Prevalence and molecular characterization of Giardia duodenalis in dogs in Israel

Three hundred and two stool samples were collected from municipal shelters and owned dogs in different geographical locations in Israel from December 2016 to September 2017 and examined for Giardia and assemblage type by PCR targeting the 18S rRNA and β-giardin genes. Overall Giardia prevalence was 24.5 % (74/30). Giardia prevalence was 1.9-fold higher in dogs ≤ 6 months old compared to > 6 ≤ 12 months old and older dogs [25/61 (41 %), 18/73 (24.6 %) and 31/166 (18.7 %), respectively, (p = 0.001)], 2.3-fold higher in winter [32/90 (35.5 %)] compared to its prevalence during autumn [15/60 (25 %)], spring [10/62 (16.1 %)] and summer [17/89 (19.1 %), p = 0.003)], and 2.7-fold more frequent among diarrheic dogs [23/43 (53.4 %)] compared to those with formed stools [51/253 (20.1 %)], (p = 0.001)]. The Giardia sp. assemblages detected were C and D. Higher infection rates in young, diarrheic dogs, sampled during winter, and housed in municipal shelters, indicates the need for targeted preventive measures.     

Neuroinflammatory diseases of the central nervous system of dogs: A retrospective study of 207 cases (2008–2019)

In this study we describe 207 cases of neuroinflammatory diseases of the central nervous system (CNS) in dogs autopsied at the Athens Veterinary Diagnostic Laboratory (University of Georgia, United States) from 2008 to 2019. Idiopathic and infectious diseases were diagnosed in 111 cases (53.6%) and 96 cases (46.4%), respectively. Idiopathic diseases consisted of granulomatous meningoencephalomyelitis (n = 42; 37.8% of idiopathic cases), nonspecific lymphoplasmacytic meningoencephalomyelitis (n = 39; 35.1%), necrotizing meningoencephalomyelitis (n = 22; 19.8%), presumed steroid-responsive meningitis-arteritis (n = 6; 5.4%), and necrotizing leukoencephalitis (n = 2; 1.8%). Infectious diseases consisted of bacterial infections (n = 49; 51% of infectious cases), viral infections (n = 39; 40.6%), fungal infections (n = 5; 5.2%), and parasitic infections (n = 3; 3.1%). Our study provides an overview of the most frequent neuroinflammatory diseases of the CNS of dogs in our diagnostic routine; indicates that a comprehensive diagnostic approach, including a thorough evaluation of the pathology findings and ancillary laboratory testing results, is important for an adequate diagnosis of neurologic diseases in dogs; and underscores the problems associated with the variability in tissue sample collection methods among cases. The great number of nonspecific lymphoplasmacytic meningoencephalitis also highlights the need for development of molecular laboratory tests to identify potential infectious agents in these cases.     

The epidemiology and economics of pooled testing for disease investigations of lead exposure involving beef cattle in Saskatchewan (2007–2019)

From 2007 to 2019, the Western College of Veterinary Medicine Disease Investigation Unit conducted lead investigations in 12 beef cow-calf herds and tested 1104 presumed exposed but clinically unaffected cattle, 49 of which were unsafe for slaughter (blood lead ≥ 0.1 ppm). In all investigations, the lead source should be evaluated, and all potentially exposed animals intended for food should be tested. Clinically affected animals should be tested individually. Individual testing of clinically unaffected animals may be expensive for large groups. However, pooling a conservative number of blood samples (n = 2 to 5) from clinically unaffected cattle may efficiently identify groups that are safe for slaughter. If a pooled test produces a blood lead concentration over the minimum threshold (0.1 ppm/n), these samples should be individually re-tested. Herd size, lead toxicity prevalence, pool size, and number of pools that require individual re-testing all affect the potential cost savings of pooled testing.     

Use of n-alkanes to estimate feed intake in ruminants: a meta-analysis

Precise techniques to estimate feed intake by ruminants are critical to enhance feed efficiency and to reduce greenhouse gas emissions and nutrient losses to the environment. Using a meta-analysis, we evaluated the accuracy of the n-alkane technique to predict feed intake in cattle and sheep and assessed the relationships between feed intake and fecal recovery (FR) of n-alkanes. The database was composed of 28 studies, including 129 treatments (87 and 42 for cattle and sheep, respectively) and 402 animals (232 cattle and 170 sheep) fed at troughs, from published studies. Relationships between observed (in vivo measurement) and predicted feed intake by C31:C32 and C32:C33 n-alkane pairs were evaluated by regression. Meta-regression addressed the relationships between the difference in FR of n-alkane pairs and the error in intake estimation, as well as the amount and duration of C32 n-alkane dosing. Regression of observed intake on n-alkane-based estimates revealed good relationships in cattle (adjusted R² = 0.99 for C31:C32, and adjusted R² = 0.98 for C32:C33; P < 0.0001) and in sheep (adjusted R² = 0.94 for C31:C32, and adjusted R² = 0.96 for C32:C33; P < 0.0001). FR of natural n-alkanes showed a coefficient of variation of about 15% and 16% for C31 and C33, respectively, in cattle. In sheep, the coefficient of variation was 8% and 14% for C31 and C33, respectively. The relationships between the difference of FR of n-alkane pairs and the error in feed intake estimation in cattle were characterized by an adjusted R² = 0.83 for C31:C32 (P < 0.0001) and adjusted R² = 0.93 for C32:C33 (P < 0.0001). In sheep, they were characterized by an adjusted R² = 0.69 for C31:C32 (P < 0.001) and adjusted R² = 0.76 for C32:C33 (P < 0.001). The n-alkane technique provided the reliability for estimating feed intake in cattle and sheep in barn experiments. The present meta-analysis demonstrated that without correction for differences in FR of n-alkane pairs, deviation in feed intake prediction would occur. However, further research is necessary to determine the relationship between the n-alkane dosing procedure (daily amount and duration of dosing) and FR of n-alkane.     

Prevalence of Coxiella burnetii in Central and Eastern European dairy herds

The aim of the present study was to assess the prevalence of Coxiella burnetii in dairy herds in Central and Eastern European countries based on ELISA and PCR tests. A total of 370 bulk tank milk samples were collected in 2019 originating from Croatia (n = 13), Czech Republic (n = 138), Hungary (n = 126), Serbia (n = 24), Slovakia (n = 53) and Slovenia (n = 16). Prevalence of C. burnetii differed according to the country of origin with Croatia showing 100.00%, the Czech Republic 98.55%, Hungary 97.61%, Serbia 70.83%, Slovakia 90.56% and Slovenia showing 62.50% average percentages of the positive herds. C. burnetii specific ELISA showed 100.00% positivity in all examined countries if herds consisted of equal or above 250 milking cows. The growing number of farms managing large number of animals, where cattle density is high correlates with the increasing prevalence of C. burnetii in the region.     

Clinical, ultrasonographic, and pathologic findings in 70 camels (Camelus dromedarius) with Johne��s disease

This study evaluated the use of ultrasonography for the diagnosis of Johne’s disease in camels (Camelus dromedarius). Seventy camels with confirmed Johne’s disease were examined by ultrasonography and subsequent necropsy; 15 healthy camels were included as controls. The most outstanding findings were visible enlargement of the mesenteric lymph nodes in 52 (74%) camels. Lesions had either echogenic (26%; n = 18) or anechoic (69%; n = 48) capsule and the contents were either anechoic (21%; n = 15), echogenic (27%; n = 19), or heterogeneous (46%; n = 32). Clumps of echogenic tissue interspersed with fluid pockets were imaged between the intestinal loops in 9 (13%) camels. There was mild, moderate, or severe thickening and corrugation of the intestinal wall, excessive anechoic fluid in the abdominal cavity in 18 (26%) camels, increased hepatic brightness in 30 (43%) camels, and pericardial and pleural effusions in 22 (31%) camels. Sensitivity values for detecting intestinal lesions and enlarged mesenteric lymph nodes were 95% and 84%, respectively.     

Long-bone fractures in llamas and alpacas: 28 cases (1998–2008)

Treatment and outcome of camelids with long-bone fractures are described. Medical records (1998–2008) of camelids (n = 28) with long-bone fractures were reviewed for signalment, time to presentation, fracture type, method of repair, duration of hospitalization, and post-operative complications. Follow-up information was obtained via telephone interviews with owners. Mean age and weight at presentation were 3.4 years and 56.3 kg, respectively. Twenty-six fractures were treated with internal fixation (n = 11), external fixation (n = 10), combination of internal and external fixation (n = 3), amputation (n = 1), and external fixation followed by amputation (n = 1). Long-term follow-up information was obtained for 19 of the 26 animals. The post-operative complication rate was 23% and owner satisfaction was high. Animals with open fractures were more likely to experience complications. Internal fixation was associated with superior alignment and outcome. Internal fixation techniques should be recommended for camelids.     

Prevalence of intestinal parasites in dogs from public shelters in Serbia

Data on endoparasitic infections in dogs from dog shelters in Southeastern Europe are limited; thus, this study aimed to add to the existing knowledge on this topic by reporting on the prevalence of intestinal parasites in dogs from public dog shelters in the Republic of Serbia. In 2017 and 2018, individual and pooled fecal samples, were collected from 1267 dogs from six shelters. All samples were qualitatively examined for parasites using flotation tests. Seven taxa of intestinal parasites were identified: Cystoisospora spp., ascarids: Toxocara canis and Toxascaris leonina, hookworms, Trichuris vulpis, taeniids and Dipylidium caninum. The overall prevalence of intestinal parasites was 58. 3 % (78. 1 % in young dogs and 53.1 % in adult dogs). The parasites detected in both young (<1 year old) and adult dogs (>1 year old) were Cystoisospora spp. (20 % and 4.9 %), T. canis (33.5 % and 14.7 %), T. leonina (7.7 % and 2.3 %), and hookworms (16.9 % and 15 %), respectively. However, T. vulpis (9.6 %), taeniids (1.3 %), and D. caninum (5.4 %) were detected only in adult dogs. In the Belgrade shelter, young dogs had a higher prevalence of endoparasitic infections (18.9 %, 49/260) than adult dogs (14.8 %, 149/1007). In the Subotica, Jagodina and Niš shelters, young dogs had significantly higher (p < 0.001 and p < 0.05, respectively) prevalence of endoparasitic infections (10 %, 12.3 % and 14.6 %) than adult dogs (5.3 %, 8 % and 7.2 %). These results will be useful for establishing health care programs in dog shelters and implementing effective strategies for the control of intestinal parasites.     

Classification of Arcobacter species isolated from aborted pig fetuses and sows with reproductive problems in Brazil

Seventeen field isolates of Arcobacter species were recovered in Brazil from aborted porcine fetal livers (n = 3), kidneys (n = 2), and thoracic fluid (n = 1). Arcobacter species were also recovered from uterine and oviductal tissues (n = 5) and a placenta from sows with reproductive problems. These isolates were initially presumed to be Arcobacter cryaerophilus on the basis of aerobic growth at 30°C, indoxyl acetate hydrolysis, catalase and oxidase reactions, growth on MacConkey agar, sensitivity to 3.5% sodium chloride, and susceptibility to nalidixic acid (40 mg/ml). The isolates were confirmed as Arcobacter using polymerase chain reaction, and were classified as A. cryaerophilus 1A (24%), A. cryaerophilus 1B (71%), and A. butzleri (6%) using restriction fragment length polymorphism.     

Detection of Aspergillus-specific antibodies by agar gel double immunodiffusion and IgG ELISA in feline upper respiratory tract aspergillosis

Feline upper respiratory tract aspergillosis (URTA) is an emerging infectious disease. The aims of this study were: (1) to assess the diagnostic value of detection of Aspergillus-specific antibodies using an agar gel double immunodiffusion (AGID) assay and an indirect immunoglobulin G (IgG) ELISA; and (2) to determine if an aspergillin derived from mycelia of Aspergillus fumigatus, Aspergillus niger and Aspergillus flavus can be used to detect serum antibodies against cryptic Aspergillus spp. in Aspergillus section Fumigati. Sera from cats with URTA (group 1: n = 21) and two control groups (group 2: cats with other upper respiratory tract diseases, n = 25; group 3: healthy cats and cats with non-respiratory, non-fungal illness, n = 84) were tested. Isolates from cats with URTA comprised A. fumigatus (n = 5), A. flavus (n = 1) and four cryptic species: Aspergillus felis (n = 12), Aspergillus thermomutatus (Neosartorya pseudofischeri, n = 1), Aspergillus lentulus (n = 1) and Aspergillus udagawae (n = 1).Brachycephalic purebred cats were significantly more likely to develop URTA than other breeds (P = 0.013). The sensitivity (Se) of the AGID was 43% and the specificity (Sp) was 100%. At a cut-off value of 6 ELISA units/mL, the Se of the IgG ELISA was 95.2% and the Sp was 92% and 92.9% for groups 2 and 3 cats, respectively. Aspergillus-specific antibodies against all four cryptic species were detected in one or both assays. Assay Se was not associated with species identity. Detection of Aspergillus-specific antibodies by IgG ELISA has high Se and Sp for diagnosis of feline URTA.     

Preliminary studies of chemical immobilization of captive juvenile estuarine (Crocodylus porosus) and Australian freshwater (C. johnstoni) crocodiles with medetomidine and reversal with atipamezole

ObjectiveTo establish a safe, reliable and reversible immobilization protocol for captive juvenile crocodiles.Study designProspective, randomized, clinical study.AnimalsThirty male estuarine crocodiles (body mass 1–12.1 kg) and 10 male Australian freshwater crocodiles (body mass 4.1–12.8 kg).MethodsAn optimized dose of medetomidine (0.5 mg kg^?1) was administered intramuscularly (IM) into the tail (Group 1; n = 5), pelvic limb (Group 2; n = 5) and thoracic limb (Groups 3 and 4; n = 5 in each group) of estuarine crocodiles weighing 3–12.1 kg. Their heart and respiratory rates and degree of immobilization were monitored every 15 minutes until recovery and daily thereafter for 3 subsequent days. In Group 4 (n = 5), medetomidine was antagonized with an optimized dose of atipamezole (2.5 mg kg^?1) given IM into the thoracic limb and time to recovery recorded. The effects of increasing doses of medetomidine given IM in the thoracic limb (n = 4) and intravenously (n = 6) were determined in 1–2 kg estuarine crocodiles. Australian freshwater crocodiles (4.1–12.8 kg) were administered medetomidine IM into the thoracic limb in divided doses at 0.5 mg kg^?1 (n = 5) and 0.75 mg kg^?1 (n = 5) and similarly monitored.ResultsImmobilization was achieved only in the estuarine crocodiles >3 kg and when medetomidine was administered into the thoracic limb. Immobilization was achieved within 30 minutes and the duration of immobilization lasted approximately 90 minutes. Immobilization in estuarine crocodiles was readily reversed with atipamezole. A dose of 0.75 mg kg^?1 was required to immobilize Australian freshwater crocodiles and the onset of immobilization was longer and the duration shorter than seen in the estuarine crocodiles. The heart and respiratory rates of all immobilized animals decreased significantly and arterial blood pressure became undetectable in the animals in which it was measured.Conclusions and clinical relevanceMedetomidine administered in the thoracic limb of captive estuarine and Australian freshwater crocodiles, ranging from 3 to 12.8 kg, provides a predictable onset and duration of immobilization sufficient for physical examination, sample collection, short minor procedures and translocation of the animals. Atipamezole administered in the thoracic limb results in complete reversal of the effects of medetomidine in the estuarine crocodile and a rapid return to normal behaviour.     

Acute lead poisoning in western Canadian cattle — A 16-year retrospective study of diagnostic case records

This study describes the epidemiology of acute lead poisoning in western Canadian cattle over the 16-year period of 1998 to 2013 and reports background bovine tissue lead concentrations. Case records from Prairie Diagnostic Services, Western College of Veterinary Medicine, identified 525 cases of acute lead toxicity over the investigational period. Poisonings were influenced by year (P < 0.0001) and month (P < 0.0001). Submissions were highest in 2009 (15.6%), 2001 (11.2%), and 2006 (9.9%). Most cases were observed during May, June, and July (62.3%). Cattle 6 months of age and younger were frequently poisoned (53.5%; P < 0.0001). Beef breeds were predominantly poisoned. Mean toxic lead concentrations (mg/kg wet weight) in the blood, liver, and kidney were 1.30 ± 1.70 (n = 301), 33.5 ± 80.5 (n = 172), and 56.3 ± 39.7 (n = 61). Mean normal lead concentrations in the blood, liver, and kidney were 0.036 ± 0.003 mg/kg (n= 1081), 0.16 ± 0.63 mg/kg (n = 382), and 0.41 ± 0.62 mg/kg (n = 64).     

A composite scale to recognize abdominal pain and its variation over time in response to analgesia in rabbits

ObjectiveTo refine a composite scale for pain evaluation in rabbits and evaluate it for pain variations over time. To determine the differences between objective-Centro Animali Non Convenzionali Rabbit Scale (CANCRS) and subjective-Visual Analogue Scale (VAS) in assessing abdominal pain.Study designObservational case–control study.AnimalsA total of 86 rabbits, 47 healthy animals and 39 animals with gastrointestinal stasis syndrome (RGIS), participated in the study; of 39 animals with RGIS, 32 animals participated in the second part of the study.MethodsIn part 1, rabbits underwent pain assessments with VAS and CANCRS. In part 2, the animals underwent four pain assessments with three CANCRS. The first assessment was performed prior to pain management, the others after 30, 60 and 90 minutes. Statistics included Mann–Whitney U test for in-between group comparisons and analysis of variance to assess differences over time. Sensitivity and specificity for each variable of CANCRS were calculated to obtain weighting factors.ResultsCANCRS showed differences between healthy and diseased rabbits (p = 0.0001), and median scores were 5 [interquartile range (IQR): 4–6) and 9 (IQR: 7–11), respectively. VAS showed differences between healthy and diseased rabbits (p = 0.02), and median scores were 4 (IQR: 2–5.35) and 5.3 (IQR: 2.65–6.45), respectively. The cut-off scores for CANCRS and VAS for differentiation between healthy and diseased rabbits were 7 (specificity 89%, sensitivity 79%) and 4.4 (specificity 59%, sensitivity 69%), respectively. Internal validity testing of CANCRS was significant at each time point.Conclusions and clinical relevanceSome variables should be excluded from CANCRS when assessing abdominal pain. CANCRS performed better than VAS, and it detected variations in pain in response to analgesia.     

Zoonotic intestinal parasites and vector-borne pathogens in Italian shelter and kennel dogs

This study investigated the presence of zoonotic parasites and vector-borne pathogens in dogs housed in kennels and shelters from four sites of Italy. A total of 150 adoptable dogs was examined with different microscopic, serological and molecular methods.Overall 129 dogs (86%) were positive for one or more parasites and/or pathogens transmitted by ectoparasites. Forty-eight (32%) were positive for one infection, while 81 (54%) for more than one pathogen. The most common zoonotic helminths recorded were hookworms, roundworms and Capillaria aerophila, followed by mosquito-borne Dirofilaria spp. and Dipylidium caninum. One hundred and thirteen (77.9%), 6 (4.1%) and 2 (1.4%) dogs were positive for Rickettsia spp., Leishmania infantum and Anaplasma spp., respectively.The results show that dogs living in rescue facilities from the studied areas may be infected by many zoonotic internal parasites and vector-borne pathogens, and that control measures should be implemented.     

Determination and correlation of anti-Neospora caninum antibodies in dogs and cattle from Mexico

The aim of the present study was to determine and to compare through an indirect enzyme linked immunosorbent assay (ELISA) test, the presence of anti-Neospora caninum antibodies in city and farm dogs, as well as in farm cows, and the relationship among them. The correlation between anti-N. caninum antibodies in farm dogs and cattle was also assessed. The research was conducted in the dairy region of Tizayuca, Hidalgo, Mexico. The frequency of anti-N. caninum antibodies was significantly higher in farm dogs (n = 14) (51%) when compared to those from the city (n = 6) (20%) (P < 0.05), suggesting that farm dogs have a higher risk of exposure to the parasite. There was no significant difference in seropositivity between males (n = 11) (39%) and females (n = 9) (33%) (P > 0.05). The frequency of anti-N. caninum antibodies in farm cattle was significantly higher in farms with dogs (n = 158) (58%) when compared to those with no dogs (n = 43) (35%) (P < 0.05). These results suggest the possible transmission of the parasite from dogs to cattle.     

Intrauterine iodine administration is superior to antibiotics for reconception after late-embryonic losses in dairy cows

This field study was conducted to compare conception and insemination efficiency responses to intrauterine polyvinylpyrrolidone-iodine (PVP-I) and antibiotic (AB) treatments in dairy cows that experienced pregnancy loss. Data were collected from lactation cows with a history of pregnancy loss 27 to 70 days post-insemination (n = 97) during the 1st to 3rd lactation (days in milk = 196 ± 28). Cows were subjected to 1 of 3 treatments: i) 50 mL saline solution intrauterine infusion (S; n = 23); ii) 2% PVP-I (n = 42); or iii) 150 mg of amoxicillin trihydrate and 40 mg/mL gentamicin sulphate (n = 32). All cows followed the progesterone-based fixed-time insemination protocol. Data were analyzed by Chi-square test and 1-way analysis of variance. The PVP-I treatment (n = 25; 59.5%) was as effective as the AB treatment (n = 19; 59.4%), compared to the S treatment (n = 5; 21.7%) to achieve a new conception. The cows in group PVP-I conceived in a shorter time than those in group AB (46.0 ± 8.7 days versus 105.0 ± 10.0 days; P < 0.05) with a more efficient insemination to conception ratio (2.32 ± 0.43 versus 4.10 ± 0.32; P < 0.05). Data suggest that intrauterine PVP-I administration is superior to intrauterine AB administration in rescheduling reproductive protocol upon late embryonic and fetal losses.     

Daytime shelter-seeking behavior in domestic horses

We examined daytime shelter-seeking behavior (SSB) in domestic horses housed outdoors and studied the relationship of temperature, precipitation, and wind speed with SSB. We studied 50-60 Arabian horses (depending upon time of year) and 3-5 draft horses. Horses were divided among 8 pastures containing sheds. There were 2 study phases. In the first, up to 676 scan samples were taken for each pasture over a 12-month period (total observations = 5,025). At each observation, we noted whether or not a shed was being used. In the second phase, randomly selected focal animals were chosen from each pasture and observed twice per week for 16 weeks. Forty-four focal animals were observed (total observations = 3930). At each sampling time, we noted weather conditions and recorded whether each subject was standing or lying inside or next to shelters. Shelter usage ranged from a low of <10% of observations in many weather conditions to a high of 62% of observations when it was snowing and wind speed was >4.9 m/s. When wind was >2.2 m/s, there was a significant effect of rain on shelter usage, that is, more horses used shelters in rainy, breezy conditions (P < 0.01). When wind was >2.2 m/s, there was a significant effect of snow on shelter usage, that is, more horses used shelters in snowy, breezy conditions (P < 0.01). Though overall shelter usage was typically <10%, it appears that shelter access is very important in certain weather conditions.     

Technical note: using an automated head chamber system to administer an external marker to estimate fecal output by grazing beef cattle

The objective of this experiment was to determine if titanium dioxide (TiO₂) dosed through an automated head chamber system (GreenFeed; C-Lock Inc., Rapid City, SD, USA) is an acceptable method to measure fecal output. The GreenFeed used on this experiment had a 2-hopper bait dispensing system, where hopper 1 contained alfalfa pellets marked with 1% titanium dioxide (TiO₂) and hopper 2 contained unmarked alfalfa pellets. Eleven heifers (BW = 394 ± 18.7 kg) grazing a common pasture were stratified by BW and then randomized to either 1) dosed with TiO₂-marked pellets by hand feeding (HFD; n = 6) or 2) dosed with TiO₂-marked pellets by the GreenFeed (GFFD; n = 5) for 19 d. During the morning (0800), all heifers were offered a pelleted, high-CP supplement at 0.25% of BW in individual feeding stanchions. The HFD heifers also received 32 g of TiO₂-marked pellets at morning feeding, whereas the GFFD heifers received 32 g of unmarked pellets. The GFFD heifers received a single aliquot (32 ± 1.6 g; mean ± SD) of marked pellets at their first visit to the GreenFeed each day with all subsequent 32-g aliquots providing unmarked pellets; HFD heifers received only unmarked pellets. Starting on d 15, fecal samples were collected via rectal grab at feeding and every 12 h for 5 d. A two-one sided t-test method was used to determine agreement and it was determined that the fecal output estimates by HFD and GFFD methods were similar (P = 0.04). There was a difference (P < 0.01; Bartlett’s test for homogenous variances) in variability between the dosing methods for HFD and GFFD (SD = 0.1 and 0.7, respectively). This difference in fecal output variability may have been due to variability of dosing times-of-day for the GFFD heifers (0615 ± 6.2 h) relative to the constant dosing time-of-day for HFD and constant 0800 and 2000 sampling times-of-day for all animals. This research has highlighted the potential for dosing cattle with an external marker through a GreenFeed configured with two (or more) feed hoppers because estimated fecal output means were similar; however, consideration of the increased variability of the fecal output estimates is needed for future experimental designs.     

Prevalence and risk factor investigation of Campylobacter species in beef cattle feces from seven large commercial feedlots in Alberta,Canada

This fecal prevalence study targeted cattle from 7 large (10 000 to > 40 000 head) commercial feedlots in Alberta as a means of establishing Campylobacter levels in cattle just prior to animals entering the food chain. Overall, 87% [95% confidence interval (CI) = 86–88] of 2776 fresh pen-floor fecal samples were culture positive for Campylobacter species, with prevalences ranging from 76% to 95% among the 7 feedlots. Campylobacter spp. prevalence was 88% (95% CI = 86–90) in the summer (n = 1376) and 86% (95% CI = 85–88) in the winter (n = 1400). In addition, 69% (95% CI = 66–71) of 1486 Campylobacter spp. positive samples were identified as Campylobacter jejuni using hippurate hydrolysis testing. Of those, 64% (95% CI = 58–70) of 277 and 70% (95% CI = 67–72) of 1209 Campylobacter isolates were identified as C. jejuni in winter and summer, respectively. After accounting for clustering within pen and feedlot, feedlot size and the number of days on feed were associated with Campylobacter spp. isolation rates. The high isolation rates of Campylobacter spp. and C. jejuni in feedlot cattle feces in this study suggest a potential role for feedlot cattle in the complex epidemiology of campylobacters in Alberta.     

Rapamycin administration during an acute heat stress challenge in growing pigs

Study objectives were to determine the effects of rapamycin (Rapa) on biomarkers of metabolism and inflammation during acute heat stress (HS) in growing pigs. Crossbred barrows (n = 32; 63.5 ± 7.2 kg body weight [BW]) were blocked by initial BW and randomly assigned to 1 of 4 environmental-therapeutic treatments: 1) thermoneutral (TN) control (n = 8; TNCon), 2) TN and Rapa (n = 8; TNRapa), 3) HS control (n = 8; HSCon), or 4) HS and Rapa (n = 8; HSRapa). Following 6 d of acclimation to individual pens, pigs were enrolled in two experimental periods (P). During P1 (10 d), pigs were fed ad libitum and housed in TN conditions (21.3 ± 0.2°C). During P2 (24 h), HSCon and HSRapa pigs were exposed to constant HS (35.5 ± 0.4°C), while TNCon and TNRapa pigs remained in TN conditions. Rapamycin (0.15 mg/kg BW) was orally administered twice daily (0700 and 1800 hours) during both P1 and P2. HS increased rectal temperature and respiration rate compared to TN treatments (1.3°C and 87 breaths/min, respectively; P < 0.01). Feed intake (FI) markedly decreased in HS relative to TN treatments (64%; P < 0.01). Additionally, pigs exposed to HS lost BW (4 kg; P < 0.01), while TN pigs gained BW (0.7 kg; P < 0.01). Despite marked changes in phenotypic parameters caused by HS, circulating glucose and blood urea nitrogen did not differ among treatments (P > 0.10). However, the insulin:FI increased in HS relative to TN treatments (P = 0.04). Plasma nonesterified fatty acids (NEFA) increased in HS relative to TN treatments; although this difference was driven by increased NEFA in HSCon compared to TN and HSRapa pigs (P < 0.01). Overall, circulating white blood cells, lymphocytes, and monocytes decreased in HS compared to TN pigs (19%, 23%, and 33%, respectively; P ≤ 0.05). However, circulating neutrophils were similar across treatments (P > 0.31). The neutrophil-to-lymphocyte ratio (NLR) was increased in HS relative to TN pigs (P = 0.02); however, a tendency for reduced NLR was observed in HSRapa compared to HSCon pigs (21%; P = 0.06). Plasma C-reactive protein tended to differ across treatments (P = 0.06) and was increased in HSRapa relative to HSCon pigs (46%; P = 0.03). Circulating haptoglobin was similar between groups. In summary, pigs exposed to HS had altered phenotypic, metabolic, and leukocyte responses; however, Rapa administration had limited impact on outcomes measured herein.