Background Equine gastrointestinal nematodes (GINs) have been the subject of intermittent studies in Australia over the past few decades. However, comprehensive information on the epidemiology of equine GINs, the efficacy of available anthelmintic drugs and the prevalence of anthelmintic resistance (AR) in Australasia is lacking. Herein, we have systematically reviewed existing knowledge on the horse GINs recorded in Australia, and main aspects of their pathogeneses, epidemiology, diagnoses, treatment and control. Methods Six electronic databases were searched for publications on GINs of Australian horses that met our inclusion criteria for the systematic review. Subsets of publications were subjected to review epidemiology, diagnoses, pathogeneses, treatment and control of GINs of horses from Australia. Results A total of 51 articles published between 1950 to 2018 were included. The main GINs reported in Australian horses were cyathostomins (at least 28 species), Draschia megastoma , Habronema muscae , H. majus , Oxyuris equi , Parascaris equorum , Strongyloides westeri and Trichostrongylus axei across different climatic regions of Queensland, New South Wales, Victoria, and Western Australia. Nematodes are diagnosed based on the traditional McMaster egg counting technique, though molecular markers to characterise common GINs of equines were characterised in 1990s. The use of anthelmintic drugs remains the most widely-used strategy for controlling equine GIN parasites in Australia; however, the threshold of faecal egg count that should trigger treatment in horses, remains controversial. Furthermore, anthelmintic resistance within GIN population of horses is becoming a common problem in Australia. Conclusions Although GINs infecting Australian horses have been the subject of occasional studies over the past few decades, the effective control of GIN infections is hampered by a generalised lack of knowledge in various disciplines of equine parasitology. Therefore, coordinated and focused research is required to fill our knowledge gaps in these areas to maximise equine health and minimise economic losses associated with the parasitic infections in Australia. Electronic supplementary material The online version of this article (10.1186/s13071-019-3445-4) contains supplementary material, which is available to authorized users.

BackgroundIvermectin is widely used in veterinary practice for the treatment of ecto- and endo-parasites. In wildlife, an extra-label use this parasiticide is sometimes associated with toxicity. Different treatment regimens have been used in ivermectin toxicosis. The present report describes a successful reversal of ivermectin toxicity by intravenous administration of a commercially available lipid emulsion in a captive African lion (Panthera leo).Case presentationA 2-year old captive African lion (Panthera leo) weighing ~130 kg was presented with acute neurological impairment and bilateral blindness that had developed 24 h after ivermectin exposure. The animal was treated with a commercially available lipid emulsion along with supportive therapy and experienced complete recovery.ConclusionTo our knowledge, this is the first case report of the use of lipid emulsion in the management of ivermectin induced blindness in an African lion and it appears that intravenous lipid emulsion may be an effective therapy in ivermectin toxicity in lions. Further testing in expanded clinical trials is clearly warranted.

The mitochondrial gene coding for subunit 4 of the NADH dehydrogenase complex I (nad4) has been isolated and characterized from lettuce, Lactuca sativa. Analysis of nad4 genes in a number of plants by Southern hybridization had previously suggested that the intron content varied between species. Characterization of the lettuce gene confirms this observation. Lettuce nad4 contains two exons and one group IIA intron, whereas previously sequenced nad4 genes from turnip and wheat contain three group IIA introns. Northern analysis identified a transcript of 1600 nucleotides, which represents the mature nad4 mRNA and a primary transcript of 3200 nucleotides. Sequence analysis of lettuce and turnip nad4 cDNAs was used to confirm the intron/exon border sequences and to examine RNA editing patterns. Editing is observed at the 5' and 3' ends of the lettuce transcript, but is absent from sequences that correspond to exons two, three and the 5' end of exon four in turnip and wheat. In contrast, turnip transcripts are highly edited in this region, suggesting that homologous recombination of an edited and spliced cDNA intermediate was involved in the loss of introns two and three from an ancestral lettuce nad4 gene.

Coxiellosis caused by Coxiella burnetii is a cosmopolitan zoonosis, which causes significant losses through abortions and stillbirths in small ruminants. A cross-sectional seroprevalence study was conducted in two major sheep and goat farming districts of Punjab (Layyah and Muzaffargarh), Pakistan. In total, 542 small ruminants (271 sheep and goats each) of both sexes (60 males and 482 females) of different age groups from 104 flocks (52 flocks of either species) were randomly selected for the collection of sera and related epidemiological information. The sampling plan was devised at the expected prevalence of 50%, confidence interval (CI) of 95%, and error margin of 5%. A commercial indirect enzyme-linked immunosorbent assay (iELISA; ID Vet) was used to test the samples for the presence of both phase I and II antibodies. A high herd level prevalence (73.1%, 95% CI 63.5-81.3) was recorded in the studied districts. Individual level seroprevalence was recorded as 30.8% (95% CI 26.9-34.9). Higher value was recorded in females (32%) when compared with males (21.7%). Higher prevalence (34.8%, 95% CI 21.4-50.2) was observed in animals of 1 year (nulliparous) than to primiparous (24.8%, 95% CI 17.4-33.5) and multiparous (32.3%, 95% CI 27.6-37.3) animals. Univariable analysis indicated that caprine species (odds ratio [OR] 1.96, p = 0.22), females (OR = 1.70, p = 0.104), infestation with ticks (OR = 234.39, p < 0.001), abortion history (OR 1.96, p = 0.14), retention of fetal membranes (OR 1.50, p = 0.35), keeping a single breed in a herd (OR 1.50, p = 0.56), and mixed feeding management (OR 1.37, p = 0.33) were the variables found associated with high prevalence of antibodies to C. burnetii. The study indicates that seroprevalence of coxiellosis was high in the studied small ruminant population and further studies are required to discern its epidemiology more precisely.

Background Cyathostomins are the most important and common parasitic nematodes of horses, with > 50 species known to occur worldwide. The frequent and indiscriminate use of anthelmintics has resulted in the development of anthelmintic resistance (AR) in horse nematodes. In this study we assessed the efficacy of commonly used anthelmintics against cyathostomins in Australian thoroughbred horses. Methods Two drug efficacy trials per farm were conducted on two thoroughbred horse farms in the state of Victoria, Australia. In the first trial, the horses on Farm A were treated with single and combinations of anthelmintics, including oxfendazole (OFZ), abamectin (ABM), abamectin and morantel (ABM + MOR), moxidectin (MOX) and oxfendazole and pyrantel (OFZ + PYR), at the recommended doses, whereas the horses on Farm B only received MOX, at the recommended dose. The faecal egg count reduction test (FECRT) was used to determine the efficacy and egg reappearance period (ERP) of anthelmintics. Based on the results of the first trial, the efficacies of MOX and a combination of ABM + MOR were reassessed to confirm their activities against cyathostomins. Results Of the five anthelmintic products tested on Farm A, resistance against OFZ, ABM and OFZ + PYR was found, with efficacies of − 41% (− 195% lower confidence limit [LCL]), 73% (60% LCL) and 82% (66% LCL) at 2 weeks post-treatment, respectively. The FECRT showed high efficacies of MOX and ABM + MOR (100%) at 2 week post-treatment and shortened ERPs for these anthelmintics (ABM + MOR: 4 weeks; MOX: 5 weeks). Resistance to MOX was found on Farm B, with a reduced efficacy of 90% (70% LCL) and 89% (82% LCL) at 2 weeks post-treatment in trials one and two, respectively. Conclusions This study provides the first evidence of MOX- and multidrug-resistant (ABM and combinations of anthelmintics) cyathostomins in Australia and indicates the need for continuous surveillance of the efficacy of currently effective anthelmintics and large-scale investigations to assess the ERP for various anthelmintics. Graphical Abstract