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Abstract

OBJECTIVE To determine the effects of topical ocular application of 1% trifluridine ophthalmic solution in dogs with experimentally induced recurrent ocular canine herpesvirus-1 (CHV-1) infection.

ANIMALS 10 specific pathogen–free Beagles.

PROCEDURES 12 months prior to the beginning of the randomized, masked, placebo-controlled 30-day trial, latent ocular CHV-1 infection was experimentally induced in each dog by topical ocular inoculation of both eyes with a field strain of CHV-1. Recurrent ocular CHV-1 infection was induced by oral administration of prednisolone for 7 days (starting day 1). Starting on the fourth day of prednisolone administration, each dog received 1% trifluridine solution or artificial tears (placebo) topically in both eyes 6 times daily for 2 days and then 4 times daily for 12 days. Ophthalmic examinations were performed every 2 days, and ocular disease scores were calculated. Ocular samples for CHV-1 PCR assays and blood samples for clinicopathologic analyses and assessment of CHV-1 serum neutralization antibody titers were collected at predetermined intervals.

RESULTS Conjunctivitis was clinically detected in all dogs by day 4. Compared with dogs receiving placebo, mean and total clinical ocular disease scores were significantly lower and median CHV-1 shedding duration was significantly shorter for the trifluridine-treated dogs. Both groups had increasing CHV-1 serum neutralization antibody titers over time, but no significant differences between groups were detected. Clinicopathologic findings were unremarkable throughout the study.

CONCLUSIONS AND CLINICAL RELEVANCE Topical ocular application of 1% trifluridine ophthalmic solution was well tolerated and effective at reducing disease scores and viral shedding duration in dogs with experimentally induced ocular CHV-1 infection, but may require frequent administration.

Full access
in American Journal of Veterinary Research

Objective

To determine whether horses in New York should be vaccinated against equine monocytic ehrlichiosis (EME).

Design

Decision-tree analyses of data from a cross-sectional study and a case-control study.

Sample Population

Horses in New York.

Procedure

Annual expected monetary loss per horse attributable to EME was calculated for vaccinated and nonvaccinated horses in New York. Because risk of being seropositive was dependent on county in which the horse was located, farm elevation, and use of each horse, decision-tree analyses were stratified by these factors.

Results

Annual expected monetary loss per horse attributable to EME for horses vaccinated by veterinarians ranged from $21 to $21.83/horse/y; for horses vaccinated by owners ranged from $10 to $10.83/horse/y; and for nonvaccinated horses ranged from $0 to $4.03/horse/y. Assuming 78% of vaccinated horses were protected and mean losses associated with EME included costs for horses that died, annual incidence density at which expected monetary loss for vaccinated horses was equal to that for nonvaccinated horses was 12 cases/1,000 horses/y and 25 cases/1,000 horses/y for horses vaccinated by owners or by veterinarians, respectively.

Clinical Implications

Annual vaccination minimizes monetary losses attributable to EME only when the annual incidence density exceeds 12 to 25 cases/1,000 horses/y. In New York, expected monetary losses are minimized when horses are not vaccinated because of the low annual incidence density in most regions. (J Am Vet Med Assoc 1996;208: 1290–1294)

Free access
in Journal of the American Veterinary Medical Association

Objective

To determine whether preferentially vaccinated horses were at risk for exposure to Ehrlichia risticii, whether horses with equine monocytic ehrlichiosis (EME) were likely to have been nonvaccinated, and whether clinical severity and financial costs associated with care and treatment of EME were less for vaccinated horses with EME than for nonvaccinated horses with EME.

Design

Cross-sectional and case-control studies.

Procedure

Information on usage of E risticii bacterins to control EME was collected for 2,587 horses located on 511 farms throughout New York. Each horse was tested for serum antibodies directed against E risticii. Data on efficacy of vaccination to reduce the prevalence and clinical severity of EME and monetary losses associated with EME were collected from 68 horses with EME and 132 clinically normal horses.

Results

A correlation was not detected between the county seropositive proportion and the proportion of horses vaccinated against EME. Among horses diagnosed for EME, median date of diagnosis was not delayed for vaccinated horses, compared with that for nonvaccinated horses. Mean cost per case was not significantly different for nonvaccinated horses, compared with that for vaccinated horses ($1,082 and $1,001, respectively). Vaccination was not associated with a reduction in prevalence or in severity of EME-related clinical signs.

Clinical Implications

Administering killed E risticii bacterin once a year to control EME in New York appears to have limited success. Among horses in which EME was diagnosed, severity of illness and financial costs attributable to EME were indistinguishable for vaccinated and nonvaccinated horses. (J Am Vet Med Assoc 1996;208: 1285–1289)

Free access
in Journal of the American Veterinary Medical Association

Objective

To investigate the effect of gender, body condition, and age as risk factors for the development of hyperlipemia in a population of donkeys.

Design

Retrospective survival analysis.

Animals

130 donkeys with hyperlipemia from a source population of 4,126 donkeys.

Procedure

A Kaplan-Meier product limit survival method was used to evaluate the effect of gender and body condition on the probability of diagnosis of clinical hyperlipemia. Cox's proportional hazard model was used to evaluate the risk of being diagnosed with hyperlipemia controlling for gender, body condition, and age at entry into the population.

Results

Female donkeys and donkeys of obese body condition were more at risk for developing hyperlipemia than males or those of moderate or poor body condition, respectively. None of the females in the study was pregnant. Donkeys were more likely to become hyperlipemic soon after entering the source population. Investigation of the effect of age at entry into the population indicated that older animals were at higher risk than younger animals and, controlling for age, the hazard ratios associated with being female and being overweight were 2 and 1.5, respectively.

Clinical Implications

Although pregnancy and lactation are widely acknowledged as risk factors for hyperlipemia, in this population, females and obese donkeys were at highest risk, regardless of pregnancy status. Risk was greatest around the time donkeys first entered the source population. Control of body condition, reduction of stress, and close monitoring of high-risk donkeys might reduce incidences of, or allow more timely intervention for, this potentially fatal condition. (J Am Vet Med Assoc 1996;209:1449–1452)

Free access
in Journal of the American Veterinary Medical Association

SUMMARY

An indexing system for hygiene variables associated with egg production was developed by use of data collected from chicken flocks in southern California. The data were analyzed by factor and regression analysis.

On the basis of our findings, hygiene index in relation to egg production consists of ventilation system, cooling system, manure removal, and truck movement. Flocks kept under natural ventilation produced, on the average, 2% more hen-day eggs than flocks kept under artificial ventilation. Flocks placed in houses with roof sprinklers produced 3.3% more hen-day eggs, compared with flocks placed in houses with inside foggers and pad. Flocks kept under the system of frequent removal of manure produced 2% more hen-day eggs than flocks kept under the system for which the manure was removed less frequently. Flocks kept in farms that restricted trucks collecting dead birds from entering the premises produced 3.4% more hen-day eggs than those that allowed such trucks to enter the farm.

Free access
in American Journal of Veterinary Research

Summary

Three commercial tests that measure progesterone content in milk were evaluated for accuracy of estrus detection. The tests were evaluated on 96 milk samples collected from Holstein cows at a commercial dairy farm in central Florida. The test results were compared with the results of radioimmunoassay on the same sample. Comparisons were made by calculating the sensitivities, specificities, and predictive values. The significance of the statistical association between the tests and the radioimmunoassay was evaluated by use of the McNemar χ2 test. Decision-tree analysis was used to determine the most useful testing strategy, considering both cost and accuracy. The cowside progesterone assay on estrus-mount detector-positive cows was more profitable than use of estrus-mount patches alone. The return on investment was higher with the cowside test, making it preferred as a field test for detecting estrus.

Free access
in Journal of the American Veterinary Medical Association

Abstract

Objective—To determine the effects of matrix metalloproteinase (MMP)-13, compared with interleukin (IL)-1α, on cartilage matrix molecule gene expression in a coculture system of equine cartilage explants and synoviocytes.

Sample Population—Articular cartilage and synovium specimens harvested from femoropatellar joints of 4 horses, aged 3 to 5 years.

Procedures—Synoviocytes were isolated and cocultured with cartilage explants. Cultures were treated with human recombinant MMP-13 (1, 25, or 100 ng/mL) or IL-1α (0.01, 0.1, 1.0, or 10 ng/mL) for 96 hours, with medium exchange at 48 hours. Cartilage extracts and media were analyzed for glycosaminoglycan (GAG) content, and results were adjusted to cartilage DNA content. Quantitative PCR was performed on mRNA from cartilage (MMP-3, MMP-13, aggrecan, and collagen type IIB [COL2A1]) and synoviocytes (MMP-3 and MMP-13), and results were adjusted to 18S ribosomal subunit mRNA expression. Treatments were performed in triplicate, and the experiment was repeated 4 times.

Results—Cultures treated with MMP-13 or IL-1α had increased media GAG concentration at 48 and 96 hours. Aggrecan and COL2A1 mRNA expression were increased by application of MMP-13 or IL-1α. Gene expression of the catabolic mediator, MMP-3, in cartilage and synoviocytes was increased in cultures treated with MMP-13 or IL-1α. Expression of MMP-13 mRNA in cartilage was increased by IL-1α, but decreased in synoviocytes by MMP-13 treatment.

Conclusions and Clinical Relevance—Results support the use of recombinant MMP-13 in a coculture system of synoviocytes and cartilage explants for the study of osteoarthritis.

Full access
in American Journal of Veterinary Research

Abstract

OBJECTIVE

To determine setting and temperature properties of diluted polymethyl methacrylate (PMMA) bone cement in vitro to assess utility for vocal fold augmentation in horses.

SAMPLES

4 dilutions of PMMA equivalent to volumes of 15 mL, 20 mL, 25 mL, and 30 mL PMMA powder (PMMAp) in 10 mL solvent.

METHODS

For each volume PMMAp, setting times (tset), peak temperatures (Tmax), and times to peak temperature (tmax) were determined using a temperature data logger in a 4-mL volume of PMMA. Injectability was assessed in vitro by documenting the force required to inject 0.2 mL PMMA through an 18-gauge 3.5-inch spinal needle attached to a 6-mL syringe at 1-minute intervals. Working time (twork) was calculated from a linear regression of injectability.

RESULTS

Peak temperatures increased with increasing volume of PMMAp: 56 °C, 86 °C, 99 °C, and 101 °C. Times for tset, twork, and tmax were inversely proportional to PMMA concentrations, resulting in tset of 23, 21, 17, and 14 minutes; twork of 22.75, 12.25, 7, and 4 minutes; and tmax of 28, 24, 19, and 16 minutes, respectively, for 15, 20, 25, and 30 mL PMMAp. Pairwise comparisons for all analyses were significant apart from Tmax for 25 and 30 mL PMMAp (P = .96) and twork for 20 and 25 mL PMMAp (P = .06).

CLINICAL RELEVANCE

Decreasing the concentration of PMMA bone cement resulted in longer working times and setting times; however, peak temperatures did not differ between the 2 strongest concentrations. Further research is warranted to quantify diluted PMMA properties for in vivo use for vocal fold augmentation in horses.

Open access
in American Journal of Veterinary Research

Abstract

Objective—To determine the total number of Cryptosporidium parvum oocysts and Giardia spp cysts shed by dairy calves during the period when they are most at risk after natural infection.

Animals—478 calves naturally infected with C parvum and 1,016 calves naturally infected with Giardia spp.

Procedure—Oocysts or cysts were enumerated from fecal specimens. Distribution of number of oocysts or cysts versus age was used to determine the best fitting mathematic function. Number of oocysts or cysts per gram of feces for a given duration of shedding was computed by determining the area under the curve. Total number of oocysts or cysts was calculated by taking the product of the resultant and the expected mass of feces.

Results—Intensity of C parvum oocyst shedding was best described by a second-order polynomial function. Shedding increased from 4 days of age, peaked at day 12, and then decreased. An infected 6-day-old calf would produce 3.89 X 1010 oocysts until 12 days old. Pattern of shedding of Giardia spp cysts was best described by exponential functions. Intensity of shedding increased from 4 days of age, peaked at day 14, and then decreased. An infected calf would produce 3.8 X 107 cysts from day 50 until day 56.

Conclusion and Clinical Relevance—The large number of oocysts and cysts shed indicates that shedding by dairy cattle poses a risk for susceptible calves and people. Estimates reported here may be useful to aid in designing cost-effective strategies to manage this risk. (Am J Vet Res 2001;62:1612–1615)

Full access
in American Journal of Veterinary Research

Abstract

Objective—To identify risk factors associated with Cryptosporidium parvum infection in dairy calves.

Animals—108 case animals and 283 control animals.

Procedures—Case animals were calves infected with C parvum, and controls were infected with Cryptosporidium bovis (n = 67) or calves not infected with Cryptosporidium spp. Fecal samples were tested via the flotation concentration method for Cryptosporidium spp. Samples were genotyped by sequencing of the 18s rRNA gene. Associations between host, management, geographic, and meteorologic factors and Cryptosporidium genotype were assessed.

Results—Younger calves and calves housed in a cow barn were more likely to be infected with both genotypes. Herd size and hay bedding were associated with an increased risk of infection with C parvum, and Jersey breed was a risk factor for C bovis infection. Compared with a flat surface, a steeper slope was significantly associated with a decreased likelihood of infection with both genotypes, and precipitation influenced the risk of C parvum infection only.

Conclusions and Clinical Relevance—Risk factors for calf infection with C parvum differed from those for infection with C bovis. Results may be useful to help design measures that reduce animal exposure and decrease public health risk and economic losses associated with C parvum infection in cattle.

Full access
in American Journal of Veterinary Research