Effect of different dose schedules of latanoprost on intraocular pressure and pupil size in the glaucomatous Beagle

Objective To evaluate the changes in intraocular pressure and pupil size in glaucomatous dogs after instillation of 0.005% latanoprost (Xalatan, Pharmacia and Upjohn, Kalamazoo, MI, USA) once in the morning, or once in the evening, or twice daily in five‐day multiple‐dose studies. Animals studied Eight Beagles with the moderate stage of inherited primary open‐angle glaucoma. Procedures Applanation tonometry (IOP) and pupil size (PS) measurements were obtained at 8 am, 10 am, 12 noon, 2 pm, and 4 pm in eight glaucoma dogs. Methylcellulose (0.5% as placebo) was instilled in the control eye, and 0.005% latanoprost was instilled in the opposite drug eye. Control and drug eyes were selected using a random table. For these three studies, 0.5% methylcellulose and 0.005% latanoprost were instilled the second through the fifth days with instillations in the morning (8.30 am), or evening (8 pm), or twice daily (8.30 am and 8 pm). Statistical comparisons between drug groups included control, placebo, and treated (0.005% latanoprost) eyes for three multiple‐dose studies. Results In the 8‐am latanoprost study, the mean ± SEM diurnal declines in IOP for the placebo and drug eyes for the first day were 6.5 ± 3.6 mmHg and 8.4 ± 4.0 mmHg, respectively. The mean ± SEM diurnal changes in IOP after 0.005% latanoprost at 8 am once daily for the next four days were 23.3 ± 5.0 mmHg, 25.4 ± 2.1 mmHg, 25.7 ± 1.7 mmHg, and 26.1 ± 1.7 mmHg, respectively, and were significantly different from the control eye. A significant miosis also occurred starting 2 h postdrug instillation, and the resultant mean ± SD pupil size was 1.0 ± 0.1 mm. In the first day of the second latanoprost study, the mean ± SEM diurnal changes in the placebo and drug eye IOPs were 11.6 ± 3.8 mmHg, and 12.0 ± 4.4 mmHg, respectively. For the following four days with latanoprost instilled at 8 pm, the mean ± SEM diurnal changes in IOP in the drug eyes were 24.9 ± 2.1 mmHg, 22.4 ± 1.8 mmHg, 21.6 ± 1.9 mmHg, and 26.6 ± 2.2 mmHg, respectively. Compared to the fellow placebo eyes, the diurnal changes in IOP were significantly different. Significant changes in pupil size were similar to the IOP changes, with miosis throughout the day and return to baseline pupil size the following morning before drug instillation. In the last study, the mean ± SEM diurnal changes in IOP for the placebo and drug eyes for the first day were 6.6 ± 2.1 mmHg and 9.4 ± 2.8 mmHg, respectively. For the four subsequent days with latanoprost instilled twice daily, the mean ± SEM diurnal IOP changes were 19.6 ± 1.5 mmHg, 19.1 ± 1.4 mmHg, 19.9 ± 1.7 mmHg, and 20.3 ± 0.7 mmHg, respectively, and were significantly different from the placebo eyes. The mean changes in PS were 3.1 ± 0.7 mm. Conclusion 0.005% latanoprost instilled once daily (am or pm) as well as twice daily produces significant decreases in IOP and PS in the glaucomatous Beagle. The evening instillation of 0.005% latanoprost produced less daily fluctuations in IOP than when the drug was instilled in the morning. 0.005% latanoprost instilled twice daily produced the greatest decline in IOP with the least daily fluctuations, but longer duration miosis.     

Antibody Testing Against Canine Coronavirus by Immunoperoxidase Plaque Staining

The application of the immunoperoxidase (IP) plaque staining procedure (IP test) to the diagnosis of canine coronavirus (CCV) infection was investigated. The IP test did not react with sera from either 15 specific pathogen-free (SPF) dogs or 7 SPF dogs immunized with a multivalent vaccine, including canine parvovirus type 2, canine distemper virus, canine adenovirus type 2, and canine parainfluenza virus. To compare the IP test with the neutralizing test (NT), sera from 240 healthy dogs and from 3 experimentally CCV-infected dogs were examined. All 60 sera positive for NT antibody were positive for IP antibody, and all 180 sera negative for NT antibody were negative for IP antibody in the healthy dogs. The IP titres showed similar changes with time after CCV inoculation to those of the NT titres in the experimentally infected dogs. These findings indicate that the IP test specifically detected anti-CCV antibodies. When the IP test and NT were compared in dogs with diarrhoeic signs. 2.1% of 48 sera and 20.3% of 74 sera, which were all negative for NT antibody, were positive for IP antibody in the dogs of under one year of age and at least one year of age, respectively. The difference between the IP and NT titres (log₁₀ [reciprocal of IP titre] – log₁₀ [reciprocal of NT titre]) for the diarrhoeic dogs of under one year of age (2.350±0.931) was significantly larger than that for the healthy dogs (0.982±0.447) (p<0.0001), the NT titre being negative or very low, despite a high IP titre in many diarrhoeic dogs. Hence, the IP test is more able to detect anti-CCV antibodies, especially in dogs showing clinical signs. The IP-positivity rate was significantly higher in the diarrhoeic dogs of under one year of age (48.7%) than in the healthy dogs (25.0%) (² = 19.844, p<0.0001), suggesting that CCV may contribute to diarrhoea in many juvenile dogs.     

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.     

A prospective study of postoperative surgical site infections in dogs and cats

OBJECTIVE: To assess postoperative surgical site infection (SSI) rate and to identify associated predictive factors. STUDY DESIGN: Prospective clinical study. ANIMALS: Dogs and cats that had surgery (1010 interventions) during 58 weeks from April 1999 to June 2000. METHODS: Data sheets were completed by clinicians. Patients were controlled for clinical evidence of SSI at suture removal. Two definitions of SSI ("infection" and "infection/inflammation") were developed specifically for this study and used for statistical analysis. Logistic regression models were built in order to identify significant predictive factors for SSI. RESULTS: Wounds with "infection/inflammation" occurred in 5.8% and "infected" wounds in 3% of patients. The outcome "infection" was associated with 3 major risk factors (duration of surgery, increasing number of persons in the operating room, dirty surgical site) and 1 protective factor (antimicrobial prophylaxis). The outcome "infection/inflammation" was associated with 6 significant factors (duration of anesthesia, duration of postoperative intensive care unit stay, wound drainage, increasing patient weight, dirty surgical site, and antimicrobial prophylaxis). CONCLUSIONS: SSI frequency in companion animals is comparable with the frequency observed in human surgical patients. Several significant predictive factors for SSI in small animals surgery were identified. CLINICAL RELEVANCE: Baseline information for SSI surveillance in our hospital and for comparison with other studies was defined. The factors identified may help to predict infections in surgical patients and to take adequate preventive measures for patients at risk.     

Occurrence of Anti-Toxoplasma gondii Antibodies in Dogs in the Urban Area of Monte Negro,Rondônia,Brazil

The prevalence of anti-Toxoplasma gondii antibodies in dogs in an urban area of the municipality of Monte Negro, Rondônia, Brazil, was evaluated using an indirect immunofluorescent antibody test (IFAT). Blood samples were taken from 157 dogs living in 85 of the 94 blocks of the city. A seropositivity of 76.4% (120/157) was found and associations between the prevalence and the variables sex, age, type of raising and food were studied. The prevalence tended to increase with age (p<0.05); dogs over 24 months old had 85.5% (100/117) positivity, compared with 50% (20/40) in dogs less than 24 months old, showing postnatal exposure to the agent. It was also observed that dogs with access to the streets showed greater prevalence (84.9%) than companion animals (58.8%). There was no association between sex or the type of food (home-made or commercial) and anti-T. gondii antibodies.     

Internal quality control of a turbidimetric immunoassay for canine serum C-reactive protein based on pooled patient samples

BACKGROUND: Optimized internal quality control (IQC) procedures are important to ensure that only results without medically important errors are used for medical decision-making and to ensure that unnecessary rejection of valid analytical runs is avoided. Additionally, estimates of the analytical performance can be derived from IQC data. In the absence of available species-specific standards of a compound, the use of alternative control materials based on patient samples is a possibility, although investigations on the suitability of this approach are needed. OBJECTIVES: The objective of the study was to plan and implement a simple IQC procedure with control material based on pooled canine serum samples for a turbidimetric immunoassay (TIA) for the determination of human C-reactive protein (CRP) that recently was validated for the determination of canine serum CRP, and to assess the clinical analytical performance of the assay. METHODS: Proposed guidelines for the planning and implementation of IQC procedures were followed by using 2 control materials. Quality requirements of the assay were defined objectively by means of available data on biological variation, and goals for IQC performance were defined according to recommendations (probability of error detection [P(ed)] >.90 and of false rejection [P(fr)] <.05). Analytical performance was evaluated by means of medical decision charts. RESULTS: The control rule of 1(2.5s) (ie, rejection of the analytical run if at least 1 of 2 control materials deviates from the mean by more than 2.5 SD) fulfilled the criteria of predicted IQC performance (P(ed) =.94-1.00, P(fr) =.03). The IQC method was successfully implemented over a 14-week period. The observed coefficient of variation in the period of monitoring was 3.8% (low) and 2.9% (high), which equals excellent analytical performance. CONCLUSIONS: It was possible to plan and implement a simple IQC procedure for the CRP-TIA with control materials based on canine serum samples that fulfilled the criteria of high error detection and low false rejection of valid analytical runs. The assay showed excellent long-term analytical performance over a 14-week period.     

Determination of free and total cyst(e)ine in plasma of dogs and cats

BACKGROUND: In human blood, the amino acid cysteine forms disulfide bonds with itself and with other sulfhydryl compounds in their free form and with sulfhydryls in protein. Protein-bound cysteine is lost when plasma proteins are removed before amino acid analysis. OBJECTIVE: The purpose of this study was to assess the time course and extent of cyst(e)ine (cysteine + half-cystine) loss in dog and cat plasma. METHODS: An equal volume of 6% sulfosalicylic acid was added to plasma aliquots at 0, 2, 4, 10, 16, 24, 36, 48, 60, and 72 hours after separation of blood cells. Tris-2-carboxyethyl-phosphine hydrochloride (TCEP - HCl), a reducing agent, was used to regenerate total plasma cyst(e)ine after 3 months of sample storage (-20 degrees C). RESULTS: Initial free cyst(e)ine concentrations (mean +/- SEM) were higher in canine plasma (77 +/- 4 micromol/L) than in feline plasma (37 +/- 3 micromol/L). Free plasma cyst(e)ine concentrations in dogs and cats decreased after first-order kinetics, with a half-life of 23 and 69 hours, respectively. Total plasma cysteine after TCEP - HCl treatment was similar for dogs (290 micromol/L) and cats (296 micromol/L), but the percentage of free cysteine was higher (P = .02) in dogs (27%) than in cats (13%). Over half of the cyst(e)ine, homocysteine, cysteinylglycine, and glutathione were bound in vivo to plasma proteins. CONCLUSION: These results emphasize the importance of removing plasma proteins within 1 hour after blood collection for reliable assay of free plasma cyst(e)ine.     

Treatment of canine Alopecia X with trilostane

Sixteen Pomeranians and eight miniature poodles presenting with clinical signs of alopecia X, elevated blood concentrations of 17-hydroxyprogesterone post stimulation with adrenocorticotropic hormone and increased urinary cortisol/creatinine ratios were treated with trilostane, a competitive inhibitor of 3beta-hydroxysteroid dehydrogenase. Trilostane was given once or twice daily at a mean dose of 10.85 mg kg(-1) day(-1). Adrenal function was evaluated with a follow-up of 28 months in the Pomeranians and 33 months in the miniature poodles. Treatment with trilostane led to complete hair re-growth in 85% of the Pomeranians and in all of the miniature poodles within 4 to 8 weeks. No adverse events attributed to treatment with trilostane were recognized. The hair re-growth might have been the result of a down-regulation of adrenal steroids and/or of the noncompetitive inhibition of the oestrogen receptors at the hair follicle level.     

Suspected wood poisoning caused by Simarouba amara (marupá/caixeta) shavings in two dogs with erosive stomatitis and dermatitis

Two male Labrador retrievers developed bleeding erosions/ulcerations involving the oral mucosa, mucocutaneous junctions of the lips, nose, prepuce and anus, ulcerated nodules on the chin, and crusting lesions on the elbows, hocks and scrotum. One of the dogs was anorexic and depressed, had haematological abnormalities consistent with damage to the liver and signs of neurological disease. As these dogs had recently been exposed to bedding containing Simarouba amara shavings and because of the striking similarities of clinical signs to those described for horses, a probable diagnosis of wood poisoning was made. This assumption was supported by the clinical course as healing of skin lesions occurred when the dogs were no longer exposed to the bedding.     

Canine distemper virus infection of canine footpad epidermis

Infection of the footpad epidermis can occur in natural canine distemper virus (CDV) infection of dogs. Footpads from 19 dogs experimentally inoculated with virulent distemper strain A75/17 and from two nonexposed dogs were examined histopathologically and assessed for the presence of viral antigen and nucleoprotein mRNA, as well as number of inflammatory and apoptotic cells. Dogs were divided into four groups based on inoculation status and postmortem examination: inoculated dogs with severe distemper (group 1, n = 7); inoculated dogs with mild distemper (group 2, n = 4); inoculated dogs without distemper (group 3, n = 8); and noninoculated dogs (group 4, n = 2). Footpads from dogs of all groups had a comparably thick epidermis. Eosinophilic viral inclusions and syncytial cells were present in footpad epidermis of one dog of group 1. Footpads of group 1 dogs contained viral antigen and mRNA in the epidermis with strongest staining in a subcorneal location. Additionally, in these dogs footpad dermal structures including eccrine glands and vascular walls were positive for virus particles. No CDV antigen or mRNA was present in the footpad epidermis and dermis of any other dog. Group 1 dogs had more CD3-positive cells and apoptotic cells within the basal layer of the epidermis when compared to the other groups. These findings demonstrate that in experimental infection CDV antigen and mRNA were colocalized in all layers of the infected canine footpad epidermis. The scarcity of overt pathological reactions with absence of keratinocyte degeneration indicates a noncytocidal persisting infection of footpad keratinocytes by CDV.