treatment. Neutrophil function from seven healthy foals less than 7 d of age and with circulating IgG concentrations of > or = 8 g/L was similarly evaluated on a single occasion. RESULTS: Plasma treatment significantly increased circulating IgG concentrations for healthy and septic foals. Oxidative burst activity of neutrophils from septic foals was significantly increased 5 days following treatment, relative to 0 h post treatment. Other differences were not significant but suggested a transient decrease in phagocytosis by neutrophils from healthy foals and increased phagocytosis by neutrophils from septic foals immediately following transfusion. Oxidative burst activity of neutrophils from septic foals tended to be less than that of healthy foals at all sampling times. Serum IgG concentrations were not correlated with neutrophil phagocytosis, but were correlated with oxidative burst activity. CONCLUSIONS: Plasma transfusion did not improve neutrophil function of healthy foals, suggesting that such treatment may be of equivocal benefit for healthy neonates. Conversely, improved neutrophil function was observed following treatment of septic foals, suggesting that plasma transfusion was beneficial for these foals. Oxidative burst activity of neutrophils from septic foals was lower than that of neutrophils from healthy foals and was significantly improved 5 days post treatment, when compared with values obtained immediately following treatment.     

Exploratory celiotomy for gastrointestinal disease in neonatal foals: a review of 20 cases

The medical records of 20 neonatal foals in which exploratory celiotomies were performed for gastrointestinal disease were reviewed. In all 20 foals, persistent pain and/or progressive abdominal distension were the primary clinical findings influencing the decision to operate. However, ancilliary laboratory data were important to the proper medical management of these foals during anaesthesia and following surgery. Surgical diagnoses of the 20 foals included ileus (nine foals; 45 per cent), small colon obstruction (five foals; 25 per cent), large colon displacement (three foals; 15 per cent), small intestinal displacement (two foals; 10 per cent), and perforated gastric ulcer (one foal; 5 per cent). Seventeen foals were recovered from anaesthesia, 13 of these were discharged from the hospital, seven were alive six months or more following discharge. Sepsis was the cause of death in six of the 10 foals that died following recovery.     

Methods for the treatment of twin pregnancy in the mare

Within a group of 130 mares which, in the event, carried twin pregnancies, 29 (22.3 per cent) produced their twins following diagnosis of a single palpable follicle at service and a single pregnancy 42 days later. The whole group of 130 twin-pregnant mares gave birth to only 17 live foals (13 per cent). Breeding results for the following season were available for 102 of these mares, when 38 (37 per cent) produced live foals. Thus over the two seasons an average 23 per cent of this group produced live foals. In a second group, comprising 70 mares, twin pregnancy had been diagnosed in all of them by rectal palpation. Five methods of treatment were then applied to five subgroups of mares and 20 (28 per cent) of the 70 mares produced live foals that season. Breeding results for the following season were available for 53 of these mares; 33 (61 per cent) then produced live foals. Thus over the two seasons an average 46 per cent of the treated group produced live foals. The administration of a prostaglandin analogue at less than 35 days of gestation was outstandingly successful as a method of treatment.     

Influence of screw insertion order on compression generated by bone plates in a fracture model

Present recommendations regarding order of screw insertion for compression plate osteosynthesis in veterinary training are variable. We hypothesized that placement of a neutrally positioned screw would reduce the magnitude of compression that could be generated by a subsequently placed compression screw. Canine tibial diaphyseal segments were fixed to a plate attached to a bone surrogate and load cell, and the compression generated by screw tightening was measured. Three different screw insertion order patterns were evaluated using both dynamic compression plate (DCP) and limited contact dynamic compression plate (LC-DCP) implants. In group CN, the first screw was placed in compression mode and the second in neutral mode; in group NC, the first screw was placed in neutral mode and the second in compression mode; in group LNC, the first screw was placed partially tightened in neutral mode and the second in compression mode followed by complete tightening of the neutral screw. Screw insertion order significantly influenced the amount of compression generated with both groups CN and LNC demonstrating significantly greater compression generation when compared with group NC (p <0.0001). Compression generated by group CN constructs was also significantly greater than group LNC (p = 0.0013). Evaluation of group CN data to assess the influence of plate and drill guide combinations on compressive force generated did not demonstrate a statistically significant difference. To maximize compression using a load screw in a bone plate, following securement of the opposite bone fragment to the plate, it should be placed before a neutral screw is placed.     

Technique and outcome of nares amputation (Trader's technique) in immature shih tzus

Dogs with brachycephalic conformation frequently suffer from stenotic nares. This study investigated the clinical effects of stenotic nares resection in shih tzu puppies using an amputation technique first described in 1949. The authors hypothesized that surgical correction of the stenotic nares would result in improvement of nasal discharge/noise, breathing difficulty (dyspnea), and exercise limitations (exercise intolerance), and that the technique would provide a cosmetic result. Based on the results of this study, the authors recommend early surgical correction (amputation) of stenotic nares in shih tzu puppies as an effective and cosmetic technique.     

Seroprevalence of equine herpesvirus 1 in mares and foals on a large Hunter Valley stud farm in years pre- and postvaccination

OBJECTIVE: To examine the prevalence of equine herpesvirus 1 antibody in mares and foals on a large Hunter Valley Thoroughbred stud farm in New South Wales before and after the introduction of an inactivated whole virus vaccine. DESIGN: Cross-sectional serological surveys performed in February 1995 and 2000 to determine the prevalence of EHV-1 antibody-positive mares and foals. A further cross-sectional survey was carried out in 2001 to complement the 2000 data. STUDY POPULATION: Two hundred and twenty-nine mares and their foals were sampled in 1995 and 236 mares and their foals were sampled in 2000. The study population comprised all of the mares with foals at foot on this property at each sample period. Fifty mares were sampled in both studies. A further 264 mares and their foals were sampled in 2001. PROCEDURE: A blood sample was collected from each mare and foal at the beginning of February 1995, 2000 and 2001. Each sample was tested in triplicate using an antibody-detection ELISA that is type-specific for EHV-1 and EHV-4 antibodies. RESULTS: The prevalence of EHV-1 antibody-positive mares was not statistically different in 2000 compared to 1995. However, the prevalence of antibody-positive foals was significantly lower in 2000 than in 1995. In 2001, the prevalence of antibody-positive mares was higher than in 2000, but not different from that in 1995. The prevalence of antibody-positive foals in 2001 was not significantly different from the prevalence observed in 1995 or that observed in 2000. However, when the three studies were compared there was a significant variation in the prevalence of EHV-1 positive foals due to the variation between the 1995 and the 2000 data. CONCLUSIONS: Mares are the source of virus from which foals are infected early in life and following analysis of the 2001 data, the difference in the prevalence of EHV-1 antibody-positive foals between 1995 and 2000 was likely to be a reflection of seasonal, nutritional and management factors, rather than the result of vaccination.     

Oral lactose tolerance test in foals: technique and normal values

Oral lactose tolerance tests were evaluated in 25 healthy foals (principals) assigned to 4 groups of approximately 1 week, 4 weeks, 8 weeks, and 12 weeks of age. Lactose monohydrate (1 g/kg of body weight [in a 20% water solution]) was administered via nasogastric tube after a 4-hour fast. Plasma glucose concentrations were monitored before dosing (0 minutes) and sequentially for 300 minutes. Six control foals were given a volume of water equivalent to the volume of lactose monohydrate administered to principal foals. After oral lactose loading, mean plasma glucose concentrations of all principal foals increased from 99.76 mg/dl at 0 minutes to 176.80 mg/dl by 90 minutes. Peak increases in plasma glucose concentrations were attained by 8% of the foals (2 foals) at 30 minutes, 76% (19 foals) at 60 minutes, and 16% (4 foals) at 90 minutes. The mean plasma glucose concentration increase of principal foals, regardless of age or time of peaking, was 77.04 mg/dl. There was no significant (P greater than 0.05) difference in fasting plasma glucose concentrations (0 minutes) among the 4 groups of principal foals or between principal and control foals; however, there was a significant (P less than 0.05) difference in peak glucose concentrations between 1-week-old and 12-week-old principal foals, with the older foals having the higher concentrations. Mean plasma glucose concentrations of control foals decreased from 79.67 mg/dl at 0 minutes to 55.17 mg/dl by 180 minutes. The mean peak decrease in plasma glucose concentrations of control foals, regardless of time of peaking, was 24.50 mg/dl.(ABSTRACT TRUNCATED AT 250 WORDS)     

A modification of the Mustardé technique for the surgical repair of a large feline eyelid coloboma

A one‐year‐old male domestic short haired cat was referred because of an area of keratitis that had developed adjacent to a particularly large unilateral eyelid coloboma. The defect was repaired using an undescribed three‐stage surgical technique, which is essentially a combination of existing techniques and consists of using the lower lid to re‐construct the upper lid and replacing the resultant lower lid defect with a full thickness graft from the upper lip. This technique is described and the results illustrated by photographs. A good functional and cosmetic result was achieved.     

Ventral abdominal approach for screw fixation of sacroiliac luxation in clinically affected cats

OBJECTIVE: To investigate sacroiliac luxation repair with positional screw insertion from the ventral surface of the sacral wing via a ventral abdominal approach in cats. ANIMALS: 18 European shorthair cats. PROCEDURES: All cats underwent clinical examination including orthopedic and neurologic examination and assessment of lameness and pain before and immediately after surgery and 6 and 16 weeks after surgery. All sacroiliac luxations were stabilized with a single positional 2.4-mm cortical titanium self-tapping screw. The pelvic floor was also repaired in selected cats. Screw entry points and angles determined in a prior study of cadavers were used. Radiographs were taken before surgery and during follow-up evaluations to assess postoperative sacroiliac luxation reduction, implant placement, and repair stability. RESULTS: All implants were placed correctly. Iatrogenic sciatic nerve injuries occurred in 2 cats. Median time to ambulation was 1.5 days for cats with sacroiliac luxation as the sole injury. Radiographic outcome of sacroiliac luxation repair was excellent in 15 of 17 repairs, good in 1 of 17 repairs, and poor in 1 of 17 repairs. Clinical outcome was excellent in 11 of 15 cats and good in 4 of 15 cats. CONCLUSIONS AND CLINICAL RELEVANCE: Insertion of a positional screw across the sacroiliac joint via a ventral abdominal approached can be an alternative to conventional techniques of sacroiliac luxation repair in cats. This novel technique allowed repair of bilateral sacroiliac luxation, repair of pelvic floor fractures, and treatment of soft tissue injuries of the abdominal cavity or abdominal organs with a single approach.     

The effect of intravenous fresh frozen plasma administration on fibrinogen and albumin concentrations in sick neonatal foals

This study investigated the immediate (6 h or less) effects of fibrinogen and albumin contained in transfused equine origin fresh frozen plasma on those proteins when measured in sick neonatal foals. Fibrinogen and albumin concentrations were measured in the administered plasma and in 31 sick foals at admission to a referral neonatal intensive care unit. Additional samples were obtained from the foals at 2 and 6 h following transfusion. No changes in albumin concentration were recognised. The main determinant of fibrinogen concentration following transfusion was the concentration of fibrinogen in the foal at admission. Importantly, intravenous transfusion of equine fresh frozen plasma did not result in immediate (6 h or less) increases or decreases in the fibrinogen concentration in the recipient foals. Fibrinogen from the donor contained within transfused plasma will not directly affect fibrinogen concentrations measured at later times.