Effect of dietary soy on serum thyroid hormone concentrations in healthy adult cats

OBJECTIVE: To compare effects of short-term administration of a soy diet with those of a soy-free diet on serum thyroid hormone concentrations in healthy adult cats. ANIMALS: 18 healthy adult cats. PROCEDURE: Cats were randomly assigned to receive either a soy or soy-free diet for 3 months each in a crossover design. Assays included CBC, serum biochemical profile, thyroid hormone analysis, and measurement of urinary isoflavone concentrations. RESULTS: Genistein, a major soy isoflavone, was identified in the urine of 10 of 18 cats prior to dietary intervention. Compared with the soy-free diet, cats that received the soy diet had significantly higher total thyroxine (T4) and free T4 (fT4) concentrations, but unchanged total triiodothyronine (T3) concentrations. The T3/fT4 ratio was also significantly lower in cats that received the soy diet. Although the magnitudes of the increases were small (8% for T4 and 14% for fT4), these changes resulted in an increased proportion of cats (from 1/18 to 4/18) that had fT4 values greater than the upper limit of the laboratory reference range. There was no significant effect of diet on any other measured parameter. CONCLUSIONS AND CLINICAL RELEVANCE: Short-term administration of dietary soy has a measurable although modest effect on thyroid hormone homeostasis in cats. Increase in T4 concentration relative to T3 concentration may result from inhibition of 5'-iodothyronine deiodinase or enhanced T3 clearance. Soy is a common dietary component that increases serum T4 concentration in cats.     

Equine amnionitis and fetal loss: The case definition for an unrecognised cause of abortion in mares

A series of abortions occurred in mares in New South Wales during 2004 that involved similar and unusual findings on post mortem examination of aborted fetuses and fetal membranes. The term Equine Amnionitis and Fetal Loss (EAFL) was developed to describe the condition. This form of abortion had not been previously recognised in Australia. The pathology alone is not specific for EAFL and diagnosis requires demonstration of a combination of certain pathological and bacteriological features. The purpose of this paper is to describe patterns considered consistent with EAFL cases as a working case definition for use by veterinarians and veterinary pathologists in identifying future cases of EAFL. More detailed papers are in preparation to fully describe the epidemiological, histopathological, and microbiological aspects of EAFL.     

Nocardia infections in cats: a retrospective multi-institutional study of 17 cases

OBJECTIVE: To record 17 cases of nocardiosis in cats from eastern Australia and to compare this series with cases previously reported. DESIGN: Retrospective/prospective study. RESULTS: Nocardia spp infections were diagnosed in 17 cats over 14 years from the three eastern states of Australia. There were no isolates from dogs during this period, but one isolate from a koala and two from dairy cows. The majority of cats presented with spreading lesions of the subcutis and skin associated with draining sinus tract(s). Early cutaneous lesions consisted of circumscribed abscesses. Infections spread at a variable rate, generally by extension to adjacent tissues. Lesions were generally located in regions subjected to cat bite or scratch injuries, including limbs, body wall, inguinal panniculus and nasal bridge. In some other cases, lesions were situated on distal extremities. The clinical course was variable, from chronic, indolent, initially localised infections to acute fulminating disease. Of the 17 cats, 14 were domestic crossbreds and three were purebreds. There was a preponderance of male cats (12 castrated, 1 entire young adult, 1 entire kitten). Nine of 17 cats were 10 years or older. Interestingly, the majority of infections were attributable to N nova. Immediate and/or predisposing causes could be identified in all cases, and included: renal transplantation [one cat]; chronic corticosteroid administration [three cats]; catabolic state following chylothorax surgery [one cat]; fight injuries [seven cats]; FIV infections [three of seven cats tested]. Of the 17 cats, three were apparently cured. Four were thought to be cured, but infection recurred after several months. Three cats responded partially but were euthanased, while another was improving when it died of unrelated complications. Two died despite treatment and two were euthanased without an attempt at therapy. For two cats there were either insufficient records or the patient was lost to follow up. CONCLUSION: Nocardiosis is a rare, serious disease. Currently it is more common in cats than dogs. Nocardial panniculitis may be clinically indistinguishable from the syndrome caused by rapidly growing mycobacteria. Although the prognosis is guarded, patients with localised infections caused by N nova often respond to appropriate therapy. If definitive treatment is delayed because of misdiagnosis, the disease tends to become chronic, extensive and refractory. Insufficient duration of therapy leads to disease recurrence.     

Genetic heterogeneity of variance in production traits of laying hens

Genetic parameters for mean and for environmental variation in egg weight, body weight, age at first egg, and egg production were estimated in eight layer lines. The data were recorded from years 1999-2007, with on average of 6500 birds per line. An iterative mean-variance REML method was applied with a sire-plus-dam model for mean, a sire model for variance, and a fixed effect of hatch within generation for both mean and variance. The estimated heritability of environmental variation averaged about 5% for body weight, 3% for egg weight, and 11% for age at first egg, but was inconsistent among the lines for egg production (0-15%). Correlations between means and variances were slightly positive for body weight, egg weight, and age at first egg; and strongly negative for egg production. Age at first egg had the highest heritability of environmental variation; and favourable correlations with egg production and with variation in other production traits indicate that reducing variation in this trait may have potential benefits for the breeding industry.     

Assessment of single nucleotide polymorphisms in genes residing on chromosomes 14 and 29 for association with carcass composition traits in Bos indicus cattle

Objective of this study was to assess the association of SNP in the diacylglycerol O-acyltransferase 1 (DGAT1), thyroglobulin (TG), and micromolar calcium-activated neutral protease (CAPN1) genes with carcass composition and meat quality traits in Bos indicus cattle. A population of Brahman calves (n = 479) was developed in central Florida from 1996 to 2000. Traits analyzed were ADG, hip height, slaughter weight, fat thickness, HCW, marbling score, LM area, estimated KPH fat, yield grade, retail yield, sensory panel tenderness score, carcass hump height, and cooked meat tenderness measured as Warner-Bratzler shear force at 7, 14, and 21 d postmortem. Single nucleotide polymorphisms previously reported in the TG and DGAT1 genes were used as markers on chromosome 14. Two previously reported and two new SNP in the CAPN1 gene were used as markers on chromosome 29. One SNP in CAPN1 was uninformative, and another one was associated with tenderness score (P < 0.05), suggesting the presence of variation affecting meat tenderness. All three informative SNP at the CAPN1 gene were associated with hump height (P < 0.02). The TG marker was associated with fat thickness and LMA (P < 0.05), but not with marbling score. No significant associations of the SNP in the DGAT1 gene were observed for any trait. Allele frequencies of the SNP in TG and CAPN1 were different in this Brahman population than in reported allele frequencies in Bos taurus populations. The results suggest that the use of molecular marker information developed in Bos taurus populations to Bos indicus populations may require development of appropriate additional markers.     

Characterization of normal tidal breathing flow-volume loops for Thoroughbred horses

The purpose of this study was to characterize the normal equine tidal breathing flow-volume loop (TBFVL). The study was performed using 18 healthy Thoroughbred horses. TBFVLs constructed from data collected from resting horses had a typical biphasic inspiratory and expiratory phase. The interindividual variability of the indices used to describe TBFVLs was in the range 16–32%, which is comparable to the variability of other measures of equine pulmonary mechanics. The large variability of these data probably limits the value of resting TBFVL indices for detecting subclinical respiratory conditions in individual horses. Factor analysis of these data revealed that in excess of 90% of the variance of the initial response variables could be explained in terms of three common factors. Varimax rotation of these three common factors provided three subsequent factors that were readily identifiable as (1) a factor describing the time-volume relationships of TBFVLs, responsible for 81% of the total variance, (2) a factor explaining the expiratory portion of the TBFVL, explaining 12% of the variance, and (3) a factor describing the inspiratory portion of the loops, responsible for the remaining 7% of the variance. The analysis also provided standardized factor scoring coefficients for use in subsequent studies using similar experimental techniques.Abbreviations EF₂₅ expiratory flow at expiratory volume plus 25%V _E - EF₅₀ midtidal expiratory flow - f respiratory rate - IF₂₅ inspiratory flow at 25% of inspiratory volume - IF₅₀ midtidal inspiratory flow - MSA measure of sampling adequacy - PEF peak expiratory flow - PIF peak inspiratory flow - TBFVL tidal breathing flow-volume loop - T _E expiratory time - T _I inspiratory time - USPTM ultrasonic pneumotachometer - V _E expiratory volume - V _I inspiratory volume