Search Results

Abstract

Objective—To compare 5 methods of preparation of RNA from feline urine samples for use in a feline calicivirus (FCV), p30 gene-based, real-time reverse-transcriptase polymerase chain reaction (RT-PCR) assay.

Sample Population—Urine and blood samples from 6 specific-pathogen-free cats.

Procedures—Aliquots of each urine sample (unmodified, centrifuged, or mixed with whole or hemolyzed blood) were spiked with FCV and serially diluted in urine. Serial dilutions of FCV in tissue culture medium were used as positive controls. Viral RNA was prepared via dilution and thermal inactivation (DT method), polyethylene glycol precipitation (PEG method), isolation with oligo(dT)₂₅-coated magnetic beads (dTMB method), or extraction by use of 2 silica gel–based columns (RN or QA method). Lower detection limits and mean RT-PCR threshold cycle (C_t) values associated with each RNA preparation method and sample type were compared.

Results—Because DT-prepared samples yielded negative results via RT-PCR assay, this method was not evaluated. Lower detection limits (TCID₅₀/sample) for the assay in urine were 1,950, 104, 11, and 7 for PEG-, dTMB-, RN-, and QA-prepared samples, respectively. For RN and QA preparations, C_t values were similar and significantly lower than those for dTMB and PEG preparations. Overall, urine modifications did not affect FCV RNA detection in dTMB-, QA-, and RN-prepared samples.

Conclusions and Clinical Relevance—Of the methods evaluated, the RN and QA methods of RNA preparation were most appropriate for the FCV RTPCR assay. An RT-PCR assay optimized for detection of FCV in feline urine may aid investigations of FCVinduced urinary tract diseases in cats. (Am J Vet Res 2005;66:915–920)

Abstract

Objective—To determine clinical, histologic, and immunohistochemical findings for dogs with wart-like lesions involving the paw pads.

Design—Retrospective case series.

Animals—24 dogs (18 Greyhounds and 6 dogs of other breeds).

Procedures—Medical records were reviewed for information on signalment, physical examination findings, concurrent disease processes, location of all lesions, and, when available, results of histologic examination of biopsy specimens. Available biopsy specimens (n = 11) were submitted for immunohistochemical staining and a PCR assay to identify viral inclusion bodies.

Results—In Greyhounds, most lesions involved the pads of the third and fourth digits, had a consistent histologic appearance without evidence of inflammation, were negative for papillomavirus, and had an unsatisfactory response to treatment. In other breeds, lesions often involved the pads of non–weight-bearing digits, had histologic evidence of inflammation, were positive for papillomavirus, and responded to surgical treatment.

Conclusions and Clinical Relevance—Results suggested that wart-like lesions involving the paw pads of Greyhounds were a distinct clinical entity with features resembling porokeratosis plantaris discreta in humans. In Greyhounds, these lesions were not associated with an underlying viral etiology and, therefore, should not be considered plantar warts. Alternative treatments should be investigated because current treatments were generally unsuccessful in Greyhounds. Wart-like lesions of the paw pads in other breeds were often associated with papillomavirus, and surgical excision appeared curative.

Abstract

Objective—To evaluate 2 rapid, patient-side assays for detection of Cryptosporidium parvum in feces from neonatal calves with diarrhea.

Design—Diagnostic test evaluation.

Sample Population—Fecal samples from 96 neonatal (1 to 30 days old) calves with diarrhea.

Procedure—Results of the rapid assays were compared with results of microscopic examination of fecal smears that had been stained with diamant fuchsin stain.

Results—One of the rapid assays correctly identified 56 of 62 (90%) fecal samples positive for C parvum oocysts and 33 of 34 (97%) fecal samples negative for oocysts. The other assay correctly identified 53 of 62 (85%) fecal samples positive for oocysts and 33 of 34 (97%) fecal samples negative for oocysts.

Conclusions and Clinical Relevance—Results suggest that these 2 rapid assays are accurate when used to detect C parvum in fecal samples from neonatal calves with diarrhea. ( J Am Vet Med Assoc 2004;225:1090–1092)

Abstract

Objective—To compare degree of viremia and disease manifestations in calves with type-I and -II bovine viral diarrhea virus (BVDV) infection.

Animals—16 calves.

Procedure—Colostrum-deprived calves obtained immediately after birth were assigned to 1 control and 3 treatment groups (4 calves/group). Calves in treatment groups were inoculated (day 0) by intranasal instillation of 10⁷ median tissue culture infective dose BVDV 890 (type II), BVDV 7937 (type II), or BVDV TGAN (type I). Blood cell counts and virus isolation from serum and leukocytes were performed daily, whereas degree of viremia was determined immediately before and 4, 6, 8, and 12 days after inoculation. Calves were euthanatized on day 12, and pathologic, virologic, and immunohistochemical examinations were performed.

Results—Type-II BVDV 890 induced the highest degree of viremia, and type-I BVDV TGAN induced the lowest. Virus was isolated more frequently and for a longer duration in calves inoculated with BVDV 890. A parallel relationship between degree of viremia and rectal temperature and an inverse relationship between degree of viremia and blood cell counts was observed. Pathologic and immunohistochemical examinations revealed more pronounced lesions and more extensive distribution of viral antigen in calves inoculated with type-II BVDV.

Conclusions and Clinical Relevance—Degree of viremia induced during BVDV infection is associated with severity of clinical disease. Isolates of BVDV that induce a high degree of viremia may be more capable of inducing clinical signs of disease. Strategies (eg, vaccination) that reduce viremia may control clinical signs of acute infection with BVDV. (Am J Vet Res 2001;62:1095–1103)

Abstract

Case Description—A 5-month-old captive female striped skunk (Mephitis mephitis) was evaluated because of lethargy, signs of depression, azotemia, and erythema of the skin around the eyes.

Clinical Findings—Antemortem diagnostic tests revealed renal disease but failed to identify an etiologic agent. A diagnosis of severe nonsuppurative interstitial nephritis was made on the basis of results of histologic examination of renal biopsy specimens.

Treatment and Outcome—The skunk was administered isotonic fluids SC daily and later every other day because of the handling-related stress. Because of the skunk's deteriorating condition, it was euthanized after 24 days of supportive care. Aleutian disease was diagnosed on the basis of positive results of a PCR assay that targeted the DNA from Aleutian disease virus (ADV); positive results for ADV were also obtained by use of plasma counterimmunoelectrophoresis and an ELISA. Genetic sequencing of the 365-base pair PCR product revealed 90% sequence identity with mink ADV.

Clinical Relevance—In the skunk of this report, infection with a skunk-specific parvovirus resulted in clinical signs and pathologic changes similar to those associated with ADV infection in mink. For skunks with signs of renal failure, differential diagnoses should include parvovirus infection. In confirmed cases of infection with this ADV-like virus, appropriate quarantine and biosecurity measures should be in place to prevent spread to other susceptible animals within a zoological collection.