The efficacy of systemically administered anti-arthritic drugs in an induced equine carpitis model

The efficacy of two systemically administered drugs for the treatment of equine joint injuries was assessed in a randomized blinded trial using the chemically induced equine carpitis model previously used to determine the dose and efficacy of both products. After a 10-day acclimation period, carpitis was induced by intracarpal injection of Complete Freund's Adjuvant (CFA) in twenty mature horses free of clinical and radiographic evidence of synovitis or DJD. Five days after model induction, the horses were stratified based on lameness evaluation and randomly assigned to 2 groups of 10 horses each.Parameters evaluated included lameness score, maximum range of carpal flexion, carpal circumference, stride length, and synovial fluid protein. These parameters were measured prior to model induction, 5 days after model induction (immediately prior to initial treatment) and once weekly for 6 weeks. Radiographs of the carpus were taken prior to model induction and 6 weeks. after treatment began. Treatment began 5 days after model induction. One group of 10 horses received 40 mg sodium hyaluronate by intravenous injection weekly for 3 weeks and the other group of 10 horses received intramuscular injections of 500 mg PSGAG every 4 days for 7 treatments.Both treatment groups showed significant improvement from pretreatment baseline values (based upon percent recovery to normal pre-model induction values) for lameness score, stride length and maximum carpal flexion (p<0.05) at each post treatment evaluation. The PSGAG treated group had significant improvement in synovial fluid protein at post treatment weeks 2 and 3. The improvement (percent recovery) in the PSGAG treated group was significantly (p<0.05) better than that of the intravenous sodium hyaluronate treated group for stride and flexion at post treatment weeks 1 through 6, for lameness score at post treatment weeks 1 through 3 and for carpal circumference at post treatment week 4.Both intravenous sodium hyaluronate and intramuscular PSGAG induced significant improvement in clinical lameness parameters; intramuscular PSGAG yielded consistently better results in this experimental model.     

On-the-farm incidence and nature of equine dystocias

The characteristics of parturition and dystocia were recorded on standardized forms by foaling attendants on 8 farms for 517 spontaneous parturitions. Dystocias were classified from examination of the forms into those with malposition (involving the fetal body), malposture (involving fetal extremities), and normal position and posture in which traction was considered essential. Dystocias occurred in 58 of 517 (11.2%) parturitions and involved normal fetal position and posture (31.0%), malposition of body (22.6%), and malposture of extremities (41.4%). Other recorded frequencies were for emergence of an intact chorioallantois at the labia (2.0%), hiplock (1.2%), posterior presentation (0%), uterine torsion (0%), deformed fetal limbs *8.4%), stillbirth (1.2%), death of foal within 24 hours (1.2%), life-threatening injury to the mare (1.5%), and retained placenta (13.5%). The frequencies of a prolonged or excessive Stage 1 culminates in rupture of chorioallantois, (11.5%), deformed foal limbs (24.0%), relatively large foal (26.8%), and retained placenta (22.0%) were greater (P<0.05) for mares with dystocia than for mares without dystocia (2.6, 6.7, 7.9 and 10.5%, respectively).Ten of 14 (72%) dystocias with normal position and posture were attributable to a relatively large foal or weak maternal contractions. All of 16 malpositions of the body involved a tendency toward the dorso-pubic position (upside-down) and 31% were accompanied by malpostures of the extremities. Observations suggested that alternate standing and lying by the mare played a role in preventing and aiding in the self-correction of malpositions. Most (55%) of 24 malpostures involved retention of a front foot. The primary indicators of a problem were the absence of any fetal parts or membranes at the labia for a prolonged time after rupture of the chorioallantois (28% of dystocias) or the emergence of only one foot (34%).The interval from foal delivery to placental discharge was shorter (P<0.01) for Miniature Horses (17±3 min; n=17) than for the larger breeds (54±2 min; n=395). In 3 of 19 (16%) miniatures, the placenta and foal were delivered simultaneously. It was judged necessary to rupture manually an intact amnion in 2 of 5 miniatures on one farm.     

Incidence, Endocrinology, Vascularity, and Morphology of Hemorrhagic Anovulatory Follicles in Mares

The incidence of hemorrhagic anovulatory follicles (HAFs) is approximately 5% and 20% of estrous cycles during the early and late ovulatory season, respectively. The structures are more common in old mares (eg, >20 years), tend to occur repeatedly in individuals, and occur most frequently during the late follicular phase. In a recent study, the day of ovulation in controls and the first day of HAF formation, as indicated by cloudiness of follicular fluid, were defined as day 0. On day -1, future ovulating and HAF groups did not differ in follicle diameter or in the frequency of discrete gray-scale ultrasonic indicators of impending ovulation; however, in future HAFs, a greater percentage of the circumference of the follicle exhibited color-Doppler signals of blood flow. No differences were found between the two groups in systemic concentrations of progesterone, luteinizing hormone (LH), and follicle-stimulating hormone (FSH) on days -4 to 2, but estradiol was elevated in the HAF group on day -3. The wall of the HAFs developed well-vascularized luteal tissue as indicated by echotexture and color Doppler signals and by the production of near normal levels of progesterone. In conclusion, HAFs formed from viable preovulatory follicles that did not differ from ovulatory follicles in diameter or gray-scale echotexture. Estradiol concentrations were elevated a few days before the failure of ovulation, and the wall of the follicle was more extensively vascularized on day -1.     

Water acceptance and intake in horses under shipping stress

A study was conducted to measure water acceptance and intake in Quarter Horse mares after transportation (4 h) to a new location, Armstrong Equine Service (AES). Another objective was to increase that water intake by means of a flavor additive (apple or clover). Twelve mares were randomly assigned either New Mexico State University (NMSU) water or AES water then switched in a crossover design and repeated. Mares wore heart rate monitors to measure an indication of stress pretransit for 45 min, in-transit to AES for 4 h and post-transit for 1 h. Mares were weighed pre-and post- transit. Blood was drawn pre-transit and 4 days later before return to NMSU from AES. At AES, water intake was monitored for 4 days in both experiments. During experiment 1, water intake was similar (P=0.5) for both sources of water, except on day 3 when mares consumed more AES water than NMSU water (35 vs 301). Serum Na values in these mares ranged from 127 to 129 mEq/ 1 (132-146 is normal), while serum C1 ranged from 92 to 94 mEqfl (99-109 is normal). In experiment 2, mares were subjected to the same protocol as experiment 1, except that water was from AES. After 4 h transport, six mares continued to AES, where three received clover-flavored water and three received apple-flavored water. Six mares remained at NMSU after transportation, with three receiving apple and three clover flavoring. Flavored water intake was monitored for 2 days. Mares showed clear preference for apple on day 1 (P<.05) and day 2 (P<.07). Without flavoring, mares con- sumed more (P>.05) water at NMSU than AES. Mares adjusted to a new water more easily in a familiar, rather than unfamiliar, environment.     

Evidence for Genetic Involvement in Feline Dilated Cardiomyopathy

Quantitative genetic evaluation of clinical dilated cardiomyopathy (DCM) was conducted in a large cattery with known history. Data showed that clinically affected cats were significantly more interrelated than randomly chosen case-control populations from the same colony. The results of this study suggest that quantitative inheritance, either interactive with or independent of nutrition or presently unknown factors, is involved in feline dilated cardiomyopathy. (Journal of Veterinary Internal Medicine 1993; 7:383–387. Copyright © 1993 by the American College of Veterinary Internal Medicine.)     

COMPUTED TOMOGRAPHY AND BLOOD GAS ANALYSIS OF ANESTHETIZED BLOODHOUNDS WITH INDUCED PNEUMOTHORAX

Increasingly severe degrees of pneumothorax were produced in 6 adult anesthetized bloodhounds. Computed tomography (CT) of the thorax was performed on each dog to evaluate the effects of pneumo thorax on thoracic and on pulmonary cross-sectional area (TA and PA). Arterial PO₂ (PaO₂) and PCO₂ (PaCO₂), heart rate (HR), and mean arterial blood pressure (MAP) were determined and related to the severity of pneumothorax. Volumes of air equal to 1, 1.5 and 2 times functional residual capacity of the lung produced approximately 33%, 40%, and 50% reductions in pulmonary area respectively. These amounts of atelectasis correspond to a radiographically "moderate" degree of pneumothorax. As severity of pneumothorax increased, thoracic area consistently increased, PaO₂ consistently decreased, and PaCO₂ consistently increased, with all being statistically significant relationships (p<0.0001); but HR and MAP were variable and showed no statistical correlation to the degree of pneumothorax (p>0.2).     

Intracapsular Prostatic Omentalization: A New Technique for Management of Prostatic Abscesses in Dogs

Twenty dogs with abscessation of the prostate gland were treated by celiotomy, drainage, and digital exploration of the gland through bilateral capsulectomy wounds. Omentum was introduced through the capsulectomy wounds and packed into the abscess cavities around the prostatic urethra. Most dogs were discharged from the hospital within 48 hours of the surgery. Long-term resolution of the problem (no recurrence within 12 months) was achieved in 19 dogs. One dog had recurrent abscessation that was managed by the placement of dependant Penrose drains. Temporary tube cystostomy was performed postoperatively in one dog for the management of transient dysuria. One dog with septic peritonitis resulting from preoperative abscess rupture was managed by concurrent open peritoneal drainage. Intracapsular prostatic omentalization was a simple and effective means of managing prostatic abscessation with minimal requirement for postoperative hospitalization of the patient. The frequency of serious complications, including postoperative urinary incontinence, was low.     

The Effects of Implant Orientation, Canal Fill, and Implant Fit on Femoral Strain Patterns and Implant Stability During Catastrophic Testing of a Canine Cementless Femoral Prosthesis

Cementless femoral stems were placed into 12 normal greyhound femora. The implanted femora were divided into three groups by stem orientation and implant size and loaded in axial compression at a rate of 25 newtons (N) per second until failure. Rosette strain gauges were used to measure femoral principal strains at 500 N, 1,000 N, 1,500 N, and at maximum load. During maximum load, varus orientation of the femoral stem had significantly higher tensile hoop strains in the proximomedial cortex, whereas neutral orientation had higher tensile hoop strains along the cranial cortex. Femoral fractures occurred in these areas of peak tensile strain. There was no difference in maximum load between groups, therefore varus orientation did not predispose to fracture. Maximizing canal fill and implant fit increased implant stability.     

USE OF COMPUTED TOMOGRAPHY AND COMPUTED TOMOGRAPHIC MYELOGRAPHY FOR ASSESSMENT OF SPINAL TUMORAL CALCINOSIS IN A DOG

Spinal tumoral calcinosis is reported in a Berner sennenhund puppy. The condition was manifested clinically as a non-ambulatory tetraparesis associated with neck pain. On survey radiographs there was a focal calcified mass at the atlantoaxial articulation. Computed tomography and computed tomographic myelography gave additional information on the extent of the mass and on the degree of spinal cord compression. The mass was removed surgically and the dog made a complete recovery.