Outbreak of Philophthalmus gralli in four greater rheas (Rhea americana)

Using slit‐lamp biomicroscopy, conjunctival biopsy, and morphological identification, a flock of four Greater rheas (Rhea americana) in Arizona were diagnosed with conjunctivitis secondary to Philophthalmus gralli (P. gralli) infection. Aquatic snails from the exhibit’s water source were identified as Melanoides tuberculatus, a known vector for P. gralli. Comparison of partial sequences of DNA regions from P. gralli adults removed from the rheas and metacercariae from the aquatic snails demonstrated a 100% match, confirming the source of infection. The flock was divided into two treatment groups: the most severely affected rheas received both manual removal of trematodes and praziquantel 1% ointment OU q12 h and the least severely affected rheas were only given praziquantel 1% ointment OU q12 h. The rheas were permanently relocated away from the infected water source and aquatic snails. Initial resolution was seen at 17 weeks in the most severely affected rhea, which had 675 adult P. gralli removed and topical praziquantel. The two rheas that only received topical praziquantel showed resolution within 3 and 15 weeks. Current recommendations for treating P. gralli include: manual removal of trematodes, topical praziquantel 1% ointment, and relocation away from infected water sources and aquatic snails.     

Has the optimum time for faecal nematode egg count reduction testing in sheep in New Zealand changed?

Abstract

AIM: To determine what, if any, changes have taken place in the optimum time, for undertaking faecal egg count reduction tests (FECRT) in sheep in New Zealand.

METHODS: A comparison was made between the numbers and types of nematode genera adequately represented for testing purposes (faecal nematode egg count (FEC) of >50 epg) in initial FECRT case submissions to a veterinary laboratory in New Zealand, during two 4-year periods, in 1992–1995 and 2006–2009.

RESULTS: Although there were some minor differences between them, the seasonal patterns of occurrence remained basically the same for all parasite genera in both datasets, with their individual peak periods of representation occurring during February to May in all instances. Not surprisingly, this period of maximum seasonal occurrence for each parasite genus also coincided with those months of the year when the greatest numbers of worm genera were adequately represented for faecal nematode egg count reduction (FECR) testing.

CONCLUSIONS: The results of this study indicate that the optimum time for conducting FECRT in sheep in New Zealand continues to be during the late summer-autumn months of February to May. However, they also reaffirmed that even during this optimal period there are still likely to be many occasions when relatively few nematode genera may be sufficiently well represented for satisfactory FECR testing. Accordingly, veterinary practitioners ought to be aware that, in order to obtain a complete picture of the resistance status of all worm genera on a particular property, such testing may need to be carried out on more than one occasion.     

Libyostrongylus infections in ostriches — a brief review with particular reference to their detection in New Zealand

Following the recent discovery of Libyostrongylus douglassii in ostriches in New Zealand, information relating to this nematode is reviewed. Amongst some of the topics considered are the parasite's distribution and prevalence, its life cycle and survival, and its diagnosis and control. Of particular interest from a New Zealand perspective is the potential for the parasite to infect other ratites, especially the kiwi. While the current evidence suggests that this may be unlikely to occur, the possibility that it might be able to do so cannot be ruled out entirely.     

Serological changes observed in horses infected with Anoplocephala perfoliata after treatment with praziquantel and natural reinfection

The serological changes in two groups of horses known to be harbouring Anoplocephala perfoliata were studied; 12 were treated with 1.5 mg/kg praziquantel and 200 microg/kg ivermectin, and 14 were treated with 200 microg/kg ivermectin. Serological and faecal analyses were carried out on each animal at intervals for 758 days. The titres of antibodies specific for A perfoliata decreased from the day of treatment to day 28 in both groups, and continued to decrease in the group treated with praziquantel and ivermectin, with the first significant decrease from the other group at day 121. From day 151 to day 295 the first significant increase in antibody levels in the group treated with both drugs was observed; no A perfoliata eggs were detected in the faeces of these animals until day 295 when five of the 10 were positive.     

Single‐voxel and multi‐voxel spectroscopy yield comparable results in the normal juvenile canine brain when using 3 Tesla magnetic resonance imaging

Conventional magnetic resonance imaging (MRI) characteristics of canine brain diseases are often nonspecific. Single‐ and multi‐voxel spectroscopy techniques allow quantification of chemical biomarkers for tissues of interest and may help to improve diagnostic specificity. However, published information is currently lacking for the in vivo performance of these two techniques in dogs. The aim of this prospective, methods comparison study was to compare the performance of single‐ and multi‐voxel spectroscopy in the brains of eight healthy, juvenile dogs using 3 Tesla MRI. Ipsilateral regions of single‐ and multi‐voxel spectroscopy were performed in symmetric regions of interest of each brain in the parietal (n = 3), thalamic (n = 2), and piriform lobes (n = 3). In vivo single‐voxel spectroscopy and multi‐voxel spectroscopy metabolite ratios from the same size and multi‐voxel spectroscopy ratios from different sized regions of interest were compared. No significant difference was seen between single‐voxel spectroscopy and multi‐voxel spectroscopy metabolite ratios for any lobe when regions of interest were similar in size and shape. Significant lobar single‐voxel spectroscopy and multi‐voxel spectroscopy differences were seen between the parietal lobe and thalamus (P = 0.047) for the choline to N‐acetyl aspartase ratios when large multi‐voxel spectroscopy regions of interest were compared to very small multi‐voxel spectroscopy regions of interest within the same lobe; and for the N‐acetyl aspartase to creatine ratios in all lobes when single‐voxel spectroscopy was compared to combined (pooled) multi‐voxel spectroscopy datasets. Findings from this preliminary study indicated that single‐ and multi‐voxel spectroscopy techniques using 3T MRI yield comparable results for similar sized regions of interest in the normal canine brain. Findings also supported using the contralateral side as an internal control for dogs with brain lesions.     

High field magnetic resonance imaging contributes to diagnosis of equine distal tarsus and proximal metatarsus lesions: 103 horses

Injury of the distal tarsus and proximal metatarsus commonly causes lameness. Magnetic resonance imaging (MRI) allows concurrent assessment of both the distal tarsal joints and suspensory ligament origin, and aids identification of lesions that may otherwise go undetected by other modalities. In this retrospective observational study, the medical records of a veterinary imaging center were searched for MRI exams of the distal tarsus and proximal metatarsus for the years 2012 through 2014. Studies for 125 limbs of 103 horses were identified and retrospectively evaluated by two board‐certified veterinary radiologists. Soft tissue and osseous changes were characterized and graded by degree of severity. The patients’ signalment, lameness severity, and results of diagnostic analgesia were recorded. Osteoarthritic changes of the distal intertarsal and tarsometatarsal joints were the most common findings. Other findings included bone marrow lesions, degenerative changes of the small cuboidal bones, subchondral cystic lesions, and intertarsal desmopathy. Suspensory ligament desmopathy was found in 53% of limbs. Fourty‐seven percent of limbs that responded to analgesia of the proximal suspensory ligament had more severe lesions in the distal tarsus. Bone marrow lesions of the third tarsal bone were the only MRI finding that correlated with grade of lameness in patients for which lameness grade was reported. The grade of lameness has a poor correlation with the severity of lesions found on MRI. The findings support the use of MRI for simultaneous evaluation of the proximal metatarsus and distal tarsus, particularly given the difficulty of lesion localization with diagnostic analgesia.     

Genetic‐Quantitative Study of the First‐Service Pregnancy Probability of Murrah Heifers

Because of the importance of reproduction in stock breeding systems, it is necessary to find selection criteria that increase reproductive efficiency. The aim of this study was to estimate genetic parameters for the probability of conception on first service (PROB) in Murrah heifers, and its association with other traits of economic interest [age at first calving (AFC), service period, calving interval and milk yield at 270 days], with the purpose of evaluating their use as selection criteria. Reproductive information and first lactation records of 1200 Murrah heifers were used to perform two‐trait analyses between PROB and the other characteristics. Bayesian inference was used to estimate the variance components, considering PROB as threshold and the other as linear factors. The results demonstrate that this trait has heritability of 0.15, indicating the possibility of a genetic gain by using it for selection. With respect to the genetic correlation estimates, the only high‐magnitude association was with AFC (?0.899), which is the current criterion indicating sexual precocity of females. In the light of the parameters estimated, the first‐service pregnancy rate is an alternative for indication of sexual precocity, although presenting a smaller genetic gain than the current standard AFC. Nevertheless, additional research should be conducted regarding this trait to assess the economic importance of its use in dairy buffalo production systems.     

Suppression of volcanism during rapid extension in the basin and range province, united states

Continental extension and volcanism are generally thought to be complementary. Stratigraphic and structural data from some highly extended parts of the Basin and Range province reveal instead that rapid extension appears to have suppressed volcanism. This relation may reflect enhanced crystallization of midcrustal magmas during extension resulting from exsolution of magmatic volatiles, increased interaction of magmas with meteoric water, and dispersal of magma into smaller bodies. Some rift environments may thus be characterized by voluminous synextensional plutonism with little or no concomitant volcanism.