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- Author or Editor: Sharon J. Spier x
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Summary
Packed cell volume, total plasma protein, serum sodium, potassium, and ionized Ca2+ concentrations, and blood pH were determined at the time of admission and following surgery in 147 horses with acute abdominal crisis. Horses were allotted to 3 categories on the basis of the surgical lesion: (1) nonstrangulating obstruction of the ascending or descending colon (category A, n = 76), (2) strangulating and nonstrangulating infarction of the cecum or ascending colon (category B, n = 37), and (3) strangulating and nonstrangulating infarction of the small intestine (category C, n = 25). Horses with low serum ionized Ca2+ concentration following surgery were given 23% calcium gluconate (100 to 300 ml) IV to effect, and ionized Ca2+ concentration was determined following treatment.
The serum ionized Ca2+ concentrations of horses in categories A, B, and C before and after surgery were lower than our normal laboratory reference range. Prior to surgery, serum ionized Ca2+ concentration measured from horses in category B and C was lower than that in horses in category A. There was no difference in ionized Ca2+ concentration in serum samples obtained before surgery in horses from category B and C, and in serum samples obtained following surgery. There was a decrease in ionized Ca2+ concentration during surgery in horses in category A. There was no change between preoperative and postoperative ionized Ca2+ concentration in the samples obtained from horses in category B and C. After calcium gluconate administration, all horses with low serum ionized Ca2+ after surgery had concentrations within our normal range.
Measurement of serum ionized Ca2+ in horses with an acute abdominal crisis is recommended. If concentrations are low, calcium gluconate diluted in fluids and administered iv to effect appears to provide an effective method of treatment.
Abstract
Objective—To determine the incidence of complications and identify risk factors associated with development of complications following routine castration of equids.
Design—Retrospective case series.
Animals—311 horses, 10 mules, and 3 donkeys.
Procedures—Medical records of equids undergoing routine castration were reviewed. Age, breed, surgical techniques (closed vs semiclosed castration and use of ligatures), anesthesia method (general IV anesthesia vs standing sedation with local anesthesia) and repeated administration of IV anesthetic agents, administration of antimicrobials and anti-inflammatory drugs, and details regarding development, management, and outcome of complications were recorded. Odds ratios and 95% confidence intervals were determined. Associations between additional doses of anesthetic agents during surgery and development of complications were analyzed with a Jonckheere-Terpstra test.
Results—33 of 324 (10.2%) equids developed a complication after surgery; 32 recovered and 1 was euthanized because of eventration. Equids that underwent semiclosed castration had significantly higher odds of developing a complication (OR, 4.69; 95% confidence interval, 2.09 to 10.6) than did those that underwent closed castration. Equids that received additional doses of anesthetic agents to maintain adequate general anesthesia developed complications more frequently than those that did not require this treatment.
Conclusions and Clinical Relevance—Incidence of complications was low, and most evaluated variables were not significantly associated with development of complications following castration in equids. However, findings suggested that the choice of surgical technique (closed vs semiclosed) is an important factor in this regard. Future studies should investigate whether duration of surgery is associated with complications following castration in equids.
Abstract
Objective—To describe the clinical course and outcome in horses in which Corynebacterium pseudotuberculosis infections were associated with musculoskeletal disease and lameness.
Design—Retrospective case series.
Animals—35 horses.
Procedures—Clinical and clinicopathologic data were collected from horses diagnosed with lameness associated with C pseudotuberculosis infection between 1999 and 2009.
Results—32 (91.4%) horses had grade 4/5 lameness. Three (8.6%) horses had grade 5/5 lameness. Abscesses were diagnosed by clinical or ultrasonographic examination. Abscesses were located in the axillary or triceps region in 25 (71.4%) horses, the stifle region in 2 (5.7%), and the popliteal lymph node in 1 (2.9%). Diffuse lymphangitis was seen in 4 (11.4%) horses, osteomyelitis in 2 (5.7%) horses, and septic arthritis in 2 (5.7%) horses. Horses commonly had clinicopathologic abnormalities characterized by neutrophilia (96.4%), anemia (67.8%), hypoalbuminemia (66.6%), or hyperfibrinogenemia (42.8%). Treatment included surgical drainage of the abscess in 21 (60%) horses, performed under ultrasonography in 20 horses; anti-inflammatory medications in 34 (97.1 %) horses; and antimicrobials in 30 (85.7%) horses.
Conclusions and Clinical Relevance—C pseudotuberculosis infection of the limbs in horses typically results in severe lameness but may have a favorable prognosis. The diagnosis may be challenging, and results of blood work consistent with inflammation are nonspecific, but anemia, hyperglobulinemia, and increased synergistic hemolysis inhibition titers are common. Ultrasonography may localize the lesions and facilitate surgical drainage to alleviate lameness. When C pseudotuberculosis musculoskeletal infection results in osteomyelitis or septic arthritis, the prognosis for survival is poor.
Abstract
Objective—To determine the outcome of penetrating injuries to the central region of the foot in equids and identify factors that may affect treatment and outcome.
Design—Retrospective case series.
Animals—63 equids (61 horses, 1 pony, and 1 mule).
Procedures—Records of equids incurring puncture wounds through the frog (cuneus ungulae) or collateral sulci of the foot between 1998 and 2008 were reviewed. Evaluated factors that were hypothesized to affect outcome included signalment, degree of lameness, foot affected, duration between injury and admission, and treatment. Injuries were graded from 1 (< 1 inch; involving superficial corium only) to 4 (involving a synovial structure) on the basis of severity of penetration as determined by radiographic evidence or findings on synoviocentesis at the time of admission.
Results—Overall, 60% (38/63) of equids returned to soundness. Thirteen equids were euthanized on the basis of synovial structure involvement and financial constraints. Of 35 equids that were treated conservatively, which may have included undergoing a surgical procedure with the horse standing, 32 (91.4%) returned to their previous level of soundness. Fifteen equids underwent surgical treatment under general anesthesia, of which 6 (40%) became sound for intended use. Ten of 34 (29%) equids with synovial structure involvement regained soundness. Equids treated earlier after injury had a better prognosis. Equids with a hind foot injury had a more favorable outcome than those with a forefoot injury.
Conclusions and Clinical Relevance—Results suggested that penetrating injuries located centrally in the foot of equids without involvement of a synovial structure have a favorable prognosis, especially if managed early. Penetration of a synovial structure provided a poor prognosis.
Objective
To describe clinical manifestations of Corynebacterium pseudotuberculosis infection in horses and to evaluate diagnostic methods for identification of this disease.
Design
Retrospective case series.
Animals
538 horses with a diagnosis of C pseudotuberculosis infection.
Results
Median age of horses with external abscesses was similar to that in horses with internal abscesses. Breed and sex did not appear to be associated with infection. Cases were detected during all 12 months; however, the disease was most common in the fall and early winter, with the highest incidence in September, October, and November in every year. Most horses (492/538, 91.4%) had a single episode of infection, without recurrence in subsequent years. Of 538 horses, 308 had pectoral abscesses, although infection was documented in many other anatomic locations. Forty-two horses had internal abscesses involving the abdomen or thoracic cavity. Corynebacterium pseudotuberculosis infection was readily identified by bacterial culture of aspirate samples from abscesses. The synergistic hemolysis inhibition test was useful for diagnosis of internal abscesses; however, it was unreliable for the diagnosis of external abscesses. Horses with external abscesses responded well to conventional treatment, in contrast to those with internal abscesses. The overall case fatality was low (3.9%), and was considerably lower for horses with external abscesses (0.8%) than for horses with internal abscesses (40.5%).
Clinical Implications
Serology (synergistic hemolysis inhibition titers ≥ 512) is useful for diagnosis of internal abscesses, but not reliable for diagnosis in horses with exernal abscesses. Prognosis for horses with internal abscesses is considerably poorer than for those with external abscesses. (J Am Vet Med Assoc 1996;209:804–809)
Objective
Evaluate histories, clinical signs, and laboratory data of 69 horses homozygous by DNA testing for hyperkalemic periodic paralysis (HPP).
Design
Cohort study.
Sample Population
69 of 189 horses testing homozygous for HPP between October 1992 and November 1994.
Procedure
Questionnaires addressing signalment, training regimes, medical history, and current status of affected horses were sent to owners, trainers, or attending veterinarians. Data from completed questionnaires were tabulated and evaluated, using descriptive statistics.
Results
Sixty-nine (37%) of 189 questionnaires were completed and returned. Clinical episodes of muscle weakness or paralysis varied in severity and frequency from mild muscle fasciculations to recumbency and death. Sixty-three of 68 HPP-affected horses were reported to have had stridor associated with exercise, excitement, stress, or episodes of muscle paralysis. Common endoscopic findings in affected horses included pharyngeal collapse, pharyngeal edema, laryngopalatal dislocation, and laryngeal paralysis. Twelve of 27 horses receiving acetazolamide had decreases in stridor while receiving medication.
Clinical Implications
Most horses testing homozygous for HPP had clinical signs associated with pharyngeal and laryngeal dysfunction. Hyperkalemic periodic paralysis should be included on a differential list for horses examined for signs of laryngeal or pharyngeal dysfunction or stridor. Treatment with acetazolamide may help to control respiratory tract signs associated with this disease. (J Am Vet Med Assoc 1996;209:798–803)
SUMMARY
A commercially available Salmonella bacterin was administered to Holstein calves starting at 1 to 19 weeks of age. Serum samples were obtained before administering bacterin and at 2-week intervals thereafter. An elisa with Salmonella dublin lipopolysaccharide (lps) or S dublin whole cells as antigen, was used to measure specific IgG and IgM responses. Antibody responses to lps were not detected from calves < 12 weeks old inoculated with killed bacterin. Immunoglobulin responses to whole-cell antigen were detected from all age groups of calves inoculated with the same killed Salmonella bacterin. Calves < 11 weeks old are able to produce immunoglobulins to some whole-cell antigens, but are unable to produce anti-lps immunoglobulins when inoculated with killed Salmonella bacterin. This age-related response to killed Salmonella antigens may account, in part, for increased susceptibility to salmonellosis in calves < 12 weeks old. In comparison to the response for killed antigen, 8 calves given modified-live aromatic-dependent S dublin bacterin at 1 to 3 weeks of age had detectable anti-lps immunoglobulins after immunization, although the response was not as rapid and was of a lesser magnitude than that of older calves given killed Salmonella bacterin.
Summary
Ouabain, a cardiac glycoside, binds to the Na+ K+-adenosine triphosphatase (Na+ pump) and prevents active transport of Na+ and K+ across cell membranes. We used [3H]ouabain to quantify the number and affinity of Na+ pumps in skeletal muscle from Quarter Horses with the muscular disorder hyperkalemic periodic paralysis (hypp). [3H]Ouabain-binding properties of gluteal muscle from clinically normal and affected horses were used to determine whether altered Na+ pump number or affinity could contribute to the pathologic features of muscle in affected horses. Foals and adult horses with hypp were compared with age-matched clinically normal horses. The number of [3H]ouabain-binding sites in adult gluteal muscle was not different between the 2 types of horses (85.7 ± 8.9 pmol of [3H]ouabain-binding sites/g [wet muscle weight] in horses with hypp vs 100.2 ± 8.8 pmol/g in clinically normal adult horses). Gluteal muscles in hypp-affected and clinically normal foals also contained a similar number of [3H]ouabain-binding sites (222.3 ± 21.0 pmol/g vs 225.3 ± 24.2 pmol/g, respectively). The affinity of these binding sites for ouabain was not different, between adults or foals, in clinically normal or affected horses. Our results indicate that membrane events underlying the periodic episodes of paralysis in horses with hypp are not attributable to quantitative changes in Na+ pump number or affinity. Our data cannot exclude the possibility that the specific activity of the Na+ pump is altered in muscle from hypp-affected horses.
Abstract
Objective—To use an extracorporeal circuit to evaluate effects of intraluminal distention on the jejunum of healthy horses.
Sample Population—2 jejunal segments from each of 5 horses.
Procedure—Jejunal segments were harvested and maintained in an extracorporeal circuit. One segment was subjected to distention (intraluminal pressure, 25 cm H2O) followed by decompression, and 1 segment was maintained without distention. The influence of distention-decompression on vascular resistance was calculated. Mucosal permeability was evaluated by measuring the clearance of albumin from blood to lumen. After distention and decompression, tissue specimens were collected for histomorphologic evaluation. In addition, the contractile response of the circular smooth muscle layer was determined following incubation with 3 prokinetic agents.
Results—Intestinal vascular resistance increased during intraluminal distention and returned to baseline values after decompression. Albumin clearance rate increased after distention, compared with baseline and control values. Histologic examination of the distended segments revealed grade-1 and -2 lesions of the mucosal villus. Edema and hemorrhage were evident in the submucosa and muscular layers. Mesothelial cell loss, edema, and hemorrhage were also evident in the serosa. Mucosal surface area and villus tip height decreased and submucosal volume increased in the distended tissue. Compared with responses in control specimens, distention decreased the contractile response induced by cisapride, erythromycin, and metoclopramide.
Conclusions and Clinical Relevance—Intraluminal distention of the jejunum followed by decompression increased mucosal permeability and injury and decreased responses to prokinetic agents. Horses with intraluminal intestinal distention may have a decreased response to prokinetic agents. (Am J Vet Res 2002;63:267–275)
