Evaluation of the healing of surgically created small colon serosal lesions in horses, treated by homologous pericardium implantation: An experimental study

The healing of serosal lesions created in the small colon of horses and treated by homologous pericardium implantation was evaluated. A standing left flank laparotomy was performed in 6 horses. The small colon was partially exposed, and a defect measuring 2 × 2 cm was created in the serosa between the mesenteric border and the anti-mesenteric taenia. A square piece of homologous pericardium preserved in a 98% glycerin solution was rehydrated, dried, and sutured over the defect. Recovery of the animals was uneventful, with no signs of abdominal discomfort and no significant changes in physiologic variables, intestinal motility, behavior, appetite, or defecation pattern. The same was true for the erythrogram (packed cell volume, red cell count, and hemoglobin concentration), leukogram, and plasma fibrinogen values. The animals were reoperated on through the ventral midline approach after 4, 5, 6, 7, 8, and 35 weeks, respectively, and the implants were inspected visually and collected for microscopic study. No adhesions were found. Initially, there was a rim of fibrotic tissue covering the suture line, which regressed over time and was no longer evident after 7 weeks. From that moment on, progressive integration of the implant to the intestinal serosa was observed. Histopathologic examination revealed a late healing process, with infiltration of mononuclear cells, fibroblasts, neovascularization, and mature collagen fibers, which increased in intensity up to 6 weeks and then progressively regressed. At 5 weeks, it was already difficult to distinguish between the implant and the intestinal serosa. Our conclusion was that homologous pericardium implants have good acceptance in intestinal serosal lesions in horses and offer a good perspective for clinical application.     

A Prosthetic Implant for the Equine Carpal Joint: Surgical Technique and Results

A prosthesis designed to partially replace the articular surfaces of the radial and third carpal bones was implanted bilaterally in 6 normal horses. The prosthesis consisted of a convex metal alloy component, and a concave ultra-high molecular weight polyethylene component, for implantation into the radial and third carpal bones, respectively. One horse underwent the soft tissue approach only to serve as a control. Effects on joint motion and pathologic changes were monitored over a 6-month period using clinical examination, synovial fluid analysis, electrogoniometry, high-speed cinematography, radiography, and gross and microscopic pathologic examination. Six months following implantation, all horses that received implants would trot, with slight to moderate lameness. Electrogoniometric and cinematographic evaluation of joint motion demonstrated a reduction in amplitude of the carpus in 4 horses receiving implants; however, in 2 horses, the reduction was less than, or equivalent to, that of the control horse. One horse that received the prosthesis was rideable, and was able to run with minimal lameness. Radiography, synovial fluid analysis, and gross and microscopic pathologic examination revealed varying degrees of synovitis and osteoarthritis. Biomechanical alterations of the middle carpal joint and release of wear particles from the prosthesis were considered to be major causes of these secondary changes. Changes in design of the prosthesis, intended to more accurately maintain normal joint biomechanics are proposed.     

Epiglottic Augmentation in the Horse

Epiglottic augmentation with injectable bovine collagen or an autogenous or allogenous auricular cartilage graft was performed in 12 horses with endoscopically and radiographically normal epiglottises. The grafting procedures were easy to perform and did not cause apparent discomfort. Cartilage graft extrusion or resorption may have occurred, but was not seen by endoscopy and lateral laryngeal radiography. Only collagen implants remained evident endoscopically, as smooth round submucosal bulges ventral to the epiglottic cartilage. Two horses with collagen implants, and all horses with cartilage autografts and allografts, were euthanatized at week 16. One horse with a collagen implant was euthanatized at week 4 and one at week 6. The epiglottis appeared thickened in three horses with collagen implants, two horses with autogenous grafts, and three horses with allogenous grafts. Pharyngeal lymphoid tissue was hyperplastic in two horses with autografts and three horses with allografts, but not in horses with collagen implants. Collagen grafts persisted as one or two smooth bulges 8 mm in diameter. Collagen incited a brisk foreign body reaction that was surrounded by a fibrous connective tissue capsule. Epiglottises of the horses with collagen implants were significantly thicker 20 mm from the tip than those of normal horses and horses with allografts. Cartilage graft incorporation was not evident grossly and was seen on microscopic examination in only one autograft. Thickening was caused by submucosal fibrosis.     

Cervical vertebral canal endoscopy in the horse: intra- and post operative observations

Reasons for performing study: Despite modern medical diagnostic imaging, it is not possible to identify reliably the exact location of spinal cord compression in horses with cervical vertebral stenotic myelopathy (CVSM). Vertebral canal endoscopy has been successfully used in man and a technique for cervical vertebral canal endoscopy (CVCE) has been described in equine cadavers. Objective: To determine the feasibility and safety of CVCE in healthy mature horses. Methods: Six healthy mature horses were anaesthetised. A flexible videoendoscope was subsequently introduced via the atlanto‐occipital space into the epidural space (epiduroscopy, Horses 1–3) or the subarachnoid space (myeloscopy, Horses 4–6) and advanced to the 8th cervical nerve. Neurological examinations were performed after surgery and lumbosacral cerebrospinal fluid (CSF) analysed in horses that had undergone myeloscopy. Results: All procedures were completed successfully and all horses recovered from anaesthesia. Anatomical structures in the epidural space (including the dura mater, nerve roots, fat and blood vessels) and subarachnoid space (including the spinal cord, blood vessels, arachnoid trabeculations, nerve roots and the external branch of the accessory nerve) were identified. During epiduroscopy, a significant increase in mean arterial pressure was recognised, when repeated injections of electrolyte solution into the epidural space were performed. In one horse of the myeloscopy group, subarachnoid haemorrhage and air occurred, resulting in transient post operative ataxia and muscle fasciculations. No complications during or after myeloscopy were observed in the other horses. CSF analysis indicated mild inflammation on Day 7 with values approaching normal 21 days after surgery. Conclusions: Endoscopic examination of the epidural and subarachnoid space from the atlanto‐occipital space to the 8th cervical nerve is possible and can be safely performed in healthy horses. Potential relevance: Cervical vertebral canal endoscopy might allow accurate identification of the compression site in horses with CVSM and aid diagnosis of other lesions within the cervical vertebral canal.     

Evaluation of Cervical Spinal Fusion as a Treatment in the Equine "Wobbler" Syndrome

Cervical vertebral interbody fusion was performed on 30 horses affected with cervical vertebral malformation (CVM) or "wobbles" to assess the efficacy of the surgery in either preventing progression of or reversing the neurologic deficit induced by the syndrome. Evaluation of each horse prior to surgery included clinical, radiographic, neurologic, and laboratory examination. Subjects ranged from 3 months to 8 years of age, and included 22 males and 8 females of various breeds. Three normal horses were included as controls. The Cloward method of cervical fusion was used to achieve stabilization at the affected vertebral articulation. Horses were reexamined 3 months after surgery. Clinical improvement was seen in 90% (27 of 30) of the cases. Four horses were returned to training, which had been interrupted by onset of symptoms. Seven were returned to owners as breeding animals. Twelve horses were kept for long-term studies. Seven horses were sacrificed to examine the surgical site. In 6 of the 7 horses on which necropsy was performed, the most severe histologic lesion in the spinal cord could be predicted from lesions seen radiographically. The spinal cords of control animals were normal. Osseous fusion was dependent on the completeness of removal of disc fibrocartilage during surgery. We conclude that clinical improvement in some horses affected with CVM can be achieved by cervical fusion.     

Long-term effect on the equine eye of an intravitreal device used for sustained release of cyclosporine A

OBJECTIVE: To determine the long-term toxicity of an intravitreal device releasing continuous cyclosporinee A (CsA) in normal eyes of horses by evaluating clinical signs, electroretinography, and histopathology. Animals Studied Ten adult horses with normal ophthalmic examinations were used in this study Procedure(s) Four horses had one eye implanted with a CsA device, and six horses had the right eye implanted with a CsA-containing device (10 eyes with CsA in total) and the left eye (six eyes in total) with the device without drug (control). The implants were placed in the vitreous of the eyes through a sclerotomy 1 cm posterior to the limbus in the dorso-temporal quadrant of the eye. Scotopic electroretinograms were performed prior to implantation and at 1 week, and at 1, 3, 6, 9, and 12 months postimplantation. Two of the unilaterally implanted horses were euthanized at 1 weeks postimplantation, and two at 6 weeks postimplantation. Two of the bilaterally implanted horses were euthanized at 6 months, two at 9 months, and two at 12 months postimplantation. At euthanasia, the eyes were removed, aqueous and vitreous humor aspirated, and tissues fixed in 10% buffered formalin and processed for histopathology. CsA concentrations were measured by high pressure liquid chromatography in the aqueous and vitreous humors, and in peripheral blood. RESULTS: The devices were tolerated well in 14 of 16 eyes. There was minimal postoperative inflammation in most eyes, with a normal appearance within 7 days. In two eyes implanted with the CsA device, severe inflammation resulted in phthisis bulbi by 28 days. One of these eyes exhibited suspected bacterial endophthalmitis, and one had a sterile endophthalmitis and cataract presumably from trauma to the lens during implantation. In the other 14 eyes, no change was observed in the scotopic electroretinograms (ERG) from preoperative results, and no significant differences between the right (CsA) and left (control device) eyes were observed. CsA levels in the aqueous and vitreous humor, and peripheral blood were below the detection limit of the HPLC. Histologic findings revealed only a mild lymphoplasmacytic cellular infiltrate in the ciliary body and pars plana near the implantation site. CONCLUSIONS: The CsA devices were well tolerated with no long-term complications from the implants themselves. However, complications may occur from inadvertent implantation trauma or contamination during surgery. The long-term safety of the device may make it useful for delivery of CsA in the control of equine recurrent uveitis.     

Histologic evaluation of nerve muscle pedicle graft used as a treatment for left laryngeal hemiplegia in standardbreds.

A nerve muscle pedicle (NMP) graft was placed in the cricoarytenoideus dorsalis (CAD) muscle of 6 horses with induced left laryngeal hemiplegia. The NMP graft was created by use of the first cervical nerve and omohyoideus muscle. In 1 horse (control), the first cervical nerve was transected after placement of the NMP graft. One year after the surgical procedure, horses were examined endoscopically and then anesthetized. While the larynx was observed endoscopically, the first cervical nerve was stimulated. Horses were subsequently euthanatized, and the larynx was harvested. Prior to anesthesia, the endoscopic appearance of the larynx of all horses was typical of laryngeal hemiplegia. During anesthesia, stimulation of the first cervical nerve produced vigorous abduction of the left arytenoid in principal horses but not in the control horse. The right cricoarytenoideus lateralis and CAD muscles were grossly and histologically normal. Also, the left cricoarytenoideus lateralis was atrophic in all horses as was the left CAD muscle of the control horse. In contrast, the left CAD muscle harvested from principal horses had evidence of reinnervation with type 1 or type 2 fiber grouping. One year after the NMP graft procedure, horses with left laryngeal hemiplegia had reinnervation of the left CAD muscle. In another study, reinnervation was sufficient to allow normal laryngeal function during exercise. Combined, these data suggest that the NMP graft procedure is a viable technique for the treatment of left laryngeal hemiplegia in horses.     

Use of a bioabsorbable implant for the repair of severed digital flexor tendons in four horses

A new bioabsorbable implant composed of poly-L-lactic acid was used to repair the severed digital flexor tendons of four horses. The limbs were immobilised with distal casts which were changed after six to eight weeks and removed after 12 to 16 weeks. The horses were followed clinically and ultrasonographically for from seven to 19 months after the surgery. The ultrasonographic examination after the cast had been removed showed that the implants had been well incorporated into scar tissue. Two of the horses were mildly lame at the trot seven months after the surgery, but had returned to work after 12 months. The other two horses are still lame. No complications were observed with the implant.     

DISTAL PHALANX FRACTURES IN HORSES

The case records of 274 horses with fractures of the distal phalanx were reviewed. Fifty-two horses had bilateral forelimb fractures, for a total of 326 distal phalanx fractures. The fractures were classified into one of five previously described types, based on the radiographic anatomic configuration of the fracture. Solar margin fractures, which have been briefly described in other reports and previously classified as type V fractures, were identified in 132 horses. This type of fracture is distinct from other distal phalanx fractures. Due to the high incidence of solar margin fractures, these fractures were classified as a separate type (type VI). Follow-up radiographic examinations to assess fracture healing were available for 36 horses. Twenty-two horses with distal phalanx fractures (three type I, nine type II, two type III, one type IV, one type V, and six type VI) had radiographic evidence of complete bony union of the fracture at a mean of 11 months after injury. Eight horses with complete type II fractures involving the articular surface had bony union of the body and solar margin, but not the subchondral bone at the articular surface, a mean of 11 months after injury. Six horses (four type II and two type IV) had little radiographic evidence of bony healing during the follow-up period. All fractures that eventually healed had evidence of progression toward bony union by 6 months after injury.     

Daytime shelter-seeking behavior in domestic horses

We examined daytime shelter-seeking behavior (SSB) in domestic horses housed outdoors and studied the relationship of temperature, precipitation, and wind speed with SSB. We studied 50-60 Arabian horses (depending upon time of year) and 3-5 draft horses. Horses were divided among 8 pastures containing sheds. There were 2 study phases. In the first, up to 676 scan samples were taken for each pasture over a 12-month period (total observations = 5,025). At each observation, we noted whether or not a shed was being used. In the second phase, randomly selected focal animals were chosen from each pasture and observed twice per week for 16 weeks. Forty-four focal animals were observed (total observations = 3930). At each sampling time, we noted weather conditions and recorded whether each subject was standing or lying inside or next to shelters. Shelter usage ranged from a low of <10% of observations in many weather conditions to a high of 62% of observations when it was snowing and wind speed was >4.9 m/s. When wind was >2.2 m/s, there was a significant effect of rain on shelter usage, that is, more horses used shelters in rainy, breezy conditions (P < 0.01). When wind was >2.2 m/s, there was a significant effect of snow on shelter usage, that is, more horses used shelters in snowy, breezy conditions (P < 0.01). Though overall shelter usage was typically <10%, it appears that shelter access is very important in certain weather conditions.     

Regional Limb Perfusion with Antibiotics in Three Horses

Antibiotics were delivered to chronically infected tissues by regional limb perfusion in three horses with osteomyelitis associated with orthopedic implants. Two infections were resolved with implants in place; in one, a sequestrum was resorbed. In one horse, regional antibiotic perfusion was applied to treat progressively worsening bone infection after initial implants loosened and were removed.     

Treatment of subchondral cystic lesions of the medial femoral condyle of mature horses with growth factor enhanced chondrocyte grafts: a retrospective study of 49 cases

Reasons for performing study: To evaluate the long‐term clinical outcome after allogeneic chondrocyte and insulin‐like growth factor‐I (IGF‐I) grafting of subchondral cystic lesions (SCLs) of the femoral condyle in horses. Objective: To test the hypothesis that chondrocyte and IGF‐I grafts will improve the long‐term clinical outcome in arthroscopically debrided SCLs. Methods: Medical records of 49 horses with SCLs of the femoral condyle treated by debridement and implantation of chondrocytes and IGF‐I were reviewed. Preoperative radiographs were obtained, and caudocranial radiographic projections were used to establish a ratio between cyst and femoral condyle size. Arthroscopic cyst debridement followed by filling of the bone void with autologous cancellous bone (45 horses) or tricalcium phosphate granules (4 horses) was performed. A paired syringe containing a fibrinogen and chondrocyte mixture in one syringe and calcium‐activated bovine thrombin with IGF‐I in the other was used to cover the surface. A successful outcome was defined as a horse that performed to its intended use without lameness. Results: A successful outcome was achieved in 36 of 49 horses (74%). Preoperative radiography was performed in all horses, with 33 horses having unilateral SCLs of the medial femoral condyle, 15 horses having bilateral SCLs of the medial femoral condyle, and one horse having bilateral SCLs of the lateral femoral condyle. Median age of the horses was 3.3 years. Fifteen horses had preoperative radiographic and arthroscopic evidence of osteoarthritis (OA). A successful outcome was not influenced by age of horse, presence of pre‐existing osteoarthritis or preoperative size of the subchondral cyst. Grafting resulted in success for 80% of horses >3 years old, and in 80% of horses with OA. Conclusions: Implantation of allogeneic chondrocytes supplemented with IGF‐I is an effective treatment for horses with SCLs of the femoral condyle, and particularly for older horses and horses with pre‐existing osteoarthritis. Potential relevance: Chondrocyte implantation may offer a greater chance of long‐term success in older horses and horses with osteoarthritis than has been previously reported with cyst debridement alone.     

Assessment of the utility of using intra- and intervertebral minimum sagittal diameter ratios in the diagnosis of cervical vertebral malformation in horses.

Cervical vertebral malformation is one of the most common causes of ataxia in horses. The most important factor in the diagnosis of cervical vertebral malformation is the identification of cervical vertebral canal stenosis, but published data for minimum sagittal diameter ratios in adult horses are only available for C4-C7 intravertebral sites. Intra- and intervertebral sagittal diameter ratios at C2-C7 were evaluated in 26 ataxic horses, for which a complete clinical and neuropathological evaluation was undertaken. Eight of these horses were diagnosed with cervical vertebral malformation. In these horses the majority of compressive lesions were intervertebral. The mean sagittal diameter ratios of horses with cervical vertebral malformation were significantly smaller than those of horses without cervical vertebral malformation, and for an individual horse in our study, the site with the smallest intervertebral sagittal diameter ratio was always the site at which the spinal cord was compressed. Mean sagittal diameter ratio intravertebral site measurements of horses with cervical vertebral malformation were smaller than those of horses without cervical vertebral malformation; however, the site of compression could not be predicted from the data. For our dataset, horses with a sagittal diameter ratio of < or = 0.485 at any inter- or intravertebral site could be correctly classified as having cervical vertebral malformation, and sagittal diameter ratio measurements were an effective tool to identify at least one site of compression in an individual case.     

Case-Control Comparison of Cervical Spine Radiographs From Horses With a Clinical Diagnosis of Cervical Facet Disease With Normal Horses

The accuracy of using radiographs to diagnose cervical facet osteoarthritis (CFA) in horses is undetermined. Further investigation is required to determine the clinical significance of radiographic evidence of CFA, the prevalence of radiographic changes in horses without clinical signs, and the long-term efficacy of intra-articular CFA treatment. The objectives of this study is to compare degenerative changes of the cervical facet joints of the cervical vertebrae on radiographs of horses with clinical signs of CFA with healthy cohort-matched horses, to compare clinical findings between groups, and to obtain follow-up information on the long-term outcome in treated horses. This is a retrospective case-control cohort-matched comparison study of horses treated for cervical facet disease versus horses with no clinical signs of cervical facet disease. Horses diagnosed with CFA and treated with intra-articular injection of corticosteroids were included. Follow-up information on recovery from treatment was obtained via telephone survey of owners/trainers. Healthy horses with no clinical signs of CFA were matched to treated horses by breed, sex, age, and sport as the control group. Two blinded radiologists reviewed cervical spine radiographs for each horse and recorded CFA score and intravertebral/intervertebral measurements. Clinical and radiographic parameters were compared between treatment and control groups. There was a significant difference in CFA grades for C5-6 and C6-7 between horses with presence of clinical signs and healthy horses. However, interobserver agreement between radiologists for grading CFA was moderate and only 56% of values were identical for both observers. Atrophy of the neck was present on clinical examination in most cases in the treatment group. Dressage horses were overrepresented. Overall, 64% of horses returned to their previous level of performance after treatment. Clinical examination data collected for the treatment group were retrospective and were obtained by different clinicians. Eight owners/trainers were not able to be reached for the survey. There was a significant difference in CFA grades for C5-6 and C6-7 between horses with presence of clinical signs and healthy horses. Despite these statistical differences, the clinical diagnosis of CFA based on radiographic grading alone is questionable because of the lack of agreement between the radiologists. To strengthen the diagnosis, clinical signs of facet disease, in particular atrophy of the neck muscles, need to be present to make this diagnosis. Intra-articular corticosteroid injection was effective at allowing most treated horses to return to athletic use..     

Healing of transverse humeral fractures in pigeons treated with ethylene oxide-sterilized, dry-stored, onlay cortical xenografts and allografts

Transverse humeral fractures were created in adult male pigeons (Columbia livia). They were bridged with an allograft or a xenograft, or they were allowed to heal without treatment. Tissues were examined for wound healing, bony union, infection, and sequestration of the graft at 28, 43, 85, 106, and 168 days after surgery. Neither allografts nor xenografts contributed to nor interfered with bone healing. In nontreated pigeons (controls), bony union with marked callus formation developed between misaligned fragment ends. When onlay grafts were used, bone fragments remained aligned, with minor callus formation. There was a significant (P = 0.0001) increase in the number of wounds opening after surgery and infections of the surgical site (xenograft, P = 0.0026; allograft, P = 0.0021) associated with graft use. A significant (P = 0.0001) frequency of graft sequestration was observed, regardless of graft type. A significant (P = 0.0001) frequency of foreign body reaction also was observed. Under these circumstances, the application of a graft should be considered as an alignment device, rather than a stimulus to healing.     

Equine immune-mediated hemolytic anemia associated with Clostridium perfringens infection

Background: Previous studies have suggested an association between equine immune-mediated hemolytic anemia and clostridial infections or neck abscesses.
Objective: The purpose of this report was to describe and characterize the hematologic abnormalities in a horse with Clostridium -associated immune-mediated hemolytic anemia. We also retrospectively evaluated hematologic abnormalities in 8 horses with clostridial myositis or subcutaneous emphysema.
Methods: A 7-year-old Foreign Warm-Blood gelding was evaluated for anemia and a cervical abscess. CBCs and reticulocyte counts were obtained using an Advia 120 analyzer and evaluation of Wright's-stained smears. All cases of equine Clostridium spp. myositis or subcutaneous emphysema over a 7-year period were identified in a retrospective search of the University of Minnesota Veterinary Teaching Hospital database. Clinical, hematologic, and microbiological findings were recorded.
Results: Clostridium perfringens genotype A was isolated from the neck wound of the gelding. The CBC was characterized by severe regenerative anemia, intravascular hemolysis, and RBC agglutination. A direct Coombs' test was positive. Moderate numbers of spheroechinocytes were observed. The total automated reticulocyte count was 4.5% (56,700/μL), with most reticulocytes having low absorbance (mature reticulocytes). The anemia responded to penicillin and steroidal and nonsteroidal immunosuppressive drugs. Of 8 horses with myositis, all of which involved the cervical region, 5 were anemic, 1 had a positive direct Coombs' test, and 2 had increased numbers of type III echinocytes and spheroechinocytes.
Conclusions: The presence of type III echinocytes or spheroechinocytes may be helpful in diagnosing immune-mediated hemolytic anemia associated with clostridial infections in horses. Automated reticulocyte counts may detect very low levels of reticulocytosis in hemolytic anemia in horses.     

Dorsal Laminectomy in the Horse III. Results in Horses With Cervical Vertebral Malformation

Subtotal dorsal cervical laminectomy was used to relieve spinal cord compression due to cervical vertebral malformation in 16 horses. The majority were Thoroughbred or Quarter Horse males, 1 to 4 years old. The caudal cervical vertebrae were involved in all but two instances. A Funkquist type B laminectomy was performed and the defect filled with a free autogenous nuchal fat graft. All horses recovered from surgery without complication or deterioration in neurological status. Neurological improvement occurred in 12 cases, including six that became sound. Three horses fractured a vertebral articular process and were euthanized. A modification to the shape of the laminectomy was adopted to reduce this complication.     

Chronic cervical compressive myelopathy in horses: patterns of astrocytosis in the spinal cord

The distribution and morphology of fibrous astrocytes in the cervical spinal cord of normal horses and horses with chronic compressive myelopathy were demonstrated using immunohistochemical staining for glial fibrillary acidic protein. In the spinal cord from normal horses, astrocytes with stellate cell bodies and short processes were irregularly distributed in grey matter. In the white matter, their cell bodies were small and angular in areas adjacent to grey matter and larger and more stellate-shaped in the subpial area. Astrocyte processes were fine, and evenly distributed in a predominantly radial pattern in transverse sections of cord. Gliosis was marked in the spinal cords of horses with cervical compressive myelopathy. In the grey matter at the level of compression astrocytes were often enlarged and rounded, with short, blunt processes, but the gliosis was generally mild. In the white matter, gliosis was obvious in areas of nerve fibre swelling and degeneration at the level of compression and in areas of ascending and descending Wallerian degeneration. The fine radial pattern of astrocyte fibres was replaced by a dense, irregular arrangement. Gliosis persisted in the cords of chronically affected horses after active nerve fibre degeneration had subsided. The areas of gliosis coincided with the areas of Marchi staining for degenerating myelin and with areas of myelin loss in osmium tetroxide post-fixed tissue. Histological observations were consistent with astrocytes replacing areas of extracellular space that remained after nerve fibre degeneration. it is concluded that astrocytic gliosis is a prominent and persistent alteration of the spinal cord of horses with chronic cervical compressive myelopathy.     

ULTRASONOGRAPHIC FINDINGS IN 13 HORSES WITH LYMPHOMA

Ultrasonography and radiography are commonly used for staging of lymphoma in horses, however there is little published information on imaging characteristics for horses with confirmed disease. The purpose of this retrospective, case series study was to describe ultrasonographic and radiographic findings for a group of horses with a confirmed diagnosis of lymphoma. A total of 13 horses were sampled. Lymphadenopathy (8/13), peritoneal effusion (6/13), splenic (6/13), and hepatic (5/13) lesions were the most frequently identified. The predominant splenic and hepatic ultrasonographic lesions were hypoechoic nodules, organomegaly, and changes in echogenicity. Digestive tract lesions were detected in three horses and these included focal thickening and decreased echogenicity of the small (2/13) and large intestinal (2/13) wall. Thoracic lesions were predominantly pleural effusion (4/13), lymphadenopathy (4/13), and lung parenchymal changes (3/13). Enlarged lymph nodes were detected radiographically (4/13) and/or ultrasonographically (2/13) in the thorax and ultrasonographically in the abdomen (7/13) and in the caudal cervical region (4/13). Findings supported the use of abdominal and thoracic ultrasonography for lymphoma staging in horses. Ultrasound landmarks for localizing cecal and caudal deep cervical lymph nodes were also provided.     

Phacoemulsification and implantation of foldable +14 diopter intraocular lenses in five mature horses

Presently, intraocular lenses (IOLs) are not routinely implanted after equine cataract surgery. Subsequently, horses are visual but markedly farsighted (hyperopic). This report describes the surgical results and visual status after phacoemulsification and implantation of IOLs in mature horses with spontaneous cataracts. Six eyes of 5 mature horses underwent phacoemulsification and implantation of a +14 diopter (D) foldable IOL. Recheck ocular examinations were performed at 1, 4 and 24 weeks post operatively. Refractive error was recorded at 4 weeks post operatively. Visual status, refractive error and anterior chamber depth were recorded 24 weeks post operatively: 5 of 6 operated eyes remained visual and the average refractive error was +0.4 ± 1.1D. There was a significant difference between the 24 week post operative refractive error and the population mean of +10D (P<0.0001) for aphakic horses. The average post operative anterior chamber depth was 7.89 ± 1.55 mm. One globe was enucleated 2 months post operatively. Phacoemulsification with IOL implantation resulted in a significant reduction in post operative refractive error and restored vision to within 0.4D of emmetropia in 5 of 6 operated eyes. Implantation of a +14D IOL ameliorated the hyperopia documented in aphakic horses and improved the post operative visual acuity.