Endoscopic surgery in the treatment of contaminated and infected synovial cavities

REASONS FOR PERFORMING STUDY: Contamination and infection of synovial cavities are a common occurrence in clinical practice and, if inadequately treated, may have career or life threatening consequences for affected horses. HYPOTHESIS: The objectives in treating contamination and infection of joints, tendon sheaths and bursae are most effectively met by endoscopic surgery. METHODS: Over a 6 year period, cases of synovial contamination and infection admitted to a referral clinic were evaluated and treated endoscopically. The horses received local and systemic antimicrobial drugs with minimal nonsteroidal anti-inflammatory medication but no other medical or surgical treatment. All arthroscope and instrument portals and, whenever possible, all traumatic wounds were closed. Diagnostic information, endoscopic observations and results of treatment were evaluated retrospectively. RESULTS: A total of 140 affected animals were referred and 121 cases were treated endoscopically. These involved 70 joints, 29 tendon sheaths, 10 bursae and in 12 cases a combination of synovial cavities. The most common aetiologies were open wounds (n = 54) and self-sealing punctures (n = 41). Foreign material was identified endoscopically in 41 but predicted prior to surgery in only 6 cases. Osteochondral lesions were evident at surgery in 51 and recognised before surgery in 25 cases; 32 horses had intrathecal tendon or ligament defects. Follow-up information was obtained for 118 animals; 106 (90%) survived and 96 (81%) returned to their preoperative level of performance. The presence of osteitis/osteomyelitis, other osteochondral lesions and marked deposits of pannus were associated with nonsurvival. For those animals which survived, non-Thoroughbred horses, a combination of synovial structure involvement and regional i.v. antimicrobial administration were associated with reduced post operative performance. Marked pannus, regional i.v. antimicrobial administration and duration of systemic antimicrobial administration were associated with a group combining nonsurviving animals and those with reduced post operative performance. CONCLUSIONS: Endoscopic surgery makes a valuable contribution to the management of synovial contamination and infection. POTENTIAL RELEVANCE: The information obtained from and therapeutic options offered by endoscopy justify its early use in cases of synovial contamination and infection.     

Retrospective study of 24 cases of septic calcaneal bursitis in the horse

REASONS FOR PERFORMING STUDY: Wounds to the plantar aspect of the tarsus present a diagnostic and treatment challenge. This study was undertaken to describe specific features of traumatic wounds involving the calcaneal bursa, with a view to determining which clinical examination findings and diagnostic tests results could provide reliable indicators of prognosis. OBJECTIVES: To report clinical presentation, diagnostic findings, treatment and outcome of 24 cases of septic calcaneal bursitis; and to determine the importance of the involvement of specific anatomical structures in relation to the prognosis for survival and return to athletic function. METHODS: Records of 24 horses that had suffered traumatic wounds involving the calcaneal bursae were reviewed and divided into 3 groups, based on the bursa involved and presence or absence of involvement of the tuber calcanei. Clinical, diagnostic imaging and surgical findings were recorded for each case. Differences between groups and outcome were examined for significance with Chi-squared, Fisher's Exact or Kruskal-Wallis tests, as appropriate. RESULTS: Wounds involving only the subcutaneous bursa had an excellent prognosis for survival. Seventy-five percent of horses with wounds involving the intertendinous calcaneal bursa survived. Involvement of the tuber calcanei presented a fair to guarded prognosis, with only 44% of horses with involvement of this structure surviving. CONCLUSIONS: In contrast to other studies of septic synovial structures, the time between initial injury and referral did not affect the outcome. Correct identification of invasion of the calcaneal bursa(e) and/or tuber calcanei in wounds to the plantar aspect of the tarsus allows for more accurate pronostication. Damage to the tuber calcanei presents a poorer prognosis than for cases that involve only the soft tissue structures in the region. POTENTIAL RELEVANCE: This study demonstrates the importance of correct anatomical identification of structures involved in wounds in the region of the calcaneal bursa. The use of radiography, ultrasonography and synoviocentesis are essential in these cases to provide the most appropriate treatment for the horse and accurate prognosis for the owner.     

Effects of diet restriction on life span and age-related changes in dogs

OBJECTIVE: To evaluate the effects of 25% diet restriction on life span of dogs and on markers of aging. DESIGN: Paired feeding study. ANIMALS: 48 Labrador Retrievers. PROCEDURES: Dogs were paired, and 1 dog in each pair was fed 25% less food than its pair-mate from 8 weeks of age until death. Serum biochemical analyses were performed, body condition was scored, and body composition was measured annually until 12 years of age. Age at onset of chronic disease and median (age when 50% of the dogs were deceased) and maximum (age when 90% of the dogs were deceased) life spans were evaluated. RESULTS: Compared with control dogs, food-restricted dogs weighed less and had lower body fat content and lower serum triglycerides, triiodothyronine, insulin, and glucose concentrations. Median life span was significantly longer for dogs in which food was restricted. The onset of clinical signs of chronic disease generally was delayed for food-restricted dogs. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that 25% restriction in food intake increased median life span and delayed the onset of signs of chronic disease in these dogs.     

The development of thermal resistance of the feather coat in broilers with different feathering genotypes and feeding regimes

1. This study compared the development of thermal resistance of the feather coat in broilers, with early or late feathering genes, and with or without the naked neck gene, allowed ad libitum or restricted feeding. 2. Male and female broilers of one of the 4 genotypes were reared to 6 weeks of age and allocated to one of the two feeding regimes. The thermal resistance of the back and crop region was measured at weekly intervals. A sample of birds were killed at the same ages and total feather weight, primary and secondary flight feather weight, liver weight and abdominal fat weight were measured. 3. All three main factors, sex, feeding and genotype, had significant effects on feather weight over time. The primary and secondary flight feathers were less affected by feed restriction than the feather coat as a whole. Birds with the naked neck gene showed a greater depression in growth rate than birds with a normal neck under conditions of restricted feeding. 4. The thermal resistance of the feathers on the back was greater in females, increased by early feather growth and decreased by restricted feeding. 5. Relative to metabolic body size, birds on restricted feeding had a greater feather weight and a smaller liver. There was a marked reduction in fat deposition, to almost negligible levels by 6 weeks of age. 6. Broilers given restricted feeding, in preparation for breeding, would benefit by a warmer environment, particularly those with feathering genotypes which confer a lower thermal resistance.     

Seasonal interaction of serum vitamin D concentration and bone density in alpacas

OBJECTIVE: To evaluate temporal changes in bone mineral density associated with seasonal variation in serum vitamin D, calcium, and phosphorus concentrations in alpacas. ANIMALS: 5 healthy mature neutered male alpacas. PROCEDURE: Metacarpal bone mineral density was measured at 4 times during a year. Each time alpacas were weighed, blood was collected for determination of serum calcium, phosphorus, and vitamin D concentrations, and samples of feed were analyzed for nutrient content. Vitamin D status was determined by use of an assay that measured serum 25-hydroxycalciferol concentration. Effects of changes in serum vitamin D, calcium, and phosphorus concentration and body weight with season on bone mineral density were determined. RESULTS: Bone mineral density, body weight, and serum vitamin D and phosphorus concentrations varied with season. Bone mineral density, serum vitamin D concentration, and body weight also varied among individual alpacas. Serum vitamin D concentration was lower in January than the previous October and increased from May to the following September. The decrease in bone mineral density lagged behind the decrease in serum vitamin D concentration and was lower in May, compared with the previous October. Body weight was lower in May than the previous October or following September. Solar radiation was highest in July and lowest in December. CONCLUSIONS AND CLINICAL RELEVANCE: Seasonal changes in bone mineral density are associated with changes in serum vitamin D concentrations in alpacas. Changes in bone mineral density associated with a decline in serum vitamin D concentration may predispose some alpacas to developing fractures minimal trauma.     

Transdermal absorption of a liposome-encapsulated formulation of lidocaine following topical administration in cats

OBJECTIVE: To determine plasma disposition after dermal application of a liposome-encapsulated formulation of lidocaine in cats. ANIMALS: 6 healthy adult cats with a mean (+/- SD) body weight of 4.1 +/- 0.44 kg. PROCEDURE: CBC determination and biochemical analysis of blood samples were performed for all cats. Cats were anesthetized by use of isoflurane, and catheters were placed IV in a central vein. The next day, blood samples were obtained from the catheters before and 1, 2, 3, 4, 6, 8, 10, 12, and 24 hours after applying a 4% liposome-encapsulated lidocaine cream (15 mg/kg) to a clipped area over the cephalic vein. Plasma concentrations of lidocaine were analyzed with a high-performance liquid chromatography assay. Results-Two cats had minimal transdermal absorption of lidocaine, with lidocaine concentrations below the sensitivity of the assay at all but 1 or 2 time points. In the other 4 cats, the median maximum plasma concentration was 149.5 ng/ml, the median time to maximum plasma concentration was 2 hours, and the median area under the concentration versus time curve from zero to infinity was 1014.5 ng.h/ml. CONCLUSIONS AND CLINICAL RELEVANCE: Maximum plasma concentrations of lidocaine remained substantially below toxic plasma concentrations for cats. On the basis of these data, topical administration of a liposome-encapsulated lidocaine formulation at a dose of 15 mg/kg appears to be safe for use in healthy adult cats.     

Postoperative infection with Actinobacillus spp in horses: 10 cases (1995-2000)

OBJECTIVE: To determine features of postoperative wound infection caused by Actinobacillus spp in horses undergoing clean, elective surgery and to evaluate bacterial susceptibility profiles of bacteria isolated. DESIGN: Retrospective study. ANIMALS: 10 horses. PROCEDURE: Data were retrieved from medical records and the microbiology laboratory database. RESULTS: 1,604 horses underwent clean, elective surgical procedures during the study period. Of these, 23 (1.43%) had postoperative wound infections, and Actinobacillus spp was isolated from 10 of these 23 (43%). Surgical procedures in these 10 horses included laryngoplasty with ventriculocordectomy (n = 3), arthroscopy (3), desmotomy of the accessory ligament of the superficial digital flexor tendon (2), removal of laryngoplasty prostheses (1), and hygroma resection (1). Seven horses survived, and 3 were euthanatized. All 10 Actinobacillus isolates were resistant to penicillin, and 6 were resistant to trimethoprim-sulfamethoxazole. All isolates were susceptible to ceftiofur and gentamicin. During the 5-year period of the study, Actinobacillus organisms were isolated from 35 of 513 (6.8%) samples from the general hospital population submitted for bacterial culture and antimicrobial susceptibility testing. CONCLUSIONS AND CLINICAL RELEVANCE: During the study period, Actinobacillus spp was isolated from a higher than expected percentage of horses that developed postoperative wound infections after clean, elective surgery. Susceptibility profiles for these isolates were different from typical susceptibility profiles for Actinobacillus isolates, suggesting that a pattern of resistance may be emerging.     

Primary glaucoma in Burmese cats

OBJECTIVE: To document the clinical signs and management of primary glaucoma in Burmese cats. DESIGN: A retrospective study of six affected Burmese cats, from 1996 to 2001. Procedure Six Burmese cats diagnosed with primary glaucoma were managed over periods varying from 3 months to 4.5 years. Clinical details were obtained from practice records. Gonioscopic examination of the drainage or iridocorneal angle in eyes of these affected cats was made. RESULTS: Six desexed female Burmese cats (ages 7.0 to 10.5 years) presented with complaints of either unilateral (n = 4) or bilateral (n = 2) red eye, dilated pupil or enlarged eye. In one of the affected cats, one eye had been enucleated prior to the commencement of the study, thus a total of 11 eyes were examined. Clinically, all affected eyes (n = 8) had injected episcleral blood vessels and elevated intraocular pressure. Gonioscopy revealed the presence of nine narrow and two closed iridocorneal angles. Medical therapy included topical 2% dorzolamide (n = 8), 0.5% timolol maleate (n = 1), 0.005% latanoprost (n = 1) and 0.5-1.0% prednisolone acetate (n = 8). Surgery was performed in six eyes using either diode laser (n = 5) and/or cryothermy (n = 2) and one eye was eviscerated, with implantation of a prosthesis. With therapy, five affected eyes maintained vision and normal intraocular pressure, one eye remained blind with normal intraocular pressure, one eye remained blind with elevated intraocular pressure and one eye was eviscerated. CONCLUSIONS: The Burmese cat may be predisposed to primary narrow-angle glaucoma. Early diagnosis and continuous antiglaucoma therapy can help control intraocular pressure and maintain vision.     

Effects of feeding a blend of grains naturally contaminated with Fusarium mycotoxins on swine performance,brain regional neurochemistry,and serum chemistry and the efficacy of a polymeric glucomannan mycotoxin adsorbent

The co-occurrence of Fusarium mycotoxins in contaminated swine diets has been shown to result in synergistic toxicity beyond that observed for individual toxins. An experiment was conducted, therefore, to investigate the effects of feeding a blend of grains naturally contaminated with Fusarium mycotoxins on growth, brain regional neurochemistry, serum immunoglobulin (Ig) concentrations, serum chemistry, hematology, and organ weights of starter pigs. Three levels of glucomannan polymer (GM polymer, extract of yeast cell wall, Alltech Inc.) were also tested for its efficacy to overcome Fusarium mycotoxicoses. A total of 175 starter pigs (initial weight of 10 +/- 1.1 kg) were fed five diets (seven pens of five pigs per diet) for 21 d. Diets included (1) control, (2) blend of contaminated grains, (3) contaminated grains + 0.05% GM polymer (4) contaminated grains + 0.10% GM polymer and (5) contaminated grains + 0.20% GM polymer. Diets containing contaminated grains averaged 5.5 ppm deoxynivalenol, 0.5 ppm 15-acetyldeoxynivalenol, 26.8 ppm fuuric acid, and 0.4 ppm zearalenone. Feed intake and weight gain of all pigs fed contaminated grains was significantly reduced compared to controls throughout the experiment. The weights of liver and kidney, expressed as a percentage of body weight, were lower in pigs fed the contaminated diet than in those fed the control diet. The feeding of contaminated grains significantly reduced concentrations of dopamine in the hypothalamus and pons and concentrations of dihydroxyphenylacetic acid and norepinephrine in the pons. The ratios of 5-hydroxyindoleacetic acid to serotonin, however, were elevated in the hypothalamus and pons. The feeding of contaminated grains increased serum IgM and IgA concentrations, while serum IgG concentrations were not altered. The supplementation of GM polymer prevented some of the mycotoxin-induced alterations in brain neurotransmitter and serum Ig concentrations. In summary, the feeding of grains naturally contaminated with Fusarium mycotoxins reduced growth, altered brain neurochemistry, increased serum Ig concentrations, and decreased organ weights in starter pigs. Some of the Fusarium mycotoxin-induced changes in neurochemistry and serum Ig concentrations can be prevented by the feeding of yeast cell wall polymer at appropriate concentrations, although this was not reflected in increased growth rate under these experimental conditions.     

Methionine as a methyl group donor in growing cattle

Holstein steers were used in two 5 x 5 Latin square experiments to evaluate the sparing of methionine by alternative sources of methyl groups (betaine and choline). Steers were housed in metabolism crates and limit-fed a soybean hull-based diet high in rumen degradable protein. To increase energy supply, ruminal infusions of volatile fatty acids and abomasal infusions of glucose were provided. An amino acid mixture, limiting in methionine, was infused abomasally to ensure that nonsulfur amino acids did not limit protein synthesis. Treatments for Exp. 1 were abomasal infusion of 1) water, 2) 2 g/d L-methionine, 3) 1.7 g/d L-cysteine, 4) 1.6 g/d betaine, and 5) 1.7 g/d L-cysteine + 1.6 g/d betaine. Treatments for Exp. 2 were abomasal infusion of 1) water, 2) 2 g/d L-methionine, 3) 8 g/d betaine, 4) 16 g/d betaine, and 5) 8 g/d choline. In both experiments, nitrogen retention increased in response to methionine (P < 0.05), demonstrating a deficiency of sulfur amino acids. Responses to cysteine, betaine, and choline were all small and not significant. The lack of response to cysteine indicates that the response to methionine was not due to transsulfuration to cysteine or that cysteine supply did not alter the flux of methionine through transsulfuration. The lack of response to betaine suggests that the steers' needs for methyl groups were met by the dietary conditions or that betaine was relatively inefficient in increasing the remethylation of homocysteine to methionine and, thereby, reducing the synthesis of cysteine from homocysteine. Under our experimental conditions, responses to methionine were likely due to a correction of a deficiency of methionine per se rather than of methyl group donors.