Level of nutrition and splanchnic metabolite flux in young lambs

Splanchnic metabolite flux was measured in young lambs given access to a high-concentrate diet either ad libitum (ADLIB) or at a maintenance level (MAINT) for 21 d. Net fluxes of urea N (UN), ammonia N (NH3 N), alpha-amino N (AAN), amino acids, glucose (G), and lactate (L) across the liver and portal-drained viscera (PDV) were measured in 11 crossbred ram lambs (35 kg) surgically fitted with indwelling catheters in the portal, hepatic, and mesenteric veins and mesenteric artery. During the 21-d period, daily N and ME intakes were 24.6 and 10.7 g N/d and 3.02 and 1.28 Mcal/d, respectively, for ADLIB and MAINT lambs. Intakes, thus, were 42% lower for MAINT than for ADLIB lambs. Net portal fluxes of UN, NH3 N, AAN, and L in MAINT lambs were 46%, 84%, 50%, and 74%, respectively, of that in ADLIB lambs. Expressed as a percentage of N intake, the proportion of AAN absorbed by the PDV was higher in MAINT lambs (P less than .05) than in ADLIB lambs. There was no net portal glucose absorption in either group of lambs; however, net hepatic glucose production in MAINT lambs was 48% of that in ADLIB lambs. There was net utilization of glutamine by the PDV; net glutamine flux in MAINT lambs was 49% of that in ADLIB lambs. The liver utilized AAN and NH3 N and produced UN. Splanchnic tissues modulate metabolite flux following changes in feed intake in young ruminants.     

Comparison of three methods of feeding colostrum to dairy calves

Absorption of colostral immunoglobulins by Holstein calves was studied in 3 herds in which 3 methods of colostrum feeding were used. Failure of passive transfer, as determined by calf serum immunoglobulin G1 (IgG1) concentration less than 10 mg/ml at 48 hours of age, was diagnosed in 61.4% of calves from a dairy in which calves were nursed by their dams, 19.3% of calves from a dairy using nipple-bottle feeding, and 10.8% of calves from a dairy using tube feeding. The management factor determined to have the greatest influence on the probability of failure of passive transfer in the herds using artificial methods of colostrum feeding (bottle feeding or tube feeding) was the volume of colostrum fed as it affected the amount of IgG1 received by the calf. In dairies that used artificial feeding methods, failure of passive transfer was infrequent in calves fed greater than or equal to 100 g IgG1 in the first colostrum feeding. In the dairy that allowed calves to suckle, prevalence of failure of passive transfer was greater than 50% even among calves nursed by cows with above-average colostral IgG1 concentration. Analysis of the effect of other management factors on calf immunoglobulin absorption revealed small negative effects associated with the use of previously frozen colostrum and the use of colostrum from cows with long nonlactating intervals.     

Variance of indirect blood pressure measurements and prevalence of hypertension in clinically normal dogs

In a series of 3 studies, indirect blood pressure measurements were obtained to define normal variance, identify hypertension, and estimate the prevalence of hypertension in apparently healthy dogs. In part 1, we measured values in 5 clinically normal dogs twice weekly for 5 weeks in a home setting. Mean +/- SD systolic arterial pressure (SAP) and diastolic arterial pressure (DAP) was 150 +/- 16 and 86 +/- 13 mm of Hg, respectively. The DAP significantly (P less than 0.01) decreased with repeated measurements over the 5-week period. In part 2, we assessed the variation between blood pressures measured in a clinic vs those measured in the home. Within a 2-week period, measurements were obtained from 10 clinically normal dogs in a private veterinary clinic and again in their home. Significant differences were not observed between clinic and home measurements of SAP and DAP; however, heart rate was significantly (P less than 0.05) higher in the clinic. In part 3, SD about the SAP and DAP mean values were determined in 102 clinically normal dogs. Canine hypertensive status was determined, using statistical methods and data from 102 clinically normal dogs. Values of SAP greater than 202 mm of Hg and DAP greater than 116 mm of Hg were determined to be 2 SD beyond the mean and, therefore, were interpreted to be hypertensive. Approximately 10% of the 102 apparently healthy dogs measured in this study were considered hypertensive on the basis of these criteria. In addition, a border zone of suspected hypertension was estimated, using the mean + 1.282 SD. The SAP border zone was between 183 and 202 mm of Hg, whereas the DAP border zone was between 102 and 113 mm of Hg. Of the 102 dogs, 12 had values within these zones of suspected hypertension.     

Jejunal mucosal lactase activity from birth to three weeks in conventionally raised calves fed an electrolyte solution on days 5, 6 and 7 instead of milk.

The purpose of this study was to evaluate the effect of withdrawal of lactose from the diet for 72 hours on lactase activity in the jejunal mucosa of conventionally raised calves. The descending portion of the duodenum of six Holstein calves less than 24 hours old was cannulated. The calves were fed milk except on days 5, 6 and 7 when they were given the same volume of an electrolyte solution. Sequential biopsy specimens of the proximal jejunal mucosa were obtained for three weeks and the lactase activity determined. Lactase activity was highest on day 1 and a trend toward decreased lactase activity from birth until three weeks was observed. Mean lactase activity was significantly (p less than 0.05) higher for days 1, and 3 compared to days 9, 13 and 17. The withdrawal of milk and replacement by an electrolyte solution during three days had no significant effect on jejunal mucosal lactase activity in neonatal calves.     

Estrogen suppresses melatonin-enhanced hyperactivation of hamster spermatozoa

Hamster sperm hyperactivation is enhanced by progesterone, and this progesterone-enhanced hyperactivation is suppressed by 17β-estradiol (17βE₂) and γ-aminobutyric acid (GABA). Although it has been indicated that melatonin also enhances hyperactivation, it is unknown whether melatonin-enhanced hyperactivation is also suppressed by 17βE₂ and GABA. In the present study, melatonin-enhanced hyperactivation was significantly suppressed by 17βE₂ but not by GABA. Moreover, suppression of melatonin-enhanced hyperactivation by 17βE₂ occurred through non-genomic regulation via the estrogen receptor (ER). These results suggest that enhancement of hyperactivation is regulated by melatonin and 17βE₂ through non-genomic regulation.     

Echinococcus multilocularis in Belgium: prevalence in red foxes (Vulpes vulpes) and in different species of potential intermediate hosts

Echinococcus multilocularis causes a rare but potentially lethal zoonotic infection in humans. This tapeworm is known to be endemic in foxes in several countries of Western and Central Europe. In Western Europe, the common vole (Microtus arvalis) and the water vole (Arvicola terrestris) are considered to be the most important intermediate host species of this cestode whereas the red fox is by far the most important final host. The purpose of this study was to provide data on the prevalences in Wallonia (Southern part of Belgium) both in the red fox and in different potential intermediate hosts. A total of 990 red foxes were examined between January 2003 and December 2004 for the presence of E. multilocularis. The average prevalence was 24.55% (22.38-27.87). Out of 1249 rodents or insectivores belonging to the species Apodemus sylvaticus, Arvicola terrestris, Clethrionomys glareolus, Microtus arvalis, Microtus agrestris and Sorex araneus, only one M. arvalis (out of 914-0.11% (0.003-0.61) and one C. glareolus (out of 23-4.3% (0.1-21.9) were found to be infected. However, the muskrat (Ondatra zibethicus) seems to be a good intermediate host as 11.18% (9.72-12.76) of the animals (n=1718) were found to be infected. A positive correlation was found between the prevalences in foxes and in muskrats in each of the different geological regions. This study indicates that the muskrat is highly sensitive to this zoonotic tapeworm and could perhaps represent a good bioindicator when studying the epidemiology of this parasitic infection in Belgium and in other countries where the muskrat is present.     

Use of radiographic measures and three-dimensional computed tomographic imaging in surgical correction of an antebrachial deformity in a dog

CASE DESCRIPTION: A 1-year-old 7.4-kg (16.3-lb) castrated male mixed-breed dog was evaluated because of intermittent lameness and an antebrachial angular limb deformity. CLINICAL FINDINGS: The left forelimb had gross antebrachial external rotation (approx 90 degrees ) and marked procurvatum. Radiography revealed a severe partially compensated biapical antebrachial angular limb deformity. Measurements of medial proximal radial angle (MPRA) and lateral distal radial angle (LDRA) were obtained from orthogonal radiographs of the proximal and distal segments of the radius, respectively. Elbow joint-to-carpus translation was quantified. Deformities were localized and quantified by the center of rotation of angulation (CORA) method. Computed tomographic 3-dimensional image reconstructions of the antebrachium and carpus were completed to create 3 life-size stereolithographic models. TREATMENT AND OUTCOME: 2 closing wedge radial osteotomies were performed at the level of the CORAs and stabilized with bone plates and screws. RESULTS: Frontal and sagittal plane alignments were corrected to 8 degrees and 15 degrees , respectively (reference limits, 0 degrees to 8 degrees and 8 degrees to 35 degrees , respectively). The MPRA was corrected from 55 degrees to 68 degrees , and LDRA was corrected from 32 degrees to 76 degrees (values considered normal are approx 85 degrees and 87 degrees , respectively). Elbow joint-to-carpus translation was improved by 42.5%. After 8 weeks, radiography revealed bone union. Owners considered the outcome acceptable, on the basis of limb appearance and lack of lameness at 1 year after surgery. CONCLUSIONS AND CLINICAL RELEVANCE: A segmental radiographic planning technique combined with the CORA method, computed tomography, and stereolithography may be useful in the characterization of and planning corrective surgery for forelimb deformities in dogs.     

Pseudorabies virus infection in mink: a host-specific pathogenesis

Pseudorabies virus (PRV) is an alphaherpesvirus that causes a neurological disease in many wild and domestic animals. The neuropathology elicited by PRV is quite consistent regardless of the host with the only exception of mink, in which it is characterized by a vasculopathy rather than by an encephalitis. In this study, we aimed to investigate the underlying pathogenic mechanism(s) of PRV infection in mink by using immunohistochemistry and laser capture microdissection (LCM) on material from naturally and experimentally infected animals. The inflammatory reaction induced by PRV was minimal or absent not only in the nervous system, where we identified a low number of macrophages and a few T lymphocytes, but also in the primary replication site, the oropharyngeal mucosa; however, the number of PRV-infected cells detected by immunohistochemistry was extremely high both in the peripheral mucosa and in the nervous tissue. On the other hand, the vascular pathology included parenchymal hemorrhages of various degrees and, in specific cortical areas of the brain, fibrinoid degeneration of the capillary walls. Detection of viral antigens by immunohistochemistry revealed infection of endothelial cells of capillaries situated both in the oropharyngeal mucosa and in the brain stem; the presence of PRV DNA in vessels was further demonstrated by PCR performed on LCM samples of brain capillaries. These results can be interpreted as supporting the idea that the different pathology of the disease in mink may be the consequence of an increased endotheliotropism of PRV in this species. Infection of the vessel wall may then lead to vascular pathology and impairment in endothelial cell function, resulting in a weak immune response to infection.     

Clinical differentiation between dogs with benign and malignant spirocercosis

Spirocerca lupi is a nematode infesting the canine oesophagus, where it induces the formation of a nodule that may transform into a malignant sarcoma. The current, retrospective study compared the clinical presentation, haematology, serum albumin and globulin and radiology of benign cases (n=31) and malignant cases (n=31) of spirocercosis. Dogs with spirocercosis-induced sarcoma were significantly older (6.4+/-1.91 years) than benign cases (4.93+/-2.87). In the malignant cases there were significantly (p=0.03) more sterilized females (10/31) and fewer intact males (4/31) compared to 2/31 and 13/31, respectively, in the benign cases. Hypertrophic osteopathy was observed in 38.7% of malignant cases and in none of the benign cases (p=0.0002). Common clinical signs included weight loss, regurgitation, anorexia, pyrexia (T>or=39.5 degrees ), respiratory complications and salivation but did not differ in prevalence between groups. On haematology, the malignant group had significantly (p<0.05) lower haematocrit (0.34+/-0.08 vs. 0.41+/-0.07) and higher white cell count (31.6+/-27.83 vs. 17.71+/-13.18 x 10(3)microl(-1)), mature neutrophil count (26.06+/-26.08 vs. 12.23+/-9.96 x 10(3)microl(-1)) and thrombocyte count (493.15+/-151.61 vs. 313.27+/-128.54 x 10(9)microl(-1)). There were no differences in the mean corpuscular volume and immature neutrophil count. On radiology, the mass length was not significantly different, but the height and the width of the malignant masses were significantly larger (62.59+/-15.15 mm and 73.93+/-20.94 mm) compared to the benign group (46.43+/-23.62 and 49.29+/-25.56, respectively). Spondylitis was more prevalent in the malignant group (67.86% vs. 38.46%, p=0.03). Examining secondary pulmonary changes revealed significantly higher prevalence of bronchial displacement in the malignant group (52% vs. 17%, p=0.008). Hypertrophic osteopathy appeared to be a very specific but relatively rare (poor sensitivity) marker of malignancy. Female gender, anaemia, leukocytosis, thrombocytosis, spondylitis and bronchial displacement are significantly more common in malignant cases, but appear in benign cases as well. However, if found together in a specific case, they should increase the index of suspicion for malignancy in a diagnosed spirocercosis case.     

Evaluation of Salmonella-lytic properties of bacteriophages isolated from commercial broiler houses

Because of recent interest in bacteriophage therapy in poultry, information regarding the interaction of bacteriophages and potential host bacteria in the environment should be collected. The present studies were initiated with a rather typical commercial broiler integrator within the south-central United States to examine environmental Salmonella levels in two broiler complexes, attempt to isolate Salmonella-lytic bacteriophages, and elucidate a possible reason for differing apparent Salmonella prevalence. Significantly (P < 0.05) less Salmonella was isolated from houses in complex 1 (15/44 [34%] Salmonella-positive drag swabs) as compared to houses in complex 2 (22/24 [92%]). A total of seven Salmonella-lytic bacteriophages were isolated from Salmonella-positive environments, and two bacteriophages were isolated from a single Salmonella-negative house. During the initial bacteriophage isolation, individual bacteriophages did not replicate in the Salmonella host isolated from the same environment, and lysis of additional Salmonella hosts relied on high numbers of bacteriophage to be present. This suggests that the presence of these bacteriophages in the environment of a commercial broiler house had little to no effect on the presence of Salmonella. This study highlights the need to find additional bacteriophage sources, more effective isolation methods, and more innovative approaches to using bacteriophages to treat enteric disease.