Assessment of computed tomography derived cricoid cartilage and tracheal dimensions to evaluate degree of cricoid narrowing in brachycephalic dogs

The aims of this observational, analytical, retrospective study were to (i) obtain computed tomographic (CT) cricoid dimensions (height, width, and transverse‐sectional area), (ii) compare the cricoid dimensions between brachycephalic and mesaticephalic breeds, and (iii) compare cricoid cartilage dimensions between dogs without and affected with brachycephalic airway syndrome. The study is important to help to further evaluate and understand the anatomical components of brachycephalic airway syndrome. Measurements were performed in 147 brachycephalic and 59 mesaticephalic dogs. The cricoid cartilage was found to be significantly more oval in Pugs and French Bulldogs compared to mesaticephalic breeds. The cricoid cartilage transverse‐sectional area was smallest for the Pug and, after adjusting for weight, significantly smaller for Pugs (P < 0.001), Boston Terriers (P = 0.001), and French Bulldogs (P < 0.001) compared to Jack Russell Terriers. The tracheal transverse‐sectional area at C4 of English Bulldogs was significantly smaller than for Jack Russell Terriers (P = 0.005) and Labradors (P < 0.001). The cricoid cartilage transverse‐sectional area:weight ratio was significantly lower in brachycephalic breeds compared to mesaticephalic breeds (P < 0.001). The cricoid cartilage:trachea at C4 transverse‐sectional area for brachycephalic dogs was significantly larger than for mesaticephalic dogs (<0.001), demonstrating that the trachea was the narrowest part of the airway. No significant differences were found for cricoid dimensions between dogs affected with and without brachycephalic airway syndrome. However, large individual variation was found among the brachycephalic breeds and further studies investigating the relationship between cricoid cartilage size, laryngeal collapse, concurrent tracheal hypoplasia, and/or severity of brachycephalic airway syndrome are warranted.     

A radiographic study of breed‐specific vertebral heart score and vertebral left atrial size in Chihuahuas

Although echocardiography is the gold standard for the diagnosis of cardio‐structural disease, thoracic radiography is a rapid, cost‐effective, and widely accessible method for evaluating cardiac size in dogs. The vertebral heart score (VHS) and the vertebral left atrial size (VLAS) are established as objective measures of cardiomegaly on thoracic radiographs. However, several studies have shown significant variations in the VHS among different breeds. The Chihuahua is predisposed to both congenital and acquired cardiac diseases. The aim of this prospective, single‐center, cross sectional study was thus to evaluate the VHS and the VLAS in healthy adult Chihuahua dogs. A total of 30 Chihuahuas were included. The VHS values in our sample population of Chihuahuas were 10.0 ± 0.6 (95% range, 8.9‐11.0). This was significantly greater than the canine reference value of 9.7 ± 0.5 established by Buchanan and Bücheler (P = .002). The VLAS of Chihuahuas in our study was 1.8 ± 0.2 (95% range, 1.3‐2.1). This was significantly lower than the values previously reported by Malcolm et al (2.07 ± 0.25; P = .0004). The VHS and the VLAS were not influenced by sex, body weight, short or long hair, and body condition score in normal Chihuahuas. Our results indicated that breed‐specific reference values for radiographic VHS and VLAS are needed. In Chihuahuas, the values found in this study can be used as a normal reference in order to help avoid overinterpretation of cardiomegaly in these dogs.     

Homozygosity of single nucleotide polymorphisms in the 3′ region of the canine estrogen receptor 1 gene is greater in Toy Poodles than in Miniature Dachshunds and Chihuahuas

Differences in the distribution of single nucleotide polymorphisms (SNPs) and haplotypes in the estrogen receptor α gene (ESR1) were examined in Miniature Dachshunds (n = 48), Chihuahuas (n = 20) and Toy Poodles (n = 18). Five DNA fragments located in the 40‐kb region at the 3′ end of ESR1 were amplified by polymerase chain reaction and were directly sequenced. We compared allele, genotype and estimated haplotype frequencies at each SNP in the 3′ end of ESR1 for these three breeds of small dog. The frequency of the major allele and the genotype frequency of the major allele homozygotes, were significantly higher in Toy Poodles for five SNPs (SNP #5, #14–17) than in Miniature Dachshunds, and significantly higher in Toy Poodles than Chihuahuas for three SNPs (SNP #15–17). A common haplotype block was identified in an approximately 20‐kb region encompassing four SNPs (SNPs # 14–17). The frequencies of the most abundant estimated haplotype (GTTG) and GTTG homozygotes were significantly higher in Toy Poodles than in the other two breeds. These results imply that homozygosity for the allele, genotype and haplotype distribution within the block at the 3′ end of ESR1 is greater in Toy Poodles than in Miniature Dachshunds and Chihuahuas.     

Investigation of parameters predicting the need for diagnostic imaging beyond computed tomography in the evaluation of dogs with thoracolumbar myelopathy: Retrospective evaluation of 555 dogs

Thoracolumbar myelopathy encompasses a number of disease processes such as intervertebral disc disease, discospondylitis, trauma, congenital malformations, neoplasia, and intramedullary spinal cord disease. Compressive disc herniations are most common in dogs and require imaging procedures such as myelography, computed tomography (CT), and/or magnetic resonance imaging (MRI) to determine the need and location for decompressive surgery. The purposes of this retrospective, cross‐sectional study were to evaluate all dogs undergoing thoracolumbar CT imaging as the initial diagnostic step between 2010 and 2015 and determine whether any of the imaging characteristics could be used to predict the need for additional imaging in the form of myelography, CT myelography, and/or MRI. A total of 555 dogs were identified in this time frame which underwent CT imaging for myelopathy of the thoracolumbar region. Various parameters including age, gender, sexual status, breed, chronicity, site of lesion, time of study, and contrast administration were evaluated. Findings indicated that 7.6% of dogs needed additional imaging after CT. Dachshunds were less likely to need additional imaging (P = 0.0111) as were patients scanned during normal business hours (P = 0.0075). Increasing age of the patient increased the likelihood of additional imaging (P = 0.0107). Dogs which did not have additional imaging performed were 21.89 times more likely to require surgery than those which did have additional imaging (P < 0.0001). Findings supported the use of CT as a first‐line imaging modality for dogs presenting with thoracolumbar myelopathy.     

The effect of transport on the quality of rabbit meat

The analyzed material included 40 hybrid rabbits slaughtered at the age of 90 days. The control group was transported directly after weaning, while the transport group was transported directly prior to slaughter. The experiment was designed to assess the transport stress, carcass and meat quality implications, taking into account the muscle type and sex. The transported animals were characterized by a higher level of blood cortisol, glucose and triglycerides (P < 0.0001), and a lower level of insulin (P < 0.0001) compared to the control group. In the presented study the time post‐mortem affected the pH decline in both rabbit groups (P < 0.0001). The lightness, redness and yellowness of rabbit meat were affected by the transport (P < 0.0001, P = 0.001 and P < 0.0001). The percentage of free water and its share in the total water was higher for the non‐transported rabbits compared to the transported ones (P < 0.0001). Moreover, the meat from the control group was characterized by greater plasticity compared to the transport group (P = 0.003). The chemical composition of rabbit meat was not changed by the effect of transport (P = 0.643–0.979). To conclude, the quality traits of meat from the transported hybrid rabbits clearly indicated the development of dark firm and dry‐like lower quality of meat.     

Supplementation of diets for gestating sows with zinc amino acid complex and gastric intubation of suckling pigs with zinc-methionine on mineral status, intestinal morphology and bacterial translocation in lipopolysaccharide-challenged early-weaned pigs

Eighty male pigs from 20 litters were used to evaluate dietary addition of 250 mg/kg of Zn from zinc amino acid complex (ZnAA) to sows during the last trimester of gestation and gastric intubation of 40 mg Zn from soluble zinc methionine (ZnMet) to suckling pigs at birth and on day 7 and 14 (weaning) on small intestinal morphology, Zn status and bacterial translocation in early-weaned pigs. At weaning, pigs were challenged with an intramuscular injection of saline without or with 120 μg/kg BW of lipopolysaccharide (LPS; from Escherichia coli O26:B6) and were euthanized 24 h later prior to collection of intestinal lymph nodes and small intestinal sections. Zinc concentration in serum 7 days after birth and at weaning were higher in pigs from ZnAA-supplemented sows and those receiving gastric intubation with ZnMet (P = 0.05 and P < 0.0001, respectively). Post-weaning liver tissue concentrations for Zn (P < 0.0001) and Fe (P = 0.04) were higher and for Cu lower (P < 0.0001) in pigs intubated with ZnMet. Pigs from ZnAA-supplemented compared with control-fed sows tended (P < 0.1) to have increased villi height and villus:crypt ratio in the jejunum and higher (P = 0.1) goblet cell counts in the ileum. Goblet cell counts of ZnMet-intubated (P = 0.03) and LPS-challenged pigs (P = 0.05) were also higher in the jejunum. Supplementation of ZnAA to gestating sows increased (P = 0.04) E. coli colony forming unit counts in the small intestinal mesenteric lymph nodes of early-weaned pigs. In conclusion, dietary addition of ZnAA to gestating sows and gastric intubation of ZnMet improved Zn status of suckling pigs.     

Effect of banding or burdizzo castration on plasma testosterone, acute-phase proteins, scrotal circumference, growth, and health of bulls

The objective was to assess the effect of banding or burdizzo castration performed on farms on plasma testosterone, acute-phase proteins, scrotal circumferences, growth, and well-being of bulls. 243 Continental bulls (12 months; 399.2 ± 5.72 kg) from three different farms were allocated at random, after stratification on weight within breed type, to one of three treatment groups: banding castration (BAND; n = 80), burdizzo castration (BURD; n = 83), or controls (CON; n = 80). The castration methods were conducted under local anaesthesia, and tetanus toxoid vaccine and antibiotic were also injected at castration. BAND and BURD castrates had lower (P < 0.001) plasma testosterone concentration than control bulls, with no difference between BAND and BURD castrates on 28 d post-castration. From days 0 to 14 post-castration, BAND (P = 0.0002) and BURD (P < 0.0001) castrates had lower average daily gain (ADG) than CON bulls, no difference (P = 0.46) was found between BAND and BURD castrates. From days 15 to 28, BAND castrates had lower ADG compared with BURD castrates (P = 0.03) and CON bulls (P = 0.01), while no difference (P = 0.76) was found between BURD and CON. From days 29 to 56, BAND (P = 0.01) and BURD (P = 0.002) castrates had lower ADG than CON bulls, no difference (P = 0.55) was found between BAND and BURD. From days 57 to 84, the ADG of BAND castrates was not different compared with BURD castrates (P = 0.12) and CON bulls (P = 0.38), while BURD had lower (P = 0.02) ADG compared with CON. The integrated ADG from day 0 to 112 of BAND (P = 0.0001) and BURD (P = 0.02) groups were lower compared with CON, while there was no difference (P = 0.09) between BAND and BURD castrates. On d 14 post-castration, BAND castrates had lower scrotal temperature than BURD (P < 0.0001) and CON (P < 0.0001), and BURD castrates had greater (P < 0.006) scrotal temperature than CON; BAND castrates had lower scrotal latitudinal and longitudinal circumferences than BURD castrates (P < 0.001) and CON bulls (P < 0.001), and BURD castrates had greater (P < 0.001) scrotal latitudinal and longitudinal circumferences than CON bulls. BAND (P < 0.0001) and BURD (P = 0.01) castrates had greater glucose concentration than CON bulls, and BAND castrates had greater (P = 0.04) glucose concentration than BURD. In conclusion, BAND or BURD castration significantly reduced plasma testosterone concentration; reduced average daily weight gain mainly during the first 2 weeks, which was not compensated during the subsequent 16 weeks; increased withdrawal of stored energy and increased plasma protein concentration. BURD showed an advantage over BAND in growth during days 15 to 28 following castration.     

Reduced lung lesions in pigs challenged 25 weeks after the administration of a single dose of Mycoplasma hyopneumoniae vaccine at approximately 1 week of age

Two independent studies assessed the duration of immunity of an inactivated adjuvanted Mycoplasma hyopneumoniae vaccine against mycoplasmal pneumonia in seronegative (study A, n = 52) and seropositive (study B, n = 52) pigs. The pigs were allocated randomly to treatment and were then injected with a single dose of either the vaccine or a placebo at approximately 1 week of age. Twenty-five weeks after treatment administration, the pigs were challenged with a virulent strain (LI 36, Strain 232) of M. hyopneumoniae and the extent of lung lesions consistent with mycoplasmal pneumonia was assessed 4 weeks later.In study A, the geometric mean lung lesion score (expressed as least squares mean percentages of lung lesions) was significantly (P = 0.0001) lower in vaccinated (0.3%, n = 20) than in control pigs (5.9%, n = 24) seronegative to M. hyopneumoniae at enrolment; similarly, in study B, the extent of lung lesions was significantly reduced (P = 0.0385) in seropositive vaccinated pigs (2.0%, n = 22) compared to controls (4.5%, n = 26). At the end of the investigation period, 4 weeks after challenge, mean antibody sample-to-positive (S/P) ratios were significantly higher both in seronegative (P = 0.0012) and seropositive (P = 0.0001) vaccinated pigs (mean values = 0.77 and 0.81, respectively) than in controls (mean values = 0.51 and 0.38, respectively).     

Evaluation of the effect of fluconazole on the pharmacokinetics of cyclosporin A in healthy dogs after a single dose and at steady‐state

The aim of the study was to describe the effect of fluconazole on the pharmacokinetics of cyclosporin A in healthy dogs when investigated as a single dose and at steady‐state. Five healthy adult dogs were used in the study in a crossover design receiving either 5 mg/kg of cyclosporin A (CsA) alone or 5 mg/kg of fluconazole with 2.5 mg/kg of cyclosporin A (CsA/Flu) for 35 days. Pharmacokinetic curves were performed on day 1 and day 35 in addition to sampling trough and suspected peak concentrations (C2) twice weekly with LC/MS/MS. There was no statistically significant difference noted in any pharmacokinetic value (AUC_0‐inf. [day 1, P = 0.225], AUC_tau [day 35, P = 0.225], t_½ [day 1, P = 0.279; day 35, P = 0.686], and C_max [day 1, P = 0.225; day 35, P = 0.225]) between the treatment groups by sampling day. There was a statistically significant increase in AUC (CsA P = 0.043; CsA/Flu P = 0.043) and t_½ (CsA P = 0.042, CsA/Flu P = 0.042) over time within each group_. There were no significant differences in the C_max (CsA P = 0.08; CsA/Flu P = 0.08) when comparing day 1 vs. day 35. Steady‐state cyclosporine concentrations were achieved by day 10 in both groups. Subjectively, individual variability was noted among the dogs and a much larger sample size would be beneficial in a future study.     

Insight of Dogs' Inner Mandible Anatomy using Mathematical Models

This study was performed in a sample of 20 dogs (n = 20) and aimed to: (1) characterize the mandible height (Mh), mandibular canal height (MCh) and distance between the inter‐dental alveolar margin and the mandibular canal (dIAM‐MC) dimensions, and (2) to develop mathematical models that express the insight's mandible anatomy of those important mandible structural elements allowing the prediction of their dimensions using physical parameters such as patient body weight (Wg) and the canine tooth width at the free gingival margin level‐(wCGM). Lateral‐view X‐rays of both sides of the skull were taken for all the individuals. Three mathematical prediction models were developed to calculate Mh, MCh and dIAM‐MC. Achieved proportions of the mandible considered parameters regarding its height were of 36.45% for MCh, 50.90% for dMAI‐MC and 12.65% for vMC. Statistically significant differences were registered between the Wg and wCGM (P = 0.00), Mh (P = 0.00), MCh (P = 0.00) and dIAM‐MC (P = 0.00). Only the Wg presented a strong correlation with the wCGM (R = 0.58), Mh (R = 0.70), dIAM‐MC (R = 0.60) and MCh (R = 0.68). These models will allow a clinician to estimate the size of the mandible structures by only using data obtained during the physiological examination, with a sufficiently high prediction capacity and a very low standard error. The study points out the relationships of physiological parameters such as Wg and wCGM with mandible anatomical structural elements considered as important in oral surgery. The results of this study give the surgeon a new additional tool providing more information on the mandible anatomical structures and its relationships. This reduces the risk of iatrogenic lesions during the oral surgical procedures and improves patient safety.     

Increasing feed withdrawal and lairage times prior to slaughter decreases the gastrointestinal tract weight but favours the growth of cecal Enterobacteriaceae in pigs

The objective of this study was to evaluate the influence of different feed withdrawal and lairage times prior to slaughter on the gastrointestinal tract (GIT) weight and on the fermentation pattern and numbers of Enterobacteriaceae in the cecum of pigs. A total of 72 finishing pigs (6 pens, 12 animals each) were included in the study and were sent to the slaughterhouse on three consecutive days. On each day pigs from two pens were deprived of feed for either 2 or 12 h before leaving the farm. Pigs from each of the two pens were divided in sub-groups (4 pigs each) on the moment of loading onto the truck and followed the same distribution at the slaughterhouse. Once there, each sub-group corresponding to the same feed withdrawal time was held in different holding pens for 0, 5 or 10 h before slaughter. The weight of the gastro-intestinal tract (GIT) was determined and cecal content was collected to evaluate pH, short chain fatty acids (SCFA) and ammonia (NH₃) concentrations as well as lactobacilli and Enterobacteriaceae numbers. Total GIT weight decreased as feed withdrawal (P < 0.0001) and lairage time (P < 0.001) increased within a range between 6.69 and 4.59 kg. Cecal pH increased with feed withdrawal (P < 0.0001) and lairage time (P = 0.0001) (ranging from 5.79 to 6.79) in parallel to a decrease in the total SCFA concentration (P < 0.005) (from 211 to 100 mM). The percentages of acetic and propionic acid were not modified by the experimental treatments but significant decreases were registered in the percentage of butyric acid with the increased times of both withdrawal (P < 0.0001) and lairage (P < 0.005). The percentage of valeric and branched SCFA and also NH₃ concentration showed an increase with withdrawal (P < 0.005, P < 0.0001 and P < 0.005 respectively) and lairage (P < 0.005, P < 0.0001 and P < 0.001 respectively). Lactobacilli numbers decreased as lairage time increased (from 9.97 to 8.63 log 16S rRNA gene copies/g FM; P < 0.05) and Enterobacteriaceae numbers increased with both, feed withdrawal (P < 0.05) and lairage (P < 0.05) (ranging from 8.53 to 9.95 log 16S rRNA gene copies/g FM).The previous to slaughter increase in feed withdrawal and lairage times decreased the GIT weight but involved changes in the gut microbial ecosystem caused through changes in the fermentation pattern that lead to the increase of Enterobacteriaceae numbers. This increase could represent a higher risk of carcass contamination by the enteropathogens of this group such as Salmonella. However this potential risk should be further investigated.     

Relationship between body condition score and production of multiparous beef cows

Pregnancy rate, calving interval, weaning weight, birth weight and quarterly body condition score (BCS) were collected on fall calving multiparous English crossbred cattle (ages 3 to 10) from 1994 to 2001 to evaluate the critical time of cow condition measurements that predict production. The study was initiated with 260 cows. Replacement animals entered the study at first calving (2 years of age), with 45, 54, 27, 68, 54, and 45 animals added in years two through seven, respectively. Body condition score was measured in association with calving, breeding, weaning, and midway between weaning and calving (August). Regression of the logit of the probability of pregnancy (Y) showed that pregnancy outcome was quadratically related to BCS at breeding (P < 0.0001, Y = − 4.81X² − 0.52X − 4.339) and linearly related to BCS at calving (P = 0.009, Y = 0.32X + 4.17), but was not associated with either the pre- or postpartum change in condition (P > 0.05). Calving interval varied cubically with BCS at calving and quadratically with BCS at breeding (P < 0.0001 and P = 0.002, respectively). The largest decreases in calving interval were associated with increases in body condition score at calving from 3.5 to 4.5 and from 7 to 8. Calf weight at 205 days was related to both the BCS at breeding and the change in BCS from breeding to weaning (P = 0.01 and P = 0.004). Calf weight at 205 days was also associated with BCS at weaning (P = 0.0003). Cows with either low or high BCS at weaning tended to wean lighter calves than cows with moderate condition (4.5 and 5.5). Moreover, BCS at weaning (≈ 6 months prior to calving) was related to birth weight (P = 0.01). Dams with a BCS at weaning of 7 birthed heavier calves than dams with low (3 to 4) or high (8.5) BCS. The relationship of BCS at breeding with pregnancy rate, calving interval, and weaning weight suggests that maintenance of adequate BCS immediately before, during, and after the breeding season may be most critical to sustaining adequate reproductive performance and calf gains in animals subject to the seasonal forage production associated with a Mediterranean climate.     

Hounsfield units are a useful predictor of pleural effusion cytological type in dogs but not in cats

All categories of pleural effusion subjectively display as soft tissue opacity on computed tomography (CT). Quantitative measurement using Hounsfield units (HU) has the potential to bring additional information regarding the nature of the fluid in a noninvasive way. The purposes of this retrospective cross‐sectional analytical study were to compare Hounsfield units of different pleural effusion categories in dogs and cats, assess association between specific cytologic parameters and Hounsfield units, and evaluate the effect of dependent vs. nondependent aspect of the effusion pool on Hounsfield unit. A total of 111 patients (74 dogs and 37 cats) with pleural effusion, that underwent thoracic CT and diagnostic thoracocentesis, were included in the study. Effusions were cytologically categorized as exudate, transudate, modified transudate, hemorrhage, or chyle. Significant differences existed in Hounsfield units between categories in dogs (P < 0.0001) but not in cats (P = 0.334). Canine chylous effusion (6.1 ± 4.7 HU (mean ± standard deviation)) and transudate (5.6 ± 2.0) were significantly lower than exudate (20.3 ± 9.5) and hemorrhage (21.4 ± 9.2). No significant differences were found between modified transudate (13.6 ± 10.3) and other categories. Significant, weak linear correlation was identified in dogs between Hounsfield units and total protein (P = 0.018, R² = 0.089), red blood cells (P = 0.021, R² = 0.077), and total nucleated cells (P = 0.013, R² = 0.089). The Hounsfield units of dependent effusion was not significantly higher than the nondependent effusion, except for canine chylous effusion (P = 0.008). Fourteen Hounsfield units was identified as the most clinically useful threshold: <14 HU identified transudate or chylous effusion with a sensitivity of 100% and a specificity of 69%. A threshold >14 HU had a specificity of 100% and a sensitivity of 69% for identifying exudate, modified transudate, or hemorrhage.     

Levels of mRNA for three selenoproteins in skeletal muscle of fetal and newborn pigs

Selenoproteins have wide-ranging functions throughout the body, including important roles in protection against oxidative stress, as well as muscle development and integrity. In this study, prepubertal gilts were randomly assigned to either a Se-sufficient or deficient diet (n = 12/treatment). Levels of mRNA coding for the selenoproteins glutathione peroxidase-1 (GPx-1), selenoprotein W (SelW) and selenoprotein N (SelN) and the concentration of Se in fetal and neonatal swine skeletal muscle (gluteus maximus) were measured at time intervals throughout gestation and immediately after birth. Total RNA was isolated from skeletal muscle, and cDNA was synthesized for real-time RT-PCR analysis of the selected selenoproteins. Selenium concentration in skeletal muscle of fetal and newborn pigs decreased throughout gestation (P < 0.0001) and was lower (P < 0.05) when dams were fed the low Se diet. Levels of GPx-1 mRNA in fetal skeletal muscle were unaffected by maternal Se intake nor did GPx-1 mRNA levels change during late gestation. Selenoprotein W mRNA levels increased (P = 0.01) in fetal skeletal muscle during late gestation but were reduced (P = 0.05) by low maternal intake of Se. Levels of SelN mRNA showed a gestational time by treatment interaction (P < 0.05). The increased levels of SelW mRNA in skeletal muscle during late gestation, despite a decrease in Se concentration, indicate that SelW may be an important antioxidant protein to the late term fetus and the newborn.     

Chromium propionate improves performance and carcass traits in broilers

There is evidence to suggest that poultry may have a dietary requirement for metabolically available chromium (Cr) that exceeds the amount provided through wheat soybean meal diets. The objective of the present study was to investigate the effects of dietary supplemental organic Cr from Cr propionate at different dose levels (control = 0 μg/kg, T1 = 200 μg/kg, T2 = 400 μg/kg) on the growth performance, carcass traits, and meat quality of broilers. Weight gain and feed intake of each treatment were recorded at the start and after 14, 28 and 35 d, and feed conversion ratios (FCR) were calculated accordingly. At 35 d of age, birds were randomly selected and euthanized for carcass evaluation. Results of the first trial indicate that both Cr propionate treatments increased final body weight (P < 0.05), feed efficiency (P < 0.05) and body weight gain (P < 0.0001). Furthermore, Cr propionate supplementation improved (P < 0.0001) all carcass characteristics. Interestingly, with increased Cr dosage, carcass yield, dressing percentage and breast meat yield increased linearly (P < 0.0001). The second study reveals that the feed intake in the control group was significantly higher compared to both Cr propionate supplemented groups (T1 & T2). Furthermore, the Cr propionate supplemented T2 group displayed a significantly lower FCR than the control and T1 group (P = 0.027). Finally, Cr propionate supplementation increased the dressing percentage compared to control birds (P < 0.0001). In the third experiment, Cr propionate supplementation (T1 & T2) increased final body weight and decreased FCR compared with the control treatment. These effects were highly significant (P < 0.0001) throughout all feeding phases of the trial. Cr propionate supplementation also increased (P < 0.0001) carcass yield, dressing percentage, breast meat yield, leg and thigh weights compared with the control treatment. In conclusion, growth performance, feed conversion, carcass yield, breast and leg meats of broiler birds can be significantly improved by dietary inclusion of Cr propionate. Cr propionate can be supplemented to broiler birds from 1 d old of age at a level that provides 200 or 400 μg/kg organic Cr and can increase the efficiency of broiler production.     

Reduced Burden of Salmonella enterica in Bovine Subiliac Lymph Nodes Associated with Administration of a Direct‐fed Microbial

Despite effective food safety interventions within abattoirs, Salmonella enterica remains a common contaminant of raw ground beef. Research has recently implicated peripheral lymph nodes (PLNs) as a potential route by which Salmonella contaminates ground beef. This study examined the efficacy of using Lactobacillus animalis (formerly designated Lactobacillus acidophilus; NP51) and Propionibacterium freudenreichii (NP24), at 10⁹ cfu/head/day, as a direct‐fed microbial (DFM) in feedlot cattle diets to control Salmonella within PLNs. Two studies were conducted in which cattle were randomly allocated into either control or DFM treatment groups. Diets of treated cattle were supplemented with 10⁹ cfu/head/day of the DFM, while control groups received no DFM supplementation. During slaughter at abattoirs, one subiliac lymph node (SLN) per carcass was collected from 627 carcasses from one study and 99 carcasses from the second study. Lymph nodes were cultured to estimate the presence and concentration of Salmonella. In the first study, effects of DFM supplementation varied across slaughter days. On the first and second slaughter days, prevalence was reduced by 50% (P = 0.0072) and 31% (P = 0.0093), respectively. No significant difference was observed on slaughter day three (P = 0.1766). In the second study, Salmonella was 82% less likely (P = 0.008) to be recovered from SLNs of treatment cattle. While a greater relative risk reduction was observed in the latter study, absolute risk reductions were similar across studies. A significant reduction in the concentration of Salmonella in SLNs (P < 0.0001) on a cfu/g and cfu/node basis was also observed in cattle administered NP51 and NP24 in the first study; in the second study, too few quantifiable SLNs were observed to facilitate meaningful comparisons. The results indicate that NP51 and NP24 supplementation may aid in reducing the prevalence and concentration of Salmonella in SLNs and, therefore, serve as an effective control measure to reduce Salmonella in ground beef products.     

RADIOGRAPHIC LIVER SIZE IN PEKINGESE DOGS VERSUS OTHER DOG BREEDS

Differential diagnoses for canine liver disease are commonly based on radiographic estimates of liver size, however little has been published on breed variations. Aims of this study were to describe normal radiographic liver size in Pekingese dogs and to compare normal measurements for this breed with other dog breeds and Pekingese dogs with liver disease. Liver measurements were compared for clinically normal Pekingese (n = 61), normal non‐Pekingese brachycephalic (n = 45), normal nonbrachycephalic (n = 71), and Pekingese breed dogs with liver disease (n = 22). For each dog, body weight, liver length, T11 vertebral length, thoracic depth, and thoracic width were measured on right lateral and ventrodorsal abdominal radiographs. Liver volume was calculated using a formula and ratios of liver length/T11 vertebral length and liver volume/body weight ratio were determined. Normal Pekingese dogs had a significantly smaller liver volume/body weight ratio (16.73 ± 5.67, P < 0.05) than normal non‐Pekingese brachycephalic breed dogs (19.54 ± 5.03) and normal nonbrachycephalic breed dogs (18.72 ± 6.52). The liver length/T11 vertebral length ratio in normal Pekingese (4.64 ± 0.65) was significantly smaller than normal non‐Pekingese brachycephalic breed dogs (5.16 ± 0.74) and normal nonbrachycephalic breed dogs (5.40 ± 0.74). Ratios of liver volume/body weight and liver length/T11 vertebral length in normal Pekingese were significantly different from Pekingese with liver diseases (P < 0.05). Findings supported our hypothesis that Pekingese dogs have a smaller normal radiographic liver size than other breeds. We recommend using 4.64× the length of the T11 vertebra as a radiographic criterion for normal liver length in Pekingese dogs.     

Nodules and masses are associated with malignant pleural effusion in dogs and cats but many other intrathoracic CT features are poor predictors of the effusion type

Thoracic CT may be used in the workup of patients with pleural effusion. In humans, certain pleural features on CT aid in diagnosing an underlying cause for pleural effusion, whereas this is not well studied in veterinary medicine. This retrospective cross‐sectional analytical study assessed pleural and other intrathoracic abnormalities on CT in dogs and cats with pleural effusion and explored potential discriminatory features between effusion types. Eighty‐nine dogs and 32 cats with pleural cytology and/or histopathology were categorized into malignant pleural disease (15 dogs and 11 cats), pyothorax (34 dogs and 7 cats), chylothorax (20 dogs and 11 cats), transudative (11 dogs and 2 cats), and hemorrhagic effusion (9 dogs and 1 cat). Multivariable logistic regression analysis comparing malignancy to other effusions found that older patient age (dogs: odds ratio 1.28, P = 0.015; cats: odds ratio 1.53, P = 0.005), nodular diaphragmatic pleural thickening (dogs: odds ratio 7.64, P = 0.021; cats: odds ratio 13.67, P = 0.031), costal pleural masses (dogs: odds ratio 21.50, P = 0.018; cats: odds ratio 32.74, P = 0.019), and pulmonary masses (dogs: odds ratio 44.67, P = 0.002; cats: odds ratio 18.26, P = 0.077) were associated with malignancy. In dogs, any costal pleural abnormality (odds ratio 47.55, P = 0.002) and pulmonary masses (odds ratio 10.05, P = 0.004) were associated with malignancy/pyothorax, whereas any costal pleural abnormality (odds ratio 0.14, P = 0.006) and sternal lymphadenopathy (odds ratio 0.22, P = 0.040) were inversely associated with transudates. There were, however, many overlapping abnormalities between effusion types, so further diagnostic testing remains important for diagnosis.     

Growth and carcass characteristics of lambs in relation to plasma IGF-I and some histological traits of Longissimus lumbarum and Biceps femoris as affected by breed and age at slaughter

Ten male lambs of each of Rahmani (R) and Ossimi (O) were used to study the growth and carcass characteristics within their first year of age (360 days). After suckling period (4 months), lambs were fed on the regular ration. During the course of the experiment, body weight (BW) was recorded monthly accompanied by blood sampling to determine IGF-I. Four lambs from each breed were slaughtered at 270 and 360 days of age, and Longissimus lumbarum (L. lumbarum) at the 9th, 10th and 11th ribs and Biceps femoris (B. femoris) muscles were separated to be used for chemical analysis and histological study.Breed had no effect on the growth curve of the two studied breeds. Chemical analysis indicated that (O) had higher fat (0.9%, P < 0.0001) and lower (0.3%, P < 0.01) moisture compared to (R), with no difference in protein and ash contents. The concentration of IGF-I was almost similar in both breeds up to day 270 of age, and then it was higher in (R). Number of fibers per bundle was higher (P < 0.05) in (O) than in (R) by 6.1%, while, the other histological traits were similar in the two studied breeds.Chemical analysis indicated that lambs slaughtered at 360 days of age had lower (0.7%, P < 0.0006) moisture and higher fat (17.3%, P < 0.0001) compared to day 270. Up to day 270 of age, IGF-I concentration was < 500 ng/ml before increasing to > 500 ng/ml up to the end of the experiment. No effect of age was observed on the studied histological traits.L. lumbarum muscle contained higher protein (4.2%, P < 0.0001), fat (104%, P < 0.0001) and ash (10%, P < 0.001), while moisture was less (5.6%, P < 0.0001) compared to B. femoris muscle. B. femoris muscle was higher (P < 0.0001) in number and diameter of fibers, bundle and stroma sectional areas relative to L. lumbarum by 38.2, 78.8, 53.2 and 23.8%, respectively.