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Thursday, January 29, 2009

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American Journal of Veterinary Research
January 2009, Vol. 70, No. 1, Pages 99-104

Assessment of viremia associated with experimental primary feline herpesvirus infection or presumed herpetic recrudescence in cats

Hans D. Westermeyer, DVM, Sara M. Thomasy, DVM, PhD, Helen Kado-Fong, MS, David J. Maggs, BVSc

Objective—To detect feline herpesvirus type 1 (FHV-1) in blood of cats undergoing experimental primary herpetic disease or with spontaneous disease presumed to be caused by FHV-1 reactivation.

Animals—6 young specific-pathogen–free (SPF) cats and 34 adult cats from a shelter.

Procedures—Conjunctiva and nares of SPF cats were inoculated with FHV-1, and cats were monitored for 21 days. Periodically, blood was collected for CBC, serum biochemical analyses, and detection of FHV-1 DNA via PCR assay. For shelter cats, a conjunctival swab specimen was collected for FHV-1 PCR assay, and blood mononuclear cells were tested via virus isolation (with or without hydrocortisone) and FHV-1 PCR assay.

Results—All SPF cats developed clinical and clinicopathologic evidence of upper respiratory tract and ocular disease only. Via PCR assay, FHV-1 DNA was detected in blood of all SPF cats at least once between 2 and 15 days after inoculation. Feline herpesvirus type 1 DNA was detected in conjunctival swabs of 27 shelter cats; 25 had clinical signs of herpetic infection. However, virus was not isolated from mononuclear cell samples of any shelter cat regardless of passage number or whether hydrocortisone was present in the culture medium; FHV-1 DNA was not detected in any mononuclear cell sample collected from shelter cats.

Conclusions and Clinical Relevance—A brief period of viremia occurred in cats undergoing primary herpetic disease but not in cats undergoing presumed recrudescent herpetic disease. Viremia may be important in the pathogenesis of primary herpetic disease but seems unlikely to be associated with recrudescent disease.

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American Journal of Veterinary Research
January 2009, Vol. 70, No. 1, Pages 16-22

Evaluation of the distribution of enrofloxacin by circulating leukocytes to sites of inflammation in dogs

D. M. Boothe, DVM, PhD, A. Boeckh, DVM, PhD, H. W. Boothe, DVM, MS

Objective—To determine the effect of WBC accumulation on the concentration of enrofloxacin in inflamed tissues in dogs.

Animals—6 adult Bloodhounds.

Procedures—Dogs were instrumented bilaterally with tissue chambers. Peripheral WBCs collected from each dog were exposed in vitro to radiolabeled enrofloxacin (14C-ENR). Inflammation was induced with carrageenan in 1 chamber. Ten hours later, treated cells were administered IV to each dog such that 14C-ENR was delivered at a mean ± SD dosage of 212 ± 43 μg. Samples of extracellular fluid from inflammation and control chambers and circulating blood were then collected before (baseline) and for 24 hours after WBCs were administered. Samples were centrifuged to separate WBCs from plasma (blood) or chamber fluid. Radiolabeled enrofloxacin was scintigraphically detected and pharmacokinetically analyzed. Comparisons were made between extra- and intracellular chamber fluids by use of a Student paired t test.

Results—14C-ENR was not detectable in plasma, peripheral WBCs, control chambers, or baseline samples from inflammation chambers. However, 14C-ENR was detected in extra- cellular fluid from inflammation chambers (mean ± SD maximum concentration, 2.3 ± 0.5 ng/mL) and WBCs (maximum concentration, 7.7 ± 1.9 ng/mL). Mean disappearance half-life of 14C-ENR from extracellular fluid and WBCs from inflammation chambers was 26 ± 10 hours and 17 ± 6 hours, respectively.

Conclusions and Clinical Relevance—WBCs were responsible for the transport and release of 14C-ENR at sites of inflammation. Accumulation of drug by WBCs might increase the concentration of drug at the site of infection, thus facilitating therapeutic success.

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Veterinary Patholology 46:63-70 (2009)


Feline Gastrointestinal Eosinophilic Sclerosing Fibroplasia


L. E. Craig, E. E. Hardam, D. M. Hertzke, B. Flatland, B. W. Rohrbach and R. R. Moore

A retrospective study of cases of a unique intramural inflammatory mass within the feline gastrointestinal tract was performed in order to describe and characterize the lesion. Twenty-five cases were identified from archival surgical and postmortem tissues. The lesion most often occurred as an ulcerated intramural mass at the pyloric sphincter (n = 12) or the ileocecocolic junction or colon (n = 9); the remaining cases were in the small intestine. Seven cases also had lymph node involvement. The lesions were characterized by eosinophilic inflammation, large reactive fibroblasts, and trabeculae of dense collagen. Intralesional bacteria were identified in 56% of the cases overall and all of the ileocecocolic junction and colon lesions. Fifty-eight percent of cats tested had peripheral eosinophilia. Cats treated with prednisone had a significantly longer survival time than those receiving other treatments. We propose that this is a unique fibroblastic response of the feline gastrointestinal tract to eosinophilic inflammation that in some cases is associated with bacteria. The lesion is often grossly and sometimes histologically mistaken for neoplasia.

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Journal of Veterinary Internal Medicine
Volume 23 Issue 1, Pages 43 - 49

Clinical Evaluation of a Novel Liquid Formulation of L-Thyroxine for Once Daily Treatment of Dogs with Hypothyroidism

G. Le Traon 1 , S.F. Brennan 2 , S. Burgaud 1 , S. Daminet 3 , K. Gommeren 3 , L.J.I. Horspool 4 , D. Rosenberg 5 , and C.T. Mooney 2

Background: A liquid solution of levothyroxine (L-T4) is available for treatment of canine hypothyroidism.

Hypothesis: Once daily oral administration of a liquid L-T4 solution is effective and safe for controlling hypothyroidism in dogs.

Animals: Thirty-five dogs with naturally occurring hypothyroidism.

Methods: Dogs received L-T4 solution PO once daily at a starting dosage of 20 μg/kg body weight (BW). The dose was adjusted every 4 weeks, based on clinical signs and peak serum total T4 (tT4) concentrations. Target peak serum tT4 and thyroid stimulating hormone (TSH) concentrations, 4–6 hours posttreatment, were 35–95 nmol/L and < 0.68 ng/mL, respectively. Dogs were followed for up to 22 weeks after establishment of the maintenance dose.

Results: Clinical signs of hypothyroidism improved or resolved in 91% of dogs after 4 weeks of L-T4 treatment at 20 μg/kg once daily. The maintenance dose was established in 76, 94, and 100% of dogs after 4, 8, and 12 weeks of treatment, respectively. This was 20 μg L-T4/kg BW for 79% of the dogs, 30 μg/kg BW for 15%, and 10–15 μg/kg BW in the remaining 6%, once daily. Thereafter, median peak tT4 and TSH concentrations were 51 nmol/L and 0.18 ng/mL, respectively, and remained stable during the 22-week follow-up; clinical signs did not recur.

Conclusions and Clinical Importance: All of the hypothyroid dogs had rapid clinical and hormonal responses to supplementation with the PO-administered L-T4 solution. The starting dosage of 20 μg L-T4/kg BW once daily was suitable for 79% of dogs.

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Journal of Small Animal Practice
Volume 50 Issue 1, Pages 9 - 14

Radiographic appearance of cardiogenic pulmonary oedema in 23 cats


L. Benigni, N. Morgan* C. R. Lamb

Objective: To describe the radiographic appearance of pulmonary oedema in cats with cardiac failure.

Methods: Thoracic radiographs of 23 cats presented to a first opinion practice with signs of cardiac failure were reviewed. All cats had tachypnoea and/or dyspnoea and enlarged left atrium on echocardiography.

Results: Pulmonary oedema was characterised radiographically by an increased opacity associated with a range of patterns and variable distribution. All cats had evidence of a reticular or granular interstitial pattern. This occurred in combination with alveolar pattern in 19 (83 per cent) cats, including six with air bronchograms, with increased diameter of pulmonary vessels in 16 (71 per cent) cats and with bronchial pattern in 14 (61 per cent) cats. The distribution of pulmonary oedema was considered to be diffuse/non-uniform in 14 (61 per cent) cats, diffuse/uniform in four (17 per cent) cats, multi-focal in four (17 per cent) cats and focal in the remaining one (4 per cent). Nine (39 per cent) cats were considered to have a regional distribution of oedema, including five (22 per cent) with a ventral distribution, three (13 per cent) with a caudal distribution and one (4 per cent) cat with a hilar distribution. The distribution of pulmonary opacities was bilaterally symmetrical in five (22 per cent) cats.

Clinical Significance: The variable appearance of feline pulmonary oedema is likely to complicate its radiographic diagnosis.