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  • Author or Editor: Jamie N. Henningson x
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Abstract

OBJECTIVE To assess differences in skin shrinkage between grossly visible tumor and grossly normal marginal skin of dogs for cutaneous mast cell tumors (MCTs) excised with curative intent and to determine an equation to estimate postexcisional gross tumor margins from preexcisional measurements and vice versa.

SAMPLE 19 cytologically confirmed and surgically excised cutaneous MCTs obtained from dogs.

PROCEDURES Tumors were measured in craniocaudal and dorsoventral directions before excision, immediately after excision, and after fixation in formalin. Both grossly visible tumor and surrounding grossly normal skin that comprised the surgical margin were measured at each time point. Percentage of shrinkage was compared among time points and between the tumor and surrounding grossly normal skin. Patient and histopathologic variables were correlated to skin shrinkage.

RESULTS Overall shrinkage was 17.70%. The amount of shrinkage within the grossly visible tumor (4.45%) was less than that within the surrounding grossly normal skin (24.42%). Most of the shrinkage occurred immediately after excision. There was no effect of age, sex, completeness of excision, or degree of edema. Accuracy of an equation to estimate postexcisional margins from preexcisional measurements was only 18.4%.

CONCLUSIONS AND CLINICAL RELEVANCE Grossly evident MCTs of dogs shrunk less than did the grossly normal surrounding skin. Although an equation to estimate postexcisional margins from preexcisional measurements could be derived, it likely would need to contain additional variables not included in the study reported here. Until such an equation exists, care must be used when extrapolating surgical margins from histologic margins and vice versa.

Full access
in American Journal of Veterinary Research

Abstract

Ensuring appropriate animal welfare is a high priority for the beef industry, and poorly defined abnormalities in the mobility of cattle at abattoirs have gained considerable attention recently. During the summer of 2013, abattoirs throughout the United States reported concerns about nonambulatory or slow and difficult to move cattle and cattle that sloughed hoof walls. This report describes various cattle that developed these mobility problems soon after arrival at an abattoir. Affected cattle had various clinical signs including tachypnea with an abdominal component to breathing, lameness, and reluctance to move. Some cattle sloughed 1 or more hoof walls while in lairage pens and were euthanized. Other cattle recovered after being rested overnight. Affected cattle had serum lactate concentration and creatine kinase activity increased from reference ranges. Histologic findings included diffuse necrosis of the epidermal laminae with degenerate collagen and perivascular infiltration of neutrophils in the underlying deep dermis, and were similar for digits that had and had not sloughed the hoof wall. With the exception of the sloughed hoof walls, the clinical signs and serum biochemical abnormalities observed in affected cattle were similar to those observed in pigs with fatigued pig syndrome, and we propose that fatigued cattle syndrome be used to describe such cattle. Although anecdotal evidence generated concern that cattle fed the β-adrenergic receptor agonist zilpaterol hydrochloride were at greater risk of developing mobility problems, compared with cattle not fed zilpaterol, this condition is likely multifactorial. Strategies to prevent this condition are needed to protect the welfare of cattle.

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in Journal of the American Veterinary Medical Association

Abstract

Objective—To characterize the influence of the viral protein Npro on virulence of bovine viral diarrhea virus (BVDV) and on type I interferon responses in calves.

Animals—10 calves, 4 to 6 months of age.

Procedures—BVDV virulence and type I interferon responses of calves (n = 5) infected with a noncytopathic BVDV with a deleted Npro were compared with those of calves (5) infected with a noncytopathic BVDV with a functional Npro. Rectal temperatures, clinical signs, platelet counts, and total and differential WBC counts were evaluted daily. Histologic examinations and immunohistochemical analyses of tissues were conducted to assess lesions and distribution of viral antigens, respectively. Serum type I interferon concentrations were determined.

Results—Calves infected with Npro-deleted BVDV developed leukopenia and lymphopenia, without developing increased rectal temperatures or lymphoid depletion of target lymphoid organs. There was minimal antigen deposition in lymphoid organs. Calves infected with Npro BVDV developed increased rectal temperatures, leukopenia, lymphopenia, and lymphoid depletion with marked BVDV antigen deposition in lymphatic tissues. Interferon type I responses were detected in both groups of calves.

Conclusions and Clinical Relevance—Deletion of Npro resulted in attenuation of BVDV as evidenced by reduced virulence in calves, compared with BVDV with a functional Npro. Deletion of Npro did not affect induction of type I interferon. The Npro-deleted BVDV mutant may represent a safe noncytopathic virus candidate for vaccine development.

Full access
in American Journal of Veterinary Research

Abstract

Objective—To determine the prevalence of bovine viral diarrhea virus (BVDV)–infected alpaca herds in the United States and investigate factors associated with seropositive herd status and, subsequently, determine the proportion of animals within seropositive alpaca herds that are persistently infected (PI) carriers for BVDV, obtain information regarding previous herd exposure to BVDV, determine titers of anti-BVDV antibodies of dams, and ascertain whether individual seropositive crias had received supplemental colostrum at birth.

Design—Prevalence study.

Animals—63 alpaca herds with ≥ 12 registered female alpacas.

Procedures—250 alpaca breeders were randomly selected from 562 eligible herds listed in the Alpaca Owner and Breeders Association membership directory and mailed a voluntary participation request. Sixty-three alpaca breeders participated in the study. From each herd, blood samples from ≥ 4 crias were tested for BVDV, BVDV RNA, and serum neutralizing antibodies against BVDV. A region of the genome of BVDV recovered from PI crias was sequenced to determine genetic homology.

Results—Among the 63 herds, 16 (25.4%) had seropositive crias and 4 (6.3%) had PI crias. Infections in 3 of the 4 herds with PI crias were linked as evidence by the genetic homologies of viruses. In addition to PI crias, feeding supplemental colostrum was associated with herd seropositivity.

Conclusions and Clinical Relevance—Results confirmed the importance of BVDV infections in alpacas in the United States and highlighted the importance of determining the BVDV infection status of animals before they are commingled to limit exposure of herds to BVDV infection.

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in Journal of the American Veterinary Medical Association