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Abstract

Objective—To determine susceptibility of cattle to infection with Ehrlichia equi and the agent of human granulocytic ehrlichiosis (HGE).

Design—Experimental disease and prevalence survey.

Animals—6 cattle, 2 horses, and 2,725 serum samples from healthy cattle.

Procedure—2 cattle and 1 horse were inoculated with E equi, 2 cattle and 1 horse were inoculated with the HGE agent, and 2 cattle served as sham-inoculated controls; inoculated animals were evaluated via clinical, hematologic, serologic, and real-time polymerase chain reaction tests. Prevalence of antibodies against E equi in 2,725 healthy cattle was determined by use of an indirect immunofluorescent technique.

Results—No abnormal clinical or hematologic findings or inclusion bodies within granulocytes were observed in the cattle after inoculation, and results of all polymerase chain reaction tests were negative. Seroconversion in inoculated cattle developed 10 to 12 days after inoculation (reciprocal titers, 160). Both horses developed clinical signs of ehrlichiosis. Five of 2,725 (0.18%) cattle were seropositive for E equi, with titers ranging from 20 to 80. All seropositive cattle originated from the same tick-rich region in the Sierra Nevada foothills.

Conclusions and Clinical Relevance—Results suggest that cattle are not susceptible to infection with E equi or the agent of HGE and that prevalence of exposure to E equi in healthy cattle is low. Therefore, E equi and the agent of HGE are likely of negligible importance for cattle in North America. (J Am Vet Med Assoc 2001;218:1160–1162)

Full access
in Journal of the American Veterinary Medical Association

Objective

To determine the benefits of reducing the interval between surgical cytoreduction and intratumoral administration of cisplatin.

Design

Randomized clinical study.

Animals

70 horses with 89 incompletely resected T2- and T3-stage sarcoids (n = 64) and squamous cell carcinomas (25).

Procedure

Horses were given 4 intratumoral treatments of cisplatin at 2-week intervals. The first treatment was given at the time of, or immediately after, surgical resection for horses treated in accordance with the perioperative protocol (group 1). Horses in group 2 were treated with cisplatin after the skin healed following surgical resection in accordance with the postoperative protocol.

Results

A difference was not found in duration of overall local tumor control between the 2 groups. Patterns of treatment failures and interval to failure differed between the 2 groups. Length of the surgical scar was the only factor that affected prognosis; an increase in length was associated with a poorer prognosis. A detrimental effect of postoperative treatment was only found in tumors with a high tumor proliferative fraction. Local reactions were similar for the 2 treatment groups, and chronic reactions were not observed.

Conclusions and Clinical Relevance

Intratumoral administration of cisplatin is beneficial for treatment of cutaneous tumors in horses. Tumor repopulation during the interval between surgery and intratumoral administration of cisplatin decreases treatment efficacy. These results provide evidence of rapid tumor repopulation following surgical resection without a lag period for tumors with a high proliferation index. When tumor proliferation index is not known, it may be prudent to use the perioperative protocol. (J Am Vet Med Assoc 1999;215:1655–1660)

Free access
in Journal of the American Veterinary Medical Association

Objective

To determine whether dogs living in tick-infested areas of the northeastern United States had been exposed to Ehrlichia equi, an etiologic agent of granulocytic ehrlichiosis.

Design

Analyses of dog sera.

Animals

106 ill dogs and 12 clinically normal dogs.

Procedure

Antibodies to E equi were detected by indirect fluorescent antibody staining methods and western blot analyses.

Results

10 of 106 (9.4%) sera tested from ill, privately owned dogs living in tick-infested areas of Connecticut and New York state had antibodies to E equi, a member of the E phagocytophila genogroup. Titration end points ranged from 1:80 to 1:1,280. Immunoblots revealed antibodies to proteins of E equi having molecular masses of predominantly 29, 40, 44, 105, 120, and 160 kd. There was good agreement between results of serologic testing methods, but use of the human isolate (NCH-1 strain) in western blot analyses detected 2 additional seropositive dogs found to be negative by indirect fluorescent antibody staining methods with the MRK strain.

Clinical Implications

Dogs living in areas where Ixodes scapularis is abundant may be exposed to multiple pathogens, such as E equi or Borrelia burgdorferi. Although mild or subclinical infections with E equi may develop, dogs with marked leukopenia, thrombocytopenia, or anemia should be viewed as possibly having ehrlichiosis. Laboratory diagnosis should include examinations for morulae in granulocytes or monocytes in addition to serologic analyses. (J Am Vet Med Assoc 1997;211:1134–1137)

Free access
in Journal of the American Veterinary Medical Association

Abstract

Objective—To determine molecular characteristics, antimicrobial susceptibility, and toxigenicity of Clostridium difficile isolates from horses in an intensive care unit and evaluate associations among severity of clinical disease with specific strains of C difficile.

Design—Prospective study.

Animals—130 horses.

Procedures—Feces were collected from horses admitted for acute gastrointestinal tract disease with loose feces and submitted for microbial culture and immunoassay for toxin production. Polymerase chain reaction assays were performed on isolates for toxins A and B genes and strain identification.

Results—Isolates were grouped into 3 strains (A, B, and C) on the basis of molecular banding patterns. Toxins A and B gene sequences were detected in 93%, 95%, and 73% of isolates of strains A, B, and C, respectively. Results of fecal immunoassays for toxin A were positive in 40%, 63%, and 16% of horses with strains A, B, and C, respectively. Isolates in strain B were resistant to metronidazole. Horses infected with strain B were 10 times as likely to have been treated with metronidazole prior to the onset of diarrhea as horses infected with other strains. Duration from onset of diarrhea to discharge (among survivors) was longer, systemic inflammatory response syndromes were more pronounced, and mortality rate was higher in horses infected with strain B than those infected with strains A and C combined.

Conclusions and Clinical Relevance—Horses may be infected with a number of heterogeneous isolates of C difficile. Results indicated that toxigenicity and antimicrobial susceptibility of isolates vary and that metronidazole-resistant strains may be associated with severe disease.

Full access
in Journal of the American Veterinary Medical Association

Abstract

Objective—To determine molecular characteristics of Clostridium difficile isolates from foals with diarrhea and identify clinical abnormalities in affected foals.

Design—Retrospective study.

Animals—28 foals with C difficile-associated diarrhea.

Procedure—Toxigenicity, molecular fingerprinting, and antibiotic susceptibility patterns were determined. Information on signalment, clinical findings, results of clinicopathologic testing, whether antimicrobials had been administered prior to development of diarrhea, and outcome was obtained from the medical records.

Results—Twenty-three (82%) foals survived. Toxin A and B gene sequences were detected in isolates from 24 of 27 foals, whereas the toxin B gene alone was detected in the isolate from 1 foal. Results of an ELISA for toxin A were positive for fecal samples from only 8 of 20 (40%) foals. Ten of 23 (43%) isolates were resistant to metronidazole. Molecular fingerprinting revealed marked heterogeneity among isolates, except for the metronidazole-resistant isolates. Sixteen foals had tachypnea. Hematologic abnormalities were indicative of inflammation. Common serum biochemical abnormalities included metabolic acidosis, hyponatremia, hypocalcemia, azotemia, hypoproteinemia, hyperglycemia, and high enzyme activities. Passive transfer of maternal antibodies was adequate in all 12 foals evaluated.

Conclusions and Clinical Relevance—Results suggest that a large percentage of C difficile isolates from foals with diarrhea will have the toxin A and B gene sequences. Because of the possibility that isolates will be resistant to metronidazole, susceptibility testing is warranted. Clostridium difficile isolates from foals may have a substantial amount of molecular heterogeneity. Clinical and hematologic findings in affected foals are similar to those for foals with diarrhea caused by other pathogens. (J Am Vet Med Assoc 2002;220:67–73)

Full access
in Journal of the American Veterinary Medical Association

Abstract

Case Description—A 15-year-old Saddlebred gelding used for competitive pleasure driving had a 1-year history of head shaking while pulling a cart.

Clinical Findings—The horse had cystic corpora nigra in both eyes and concomitant classic and operant conditioned responses to wearing a bridle with bilateral eye covers (blinkers).

Treatment and Outcome—Deflation and coagulation of the cysts with an infrared diode laser and behavior modification consisting of desensitization and counterconditioning were used to successfully restore performance.

Clinical Relevance—Behavioral changes in horses can result from a combination of physical and psychologic causes. A combination of appropriate medical treatment of physical abnormalities and a behavioral modification plan is necessary to successfully treat behavioral problems in these patients.

Full access
in Journal of the American Veterinary Medical Association

Abstract

OBJECTIVE

To describe an animal health database used to facilitate effective disaster response and retrospective analysis of data concerning animals other than cats and dogs affected by the 2018 California Camp Fire.

ANIMALS

Veterinary medical entries (n = 206) for evacuated or rescued animals (151) of various species, including avian, bovine, camelid, caprine, equine, ovine, and porcine species, temporarily housed at the Butte County fairgrounds in Gridley, Calif.

PROCEDURES

Case data were collected via a standardized form by volunteers with the University of California-Davis Veterinary Emergency Response Team during triage and treatment of animals brought to the shelter. Collected data were entered into a database. Multiple correspondence analysis was used to evaluate associations among patient species, types and severity of injuries, and behavior.

RESULTS

Burns, respiratory disease, gastrointestinal illnesses, and lacerations were the most prevalent illnesses and injuries among the overall shelter population for the first 12 days of the Camp Fire. Ovine patients were more likely to have had respiratory illness than were other species. The most prevalent medical conditions among equine patients were lacerations and gastrointestinal illnesses. Severe burns were most common among porcine, camelid, and avian patients. The temporal distribution of cases suggested the immediate evacuation of equine species and the delayed movement of bovine and avian species to the shelter.

CONCLUSIONS AND CLINICAL RELEVANCE

Collection of animal health information through the database allowed assessment of prevalent medical conditions among various farm animals following a wildfire. Adaptation of this database to other disasters could improve emergency response protocols by providing guidance for management of resources and allow retrospective assessment for response improvement.

Full access
in Journal of the American Veterinary Medical Association

Abstract

Objective—To evaluate deafness in American Paint Horses by phenotype, clinical findings, brainstem auditory-evoked responses (BAERs), and endothelin B receptor (EDNBR) genotype.

Design—Case series and case-control studies.

Animals—14 deaf American Paint Horses, 20 suspected-deaf American Paint Horses, and 13 nondeaf American Paint Horses and Pintos.

Procedures—Horses were categorized on the basis of coat color pattern and eye color. Testing for the EDNBR gene mutation (associated with overo lethal white foal syndrome) and BAERs was performed. Additional clinical findings were obtained from medical records.

Results—All 14 deaf horses had loss of all BAER waveforms consistent with complete deafness. Most horses had the splashed white or splashed white–frame blend coat pattern. Other patterns included frame overo and tovero. All of the deaf horses had extensive head and limb white markings, although the amount of white on the neck and trunk varied widely. All horses had at least 1 partially heterochromic iris, and most had 2 blue eyes. Ninety-one percent (31/34) of deaf and suspected-deaf horses had the EDNBR gene mutation. Deaf and suspected-deaf horses were used successfully for various performance events. All nondeaf horses had unremarkable BAER results.

Conclusions and Clinical Relevance—Veterinarians should be aware of deafness among American Paint Horses, particularly those with a splashed white or frame overo coat color pattern, blend of these patterns, or tovero pattern. Horses with extensive head and limb markings and those with blue eyes appeared to be at particular risk.

Full access
in Journal of the American Veterinary Medical Association

Abstract

Objective—To determine clinical, laboratory analysis, and necropsy findings for equids with oleander toxicosis and to identify factors associated with outcome.

Design—Retrospective case series.

Animals—30 equids.

Procedures—Medical records of equids with detectable concentrations of oleandrin in serum, plasma, urine, or gastrointestinal fluid samples and equids that had not received cardiac glycoside drugs but had detectable concentrations of digoxin in serum were identified via a medical records database search. Descriptive statistics were calculated for medical history, physical examination, laboratory analysis, and necropsy variables. Logistic regression analysis was used to identify physical examination and laboratory analysis factors significantly associated with outcome.

Results—3 of 30 (10.0%) equids died before or immediately after arrival at the hospital. Of the other 27 equids, 23 (85.2%) had gastrointestinal tract abnormalities, azotemia was detected for 19 (70.4%), and a cardiac arrhythmia was ausculted for 18 (66.7%). Mortality rate for all equids was 50.0%; mortality rate for hospitalized equids was 44.4%. The most common cause of death was cardiac dysfunction. Odds of survival to discharge from the hospital were lower for equids with cardiac arrhythmias versus those without arrhythmias and decreased with increasing Hct and serum glucose concentrations. Odds of survival increased with increasing serum chloride concentration and duration of hospitalization.

Conclusions and Clinical Relevance—Equids with oleander toxicosis frequently had simultaneous gastrointestinal tract, cardiac, and renal problems. Oleander intoxication should be a differential diagnosis for equids with colic in geographic areas where oleander is found, especially when azotemia or cardiac arrhythmias are detected concurrently.

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in Journal of the American Veterinary Medical Association

Abstract

Objectives

To identify Sarcocystis neurona-specific DNA sequences in the nuclear small subunit ribosomal RNA (nss-rRNA) gene that could be used to distinguish S neurona from other closely related protozoal parasites, and to evaluate a polymerase chain reaction (PCR) test, using broad based primers and a unique species-specific probe on CSF for detection of S neurona in equids.

Procedures

Sequencing of the nuclear small subunit ribosomal RNA gene from a new S neurona isolate (UCD 1) was performed. The sequence was compared with that of other closely related Sarcocystidae parasites. From this sequence, conserved DNA sequence primers were selected and an oligonucleotide probe was designed to hybridize with a unique region of the S neurona gene. For clinical evaluation, horses were considered test positive for S neurona infection on the basis of immunohistochemical detection of the parasites in the CNS.

Results

Sensitivity of this PCR and probe-based detection system was approximately 1 to 5 merozoites. Cerebrospinal fluid from 2 of 5 horses with histologic lesions consistent with equine protozoal myeloencephalitis were PCR- and probe-positive in a blind test of this procedure, and all uninfected horses were test negative.

Conclusion and Clinical Relevance

This PCR- based system is a useful method of confirming S neurona in CSF and has the advantage of facilitating detection of other apicomplexan protozoans that may be infective for horses. The usefulness of this test is limited by the presence of parasites free in the CSF of clinically affected horses. (Am J Vet Res 1996;57:975–981)

Free access
in American Journal of Veterinary Research