First evidence of spawning migration by goldfish (Carassius auratus); implications for control of a globally invasive species

Goldfish (Carassius auratus) was one of the first fishes to be domesticated and has been widely introduced across the globe, but is now considered one of the world's worst invasive aquatic species. Surprisingly, there is a dearth of information on its spatial and temporal movement patterns, which hampers the development of effective control programmes. We examined the movement patterns of an introduced population of C. auratus in a south‐western Australian river using passive acoustic telemetry. The study population had a high residency index within the array (i.e. proportion of all days at liberty that, on average, each fish was detected by a receiver) with fish being detected on 64% of days. The individuals were also reasonably mobile, travelling a mean of 0.30 km (linear river kilometres).day^‐1 within the array, and one fish moved 231.3 km over the 365‐day study period (including 5.4 km in a 24 hr period). Importantly, C. auratus displayed significant seasonal movement patterns including a clear shift in habitats during its breeding period with most mature individuals being detected in an off‐channel wetland during that time. The results of this study strongly suggest that C. auratus undertook a spawning migration into a lentic habitat. These results have important implications for developing control programmes for the species, such as targeting connections to off‐channel lentic systems during its breeding period.     

Distribution of Salmonella serovars and phage types on 80 Ontario swine farms in 2004

The objective of this study was to describe the distribution of Salmonella spp. on Ontario grower-finisher pig farms. Eighty swine farms were visited from January through July 2004. On each farm, fecal samples were collected from 5 pens, 2 rectal samples and 1 pooled sample from fresh manure on the floor per pen. Salmonella was isolated from 91 (11%) of the 800 rectal samples and 73 (18%) of the 397 pooled samples. Overall, Salmonella was recovered from 37 (46%) of the 80 farms. On each positive farm, Salmonella was cultured from 1 to 7 pigs or 1 to 5 pens. Of the 37 farms, 18, 13, 5, and 1 yielded 1, 2, 3, and 4 serovars, respectively. The most common serovars were S. Typhimurium var. Copenhagen, S. Infantis, S. Typhimurium, S. Derby, S. Agona, S. Havana, and S. enterica subsp. I:Rough-O. The 3 most frequent phage types were PT 104, PT 104a, and PT 104b. There was a statistically fair agreement between samples collected directly from pigs and pooled pen samples in determining the Salmonella status at the pen and farm level (kappa = 0.6, P < 0.0001). However, in 62 pens, Salmonella status, serovars, or phage types differed between the pig and pooled pen samples. The distribution of Salmonella on the swine farms in this study indicates that, in developing an intervention strategy, priority should be given to farms positive for S. Typhimurium var. Copenhagen. Also, the variation in Salmonella status between pig and pooled pen samples deserves consideration in a sampling strategy.     

Relationships between demographic variables and lead toxicosis in cattle evaluated at North American veterinary teaching hospitals

OBJECTIVE: To determine associations between age, sex, breed, and month and year of admission and the diagnosis of lead toxicosis in cattle. DESIGN: Retrospective case-control study. Sample Population-Records of all cattle evaluated at North American veterinary teaching hospitals during the years 1963 to 2002, which were available through the Veterinary Medical Database. PROCEDURES: Logistic regression was used to evaluate the associations between postulated risk factors and the occurrence of lead toxicosis in cattle and predict the occurrence of the diagnosis of lead toxicosis in cattle. RESULTS: 413 cases of lead intoxication and 202,363 control cattle were identified and met the inclusion criteria. Cattle < 4 years of age were at increased risk for the diagnosis of lead intoxication relative to cattle > or = 4 years of age. Cattle > or = 2 months and < 6 months of age had the greatest risk for lead intoxication (odds ratio, 12.3). Angus cattle were at greater risk for toxicosis (odds ratio, 1.95), compared with other breeds. The risk of lead toxicosis was greater before 1985 (odds ratio, 1.94) than the risk thereafter. The risk of lead toxicosis diagnosis was greatest in the months of May, June, July, and August. CONCLUSIONS AND CLINICAL RELEVANCE: Lead toxicosis in cattle was associated with age < 4 years and the Angus breed. A seasonal pattern existed with peak occurrence in the late spring and summer. The occurrence of lead toxicosis has declined over time.     

Surgical approaches for cesarean section in cattle

Bovine practitioners are often presented with dystocias that require a cesarean section. Many practitioners perform this surgery using the same approach each time due to their comfort with one specific approach or lack of familiarity of other available options. The goal of this article is to explain the advantages, disadvantages, and indications for each of the different approaches to aid the practitioner in achieving better surgical success rate.     

Stress alters the cellular and proteomic compartments of bovine bronchoalveolar lavage fluid

The stresses of transportation, weaning and commingling are associated with an increased incidence of bacterial and viral pneumonia in cattle. Proteins expressed in the epithelial lining fluid (ELF) of the lungs, in conjunction with resident leukocytes, represent the first line of defence against opportunistic pathogens, and stress-induced alterations in their expression may reveal markers of disease susceptibility. Bronchoalveolar lavage fluid was sampled in weaned and transported calves and ELF protein expression was compared to a control group of calves using two-dimensional electrophoresis (2DE). Serum and pulmonary haptoglobin were increased following stress concurrent with the number of blood neutrophils. Using 2DE, significant changes in expression were observed in spots identified by mass spectrometry as annexin A1 and A5, odorant-binding protein (OBP), isocitrate dehydrogenase, fibrinogen, heme-binding protein, alpha-2-HS-glycoprotein, alpha-1-antichymotrypsin and albumin. Quantification of OBP mRNA by real-time RT-PCR and OBP protein by western blot revealed gender-dependent differences in relative OBP expression in response to stress. These findings reveal stress-associated protein changes in pulmonary ELF and suggest a mechanism through which stress alters respiratory disease susceptibility.     

A comparison of two combinations of xylazine-ketamine administered intramuscularly to alpacas and of reversal with tolazoline

ObjectiveTo evaluate the anesthetic and cardiorespiratory effects of two doses of intramuscular (IM) xylazine/ketamine in alpacas, and to determine if tolazoline would reduce the anesthetic recovery time.Study designProspective randomized crossover study.AnimalsSix castrated male alpacas.MethodsEach alpaca received a low dose (LD) (0.8 mg kg⁻¹ xylazine and 8 mg kg⁻¹ ketamine IM) and high dose (HD) (1.2 mg kg⁻¹ xylazine and 12 mg kg⁻¹ ketamine IM) with a minimum of one week between trials. Time to sedation, duration of lateral recumbency and analgesia, pulse rate, respiratory rate, hemoglobin oxygen saturation, arterial blood pressure, blood-gases, and the electrocardiogram were monitored and recorded during anesthesia. With each treatment three alpacas were randomly selected to receive tolazoline (2 mg kg⁻¹ IM) after 30 minutes of lateral recumbency.ResultsOnset of sedation, lateral recumbency and analgesia was rapid with both treatments. The HD was able to provide ≥30 minutes of anesthesia in five of six alpacas. The LD provided ≥30 minutes of anesthesia in three of six alpacas. Respiratory depression and hypoxemia occurred with the HD treatment during the first 10 minutes of lateral recumbency: two animals were severely hypoxemic and received nasal oxygen for 5 minutes. Heart rate decreased, but there were no significant changes in arterial blood pressure. Tolazoline significantly shortened the duration of recumbency with the HD.ConclusionsThe HD provided more consistent clinical effects in alpacas than the LD. Intramuscular tolazoline shortened the duration of lateral recumbency in alpacas anesthetized with the HD combination.Clinical relevanceBoth doses of the combination were effective in providing restraint in alpacas and the duration of restraint was dose dependent. Supplemental oxygen should be available if using the HD and IM administration of tolazoline will shorten the recovery time.     

Evaluating the risk of tick‐borne relapsing fever among occupational cavers—Austin,TX, 2017

Tick‐borne relapsing fever (TBRF) is a potentially serious spirochetal infection caused by certain species of Borrelia and acquired through the bite of Ornithodoros ticks. In 2017, Austin Public Health, Austin, TX, identified five cases of febrile illness among employees who worked in caves. A cross‐sectional serosurvey and interview were conducted for 44 employees at eight organizations that conduct cave‐related work. Antibodies against TBRF‐causing Borrelia were detected in the serum of five participants, four of whom reported recent illness. Seropositive employees entered significantly more caves (Median 25 [SD: 15] versus Median 4 [SD: 16], p = 0.04) than seronegative employees. Six caves were entered more frequently by seropositive employees posing a potentially high risk. Several of these caves were in public use areas and were opened for tours. Education of area healthcare providers about TBRF and prevention recommendations for cavers and the public are advised.     

Landscape,fire and habitat: which features of recently burned heathland influence site occupancy of an early successional specialist?

Context

Multiple ecological drivers generate spatial patterns in species’ distributions. Changes to natural disturbance regimes can place early successional habitat specialists at an increased risk of extinction by altering landscape patterns of habitat suitability.

Objectives

We developed a series of hypotheses to evaluate the effects of landscape structure, fire history, and site-level habitat quality on site occupancy by an early successional specialist, the eastern chestnut mouse (Pseudomys gracilicaudatus).

Methods

We obtained eight years of monitoring data from 26 sites in recently burned heathland in southeast Australia. We used generalised linear models to determine which explanatory variables were related to occupancy. We also explored predictability in patterns of small mammal species co-occurrence.

Results

Landscape structure (patch area, landscape heterogeneity) was strongly related to site occupancy. Site occupancy was associated with dead shrubs in the understory and rock cover on ground layer, but was not directly influenced by recent or historical fire. Contrary to contemporary ecological theory, we found no predictable species associations in our early successional community.

Conclusions

We recommend surveys take account of landscape configuration and proximity to suitable habitat for optimal results. Fire regimes expected to promote eastern chestnut mouse population growth should encourage the retention of critical habitat features rather than be based on temporal rates of successional stages. For management to adequately account for post-disturbance patterns in early successional communities, a species-by-species, multi-scaled approach to research is necessary.