[Effects of stocking density on the behaviour and bodily state of broilers fattened with a target liveweight of 2 kg]

The current investigation is a contribution to the animal welfare debate on acceptable stocking densities in broiler chickens. Two stocking densities on similar levels as currently legally regulated (35 kg/m2 und 40 kg/m2) and two cleary lower stocking densities (18 kg/m2 und 25 kg/m2) were investigated in groups of 18 to 42 Lohmann broiler chickens (B) in three batches with each time one replication of all stocking densities. Target weight of the broiler chickens was 2 kg at 39 or 40 days of age. Mortality, final live weights and activity levels were not significantly different between stocking densities. The proportion of time birds were sitting/lying increased in general with age from about 56% to 82%, probably due to their rapid growth. Nevertheless, at the lower stocking densities there was only in single cases. Moreover, significantly more footpads showed medium grade alterations under higher density conditions; high grade alterations were also different between 35 kg/m2 and 40 kg/m2. Walking ability was only different between the lowest and the two higher densities. Altogether results reflect behavioural restriction at the higher stocking densities with increased risks for footpad alterations and lameness. In order to reach clear animal welfare improvements, e. g. in the framework of animal welfare labeling, a considerable lowering of the stocking density is consequently one important measure. However, this recommendation should be further validated under commercial conditions.

Mesh skin graft and digital pad transfer to reconstruct the weight-bearing surface in a dog

A 2-month-old dog was presented with injuries involving both hind paws. Only the 5th digit and its digital pad were present on the right paw. Following a full-thickness skin graft, the 5th digital pad was transferred distal to the metatarsal bones. The transferred pad permitted weight-bearing on the limb.

Reconstructing weight-bearing surfaces: digital pad transposition

The paw pads of dogs and cats are specialized skin structures that provide cushioned, durable, weight-bearing surfaces. Otherwise normal limbs may be rendered useless when pad tissue is lost because of trauma or tumor resection. This article reviews previously described reconstructive techniques involving the movement of pad tissue into weight-bearing defects. In addition, a case series of single-stage digital pad transfer to replace all or part of metacarpal or metatarsal defects is reported. This technique was predictably successful with minimal complications in conjunction with complete tumor resection, although results in two cases of severe paw trauma were less favorable.

Treating pedal shortening in a dog by metatarsal distraction osteogenesis

A five-month-old, male German shepherd dog was presented with a left hindlimb deformity. Wearing a cast for a prolonged period to treat left metatarsal fractures at eight weeks of age had resulted in physeal closure of the calcaneus, metatarsals and phalanges. Hyperextension of the phalanges and ulceration of the plantar skin proximal to the main tarsal pad were seen. The left foot was 40 mm shorter than the right. At seven months of age, a modified circular external skeletal fixator (CESF) was used to perform distraction osteogenesis of the metatarsal bones for 28 days. The CESF apparatus was removed after eight weeks when there was radiographic consolidation of regenerate bone. At follow-up evaluations four and 12 months after surgery, the phalangeal hyperextension and plantar skin ulceration had resolved. No lameness was detected.

Hoof repair and glue-on shoe adhesive technology

There are many different commercially available hoof repair/adhesive products. The application of these products in the treatment of various foot conditions is continuing to evolve based on sound medical and farriery principles as well as imagination. Successful application of these products depends largely on using proper hoof wall preparation and adhesive application techniques. Success also depends on a realistic expectation of the final outcome when accounting for the physical limitations of the adhesive products and the underlying hoof problem. Our results with these techniques have been encouraging and rewarding.

Tetanus in the cat--an unusual presentation

Tetanus is rare in cats owing to their innate resistance. Clinical diagnosis may not be obvious in the early stages of the disease when characteristic signs of generalised tetanus are absent. However, the history of a penetrating/neglected wound and the presence of persistent involuntary muscle rigidity in a mentally alert animal should always lead to the suspicion of tetanus. Prompt diagnosis and treatment are the keys to a successful outcome.

Hoof wall defects: chronic hoof wall separations and hoof wall cracks

Hoof wall defects in horses are common occurrences, and, fortunately, many of those detected present little or no danger to the individual horse. Those defects that are either presently a problem or have a great likelihood of being a problem do often require specialized consideration. Horse shoeing and farriery are ancient practices; over the years, a multitude of methods, theories, and management schemes have been proposed. It is unfortunate to note that few studies are available to provide an accurate incidence rate, a better understanding of the various causes, and, lastly, a comparative appreciation of the possible modes of treatment and management. This discussion reflects the thinking and experience of the author and, as such, should be read and viewed with an open and critical mind set.

Hoof wall surgery in the horse: approaches to and underlying disorders

Because of the hoof capsule, surgery of the equine foot is often perceived to be quite difficult. Knowledge of the specific disease entities that require surgical intervention as well as an in-depth understanding of the anatomy of the tissues beneath the hoof capsule is a definite prerequisite to successful surgical treatment. This article details the surgical approaches used to treat septic navicular bursitis, septic pedal osteitis, infection of the collateral cartilages, and keratomas. The principles used to treat these conditions can be applied to a variety of other conditions for which access through the hoof wall is required.

Hoof capsule distortion: understanding the mechanisms as a basis for rational management

Understanding the basic mechanisms of hoof capsule distortion enables the clinician to unravel the sometimes complex mix of abnormalities, identify early warning signs, and manage existing problems more effectively. Distortion of the hoof capsule can often seem like a complicated puzzle by the time the veterinarian is called to examine the lame horse. Evaluating each of the components of the hoof capsule, both individually and as an integrated unit, allows the clinician to tease apart the tangle of primary and secondary problems and come up with effective options for countering or attenuating the forces responsible for the distortion. Using high-quality radiography and developing an eye for detail regarding the physical and radiographic characteristics of the foot allow the clinician to identify subtle abnormalities, thereby averting a clinical problem or addressing the problem while it is still reversible. With existing problems, developing these skills enhances the clinician's ability to interpret the degree of damage accurately and to devise mechanical solutions that create an environment in which healing and restoration of function are maximized.

Examination of the equine foot

The examination of the foot must be based on observations of the hoof, followed by a careful determination of areas of pain. This must be followed by an assessment of the biomechanical forces on the hoof and limb. Finally, imaging gives insight into the nature of the injury and allows the examiner to prognosticate the outcome.

Effects of bandage configuration on paw pad pressure in dogs: a preliminary study

Seven bandage configurations were placed on the right forepaw of six English pointer dogs to evaluate the effects that configurations have on reducing pad pressure. The "clam shell" configuration resulted in less pressure being applied to all palmar pad surfaces. For the major weight-bearing pad, a basic paw bandage with an intermediate compressible foam sponge that had a hole under the major weight-bearing pad, combined with a metal splint paw cup under the sponge, resulted in a significantly lower pressure recording than for other bandage configurations. Digital pads 3 and 5 had the greatest pressure in a basic bandage configuration. Based on pressures on these pads, a basic paw bandage with an intermediate compressible foam sponge under the major weight-bearing pad, with or without a metal splint paw cup under the sponge, helped elevate the digits to relieve pressure on them. Placing a foam sponge pad, with or without a splint paw cup under the palmar paw surface, also provided less pressure on these pads.

Congenital factor XI deficiency in a domestic shorthair cat

A 6-month-old, female, domestic shorthair cat was examined after onychectomy and ovariohysterectomy because of bleeding from the paws. Prolonged activated partial thromboplastin time was discovered, Coagulation factor analyses revealed deficiency of factor XI coagulant activity. Plasma mixing studies indicated factor deficiency or dysfunction rather than factor inhibition. Feline factor XI deficiency in one adult cat has been previously reported but was attributed to factor XI inhibitors. The signalment, lack of primary disease, and the finding of persistent factor XI deficiency in the absence of coagulation inhibitors were considered compatible with congenital factor XI deficiency in the cat of this report.

Effects of 'navicular' shoeing on equine distal forelimb kinematics on different track surface

Orthopaedic shoeing applied for disorders such as navicular disease is mostly evaluated on hard track surfaces, but very often horses are ridden only on soft tracks. To compare the effects of normal shoes, eggbar shoes, and shoes with heel wedges (5 degrees) on the kinematics of the distal forelimb on hard and soft track surfaces, eleven sound Dutch Warmblood horses were led across three different tracks (an asphalt, a fibre/sand mix (= Agterberg), and a pure sand track) with three different shoe types (a normal shoe, an eggbar shoe, and a shoe with heel wedges). The hoof rotation and the maximal extension of the fetlock joint at midstance period were recorded by an infrared-light based gait analysis system (ProReflex) at walk and at trot. Statistical analysis revealed significant effects of track and shoe type, and a shoe-track interaction (p<0.05). On soft track surfaces, the equilibrium of the distal forelimb dictated a 1.5-4 degrees forward rotation of the normal or eggbar shod foot, the most on a sand track. The wedge effect on hoof rotation, however, was always significantly greater, but similar to that on the hard track surface (5 degrees forward rotation). The maximal fetlock extension was less on a soft surface, in particular on the sand track (p<0.05). This decrease was most pronounced when the horses were shod with heel wedges and was least pronounced with normal shoes. In conclusion, in particular the sand track allows a forward rotation of the hoof and thus relief of pressure in the navicular area, and a decrease in maximal fetlock extension and thus unloading of the fetlock joint. The extra forward rotation of the hoof induced by heel wedges on hard tracks was almost the same on soft track surfaces. Eggbars and fibre/sand mix tracks have intermediate effects on unloading of the distal forelimb.

Plumage condition and health of aviary-kept hens fed mash or crumbled pellets

In the present experiment, we evaluated the effects on plumage condition and health of feeding a mash or a crumbled diet to two hybrids of laying hens in an aviary system. The two diets had the same composition and calculated nutrient content. A total of 3,204 birds was studied from 20 to 80 wk of age. Two hybrids, Lohmann Selected Leghorn and SLU-1329 (two line crosses of Leghorn and Rhode Island Red), were housed in six pens each of an aviary system with groups of 269 and 265 birds, respectively. There were three replicates per treatment (diet x hybrid). Diet generally had little effect on plumage condition, health, and tonic immobility. However, birds fed the crumbled diet had significantly fewer problems with bumble foot than those fed the mash diet. Hybrids reacted differently in most traits studied; SLU-1329 had better health scores but more problems with cannibalism and salpingitis than Lohmann Selected Leghorns, whereas the reverse was found in the proportion of cases with coccidiosis. The hybrid differences found underline the importance of genotype.

Incidence of foot and skin lesions in nursing piglets and their association with behavioural activities

A total of 356 piglets from one farm were examined for foot and skin lesions every day for the first 10 days after birth, and then on alternate days until they were weaned. Over a period of 24 days 100 per cent of the piglets examined developed sole bruising, and 49.1 per cent developed sole erosions. Sole bruising lasted for an average of 13 days and sole erosions for seven days. At the beginning of the study, a higher proportion of piglets had mild sole bruising; from three to nine days of age piglets had moderate sole bruising but from days 10 to 20 mild bruising was again observed more frequently. Skin lesions were observed on the carpal aspect of the front limbs; 60.9 per cent of the piglets developed skin abrasions, 70.7 per cent developed healed wounds and 90 per cent developed hairless patches. The skin abrasions lasted on average for six days, the healed wounds for five days and the hairless patches for eight days. Piglets which developed sole bruising and/or sole erosions on the first day of life were significantly heavier than those which did not. Continuous observations of the piglets' behaviour during the first six days of life showed that sole bruising increased as the total time spent in the creep area or lying near the sow on the solid floor increased. During the first three days of life skin abrasions increased as the total time spent lying in the creep area increased. There was a positive correlation between the total time piglets spent suckling and the incidence of carpal skin abrasions between four and six days of age. Piglets with sole bruising, sole erosions or carpal skin abrasions spent less time during the day in 'other' activities such as walking, playing or fighting.

Foot lesions in finishing pigs and their associations with the type of floor

The associations between individual foot lesions and different types of floor were investigated in 4038 finishing pigs on 21 units. The overall prevalence of foot lesions was 93.8 per cent and the prevalence ranged from 79.4 per cent to 100 per cent on different units. Analysis showed that pigs kept on bedded floors, with either sparse or deep straw, had a lower prevalence of sole erosions, heel erosions and heel flaps and a higher prevalence of white line lesions, false sand cracks, wall separations and toe erosions than pigs kept on bare solid concrete floors. Partially slatted floors were associated with an increased prevalence of heel erosions, heel flaps, white line lesions, wall separations and false sand cracks, and totally slatted floors were associated with an increased prevalence of sole erosions and heel flaps.

Effect of three types of half-limb casts on in vitro bone strain recorded from the third metacarpal bone and proximal phalanx in equine cadaver limbs

OBJECTIVE

To determine effect of 3 half-limb casts on bone strains recorded from the proximal phalanx (P-1) and third metacarpal bone (MCIII) of equine cadaver limbs, using a mechanical testing machine.

ANIMALS

12 equine cadaver limbs and 4 live horses.

PROCEDURE

Bone strains were recorded at middorsal P-1 and the dorsal cortical aspect of the distal third of MCIII while limbs were variably loaded with 100 to 1,000 lb of force. To determine ability of the cast to protect the distal portion of the limb from weight-bearing loads, strains were recorded with the limb in 1 of the 3 casts and with it unsupported. To determine cast-induced discomfort, weight-supporting and transfixation pin casts were evaluated on 2 live horses

RESULTS

All 3 casts significantly reduced bone strain at P-1. Significant differences were observed: mean 61% reduction for the standard half-limb cast, 84% for the transfixation pin cast, and 97% for the weight-supporting cast at weight-bearing force of 500 lb. Only the weight-supporting cast significantly reduced strains recorded from MCIII. The weight-supporting cast was not well tolerated by 2 live horses.

CONCLUSIONS

The 3 casts significantly reduced transfer of weight-bearing forces to the distal portion of the limb. The weight-supporting cast effectively reduced strain on the P-1 to near 0, but was well tolerated by live horses. The transfixation pin cast reduced strain on the P-1 by > 80% at weight-bearing loads of 500 lb, and live horses were comfortable. Standard half-limb casts significantly reduced strains on the P-1, but to a lesser degree than did other casts.

Injuries and illnesses in working dogs used during the disaster response after the bombing in Oklahoma City

OBJECTIVES

To determine characteristics of working dogs used during the disaster response after the bombing in Oklahoma City and risk factors for injuries and illnesses of those dogs, and to document recommendations for future disaster responses.

DESIGN

Survey.

STUDY POPULATION

Information for 74 working dogs used at the bombing site.

PROCEDURES

Dog handlers were identified and asked to complete a questionnaire. Questions were asked about the training and use of each dog, use of paw protection, injuries and illnesses incurred, possible effects after completion of duty at Oklahoma City, and handler's experience.

RESULTS

Data were obtained for all 74 dogs used at the site. Handlers of 69 of 74 (93%) dogs responded. The dogs had been extensively trained and were used 491 dog-days at the site, with 46 dogs used in search, 14 in patrol, 12 in explosive-detection duty, and 2 in search/patrol. Fifteen (22%) dogs became ill. Nineteen (28%) dogs incurred 20 injuries. Footpad injuries constituted 18 of the injuries. Only 16 of 69 (23%) dogs were provided with paw protection. Dogs were more likely to be injured when they were used in a search capacity, were used during the first 2 days after the bombing, were German Shepherd Dogs, or were older.

CLINICAL IMPLICATIONS

Although working in a high-risk environment, injuries to dogs were few, and most were minor. Specific recommendations could facilitate use of dogs in disaster situations and improve safety for those dogs.

Health of laying hens in an aviary system over five batches of birds

Mortality and health were studied in laying hens kept in an aviary system on a practical scale. All management inputs were done by university staff. Five batches of birds (trials) during a period of 6 years with approximately 4,700 birds per trial were included in the study. The aviary was a three-tiered "Marielund" system divided into 4 pens. Three hybrids, reared on litter with access to perches, were used; Lohmann Selected Leghorn (LSL), Lohmann Brown (LB) and an experimental cross (SLU-1329). The hens were not beak-trimmed. The stocking density was 17 hens/m2 ground floor. Mortality varied between pens and between batches, ranging from normal rates of 3.4% to 7.8%, except in LSL in Trial 2 and LB in Trial 3 where it was much higher (15.6% and 20.9%, respectively). The dominating causes of total mortality were salpingitis and cannibalism. Coccidiosis and lymphoid leucosis contributed significantly to mortality in Trial 2. An infestation with fowl mites (Dermanyssus gallinae) occurred in Trial 1. Feather loss was most severe in LB. Keel bone deviations were recorded at increasing levels by age. Foot abscesses occurred more frequently at 35 weeks than at 55 weeks. LSL was more severely affected than LB and SLU-1329.

Computed tomographic evaluation of comminuted middle phalangeal fractures in the horse

Comminuted fractures of the middle phalanx have been well described in the horse. Choice of treatment, surgical planning and prognosis have traditionally been based upon evaluation of radiographs. However, the complex nature of comminuted fractures makes radiographic interpretation difficult. Computed tomography (CT) allows the production of cross-sectional images with spatial separation of structures which are superimposed on survey radiographs. This allows accurate assessment of the number and direction of fracture lines within the bone. In this paper we report the use of CT in the evaluation of 6 comminuted middle phalangeal fractures. Computed tomography is potentially useful in deciding the type of treatment, surgical planning and determining the prognosis.

Management of a transverse fracture in the distal phalanx of a horse

A yearling horse was presented with a septic, transverse fracture in the frontal plane of the distal phalanx. The fracture fragment was surgically removed from the parent bone via the sole. The foot was managed by corrective farriery and the horse was able to be ridden for pleasure.

Prevalence and distribution of foot lesions in finishing pigs in south-west England

This paper gives the first estimate of the prevalence and distribution of foot lesions in finishing pigs in the south-west of England for 33 years. It was based on the examination of 4038 finishing pigs from 21 units. There were 3727 out of 3974 (93.8 per cent) pigs with at least one foot lesion. The prevalence of different lesions was: toe erosion (33.0 per cent), sole erosion (62.1 per cent), heel erosion (13.0 per cent), heel flaps (14.4 per cent), white line lesions (55.4 per cent), false sand cracks (23.9 per cent) and wall separation (11.5 per cent). The hind feet were more commonly affected than the front feet, and on each foot the lateral digits were significantly more frequently affected than the medial digits. Sole erosions, heel flaps, wall separation and false sand cracks were more frequently observed on the lateral than the medial digit. Digits with sole erosions were significantly more likely to have heel flaps, white line lesions or false sand cracks than those without sole erosions. Furthermore, there was a within digit association between overgrown hooves and toe erosion. The effects of weightbearing, gait and environment on the development of foot lesions is discussed.

Incidence and risk factors for bumblefoot (pododermatitis) in rehabilitated raptors

A retrospective cohort study was conducted on 821 raptors of 12 representative species, admitted to the California Raptor Center (CRC), during 1980-1990. The incidence rate for bumblefoot was 52 cases per 100 bird-years at risk. Eagles and hawks (buteos) were more likely to develop bumblefoot, and did so earlier during their captivity than other species. Also, raptors admitted with a limb fracture had the greatest risk (OR = 4.2) of developing bumblefoot than any other condition on entry. Median time from admission to development of bumblefoot was 52 days, and median duration of bumblefoot was 23 days.

Comparison of bandaging and elevation of the claw for the treatment of foot lameness in dairy cows

OBJECTIVE

To compare the effectiveness of three treatments for sole injuries in dairy cows and to evaluate the ease and speed of applying the treatments.

DESIGN

A randomised clinical trial.

PROCEDURE

The three forms of treatment were elevating the affected claw of a lame cow with a wooden block glued to the unaffected claw (39 cows), elevating the affected claw with a rubberised shoe glued to the unaffected claw (42 cows) or applying a padded bandage to the whole foot of a lame cow (31 cows).

RESULTS

The percentages of cows that recovered from lameness at 3 and 7 days after treatment were significantly higher for cows treated with wooden blocks (P = 0.013 and P = 0.008) or rubberised shoes (P = 0.026 and P = 0.0003) than padded bandages. Cows treated with blocks had a recovery rate of 48.7% at day three and 65.8% at day seven, and cows treated with rubberised shoes, rates of 45.2% and 76.2%, respectively. Cows which had a bandage applied to the foot had recovery rates of 19.4% at day three and 32.3% at day seven. However, by day 14, there was no significant difference in recovery rate between the three treatments. Rubberised shoes were shown to offer a number of advantages over wooden blocks. The shoes were significantly quicker to attach than blocks (median of 9.5 minutes compared with 14.0 minutes, P < 0.0001) and remained on the claw longer (57.1% of rubberised shoes remained at 30 days compared to 30.8% of blocks, P = 0.025). The rubberised shoes also offered an advantage over wooden blocks for operator safety and health by reducing contact between the potentially hazardous adhesive used to attach both devices and the skin of the person applying the device.

CONCLUSIONS

Rubberised shoes are a superior method of elevating an affected claw in conditions of lameness likely to respond to removal of weightbearing forces.

Treatment of a comminuted frontal-plane fracture of the distal phalanx in a horse

Successful treatment of a comminuted frontal plane fracture of the distal phalanx in a horse is described. The bone fractured through the solar canal, close to the insertion of the deep digital flexor tendon. A hoof case was used to reduce bending and tensile stresses on the solar surface by limiting expansion of the hoof wall during weightbearing. In addition, the heel was elevated, using 3 degrees wedge pads incorporated within the hoof cast, to reduce distraction at the fracture site caused by the pull of the deep digital flexor tendon. Two casts were used over a 4-month period. Complete radiographic healing of the fracture was evident 4 months after injury. At this time the horse was lame at the trot. The owner reported the horse to be sound 7 months after injury. Reexamination 12 months after injury revealed a clinically normal foot and no lameness.

Double-plate fixation of comminuted fractures of the second phalanx in horses: 10 cases (1985-1993)

OBJECTIVE

To determine the technique used, and the outcome for, double-plate fixation of comminuted fractures of the second phalanx of horses.

DESIGN

Retrospective analysis of medical records.

ANIMALS

10 horses with comminuted fractures of the second phalanx that were treated by use of double-plate fixation.

PROCEDURE

Two 4- to 6-hole dynamic compression plates were abaxially placed to achieve arthrodesis of the proximal interphalangeal joint and fixation of the fracture of the second phalanx.

RESULTS

Arthrodesis and fracture healing were detected in all horses.

CLINICAL IMPLICATIONS

Horses with comminuted fractures of the second phalanx that are treated with double-plate fixation have an excellent prognosis for survival and use as broodstock, and have an increased potential for return to useful function.

Histologic appearance of axial osteochondral fragments from the proximoplantar/proximopalmar aspect of the proximal phalanx in horses

Osteochondral fragments from the axial proximoplantar/proximopalmar region of the proximal phalanx were removed from 38 joints in 30 horses. Ninety-three percent of the horses were Standardbreds, and 28 of the 30 had a low-grade lameness. All but 1 of the horses had hind limb involvement. A total of 43 fragments were removed. Most (71%) of the fragments involved the medial aspect of the joint and had to be dissected from a covering of synovial tissue. Histologically, the circumference of most fragments consisted of a transition zone at the attachment of the joint capsule, a region of nonarticular, non-weight-bearing cartilage, a region where organized, dense connective tissue, presumably remnants of the short sesamoidean ligament were attached, and a region consisting of irregular truncated bony surfaces covered by healing of chronic fracture. There were several areas of degenerate hyaline cartilage, but no areas of normal hyaline cartilage or areas containing related cartilage cores or other evidence of delayed endochondral ossification. Immunohistochemical staining of 4 segments from 1 horse revealed sensory substance P immunoreactive nerves in the fibrous tissue surrounding the bony fragments and within the central cancellous spaces. The histologic appearance suggests that these osteochondral fragments may be a result of fracture, rather than a manifestation of osteochondrosis.

Lag screw fixation of noncomminuted sagittal fractures of the proximal phalanx in racehorses: 59 cases (1973-1991)

Medical records of 59 racehorses with noncomminuted midsagittal proximal phalanx fractures repaired by means of lag screw fixation between 1973 and 1991 were reviewed. Fractures were classified as short incomplete fractures (7), long incomplete fractures (32), complete fractures extending into the proximal interphalangeal joint (13), and complete fractures extending through the lateral cortex of the proximal phalanx (7). Time from fracture repair to first race following fracture repair, number of racing starts, and fastest race times before and after surgery were obtained from race records and compared among horses grouped by fracture type and between horses that returned to racing and those that did not race. Five horses with short incomplete fractures, 21 horses with long incomplete fractures, 6 horses with complete fractures extending into the proximal interphalangeal joint, and 5 horses with complete fractures extending to the lateral cortex returned to racing. A significantly lower percentage of horses returned to racing following repair of complete fractures extending into the proximal interphalangeal joint (46%), than following repair of short incomplete fractures (71%), long incomplete fractures (66%), or complete fractures extending to the lateral cortex (71%). Time from fracture to repair for horses that returned to racing (mean, 14.7 days; range, 1 to 60 days) was not significantly different from that for horses that did not race (mean, 5.8 days; range, 1 to 21 days). For all fracture groups, median number of races before injury was not significantly different from median number of races after repair, and median fastest race time before fracture was not significantly different from median fastest race time after fracture repair.

Proximodorsal first phalanx osteochondral chip fragmentation in 336 horses

The results of arthroscopic surgery in the treatment of osteochondral fragmentation of the proximodorsal aspect of the first phalanx and the influence of other fetlock joint lesions on prognosis were evaluated in 336 horses. Horses were classified as: 1) returning to previous use at the same or higher class of performance; 2) returning to previous use (regardless of class of performance); or 3) failing to return to previous use. Ninety-six horses (29%) had fragmentation alone; 140 horses (42%) had fragmentation and additional fetlock lesions, and 100 horses (29%) underwent concurrent carpal arthroscopy. Of the 100 horses that underwent carpal arthroscopy, 63 had proximodorsal first phalanx fragmentation alone and 37 had other fetlock lesions associated with the fragment. There was significant association between lesion type and return to previous use for the Thoroughbred racehorse group. There was also a significant association between lesion type and return to the same or higher class of racing for the Thoroughbred racehorse group. No significant association in return to previous use existed for racehorses vs. non-racehorses, Thoroughbred racehorses vs. Quarter Horse racehorses, single vs. multiple joint involvement, and single vs multiple fragmentation per joint. The Thoroughbred racehorses in this study were sensitive to additional fetlock or carpal lesions, as was exemplified by the significant effect lesion type had on outcome.

Arthroscopic removal of an osteochondral fragment from the middle phalanx of a horse

An intraarticular osteochondral chip fracture of the distal dorsolateral aspect of the right hind middle phalanx in a 4-year-old Dutch Warmblood gelding was removed arthroscopically. Accessibility and visibility of the fragment were excellent, and there was minimal soft tissue trauma.