Yersiniosis in deer from the Otago-Southland region of New Zealand

Samples from 350 routine deer cases submitted to Invermay Animal Health Laboratory for diagnosis during 1979–1982 were examined specifically for the presence of Yersinia sp. An analysis of 57 cases of yersiniosis due to Yersinia pseudotuberculosis is made and two cases due to Yersinia enterocolitica are described. The occurrence of cases appeared strongly correlated with periods of stress, predominantlyin winter when cool wet conditions and lack of grazing combined to precipitate the disease. Animals up to one year old were most commonly affected (64% of cases). Of the 61 strains of Yersinia pseudotuberculosis isolated 35 were of Serotype I, 17 of Serotype II and nine of Serotype III. All strains of Yersinia pseudotuberculosis and the strains of Yersinia enterocolitica isolated from the two cases described were Hela cell invasive and gave a positive autoagglutination test for virulence.     

Microclimate of the fleece

Extract

The microclimate of the fleece is important for a number of reasons. First, it may be considered as a buffer system between the animal and the macroclimate and, as such, has an important influence on the way the sheep manipulates its body temperature control mechanism. Secondly, it is an important component of the environment in which can be found large numbers of micro-organisms, some of which are harmful to the animal and some harmful to the fleece. Thirdly, it influences the survival and habits of a number of ectoparasites and these, too, can be harmful to the animal and the fleece.     

Bottom-up down from the top: Honeydew as a carbon source for soil organisms

Honeydew produced by aphids is a well-studied food source for mutualistic ants. Although considerable amounts drop onto the soil surface there are hardly any studies dealing with the potential effects of this additional C source for soil organisms, particularly those living at the soil surface. We studied this question by simulating honeydew and investigating plots under Populus canescens formerly infested with aphids on two ruderal sites differing in soil organic matter content and vegetation cover. The simulated honeydew input increased microbial biomass with some delay in week 10. Both natural and simulated honeydew raised the activity densities of an epigeic Collembola taxon, the Bourletiellidae, but not of the dominant Hemisotoma thermophila. The honeydew effect varied over time and with the site, and was more pronounced at the nutrient-poor site for Collembola, but not for microbial biomass. Ant consumption reduced the amount of honeydew reaching the soil surface by 50%. The activity density of H. thermophila was negatively related to ants and spiders, hinting at a top-down control. Honeydew clearly acts as a bottom-up force for soil organisms, which is however only part of the complex network connecting the food webs of primary producers and decomposers.     

Prevalence of Ehrlichia canis, Anaplasma platys, Babesia canis vogeli, Hepatozoon canis, Bartonella vinsonii berkhoffii, and Rickettsia spp. in dogs from Grenada

To identify the tick-borne pathogens in dogs from Grenada, we conducted a serologic survey for Ehrlichia canis in 2004 (104 dogs) and a comprehensive serologic and molecular survey for a variety of tick-borne pathogens in 2006 (73 dogs). In 2004 and 2006, 44 and 32 dogs (42.3% and 43.8%) were seropositive for E. canis, respectively. In 2006, several tick-borne pathogens were identified by serology and PCR. DNA of E. canis, Anaplasma platys, Babesia canis vogeli, Hepatozoon canis, and Bartonella sp. were identified in 18 (24.7%), 14 (19.2%), 5 (7%), 5 (7%), and 1 (1.4%) dogs, respectively. Six (8.2%) dogs were seropositive for Bartonella vinsonii subsp. berkhoffii. All dogs were seronegative and PCR-negative for Rickettsia spp. Coinfection with two or three pathogens was observed in eight dogs. Partial 16S rRNA E. canis and A. platys sequences were identical to sequences in GenBank. Partial 18S rRNA gene sequences from the Grenadian H. canis were identical to each other and had one possible mismatch (ambiguous base) from H. canis detected from Spain and Brazil. Grenadian B. c. vogeli sequences were identical to B. c. vogeli from Brazil and Japan. All of the detected pathogens are transmitted, or suspected to be transmitted, by Rhipicephalus sanguineus. Results of this study indicate that dogs from Grenada are infected with multiple tick-borne pathogens; therefore, tick-borne diseases should be included as differentials for dogs exhibiting thrombocytopenia, leukopenia, fever, or lethargy. One pathogen, E. canis, is also of potential public health significance.     

Comparison of computer assisted surgery with conventional technique for treatment of abaxial distal phalanx fractures in horses: an in vitro study

Objective— To (1) evaluate and compare computer-assisted surgery (CAS) with conventional screw insertion (conventional osteosynthesis [COS]) for treatment of equine abaxial distal phalanx fractures; (2) compare planned screw position with actual postoperative position; and (3) determine preferred screw insertion direction.
Study design— Experimental study.
Sample population— Cadaveric equine limbs (n=32).
Methods— In 8 specimens each, a 4.5 mm cortex bone screw was inserted in lag fashion in dorsopalmar (plantar) direction using CAS or COS. In 2 other groups of 8, the screws were inserted in opposite direction. Precision of CAS was determined by comparison of planned and actual screw position. Preferred screw direction was also assessed for CAS and COS.
Results— In 4 of 6 direct comparisons, screw positioning was significantly better with CAS. Results of precision analysis for screw position were similar to studies published in human medicine. None of evaluated criteria identified a preferred direction for screw insertion.
Conclusion— For abaxial fractures of the distal phalanx, superior precision in screw position is achieved with CAS technique compared with COS technique.
Clinical Relevance— Abaxial fractures of the distal phalanx lend themselves to computer-assisted implantation of 1 screw in a dorsopalmar (plantar) direction. Because of the complex anatomic relationships, and our results, we discourage use of COS technique for repair of this fracture type.     

Study of the short- and long-term outcomes of 65 horses with peritonitis

The records of 65 horses with peritonitis examined at two uk referral centres over a period of 12 years were reviewed. Peritonitis was defined in terms of the horse's peritoneal fluid containing more than 5 x 10(9) nucleated cells/l. Horses that had developed peritonitis after abdominal surgery or a rupture of the gastrointestinal tract were excluded. Of the 65 horses, 56 (86 per cent) survived to be discharged. Follow-up information was obtained from practice records and telephone calls to the owners for 38 of the horses. Of these, 32 (84 per cent) had survived for at least 12 months and were considered to be long-term survivors; the others six were euthanased within 12 months. Thirteen (34 per cent) of the horses discharged had experienced complications that could have been sequelae to peritonitis and eight of the 13 were euthanased. The cause of the peritonitis was identified in 15 cases; survival rates were lowest in horses with peritonitis secondary to urinary tract involvement or intra-abdominal masses. Of the other 50 cases, 47 (94 per cent) survived to discharge, but two were euthanased owing to recurrent colic.     

Association of hyperlactatemia with age,diagnosis, and survival in equine neonates

Objective – To investigate the association between blood lactate concentration, measured at admission and following 12–36 hours of treatment, and age, diagnosis, and survival in neonatal foals. Design – Retrospective, observational study. Setting – Two equine referral hospitals. Animals – One hundred and twelve foals ≤96 hours of age were included. Interventions – Arterial or venous blood samples were obtained from all foals at admission and surviving foals at 12–36 hours. Measurements – The lactate concentration (LAC) was recorded at 2 time points: admission (LAC‐Admission) and 12–36 hours following treatment (LAC‐24 hours). Main Results – LAC decreased by 0.05 mmol/L for each increased hour of age at presentation. Premature/dysmature foals demonstrated increased odds of nonsurvival of 55% for each 1 mmol/L increase in LAC‐Admission while foals with major diagnoses of neonatal encephalopathy (NE), enteritis and ‘Other’ had increased odds of nonsurvival of 52%, 113%, and 247%, respectively, for each 1.0 mmol/L increase in LAC. Blood‐culture positive foals had significantly lower LAC than blood culture negative foals. LAC‐Admission and LAC‐24 hours were significantly larger in nonsurviving foals. LAC‐Admission of >6.9 mmol/L and LAC‐24 hours >3.2 mmol/L, respectively, correctly classified 85.6% and 94.1% of cases as survivors or nonsurvivors. No differences were found when the 24‐hour change in LAC was investigated in terms of outcome, age at admission, or major diagnosis; however, LAC‐24 hours remained significantly associated with survival. Conclusions – Admission or persistent hyperlactatemia is associated with a nonsurvival. Younger foals, premature/dysmature foals, and foals with neonatal encephalopathy had the largest LAC.