Monitoring trends in bat populations through roost surveys: methods and data from Rhinolophus hipposideros

Volunteers counted lesser horseshoe bats (Rhinolophus hipposideros) emerging from 79 roosts throughout Wales prior to parturition over a 5-year period. Analysis of the count data and environmental variables revealed that there was no statistically significant change in the number of bats counted during the monitoring period. A maximum count of 5118 lesser horseshoe bats for one of the years of the study, suggests a Welsh population of >10,000. Within years, date had a strong influence on roost count with higher counts occurring later in the year. Analyses of roosts for which data was available in most years failed to find any evidence of changes in number of emerging bats over time either between roosts or across geographical regions. Over the time period studied, the population of R. hipposideros was stable. Power analysis suggested that the present monitoring programme should be able to detect a 5% increase or decrease over a 5-year period and could detect smaller trends over longer periods of time even when some data were missing. Roost surveys can therefore be a valuable tool to assess the status of a bat species, alert conservationists to population declines and provide feedback regarding the success of conservation management for bats.     

A Review of Canine Pseudocyesis

The purpose of this article is to review the most relevant features of the physiology, clinical signs, diagnosis, treatment and prevention of canine pseudocyesis (PSC). This is a physiological syndrome, characterized by clinical signs such as: nesting, weight gain, mammary enlargement, lactation and maternal behaviour, which appears in non‐pregnant bitches at the end of metaoestrus. PSC is a frequent finding in domestic dogs. Although it is generally admitted that prolactin (PRL) plays a central role in the appearance of PSC, its precise aetiophysiology is not completely understood yet. A number of clinical studies suggest that at some point of metaoestrus circulating PRL levels rise in overtly pseudopregnant bitches. Individual differences in sensitivity to PRL as well as the existence of molecular variants of canine PRL with different bioactivity versus immunoreactivity ratios may help clarify the aetiopathology of PSC. Diagnosis of PSC is based on the presence of typical clinical signs in metaoestrous non‐pregnant bitches. Considering that PSC is a self limiting physiological state, mild cases usually need no treatment. Discouraging maternal behaviour and sometimes fitting Elizabethan collars to prevent licking of the mammary glands may suffice in these cases. Sex steroids (oestrogens, progestins and androgens) have been traditionally used to treat PSC but the side‐effects usually outweigh the benefits of these medications. Inhibition of PRL release by ergot derivatives [ bromocriptine (10–100 μg/kg per day for 10–14 days], cabergoline (5 μg/kg per day during 5–10 days), metergoline (0.2 mg/kg per day during 8–10 days) has proved to be effective for the treatment of canine PSC. Although some of these ergot derivatives present some untoward side‐effects, they are transient and can usually be managed. Predisposed bitches not intended for breeding should be spayed as ovariectomy is the only permanent preventive measure.     

Biological diversity among serotype 2 Marek's disease viruses

Selected biological characteristics were determined for 14 low-passage serotype 2 Marek's disease virus (MDV) isolates. Four of these isolates were also tested after extensive serial passage in chicken embryo fibroblast cultures. Observations were made on replication in vitro and in vivo, pathogenicity by in ovo inoculation, antigenicity, and protection against virulent MDV challenge. Among the low-passage isolates, there were some differences in pathogenicity after in ovo inoculation but relatively little difference in other characteristics, with the exception of the HN-1 strain, which replicated more rapidly in cell culture but produced generally lower in vivo responses than other isolates. After extended in vitro passage, isolates replicated much more readily in cell culture and produced lower pathologic responses in vivo than low-passage isolates, as has been reported for serotype 1 isolates. No antigenic differences among isolates were detected, but high-passage isolates induced lower levels of precipitating antibodies than low-passage isolates, indicating a possible reduction in A antigen production. The observed diversity associated with strain and passage level may be of value in the selection of optimum vaccine strains.     

Reduced growth of Lucilia cuprina larvae fed serum from sheep treated with anthelmintics

The effect of three commonly used anthelmintics, levamisole hydrochloride, ivermectin and closantel, on the development of the sheep blowfly, Lucilia cuprina, was determined. Sheep were treated with each anthelmintic using the manufacturers' recommended dose for helminth control. Both ivermectin and closantel significantly (p < 0.05) reduced the growth rate of larvae of L cuprina cultured in vitro on serum from these sheep. Levamisole hydrochloride had no effect. Ivermectin was effective for less than 6 days after treatment, whereas closantel significantly reduced larval growth 21 days after treatment. Dose-response experiments showed that lower concentrations of both ivermectin and closantel were not as effective in reducing larval growth.     

A striated muscle on the hard palate of rodents and rabbits

Summary A striated muscle of the hard palate has been previously described in some rodents and rabbits. It is not termed in the official veterinary anatomical nomenclature. The aim of this work was to verify the existence of this muscle. Heads of the golden hamster (Mesocricetus auratus), the guinea pig (Cavia aperea f. porcellus), the laboratory rat (Rattus norvegicus var. alba), the field vole (Microtus agrestis) and the domestic rabbit (Oryctolagus cuniculus f. domesticus) have been dissected. Moreover, histological sections have been prepared from heads of the field vole. In all species under study, we could detect a striated muscle of the hard palate composed of an anterior and a posterior muscle. The anterior muscle originated on the os incisivum and diverged in anterior, lateral and posterior directions. The posterior muscle originated on the processus palatinus maxillae and verged into the m. buccinator. Inter-species differences could be detected in shape and position of the muscle. The palatal muscle was innervated by the ramus buccalis of the facial nerve. Whether this muscle should be classified as an individual facial muscle or as a part of the m. buccinator remains to be discussed.