Comparison of Three Skin Preparation Techniques Part 2: Clinical Trial in 100 Dogs

The skin of 100 dogs undergoing clean or clean-contaminated surgical procedures was prepared with povidone-iodine (PI) or 4% chlorhexidine gluconate (CG) with saline or 70% isopropyl alcohol rinse. Skin bacteria at the incision site were quantified with Replication Organism Detection and Counting (RODAC) plates immediately before and after skin preparation in the preparation room, in the operating room, and postoperatively. The percentage of bacterial reduction, negative cultures, cultures with more than five colony-forming units, and skin reactions for each technique were calculated for each sample period and analyzed with the analysis of variance and Fischer tests. The percentage of bacterial reduction for all techniques was significant and comparable with results of a previous experimental study. There were no significant differences in percentages of bacterial reduction between PI and the CG techniques for surgical times up to 8 hours. There were fewer negative cultures and more cultures with high bacterial counts with PI than with CG and saline after the cleansing scrub. There were fewer negative cultures after surgery with CG and alcohol than with the other two techniques. Duration of the surgical procedure did not significantly affect the culture results. Significantly more skin reactions occurred with PI. The authors conclude that PI and 4% CG with a saline rinse are equally effective in antimicrobial efficacy under clinical conditions. However, 4% CG with a 70% isopropyl alcohol rinse may be inferior in residual antimicrobial activity.     

Comparison of an Antimicrobial Adhesive Drape and Povidone-lodine Preoperative Skin Preparation in Dogs

The antimicrobial efficacy of an adhesive drape applied after a 1-minute alcohol scrub was compared to a povidone-iodine (PI) skin preparation technique in dogs. Each technique was applied to both sides of 15 adult anesthetized dogs on premeasured, clipped areas of skin. Skin bacteria were quantified before, immediately after, and 1 hour after skin preparation. Predominant skin bacteria were isolated by swabbing the skin. The percentages of bacterial reduction immediately after and 1 hour after skin preparation, percentages of negative culture results, cultures with more than five colony-forming units, and the frequency of skin reactions were calculated and analyzed statistically. Drape adhesion was assessed subjectively. The percentage reduction in skin bacteria was significant for both techniques and comparable to that reported in humans. The adhesive drape was significantly less effective in both the immediate and 1-hour periods. Lift occurred in 66% of drape applications but was not associated with high bacterial counts. Acute contact dermatitis was more frequent after skin preparation with PI. There was no difference between the techniques in recovery of potential skin pathogens. The authors conclude that application of this antimicrobial adhesive drape after a 1-minute alcohol scrub is not as effective in the reduction of skin bacteria in dogs as is PI preparation of the skin.     

Comparison of three preoperative skin preparation techniques in ponies

The purpose of this study was to evaluate the efficacy of 3 preoperative skin preparations (povidone‐iodine [PI] removed with 70% isopropanol, and 4% chlorhexidine gluconate [CG] removed with either 70% isopropanol [CA] or sterile saline solution [CS]) in ponies. Eighteen ponies were randomly assigned to one of the 3 preoperative skin preparation groups. The skin of ponies was aseptically prepared with PI removed with alcohol, or 4% CG removed with either alcohol or sterile saline solution. The antimicrobial efficacy of each skin preparation technique was assessed quantitatively by culturing for surface bacteria with replicating organism detection and counting plates. The percentage of negative cultures, the percentage of cultures with >5 colony forming units (CFU) and the percentage bacterial reduction after the cleansing scrub, the sterile scrub, and the surgical procedures were compared. There was a significant difference between CG and PI in percentage bacterial reduction after the cleansing scrub, but no significant difference at any other time (sterile scrub, post operative skin sampling). In a comparison of the number of negative microbial cultures at each sampling point, there were no significant differences among the 3 skin preparation techniques. There were no significant differences among the treatment groups comparing the number of cultures with a high colony count (>5 CFU) after the cleansing scrub. Skin preparation with CS and PI resulted in significantly fewer cultures with >5 CFU after the sterile scrub than CA. Post operatively, CA had a higher number of samples with >5 CFU than CS and PI. PI removed with alcohol and 4% CS are equally effective in the reduction of skin bacteria after a sterile skin scrub in the operating room; however, CG was more effective in reducing bacterial numbers after the cleansing scrub. The number of cultures with high bacterial counts was greater post operatively, when alcohol was used as a rinse with chlorhexidine. In cases where a sterile scrub is not performed following a cleansing scrub, CG may be a better choice than PI. CA should not be used as a presurgical skin preparation method in ponies.     

Chlorhexidine Gluconate Versus Chloroxylenol for Preoperative Skin Preparation in Dogs

The efficacy of 3% chloroxylenol (PCMX) or 4% chlorhexidine gluconate (CG) for preoperative skin preparation was assessed in 100 dogs undergoing clean or clean-contaminated surgical procedures. Replication Organism Detection and Counting (RODAC) plates were used to quantify skin bacteria colony forming units (CFU) at the operative site before and after skin preparation and immediately postoperatively. Reduction of CFU after skin preparation and immediately postoperatively was significant for each agent. However, CFU levels were significantly lower in the CG group than in the PCMX group after surgical preparation, regardless of initial CFU numbers. No significant difference in CFU counts was observed between antiseptic groups postoperatively. Within-group comparisons showed PCMX to be significantly less efficacious when the prescrub CFU number was greater than 1,000. Bacterial reduction was similar in the CG group regardless of prescrub CFU levels. The number of negative cultures after skin preparation was significantly greater with CG than with PCMX. Chlorhexidine gluconate also had fewer cultures with heavy bacterial growth (>5 CFUs) after surgical preparation. There was no significant difference between antiseptics in the number of negative cultures or cultures with more than 5 CFUs immediately after surgery. The number of skin reactions and postoperative wound infections that occurred with each technique were similar. Three percent PCMX, as used in this study, was less effective than 4% CG in its immediate antimicrobial activity, however, this difference was not associated with an increased wound infection rate.     

Bacterial Contamination of Stethoscope Chest Pieces and the Effect of Daily Cleaning

Background

Stethoscopes are a potential source of nosocomial infection for hospitalized humans, a phenomenon not previously studied in companion animals.

Objectives

To determine if daily cleaning of stethoscope chest pieces reduces bacterial contamination between cleanings.

Animals

Client‐owned dogs and cats.

Methods

Prospective observational study. In phase 1, bacterial cultures were obtained from the chest pieces of 10 participant stethoscopes once weekly for 3 weeks. In phase 2, stethoscopes were cleaned daily and 2 culture samples were obtained once weekly, immediately before and after cleaning with 70% isopropyl alcohol, for 3 weeks.

Results

Daily cleaning eliminated bacteria immediately after each cleaning (P = .004), but did not reduce the rate of positive cultures obtained before cleaning in phase 2. Cultures were positive for 20/30 (67%) samples during phase 1 and 18/30 (60%) obtained before daily cleaning during phase 2. Recovered organisms included normal skin flora, agents of opportunistic infections, and potential pathogens. The only genus that was repeatedly recovered from the same stethoscope for 2 or more consecutive weeks was Bacillus sp.

Conclusions and Clinical Importance

Daily cleaning was highly effective at removing bacteria, but provided no reduction in precleaning contamination. Cleaning stethoscopes after use on dogs or cats infected with pathogenic bacteria and before use on immunocompromised animals should be considered.     

Comparative Evaluation of Two Surgical Scrub Preparations in Cattle

One hundred seventeen cattle that had undergone surgery were assigned randomly to two preoperative skin preparation protocols. Group 1 (60 animals) skin preparation was with povidone-iodine soap and isopropyl alcohol, whereas group 2 (57 animals) had skin preparation with chlorhexidine gluconate and isopropyl alcohol. Quantitative microbial culture plates were used to estimate the number of colony forming units (CFUs) before skin preparation (prescrub), after skin preparation (postscrub), after surgery (postoperative), and in room air (environment). A significant decrease in CFU occurred postscrub for both skin preparations ( P <.05). Chlorhexidine and alcohol preparation resulted in significantly fewer CFUs (LSMean ± SE = 2.79 CFU ± 1.74) and a greater percentage reduction in CFUs (98.64%± 2.01) postscrub than povidone and alcohol (LSMean ± SE = 10.27 CFUs ± 1.51, 93.29%± 1.85); ( P <.005). Group 2 had a significantly higher frequency of negative cultures postscrub (49.1%) compared with group 1 (18.3%) ( P <.001). The number of postoperative CFUs were not significantly different between the two treatment groups. Wound infection frequency for clean surgical procedures was not significantly different between the two skin preparation protocols (group 1 = 9.8%, group 2 = 10.7%), however, infection frequency was significantly higher for surgical procedures with a ventral abdominal approach (5 of 14, 35.7%), compared with a flank approach (1 of 41, 2.4%) or other approaches (orthopedic procedures) (1 of 16, 6.3%) ( P <.05). Both skin preparation protocols were effective and safe in decreasing the skin microflora population of cattle before surgery and although preparation with chlorhexidine gluconate and alcohol resulted in less CFUs immediafly postscrub, the frequency of surgical wound infection was similar for both protocols.     

Evaluation of surgical scrub and antiseptic solutions for surgical preparation of canine paws

The purpose of the prospective study reported here was to evaluate surgical preparation of canine paws. Three combinations of surgical scrub solutions and antiseptic solutions were used: (1) 7.5% povidone-iodine scrub/10% povidone-iodine solution; (2) 2% chlorhexidine acetate scrub/2% chlorhexidine diacetate solution; and (3) tincture of green soap/70% isopropyl alcohol. The control was warm (38 to 42 C) tap water. Four microbial colony counts were used to evaluate surgical preparation of 4 paws of 8 dogs. Specimens were obtained from the paws for a baseline microbial flora count. After surgical scrub was performed, additional specimens were obtained for bacteriologic culturing. Antiseptic was applied followed by collection of another specimen for bacteriologic culturing. A final specimen was obtained following a 24-hour period under a sterile occlusive bandage. The 3 scrub solutions and the tap water control resulted in lower colony counts following scrubbing of the paws; however, only the 3 antiseptic solutions resulted in further colony count reduction after their application. Evaluation of residual colony counts isolated from specimens taken after a 24-hour period under a sterile occlusive bandage revealed chlorhexidine and povidone-iodine scrub/antiseptic combinations to be similar in antibacterial activity, with significantly (P less than or equal to 0.05) lower colony counts than those from specimens of paws treated with either the tincture of green soap/isopropyl alcohol combination or the tap water control. The lack of a significant difference between the bacterial counts immediately after surgical preparation with povidone-iodine and chlorhexidine and their respective 24-hour residual counts, indicated no particular advantage to surgical preparation and occlusive bandaging 24 hours prior to surgery.(ABSTRACT TRUNCATED AT 250 WORDS)     

Evaluation of a one-hour saline diuresis protocol for administration of cisplatin to dogs.

A study was undertaken to determine the toxic effects of cisplatin, an antineoplastic agent, when administered immediately after a 1-hour saline diuresis. Four treatments with cisplatin (70 mg/m2 of body surface, q 3 wk) were administered IV to 6 healthy dogs over a 20-minute period after 0.9% NaCl (saline) solution was administered IV for 1 hour at a volume of 132 ml (kg)0.75. Each dog vomited at least once within 8 hours after each treatment was administered. Clinical status, body weight, and food consumption were normal throughout the 12-week study for 5 of the 6 dogs. The sixth dog developed acute renal failure and became acutely blind and deaf within 3 days after the fourth treatment with cisplatin. Serum electrolyte, creatinine, and urea nitrogen values remained within established normal limits in all dogs immediately prior to each treatment, and in 5 of 6 dogs evaluated 3 weeks after the final treatment. The serum creatinine value (3.3 mg/dl) obtained from the Beagle euthanatized 2 weeks after the fourth treatment was above established normal values. Despite normalcy for all but 1 of the creatinine values, serum creatinine concentration obtained 3 weeks after the final treatment with cisplatin was significantly (P = 0.0001) higher than pretreatment values. When compared with data from all other evaluation periods, significant decreases in glomerular filtration rate, as determined by exogenous (P less than or equal to 0.0001) and endogenous (P less than or equal to 0.0001) creatinine clearance testing, were identified 3 weeks after the fourth treatment with cisplatin.(ABSTRACT TRUNCATED AT 250 WORDS)     

Comparison of four protocols for preoperative preparation in cattle

This study was designed to evaluate 4 preoperative skin preparations, that is, more specifically, to compare the efficacy of chlorhexidine gluconate (CG) and povidone-iodine (PI), as well as 2 hair removal techniques (clipper alone or clipper followed by razor) for preoperative skin preparation in cattle. The 4 protocols resulted in a significant decrease in the number of bacterial colony-forming units (cfu). Group 4 (clipping + shaving + CG) had a significantly lower number of preoperative cfu per gel plate compared with groups 1 (clipping + PI) and 3 (clipping + shaving + PI). Skin reaction frequency was significantly higher in groups 3 and 4 (47.8% for both protocols) than in groups 1 and 2 (clipping + PI or CG) (8.7% for both). Wound infection frequency was 4.3% (4/92) and no significant difference was observed between the 4 treatment groups. The 4 protocols tested were equivalent as to efficacy and satisfactorily decreased skin microflora. Clipping alone was shown to be preferable to clipping plus shaving as a method of hair removal in cattle, with fewer skin reactions and no more wound infections.     

Pharmacokinetic evaluation of a slow-release cefotaxime suspension in the dog and in sheep

Three Merino ewes were given cefotaxime IM, and 3 were given cefotaxime subcutaneously (50 mg/kg of body weight each); each dose was suspended in 6 ml of oil. Five dogs were also given an oily suspension of cefotaxime subcutaneously (SC) (50 mg/kg of body weight). The plasma concentrations (Cp) and pharmacokinetic data obtained after cefotaxime in the oily suspension was injected IM and SC were compared with data from the same animals after they were given an aqueous solution of cefotaxime by the same routes. Key pharmacokinetic values obtained after cefotaxime was administered IV to sheep and to dogs are discussed. Mean peak Cp (Cpeak) in sheep when given the oily suspension IM was approximately 53 micrograms/ml at 0.18 to 0.40 hour, and that value in sheep given the aqueous preparation was 62 micrograms/ml 0.08 to 0.18 hour. Mean Cpeak values after the oily suspension and the aqueous preparation were injected SC were 11.0 micrograms/ml (between 0.8 and 1 hour) and 51 micrograms/ml (between 0.25 and 1 hour), respectively. Bioavailabilities were approximately 70% after IM injection was done and 90% after SC injection was done. The beta-plasma half-lives were 0.7 hour after IM injection was done and 2.9 hours after SC injection was done. Mean Cpeak in dogs when given the oily suspension SC was 30 micrograms/ml at 1.0 hour, and when dogs were given the aqueous preparation SC, Cpeak was 27 micrograms/ml at 0.6 hour. Absorption was virtually complete after the oily suspension and aqueous preparations were given.(ABSTRACT TRUNCATED AT 250 WORDS)     

A prospective comparison between stabilized glutaraldehyde and chlorhexidine gluconate for preoperative skin antisepsis in dogs

OBJECTIVE: To compare the efficacy of 0.3% stabilized glutaraldehyde and alcohol (SG+A), 0.3% SG and water (SG+W), and 4% chlorhexidine gluconate tincture (CG+A), as skin disinfectants in dogs undergoing ovariohysterectomy. STUDY DESIGN: Prospective, blinded clinical study. ANIMALS: One hundred and twenty-one dogs. METHODS: Cutaneous bacterial colony forming units (CFU) from the perioperative site after skin preparation, after antisepsis, and after surgery (incisional and paramedian), were quantified. The influence of high initial bacterial counts (> or =150 CFU) and surgical time on antibacterial efficacy was examined and the proportion of dogs from which Staphylococcus intermedius was cultured, determined. Perioperative skin reactions and wound infections were documented. RESULTS: All 3 antiseptic solutions significantly and equally reduced CFU to all post-antisepsis sampling levels irrespective of surgical duration (mean surgical times 151.6, 136.2, and 149.6 minutes for CG+A, SG+A and SG+W, respectively). Median percentage reductions in CFU ranged between 99.3% and 100%. In dogs with initial high counts and disinfected with CG+A and SG+W, the incisional samples had significantly higher counts than the post-antisepsis samples. In the CG+A and SG+W groups, the proportion of post-surgery samples yielding S. intermedius was significantly higher at the incisional than the paramedian sites. Eight mild cutaneous reactions were recorded in equal proportions for the 3 solutions. There were no recorded infections. CONCLUSIONS: All 3 preparations had an equal ability to reduce and maintain low CFU counts, with minimal cutaneous reactions. CLINICAL RELEVANCE: SG solutions are safe and effective preoperative skin antiseptics for elective clean-contaminated surgical procedures.     

Perioperative stress response in the dog: effect of pre-emptive administration of medetomidine

OBJECTIVE: To determine the effect of medetomidine on the stress response induced by ovariohysterectomy in isoflurane-anesthetized dogs. STUDY DESIGN: Prospective randomized study. ANIMALS: Twelve healthy adult female purpose-bred dogs, weighing 16.8 to 25 kg. METHODS: Two treatments were randomly administered to each of twelve dogs at weekly intervals: (1) Saline injected IM followed in 15 minutes by isoflurane anesthesia (ISO) induced by mask and maintained at an end-tidal concentration of 1.8% for 60 minutes; and (2) Medetomidine, 15 ug/lkg IM followed in 15 minutes by isoflurane anesthesia (ISO&MED) induced by mask and maintained at an end-tidal concentration of 1.0% for 60 minutes. One week after completion of these two treatments, all dogs were ovariohysterectomized. six receiving each treatment (SURG and SURG&MED). Central venous blood samples (10 mL) were obtained immediately before medetomidine or saline (baseline) and at 30, 75, and 195 minutes and 24 hours after administration of medetomidine or saline in ISO and ISO&MED. In SURG and SURG&MED, samples were obtained immediately prior to injection of medetomidine or saline (baseline) and at 30 (before skin incision), 45 (after severence of the ovarian ligament), 75 (after skin closure), 105 (30 minutes after skin closure, dog recovered and in sternal recumbency), 135, 195, 375 minutes, and 24 hours after the initial sample. Samples were analyzed for epinephrine, norepinephrine, adrenocorticotrophic hormone (ACTH), cortisol, insulin, and glucose. Data were analyzed by analysis of variance and where significant differences were found, a least significant difference test was applied. RESULTS: Premedication with medetomidine prevented or delayed the stress response induced by ovariohysterectomy in isoflurane-anesthetized dogs. CONCLUSIONS: The stress response induced by ovariohysterectomy, although significant, is of short duration. Medetomidine safely and effectively reduced surgically-induced stress responses. CLINICAL RELEVANCE: Surgically induced stress responses can be obtunded or prevented by administration of medetomidine.     

Cell cycle analysis of bovine cultured somatic cells by flow cytometry

This study was undertaken to examine the cell cycle characteristics of bovine fetal and adult somatic cells (fetal fibroblasts, adult skin and muscle cells, and cumulus cells) after culture under a variety of conditions; 1) growth to 60-70% confluency (cycling), 2) serum starvation, 3) culture to confluency. Cell -cycle phases were determined by flow cytometry with propidium iodide staining enabling the calculation of percentages of cells in G0 /G1, S and G2 /M. The majority was in G0/G1 regardless of cell type and treatment. Serum-starved or confluent cultures contained higher percentages of cells in G0/G1 (89.5-95.4%; P < 0.05). Percentages of cells in G0/G1 increased as cell size decreased regardless of the cell type and treatment. In the serum-starved and confluent cultures, about 98% of small cells were in G0/G1 . Serum-starved cultures contained higher percentages of small cells (38.5-66.9%) than cycling and confluent cultures regardless of cell type (P < 0.05) . After trypsinization of fetal fibroblasts and adult skin cells that were serum-starved and cultured to confluency, the percentages of cells in G0/G1 increased (P < 0.05) on incubation for 1.5 (95.7-99.5%) or 3 hr (95.9-98.6%). These results verify that serum starvation and culture to confluency are efficient means of synchronizing bovine somatic cells in G0/G1, and indicate that a more efficient synchronization of the cells in G0/G1 can be established by incubation for a limited time period after trypsinization of serum-starved or confluent cells.     

Prevention of experimentally induced heartworm (Dirofilaria immitis) infections in dogs and cats with a single topical application of selamectin

In a series of six controlled studies (four in dogs, two in cats), heartworm-free dogs and cats were inoculated with Dirofilaria immitis larvae (L(3)) prior to topical treatment with the novel avermectin selamectin or a negative control containing inert formulation ingredients (vehicle). Selamectin and negative-control treatments were administered topically to the skin at the base of the neck in front of the scapulae. In dogs, selamectin was applied topically at dosages of 3 or 6mgkg(-1) at 30 days post-inoculation (PI), or of 3 or 6mgkg(-1) at 45 days PI, or of 6mgkg(-1) at 60 days PI. Cats were treated topically with unit doses providing a minimum dosage of 6mgkg(-1) selamectin at 30 days PI. Of the animals that were treated 30 days PI, some dogs were bathed with water or shampoo between 2 and 96h after treatment, and some cats were bathed with shampoo at 24h after treatment. Between 140 and 199 days PI, the animals were euthanized and examined for adult D. immitis. Adult heartworms developed in all control dogs (geometric mean count, 18.7 worms) and in 88% of control cats (geometric mean count, 2.1 worms). Selamectin was 100% effective in preventing heartworm development in dogs when administered as a single topical dose of 3 or 6mgkg(-1) at 30 days after infection, 3 or 6mgkg(-1) at 45 days after infection, or 6mgkg(-1) at 60 days after infection. Selamectin was 100% effective against heartworm infections in cats when administered as a single topical unit dose of 6mgkg(-1). Bathing with water or shampoo between 2 and 96h after treatment did not reduce the efficacy of selamectin as a heartworm prophylactic in dogs. Likewise, bathing with shampoo at 24h after treatment did not reduce the efficacy of selamectin in cats. These studies demonstrated that, at the recommended dosage and treatment interval, a single topical administration of selamectin was 100% effective in preventing the development of D. immitis in dogs and cats.     

Effect of atropine on tear formation in anesthetized dogs

Tear production (as determined by the Schirmer I tear test) in five dogs given atropine (0.02 mg/kg) subcutaneously and in five dogs given 0.9% saline solution subcutaneously was compared before and during halothane anesthesia. Fifteen minutes after the atropine injections, mean tear production was 15.0 +/- 2.9 mm/minute, as compared with 23.8 +/- 2.9 mm/minute before treatment rate. There was no change in tearing 15 minutes after injection of the saline solution. Tear production declined in both groups during anesthesia. Ten minutes after anesthetic induction, mean tear formation was 20% of pretreatment value in the atropinized dogs and 54% of the pretreatment value in the dogs given saline solution. At the end of 1 hour of anesthesia, tearing was essentially zero in both groups.     

Gastric Myoelectric Activity after Experimental Gastric Dilatation-Volvulus and Tube Gastrostomy in Dogs

Gastric myoelectric activity was measured after experimental gastric dilatation-volvulus (GDV), GDV and tube gastrostomy, or tube gastrostomy in 12 dogs. Gastric myoelectric activity was recorded for 1 hour before (hour 0) and at hours 5, 24, 48, 72, and 96 after surgically induced GDV in six dogs. Three dogs with induced GDV and tube gastrostomy, and three dogs with tube gastrostomy only were also studied at hours 120, 144, and 168. The only significant change in the slow wave appearance or frequency from hours 0 to 48 was bradygastria at hour 5 in all three groups. A relative increase in the mean percentages of dysrhythmia from hours 72 to 168 in the dogs with a tube gastrostomy was caused by increases in tachygastria and arrhythmias. Dogs with GDV and tube gastrostomy had the greatest mean percentages of dysrhythmia, which were significantly more than those in dogs with GDV alone at hours 48, 72 and 96. The mean percentage of spike activity was less than or equal to 31 and varied widely. In general, there was less spike activity when the frequency of dysrhythmias was high. Thus, gastric myoelectric activity was disrupted from hours 48 to 168 after GDV with tube gastrostomy and after tube gastrostomy alone. Surgically induced GDV alone did not produce any significant or sustained dysrhythmias.     

Effects of castration on chronic bacterial prostatitis in dogs

An Escherichia coli bacterial prostatitis was experimentally induced in dogs to determine the effect of castration on chronic bacterial prostatitis. Two weeks after instillation of bacteria directly into the prostate gland, 17 of 22 adult mixed-breed male dogs had positive urine or prostatic fluid cultures or both. Seven of the 17 dogs were randomly chosen to be castrated, and 10 of the 17 served as sham-operated controls. At weekly intervals, urine was obtained from 17 dogs for aerobic microbiologic culturing. At each week, dogs with no bacterial growth in the cultured urine had prostatic fluid collected for aerobic microbiologic culture. Dogs with negative urine, prostatic fluid, and prostatic tissue needle biopsy culture results at week 7 were euthanatized. For remaining dogs, weekly cultures were continued until the dogs were euthanatized at week 12. None of the 7 castrated dogs and 6 of the 10 dogs subject to sham operation had prostatic infection at the time of necropsy. The castrated dogs had a mean infection duration of 4.2 weeks, which was statistically shorter than the 9.5-week mean duration of infection in the sham-operated controls. Cultures of prostatic tissue obtained immediately after euthanasia correlated 100% with urine and prostatic fluid cultures taken before euthanasia. All of the 6 dogs with positive prostatic cultures at termination had moderate to marked lymphoplasmacytic chronic prostatitis. The 11 dogs that were not infected at the end of the study had normal to moderate lymphoplasmacytic chronic prostatitis on histologic examination.(ABSTRACT TRUNCATED AT 250 WORDS)     

Immune production of interferon by cultured peripheral blood mononuclear cells from calves infected with BHV1 and PI3 viruses

Peripheral blood mononuclear cells (PBMC) from calves infected with bovine herpesvirus type 1 (BHV1) or parainfluenza 3 virus (PI3) were cultured in vitro in the presence of inactivated specific antigen presented on MDBK cells. In the presence of inactivated antigen, PBMC from both BHV1-infected and control calves produced interferon (IFN)-alpha in 24 hour cultures. Altering the culture conditions did not result in the detection of immune-specific IFN produced by mononuclear cells from BHV1-infected calves. However, spontaneous IFN was detected in the absence of antigen in 24 hour cultures from infected animals: this IFN was pH 2 labile and completely neutralised by antiserum to recombinant bovine IFN-gamma. Spontaneous IFN-gamma production was only seen in calves following a second BHV1 inoculation, given four to seven weeks after the primary dose. In contrast PBMC cultures from PI3 virus-infected calves did not produce IFN-gamma spontaneously, but did so in cultures which contained inactivated PI3 antigen. Mononuclear cells from control animals failed to produce either IFN-alpha or -gamma when cultured with inactivated PI3 virus. IFN-gamma was detected in PBMC cultures after the primary infection, with no increase in production occurring following subsequent PI3 virus inoculations. Immunospecific production of IFN-gamma provides a simple method for monitoring cell-mediated immunity in BHV1- and PI3 virus-infected calves and can be used for evaluating the efficacy of vaccines against these viruses.     

Prevalence of meticillin-resistant Staphylococcus pseudintermedius (MRSP) from skin and carriage sites of dogs after treatment of their meticillin-resistant or meticillin-sensitive staphylococcal pyoderma

Background – Meticillin‐resistant staphylococci are significant pathogens in veterinary dermatology, yet longitudinal studies of the impact of routine antimicrobial therapy on emergence or resolution of resistance are lacking. Objectives – To determine the prevalence of meticillin‐resistant staphylococci on skin and carriage sites in dogs with bacterial pyoderma and evaluate the prevalence of meticillin‐resistant Staphylococcus pseudintermedius (MRSP) colonization after successful treatment of pyoderma. Animals – One hundred and seventy‐three dogs that presented to a dermatology referral service with pyoderma and 41 healthy control dogs. Methods – Skin, nasal and rectal swabs for bacterial culture were collected at the time of referral and after clinical resolution of the pyoderma. Meticillin resistance was confirmed by demonstration of penicillin binding protein 2a antigen. Results – Initially, skin cultures yielded MRSP in 70 (40.5%) dogs, meticillin‐resistant Staphylococcus aureus (MRSA) in three (1.7%) and meticillin‐resistant Staphylococcus schleiferi ssp. coagulans (MRSScoag) in five (2.9%). Samples collected from the nose and rectum (carriage sites) yielded MRSP in 59 (34.1%) dogs, MRSA in 11 (6.4%) and MRSScoag in seven (4.0%). One hundred and two dogs were available for follow‐up cultures after clinical cure. Of 42 dogs initially diagnosed with MRSP pyoderma, MRSP was isolated at follow‐up from skin in 19 (45.2%) and carriage sites in 20 (47.6%). Of 60 dogs that did not have MRSP pyoderma initially, MRSP was isolated post‐treatment from the skin in 17 (28.3%), and MRSP from carriage sites increased from 7.8% (initially) to 26.7% (P = 0.0022). Conclusions and clinical importance – Colonization by MRSP often persists after resolution of MRSP pyoderma. Acquisition of MRSP during treatment appears to be common.