Hoof Conformation and Palmar Process Fractures of the Distal Phalanx in Warmblood Foals

This study evaluated onset and incidence of palmar process fractures in foals and investigated corresponding changes in hoof conformation. Radiographs of 17 warmblood foals were taken at 1 week and at 2, 4, 6, 8, and 12 months of age and examined for evidence of palmar process fractures. Hoof parameters were measured from the radiographs, and comparisons were made between fractured and nonfractured feet. All foals suffered at least one fracture during the study period, with an average age of 3.68 ± 0.20 months at fracture occurrence. Hoof conformation and fracture occurrence were not significantly correlated. Foals consistently demonstrated higher lateral heights in the right foot and higher medial heights in the left foot. Hoof angle increased until 3 months of age and then gradually dropped. Hoof-pastern axis exhibited a broken forward conformation, but approached a more correct conformation by 12 months of age. There was a significant reduction in variation of variables for hoof and pastern angle in both feet, and hoof-pastern axis in the right foot. Hoof conformation does not appear to be a causative factor of palmar process fractures. It is possible that these fractures are a normal part of bone remodeling.     

Laryngeal, laryngotracheal, and tracheal masses in cats: 27 cases (1998-2003)

Medical records of 27 cats with masses of the larynx and trachea were examined. Six cats had inflammatory masses, and 21 cats had neoplastic lesions. A definitive diagnosis was reached in 22 cats with a single biopsy. The median age of the cats was 12.0 years (range 6 to 20 years). Dyspnea was the most common clinical sign. Accurate diagnoses were best obtained through direct laryngeal or tracheal examination combined with histological examination of tissue biopsies. Kaplan-Meier survival data for all inflammatory and neoplastic lesions showed a median survival of 5 days, with 7.4% of cats alive at 1 year.     

Anesthesia of male axis deer (Axis axis): evaluation of thiafentanil, medetomidine, and ketamine versus medetomidine and ketamine.

Thiafentanil oxalate, previously known as A-3080, is a synthetic opioid used for chemical immobilization of a variety of nondomestic hoofstock species. This study compared the combination of thiafentanil oxalate, medetomidine, and ketamine (TMK; 0.09 +/- 0.02 mg/kg, 0.01 +/- 0.003 mg/kg, and 1.36 +/- 0.33 mg/kg, respectively) with the combination of medetomidine and ketamine (MK; 0.09 +/- 0.02 mg/kg and 3.48 +/- 0.55 mg/kg, respectively) for anesthetization of 17 captive male axis deer (Axis axis) for vasectomy. Nine deer received TMK and eight deer received MK via projectile syringe during the months of January and February, 2005. Mean induction and arousal times, vital signs, and arterial blood gas values were monitored and compared. All animals received supplemental oxygen during the surgical procedure. Animals receiving TMK were reversed with naltrexone (100 mg/mg thiafentanil) and atipamazole (5 mg/mg medetomidine). Animals receiving MK were reversed with atipamazole (5 mg/mg medetomidine). Two MK animals and three TMK animals required supplementation with ketamine i.v. immediately upon handling. Six of the nine animals immobilized with TMK required intubation for positive-pressure ventilation. Two of these six animals also required isoflurane to maintain anesthesia. Mean induction time was 3.5 +/- 2.0 min in the TMK group, and 9.8 +/- 6.7 min in the MK group. Despite shorter mean induction times, animals anesthetized with TMK experienced unpredictable inductions, apnea, muscle rigidity, limb movement, and significant respiratory and metabolic lactic acidosis. MK resulted in smoother inductions, better respiratory function, and less adverse metabolic disturbances, and thus was considered superior to TMK for anesthesia in captive axis deer at the dosages tested.     

Invasive slug populations (Arion vulgaris) as potential vectors for Clostridium botulinum

Background

Norwegian meadows, including those for silage production, are recently found heavily invaded by the slug Arion vulgaris in exposed areas. As a consequence, large numbers of slugs might contaminate grass silage and cause a possible threat to animal feed quality and safety. It is well known that silage contaminated by mammalian or avian carcasses can lead to severe outbreaks of botulism among livestock. Invertebrates, especially fly-larvae (Diptera), are considered important in the transfer of Clostridium botulinum type C and its toxins among birds in wetlands. C. botulinum form highly resistant spores that could easily be consumed by the slugs during feeding. This study aimed to determine whether Arion vulgaris could hold viable C. botulinum and enrich them, which is essential knowledge for assessing the risk of botulism from slug-contaminated silage. Slug carcasses, slug feces and live slugs were tested by a quantitative real-time PCR (qPCR) method after being fed ≅ 5.8 × 10⁴ CFU C. botulinum type C spores/slug.

Results

Low amounts of C. botulinum were detected by qPCR in six of 21 slug carcasses with an even spread throughout the 17 day long experiment. Declining amounts of C. botulinum were excreted in slug feces up to day four after the inoculated feed was given. C. botulinum was only quantified the first two days in the sampling of live slugs. The viability of C. botulinum was confirmed for all three sample types (slug carcasses, slug feces and live slugs) by visible growth in enrichment media combined with obtaining a higher quantification cycle (Cq) value than from the non-enriched samples.

Conclusions

Neither dead nor live invasive Arion vulgaris slugs were shown to enrich Clostridium botulinum containing the neurotoxin type C gene in this study. Slugs excreted viable C. botulinum in their feces up to day four, but in rapidly decreasing numbers. Arion vulgaris appear not to support enrichment of C. botulinum type C.     

Using 1-Hz GPS data to measure deformations caused by the Denali fault earthquake

The 3 November 2002 moment magnitude 7.9 Denali fault earthquake generated large, permanent surface displacements in Alaska and large-amplitude surface waves throughout western North America. We find good agreement between strong ground-motion records integrated to displacement and 1-hertz Global Positioning System (GPS) position estimates collected approximately 140 kilometers from the earthquake epicenter. One-hertz GPS receivers also detected seismic surface waves 750 to 3800 kilometers from the epicenter, whereas these waves saturated many of the seismic instruments in the same region. High-frequency GPS increases the dynamic range and frequency bandwidth of ground-motion observations, providing another tool for studying earthquake processes.     

Does invasive plant management aid the restoration of natural ecosystems?

Invasive alien plants of natural ecosystems, commonly referred to as weeds, can reduce the abundance and diversity of native flora and fauna, and alter ecosystem processes. Using Australia’s 20 ‘Weeds of National Significance’ (WoNS), we investigated how natural ecosystems responded following their management. We reviewed the literature and surveyed land managers involved in WoNS management programs by distributing a questionnaire through various e-mail networks. While most of the 95 papers reviewed measured the effect of management on the target WoNS, only 18 assessed the response of other plant species. In these studies, native plant species did not necessarily recover following management and in many instances the managed WoNS was replaced by other weed species. Three other studies investigated the response of invertebrate communities and an ecosystem process following WoNS management but none examined the response of vertebrates or microbial communities. A total of 168 replies were received to the land manager survey. Of the 142 land managers who evaluated their WoNS management program, 86 monitored the response of native plant species and/or other weeds, mostly using qualitative assessments. These managers reported no vegetation response after management of the WoNS (7%) or re-colonisation by a combination of native and weed species (52%) or only by native plants (33%) or the targeted WoNS (2%). Our results emphasise the need to select sites for weed management that are less degraded and thus have a higher likelihood of natural recovery and/or to incorporate activities that facilitate recovery of native plant communities in conjunction with weed removal.     

Introduced northern pike consumption of salmonids in Southcentral Alaska

The impacts of introduced northern pike (Esox lucius) on salmonid populations have attracted much attention because salmonids are popular subsistence, sport and commercial fish. Concern over the predatory effects of introduced pike on salmonids is especially high in Southcentral Alaska, where pike were illegally introduced to the Susitna River basin in the 1950s. We used pike abundance, growth, and diet estimates and bioenergetics models to characterise the realised and potential consumptive impacts that introduced pike (age 2 and older) have on salmonids in Alexander Creek, a tributary to the Susitna River. We found that juvenile salmonids were the dominant prey item in pike diets and that pike could consume up to 1.10 metric tons (realised consumption) and 1.66 metric tons (potential consumption) of juvenile salmonids in a summer. Age 3–4 pike had the highest per capita consumption of juvenile salmonids, and age 2 and age 3–4 pike had the highest overall consumption of juvenile salmonid biomass. Using historical data on Chinook salmon and pike potential consumption of juvenile salmonids, we found that pike consumption of juvenile salmonids may lead to collapsed salmon stocks in Alexander Creek. Taken together, our results indicate that pike consume a substantial biomass of juvenile salmonids in Alexander Creek and that coexistence of pike and salmon is unlikely without management actions to reduce or eliminate introduced pike.