Are the number and size of scales in Liolaemus lizards driven by climate?

Ectothermic vertebrates are sensitive to thermal fluctuations in the environments where they occur. To buffer these fluctuations, ectotherms use different strategies, including the integument, which is a barrier that minimizes temperature exchange between the inner body and the surrounding air. In lizards, this barrier is constituted by keratinized scales of variable size, shape and texture, and its main function is protection, water loss avoidance and thermoregulation. The size of scales in lizards has been proposed to vary in relation to climatic gradients; however, it has also been observed that in some groups of Iguanian lizards it could be related to phylogeny. Thus, here, we studied the area and number of scales (dorsal and ventral) of 60 species of Liolaemus lizards distributed in a broad latitudinal and altitudinal gradient to determine the nature of the variation of the scales with climate, and found that the number and size of scales are related to climatic variables, such as temperature and geographical variables as altitude. The evolutionary process that best explained how these morphological variables evolved was the Ornstein‐Uhlenbeck model. The number of scales seemed to be related to common ancestry, whereas dorsal and ventral scale areas seemed to vary as a consequence of ecological traits. In fact, the ventral area is less exposed to climate conditions such as ultraviolet radiation or wind and is, thus, under less pressure to change in response to alterations in external conditions. It is possible that scale ornamentation, such as keels and granulosity, may bring some more information in this regard.     

Molecular characterisation of Cryptosporidium isolates from pre-weaned calves in Romania: is there an actual risk of zoonotic infections?

Diarrheic fecal samples from 258 pre-weaned calves (1-30 day-old) from 9 dairy farms located in Banat region, Romania, were microscopically examined for the presence of Cryptosporidium oocysts. Overall, 65 (25%) samples were found positive. A higher percent of infection was recorded in calves aged between 8 and 14 days compared with other age categories (1-7, 8-14, 15-21 and 22-30 days; p<0.05). Genetic characterization was carried out on all Cryptosporidium-positive samples. After DNA extraction, Cryptosporidium species were determined by a nested PCR of the small subunit rRNA gene (18S) followed by RFLP analysis with SspI, VspI and MboII restriction enzymes. The restriction patterns showed that animals were infected with Cryptosporidium parvum. Subsequently, subtyping of 13 C. parvum isolates, based on sequence analysis of the 60 kDa glycoprotein (GP60) gene, showed 2 subtypes (IIaA15G2R1 and IIaA16G1R1) belonging to the subtype family IIa. This is the first molecular study of bovine Cryptosporidium infection in Romania.     

Validation of noninvasive blood pressure equipment: which peripheral artery is best for comparison studies in dogs?

Objectives

1) To determine which peripheral artery commonly used for invasive arterial blood pressure (IBP) monitoring yields the least bias when compared with noninvasive blood pressure (NIBP) values obtained at the antebrachium of the dog, and 2) to identify and describe differences in systolic (SAP), mean (MAP) and diastolic arterial pressures (DAP) among different anatomical locations.

Does body size of dairy cows,at constant ratio of maintenance to production requirements,affect productivity in a pasture‐based production system?

This study compared productivity of dairy cows with different body weight (BW), but a constant ratio of maintenance to production requirements in their first lactation, in a pasture-based production system with spring calving. Two herds, Herd L (13 and 14 large cows in 2003 and 2004 respectively; average BW after calving, 721 kg) and Herd S (16 small cows in both years; 606 kg) [Correction added after online publication 14 January 2011: 16 small cows in both years; 621 kg was changed to 16 small cows in both years; 606 kg], all in their second or following lactations, were each allocated 6 ha of pasture and rotationally grazed on 10 parallel paddocks with equal herbage offer and nutritional values. Winter hay, harvested from the same pastures, was offered ad libitum in the indoor periods in a tied stall barn. Each herd received, per lactation and year, approximately 2000 kg dry matter (DM) of concentrates and of fodder beets, equally distributed to every individual. Indoors, the L-cows ingested more DM than the S-cows (18.7 vs. 16.3 kg DM/cow per day; p < 0.01), but DM intake per 100 kg of metabolic BW was similar (13.0 vs. 13.1 kg DM/cow per day). Estimates based on the n-alkane technique gave similar results on pasture (17.9 vs. 15.5 kg DM/cow per day; p < 0.001). Roughage intakes per 100 kg of metabolic BW, at 13.5 kg DM/cow per day, were similar. Mean annual yield of energy-corrected milk (ECM)/ha was slightly higher for the S-herd than the L-herd (13,026 vs. 12,284 kg) but was associated with a higher stocking rate (on average +20%) for the S-herd. Feed conversion efficiency (1.2 vs. 1.3 kg ECM/kg DM intake) and overall milk production efficiency (45.3 vs. 47.3 kg ECM/kg metabolic BW) were similar in L- and S-cows. Thus, both dairy cow types were equally efficient in utilising pasture-based forage.     

Thermal biology and locomotor performance in Phymaturus calcogaster: are Patagonian lizards vulnerable to climate change?

Behavioral and physiological traits of ectotherms are especially sensitive to fluctuations of environmental temperature. In particular, niche-specialist lizards are dependent on their physiological plasticity to adjust to changing environmental conditions. Lizards of the genus Phymaturus are viviparous, mainly herbivorous, and inhabit only rock promontories in the steppe environments of Patagonia and the Andes. Herein, we examine the vulnerability of the southernmost Phymaturus species to global warming: the endemic Phymaturus calcogaster, which lives in a mesic environment in eastern Patagonia. We studied body temperatures in the field (T_b), preferred body temperatures in a thermogradient (T_pref), the operative (T_e) and environmental temperatures, and the dependence of running performance on body temperature. P. calcogaster had a mean T_b (27.04°C) and a mean T_e (31.15°C) both lower than their preferred temperature (T_pref = 36.61°C) and the optimal temperature for running performance (T_o = 37.13°C). Lizard activity seems to be restraint during the early afternoon due high environmental temperatures. However, both, the high safety margin and warming tolerance suggest that the expected increase in environmental temperatures due to global warming (IPCC report in 2018) would not threaten, but indeed enhance locomotor performance in this population.     

Does blood contamination of urine compromise interpretation of the urine protein to creatinine ratio in dogs?

AIMS: To determine the effect of contamination of urine with 0–5% blood, varying in haematocrit and protein concentrations, on the urine protein to creatinine ratio (UPC) in dogs, and to determine whether the colour of urine can be used to aid interpretation of UPC results.

METHODS: Urine samples were collected by free catch from 18 dogs, all of which had UPC?<0.2. Venous blood samples were also collected from each dog, and the blood from each dog was added to its own urine to produce serial concentrations of 0.125–5% blood. The colour of each urine sample was recorded by two observers scoring them as either yellow, peach, orange, orange/red or red. Protein and creatinine concentrations were determined, and dipstick analysis and sediment examination was carried out on each sample. Based on colour and dipstick analysis, samples were categorised as either having microscopic, macroscopic or gross haematuria. A linear mixed model was used to examine the effect of blood contamination on UPC.

RESULTS: The uncontaminated urine of all 18 dogs had a UPC?<0.2. Adding blood to the urine samples resulted in an increase in UPC at all contamination concentrations compared to the non-contaminated urine (p<0.001). None of the 54 samples with microscopic haematuria had UPC?>0.5. For 108 samples with macroscopic haematuria the UPC was >0.5 in 21 samples (19.4 (95% CI=13.1–27.9)%), and for 54 samples with gross haematuria 39 (72 (CI=59.1–82.4)%) had a UPC?>0.5. No samples had a UPC?>2.0 unless the blood contamination was 5% and only 3/18 (17%) samples at this blood contamination concentration had a UPC?>2.0.

CONCLUSIONS AND CLINICAL RELEVANCE: This study showed that while blood contamination of ≥0.125% does increase the UPC, if the urine remains yellow (microscopic haematuria), then there is negligible chance that a UPC?>0.5 will be solely due to the added blood. In that scenario, attributing the proteinuria present to the haematuria in the sample would be inappropriate. However blood contamination that results in discolouration of the urine sample from yellow (indicating macroscopic or gross haematuria) could increase the UPC above the abnormal range and would need to be considered as a differential for the proteinuria. Thus knowledge of urine colour, even if limited to simple colour scores (yellow, discoloured, red) could be utilised to aid interpretation of the UPC in samples with haematuria.     

Postpartum reproductive failure in cattle: is the examination of gene expression in the endometrium a key to success?

High reproductive performance is required for successful management of dairy farms. After calving, especially endometritis is one of the main reasons for reproductive failure. However, subclinical endometritis remains undetected in many cases and causes a high financial loss. To elucidate the cellular processes in the endometrium, the acquisition of the gene expression will provide helpful information. In the literature, numerous cytokines and enzymes were discussed to play important roles in preparing the endometrium for implantation. This review gives an overview about our present understanding of the functions of cyclooxygenases 1 and 2 (COX-1/COX-2), tumor necrosis factor alpha (TNFalpha), the inducible nitric oxide synthase (iNOS), haptoglobin as well as the interleukins 1 and 6 (IL-1/IL-6). Their role is not only to regulate certain physiological processes in the bovine reproductive tract, but to act also as inflammatory mediators in infectious diseases. A better understanding of cellular processes may help to improve identification and treatment of postpartum reproductive failure.     

Microsatellite diversity of the Nordic type of goats in relation to breed conservation: how relevant is pure ancestry?

In the last decades, several endangered breeds of livestock species have been re‐established effectively. However, the successful revival of the Dutch and Danish Landrace goats involved crossing with exotic breeds and the ancestry of the current populations is therefore not clear. We have generated genotypes for 27 FAO‐recommended microsatellites of these landraces and three phenotypically similar Nordic‐type landraces and compared these breeds with central European, Mediterranean and south‐west Asian goats. We found decreasing levels of genetic diversity with increasing distance from the south‐west Asian domestication site with a south‐east‐to‐north‐west cline that is clearly steeper than the Mediterranean east‐to‐west cline. In terms of genetic diversity, the Dutch Landrace comes next to the isolated Icelandic breed, which has an extremely low diversity. The Norwegian coastal goat and the Finnish and Icelandic landraces are clearly related. It appears that by a combination of mixed origin and a population bottleneck, the Dutch and Danish Land‐races are separated from the other breeds. However, the current Dutch and Danish populations with the multicoloured and long‐horned appearance effectively substitute for the original breed, illustrating that for conservation of cultural heritage, the phenotype of a breed is more relevant than pure ancestry and the genetic diversity of the original breed. More in general, we propose that for conservation, the retention of genetic diversity of an original breed and of the visual phenotype by which the breed is recognized and defined needs to be considered separately.     

Absorption of methionine sources in animals——is there more to know?

This literature review evaluates the absorption of methionine(Met) sources such as 2-hydroxy-4-methylthiobutyric acid(HMTBa), its calcium salts(HMTBa-Ca), and DL-methionine(DL-Met) by focusing on the state of knowledge regarding the absorption mechanism, experimental methodology,and factors affecting their absorption. The 2 Met sources differ in mechanism and site of absorption due to differences in their chemical characteristics and enzymatic conversion. This review addresses diffusion-and tran...     

Changes in eggshell structure and predisposition of broilers to health problems: is there a common pathophysiology?

1. A study of broiler breeder eggs differing in eggshell matrix optical density was conducted to determine the association of eggshell structural quality and the risk of disease in broilers.

2. A total of 10 000 eggs from a broiler breeder flock were examined according to the pre-established criteria, and allocated to groups classified as having a high or low density shell matrix.

3. The eggs from respective groups were incubated and hatched in a commercial hatchery. Samples of unhatched eggs from each group were subjected to detailed examination to establish the cause of reproductive failure. First, quality chicks from each group were raised as separate flocks in a commercial broiler barn. Group performance, morbidity, and mortality were monitored throughout the growth period. All birds were processed in a commercial plant, and condemnation data were compiled.

4. There were significantly more unhatched eggs, and fewer quality chicks in the group classified as having a low density eggshell matrix, in comparison to the high-density group.

5. Embryo pathology accounted for a large proportion of the overall reproductive failure in both groups, with a large proportion of embryos showing anatomical anomalies. The eggs and embryos from the low-density eggshell matrix group were three times more likely to be infected.

6. Significantly higher production losses associated with mortality/morbidity, and condemnations of carcasses at processing were observed in broilers from the low-density eggshell group compared with the high-density eggshell group.

7. It is concluded that common metabolic/physiological changes in breeder hens associated with eggshell pathology may be also risk factors linked with predisposition of broiler chicks to some health problems.

     

Epidemiology of heartworm: what is happening in South America and Mexico?

Canine heartworm has been known to exist in the Americas for more than 150 years (1847), and the first South American report was published approximately 30 years later (1875). The first human case was reported in 1887 and the first feline case in 1921. Coincidently, these two reports were from Brazil, where most surveys of the disease during the past two decades have been conducted in dogs. Feline cases are seldom found in the South American literature, although feline heartworm disease has been reported in Venezuela and Brazil. The prevalence in Mexico seems to be stable over the past 10 years (7.3-7.5%). Only 5 of the 13 South American countries have reported on canine heartworm infection prevalence. In Argentina, the national prevalence ranges from 3.5 to 12.7%; however, there was a much higher prevalence (17.7 and 23.5%) reported for two sections of Buenos Aires. In Lima, Peru, the prevalence is 4.35%, and Colombia reports 3.8-4.8% of dogs are infected. No infections were detected in 1056 dogs sampled in Chile. In Brazil, the national prevalence has declined from 7.9% in 1988 to 2% in 2001. The downward trend observed for canine heartworm in Brazil suggests that multiple pressures may be affecting the nematode transmission, including a possible decrease in mosquito vector population due to better control programs, reduction of transmission due to effective chemoprophylaxis, reduction of microfilaremic dog populations with the off-label use of injectable ivermectin, or reduction of the reproductive capacity of worms from tetracyclines used to control ehrlichiosis. Survey of a large population of captured mosquitoes indicated the most frequent species captured were vectors of heartworms (Aedes taeniorhynchus (73.9%), Aedes scapularis (20%) and Culex quinquefasciatus (2.5%), suggesting that the composition of the mosquito population is not a critical factor in the decrease in heartworm infections in dogs in South America.     

Dose measurement in small animal radiology: how intense is the influence of distance and position of the investigator in relation to the patient?

Radiation exposure of body parts of persons, needed to restrain small animal during the examination, varies depending on the distance and position in relation to the patient, the region investigated, and the exposure settings applied. The aim of the study was to quantify the effects of these factors on the ambient dose. The dosimeter was positioned with varying distance from the direct beam (from 30 to 150 cm) and on different level above the floor (55 cm, 85 cm, and 150 cm. The study consisted of two parts. In the first part a plastic water tank (thickness: 18 cm) was used as source of scatter radiation. Different exposure settings (77 kVp; 20 - 10 - 5 - 2.5 - 1.25 mAs) were applied. In the second part dose was measured during the examination of the abdomen of a large dog (thickness: 18 cm; 77 kVp, 20 mAs) and of the skull of a cat (thickness: 6 cm; 55 kVp, 20 mAs). At the level of the patient (85 cm above the floor) the dose decline relative to the distance followed a quadratic function. In the series "abdomen-dog" the mean dose values ranged from 51.6 microSv (30 cm distance) to 1.02 microSv (150 cm distance). The corresponding doses for the series "skull-cat" were 0.98 microSv and 0.02 microSv, respectively. Comparably lower doses were measured on the lines along the table, when non-irradiated parts of the body were located between the exposed patient volume and the dosimeter. At 150 cm above the floor higher doses were observed relative to the doses at the level of the table. The following conclusions can be drawn: (1.) Depending on the target volume the ambient dose varies in a wide range. (2.) An increase of the distance of only few centimetres is reducing exposure considerably. Therefore persons should make use of it whenever this is possible. (3.) Persons should stand on the short sides of the table while fixing the patient. (4.) Head and neck are relatively highly exposed. Methods to protect the thyroid gland and the eye lens are indicated. (5.) Since different exposure levels can be applied in digital radiography, the range of dose levels is rather wide. Therefore strict dose discipline (e.g. by use of exposure tables and dose indicators) is necessary to avoid continuing overexposure.     

New concepts in human oncology: is it possible to use them in veterinary medicine as well?

In human oncology, novel targeted therapy focusing on monoclonal antibodies and tyrosine kinase inhibitors has become an attractive anticancer strategy. The introduction of antiangiogenetic drugs and metronomic chemotherapy has also increased the therapeutic arsenal. Chemotherapy still plays a key role in the treatment of many tumors affecting dogs and cats. However, novel anticancer strategies (including tyrosine kinase inhibitors and monoclonal antibodies, as well as antiangiogenetic treatments) are becoming relevant in veterinary medicine, too. The goal of this review is to describe new therapeutic strategies for cancer treatment in veterinary medicine, including less well-known chemotherapeutic drugs.     

Use of computerized image analysis to quantify staphylococcal adhesion to canine corneocytes: does breed and body site have any relevance to the pathogenesis of pyoderma?

An optimized system of computerized image analysis was used to investigate variations in the adherence of Staphylococcus intermedius to canine corneocytes from four different breed groups and six different anatomical sites. S. intermedius showed significantly greater adherence to the head and neck compared with the dorsum, but adherence to the limb, axilla and groin did not differ from other sites. Furthermore, there was significantly greater adherence of S. intermedius to corneocytes from the dorsum, forelimb, axilla and groin of Boxers and Bull Terriers than Spaniels and Hounds. S. intermedius, and also Pseudomonas aeruginosa, exhibited abundant adherence, which was significantly greater than Staphylococcus aureus, Streptococcus canis, Klebsiella pneumoniae and Escherichia coli. In addition, S. intermedius adherence demonstrated a sigmoid dose-response curve with increasing bacterial concentration. These results suggest that S. intermedius adheres to canine corneocytes by a specific receptor-ligand interaction and adheres to the skin of some breeds more avidly than others. However, variations in adherence between body regions would not account for the predilection sites of canine bacterial pyoderma.