Ovis Infestation Research Articles

First Molecular Diagnosis of Oestrus ovis (Linnaeus, 1758) Larvae Causing Conjunctival Ophthalmomyiasis in Mexico City, Mexico.

Human ophthalmomyiasis is a rare ocular parasitosis that results from the accidental infestation of dipteran larvae of several species, including Oestrus ovis (Linnaeus, 1758). This study aims to present the fourth documented human case of ophthalmomyiasis in Mexico, identifying the etiological agent through morphological and molecular analyses. Additionally, we investigated the phylogenetic position and genetic distances among different specimens globally characterized based on mitochondrial Cox1 sequences. A total of five larval specimens were extracted from the patient's eye, with two specimens allocated for identification based on morphological features using a stereomicroscope, and the remaining three preserved in absolute ethanol, one of them used for subsequent analysis using molecular methods. The mitochondrial Cox1 region was amplified and sequenced using automated Sanger sequencing. The resulting sequence was deposited in GenBank under accession number OR440699 and subjected to BlastN analysis against 35 other Cox1 sequences of O. ovis from GenBank. The identity and phylogenetic position of the strains were further explored using parsimony and maximum likelihood phylogenetic methods. Morphological examination of the larval specimens extracted from the patient's eye unequivocally identified them as O. ovis species. BlastN analysis and comprehensive phylogenetic investigations involving a total of 36 Cox1 sequences confirmed the taxonomic identity of the larvae. Notably, our sequence was positioned within the cluster formed by the Brazilian and two Iranian samples. This finding underscores a shared genetic ancestry among these distinct geographical isolates and provides valuable insights into the evolutionary relationships within O. ovis populations. The presence of O. ovis infestation in Mexico City suggests potential shifts in environmental conditions favoring fly proliferation, highlighting the need for vigilance in urban healthcare settings.

First report on the occurrence of psoroptic mange in llamas (Lama glama) of the Andean region.

An outbreak of Psoroptes sp.-caused mange was detected in a llama herd of Larcas, Jujuy province, Argentina. Infested llamas showed alopecia, erythema, hyperpigmentation, hyperkeratosis, and inflammation of the ear pinnae, as well as crusts and serous, serosanguineous, or purulent drainage with unpleasant smell in the external ear canal. Microscopic evaluation of skin scrapings revealed 0.5- to 0.7-mm-long acari identified as Psoroptes sp. based on their morphology. Histology showed a typical allergic reaction with perivascular to periadnexal mixed inflammatory infiltrate. Phylogenetic tree analysis showed that the cytochrome c oxidase subunit I gene sequences analyzed from the sampled acari clustered into a single P. ovis clade including sequences isolated from rabbits and bighorn sheep, with P. natalensis as a sister taxon that infested bighorn sheep from the USA. Phylogenetic analysis of cytochrome b sequences showed three well-supported clades, one of which contained the sequences of the Larcas llamas and US bighorn sheep isolates. This is the first report on P. ovis infestation of llamas raised in their original location. Investigations on mange etiological agents acting on South American camelids and their distribution are necessary to implement control strategies to mitigate the negative impacts of these parasitic infections.

Prevalence of Taenia ovis (sheep measles) in small ruminants slaughtered by unlicensed butchers in Iraq capital city

This study was aimed at investigating the prevalence of Taenia ovis (sheep measles) in sheep and goats among the unlicensed butcher's settings in Bagdad, Iraq. A total of 1194 sheep comprising 798 males and 396 females were inspected and out of these 41 and 17 (5.1 and 4.2%) were positive of T. ovis respectively. In goat a total of 162 comprising 122 males and 40 females were inspected out of which 39 and 19 (31.9 and 47.5%) were positive for T. ovis for male and female respectively. In this study, the prevalence of T. ovis in sheep of <18 months of age (5.3%) was higher as compared to those in sheep of over 18 months of age (4.9%), the prevalence of T. ovis was higher in male sheep (5.1%) as compared to the female sheep (4.2%). The trend of the prevalence of this parasite in goats was different from what was obtained in sheep, in this case the prevalence was higher in female goats as compared to male goats. Also the prevalence of T. ovis was significantly higher in older goats as compared to younger goats. For the breed the trend was similar to that of sheep where the local breed harbored more of T. ovis as compared to the imported breeds. Our results suggest that the high prevalence of the T. ovis infestations in the unlicensed butcher's settings is of great concern for public health, therefore authorities are to design a preventive program to curtail this problem.

Oestrus ovis sinusitis in a dog

AbstractA 2‐year‐old, female Cane Corso was presented for chronic epistaxis, reverse sneezing and purulent nasal discharge. Clinical examination was unremarkable. Bloodwork revealed a mild anaemia. Computed tomography of the nasal cavity was consistent with right frontal sinusitis with suspected foreign bodies. Surgical approach of the right sinus by frontal osteotomy allowed to perform an endoscopically guided extraction of a 15‐mm white ringed worm and multiple black worm‐like structures. The evaluation by an EVPC diplomate confirmed an Oestrus ovis infestation. After endoscopic lavage of the frontal sinus, the dog went home with an ivermectin‐based treatment. It was presented 7 months later for a recurrence of the clinical signs. Tomography and surgical approach to the right frontal sinus revealed persistent presence of the O. ovis infestation. After surgical removal of the parasite and oral isoxazoline treatment, the dog had no signs of clinical recurrence. Follow‐up computed tomography scan confirmed complete resolution of the sinusitis.

Macrophage Migration Inhibitory Factor in Psoroptes ovis: Molecular Characterization and Potential Role in Eosinophil Accumulation of Skin in Rabbit and Its Implication in the Host-Parasite Interaction.

Psoroptes ovis, a common surface-living mite of domestic and wild animals worldwide, results in huge economic losses and serious welfare issues in the animal industry. P. ovis infestation rapidly causes massive eosinophil infiltration in skin lesions, and increasing research revealed that eosinophils might play an important role in the pathogenesis of P. ovis infestation. Intradermal injection of P. ovis antigen invoked massive eosinophil infiltration, suggesting that this mite should contain some relative molecules involved in eosinophil accumulation in the skin. However, these active molecules have not yet been identified. Herein, we identified macrophage migration inhibitor factor (MIF) in P. ovis (PsoMIF) using bioinformatics and molecular biology methods. Sequence analyses revealed that PsoMIF appeared with high similarity to the topology of monomer and trimer formation with host MIF (RMSD = 0.28 angstroms and 2.826 angstroms, respectively) but with differences in tautomerase and thiol-protein oxidoreductase active sites. Reverse transcription PCR analysis (qRT-PCR) results showed that PsoMIF was expressed throughout all the developmental stages of P. ovis, particularly with the highest expression in female mites. Immunolocalization revealed that MIF protein located in the ovary and oviduct of female mites and also localized throughout the stratum spinosum, stratum granulosum, and even basal layers of the epidermis in skin lesions caused by P. ovis. rPsoMIF significantly upregulated eosinophil-related gene expression both in vitro (PBMC: CCL5, CCL11; HaCaT: IL-3, IL-4, IL-5, CCL5, CCL11) and in vivo (rabbit: IL-5, CCL5, CCL11, P-selectin, ICAM-1). Moreover, rPsoMIF could induce cutaneous eosinophil accumulation in a rabbit model and increased the vascular permeability in a mouse model. Our findings indicated that PsoMIF served as one of the key molecules contributing to skin eosinophil accumulation in P. ovis infection of rabbits.

Diagnosis of Oestrus ovis infestation in sheep by PCR and enzyme-linked immunosorbent assay

The aim of this study was to assess the suitability of PCR and ELISA as diagnostic method in young sheep naturally infested by Oestrus ovis larvae. The experiment was carried out from December 2020 to April 2021 with 39 lambs divided into two groups: infested (n = 26) and control treated group (n = 13). The infested group did not receive treatment against oestrosis, and the control group was treated with closantel (10 mg/kg orally) every 28 days in order to keep the animals as free as possible of O. ovis infestation. The clinical signs varied among animals regardless of the number of recovered larvae of each lamb, however, the thick mucus and mucopurulent nasal discharge scores were less frequent in lambs from treated group. There was no correlation between the nasal discharge score and the number of O. ovis recovered larvae (R² = 0.012, P = 0.165). Three control treated animals only presented first instar larvae (L1) (1 – 4 larvae/animal) which were smaller than L1 found in the lambs of the infested group. Ninety-two percent of the lambs from infested group (24/26) were parasitized by O. ovis with number ranging from 1 to 54 larvae per animal. A gradual increase in plasma IgG (anti-antigen of O. ovis larvae) levels of animals from infested group after the third week of the trial was observed, whereas the control lambs had low levels of IgG until the end of the experiment. The PCR had low sensitivity (26 %) and high specificity (100 %), and it presented poor agreement (k = 0.177) with the larvae detection after the lamb slaughter. The oestrosis clinical signs were not related to larvae infestation intensity and ELISA showed a greater advantage over the PCR technique in identifying animals that are carrying O. ovis.

Sequence analyzing of Oestrus ovis in sheeps in Al-Diwaniyah province

A total of 364 head sheep were examine from fourteen region in Al- Diwaniyah province 224 positive to infestation and larvae were collected and sent to the laboratory of veterinary medicine, from October 2021 to March 2022 for both sexes. The rate of Oestrus ovis infestation in sheep in the study areas was 61.53%. Al-Dighara abattoir had the highest infestation rate (82.75%) and Al-Salahia had the lowest infestation rate (17.64%). DNA extraction sequencing and phylogenetic analysis were used to identify Oestrus ovis larvae (16S rRNA) gene, the sequence was recoded in the National Center Biotechnology (NCBI) with accession numbers (ON059972, ON059973, ON059974, ON059975, ON059976, ON059977, and ON059978) Iraq for O.ovis larvae. The percentage of homology sequence identity between this gene and another global gene registered in NCBI was (99–100%) with Brazil and Bosnia and Herzegovina isolates, (97.17%) with USA isolates, and (96.17, 96.33, and 96.68%) with Brazil, Bosnia and Herzegovina, and USA isolates, respectively.

Prevalence and Associated Risk Factors of Ovine Oestrosis in Dendi District of Central Ethiopia.

BackgroundOvine oestrosis is an economically important and widely distributed parasitic disease of sheep that is caused by Oestrus ovis larvae across the world. Despite the fact that Oestrus ovis is a common parasite in Ethiopia and that there are many sheep in the study area, there is no information on the prevalence, larval burden, predilection sites, and risk factors associated with Oestrus ovis infestation in sheep in the Dendi district of West Shewa Zone, Ethiopia.MethodsA cross-sectional study was conducted from November 2017 to April 2018, to estimate the prevalence, risk factors, and larval burden, and identify common predilection sites for Oestrus ovis larvae. A total of 180 sheep heads were randomly selected from five purposely selected restaurants in Ginchi town, Dendi district, transported to the laboratory, opened with a hand saw, and visually examined for infestations. The larvae were collected from positive sheep heads and counted. The sites where the larvae were obtained were recorded. The data were analyzed using SPSS version 20 software.ResultsOf the total of 180 examined sheep heads, 104 (57.8%) were infested with larvae of Oestrus ovis. In the study, a statistically significant difference (p > 0.05) was not observed in the prevalence of Oestrus ovis in relation to all considered risk factors such as sex, age, and origin of sheep. From 104 infested sheep, a total of 664 larvae were detected in different parts of sheep heads. The mean larval intensity per infected animal with Oestrus ovis was 6.38. In this study, the minimum and maximum numbers of larvae recovered were 1 and 26, respectively. The nasal cavity, nasal sinus and frontal sinus were the predilection sites of Oestrus ovis larvae identified in this study.ConclusionOestrosis is an important and common parasitic disease of sheep in the study area.

Prophylactic Effects of Ivermectin and Closantel Treatment in the Control of Oestrus ovis Infestation in Sheep.

The sheep nasal bots Oestrus ovis is parasite of the nasal cavities and sinuses of small ruminants causing oestrosis, one of the most frequent parasitic diseases in sheep and goats. The widely use of ivermectin and closantel by the sheep breeders in the treatment and prophylaxis of gastrointestinal nematodes resulted in widespread cases of anthelmintic resistance. However, there is no report about cases of O. ovis with drug-resistance. In this study, we evaluated the prophylactics and therapeutic effects of both antiparasitics in sheep with O. ovis natural infestation. The trial was carried out from early December 2019 to March 2020, with 30 crossbred males lambs allocated into three groups of 10 animals each: control (without treatment), treated with ivermectin (0.2 mg/kg subcutaneously) and treated with closantel (10 mg/kg orally). The animals were kept together grazing the same pasture area. The treatment groups were drenched in two occasions 70 days apart: on 5th December 2019 and on 13th February 2020. On 19th March 2020, all lambs were slaughtered. The lamb heads were removed and sectioned along their longitudinal and sagittal axis to search for larvae. Recovered O. ovis larvae were counted and identified according to their developmental stage (L1, L2, and L3). Seven of the control lambs were infested with O. ovis larvae ranging from six to 17 larvae (11.6 mean infestation intensity). All recovered larvae from control group were intact and active. Three animals treated with ivermectin had O. ovis larvae (1–3 larvae), however they were dead and in degeneration. The animals treated with closantel did not have any larvae. The clinical suggestive signs of oestrosis were scarce over the experimental period. The averages of daily weight gain were similar (p > 0.05) among groups. Closantel and ivermectin had high efficacy against oestrosis and O. ovis parasitism did not hinder the performance of lambs.

Ophthalmomyiasis externa caused by Oestrus ovis

External Ophthalmomyiasis caused by Oestrus ovis is the most common cause of human myiasis worldwide. Distinguishing it from other causes is important to prevent sight-threatening complications. Two patients present with pain, redness, and foreign-body sensation in affected eye. Motile larvae were seen on slit-lamp examination later diagnosed as O. ovis infestation on microbiological examination. Larvae were removed and patients were started on topical antibiotics, lubricating eye drops, and systemic antihistaminics and followed up for 3 weeks. Improvement was observed within 1 week of treatment. Early diagnosis will help to know the possibility of internal ophthalmomyiasis.

New insights into the use of a mite count reduction test for the detection of therapeutic acaricide efficacy in Psoroptes ovis in cattle

When used for the evaluation of drug efficacy against Psoroptes ovis, the diagnostic performance of different sampling strategies for a mite count reduction test (MCRT) remains unclear. In the present study, a novel simulation framework was constructed that accounted for relevant biological features of P. ovis infestations in cattle and that was parameterized with field data from 16 farms (154 animals). Second, this framework was applied to explore the impact of study specific factors (number of animals, number of sampled lesions, and number of scrapings per lesion) and biological factors (mite infestation intensity and size of lesions) on the diagnostic performance of MCRT. Its outcome provided a basis to determine the diagnostic performance of MCRT when it was applied according to the World Association for the Advancement in Veterinary Parasitology (WAAVP) and the European Medicine Agency (EMA) guidelines, and to formulate recommendations to ensure a good diagnostic performance of the MCRT. For both guidelines, the MCRT allowed to correctly detect (power 80%) reduced and normal efficacy when the therapeutic efficacy was <70%, and ≥95%, respectively. The results highlighted a reliable diagnostic performance of the MCRT when performed as recommended by WAAVP and EMA for the detection of normal drug efficacy. When used for the detection of reduced efficacy, therapeutic efficacies between 70% and 90% could not be detected with sufficient reliability. The diagnostic performance can be improved by increasing the total number of skin scrapings (increasing the number of animals, number of sampled lesions and/or number of samples per lesion). In order to help researchers and veterinarians to optimize the design of the MCRT to their field settings, the findings were translated into a simple tool.

Evaluation of tumor necrosis factor-alpha (TNF-α); gamma interferon (IFN-γ) genes and oxidative stress in sheep: immunological responses induced by Oestrus ovis (Diptera: Oestridae) infestation

This study aimed to evaluate the cell mediated immune responses against Oestrus ovis (O. ovis) in sheep through measurement of the changes in mRNA expression of the tumor necrosis factor alpha (TNF-α) and gamma interferon (IFN-γ) cytokines using quantitative Real time-PCR (qRt-PCR). Also; to detect the role of Oestrus ovis infestation in the oxidative stress markers in sheep. Fifty sheep head were examined in Cairo abattoir from the period of May to August 2019. Sera were separated and collected for measurement of nitric oxide, zinc and malondialdehyde (MDA). While TNF-α and IFN-γ mRNA were extracted from nasal mucosa. Levels of IFN-γ and TNF-α were significantly higher in infested sheep than that in non-infested one. Also, oxidative stresses were indicated by high level of nitric oxide as one of reactive oxygen species (ROS) and serum MDA as oxidative stress marker and low antioxidant capacity (zinc concentration in serum) in infested sheep. The obtained results indicated that measurements of TNF-α and IFN-γ cytokines using qRT-PCR could be used as an association and reproducible quantitative method for the diagnosis of O. ovis infestation in sheep.

Oestrosis: Parasitism by Oestrus ovis

Abstract Oestrus ovis (Linnaeus 1761) is a parasite of sheep and goats, in which the fly larvae are obligatory parasites of nasal and sinus cavities. Oestrosis is endemic in hot and dry regions, especially in Mediterranean areas of Europe, Africa and America. Infected animals firstly suffer from fly strike, when adult flies inject first stage larvae on their nostrils and secondly, hosts will suffer from nasal-sinus myiasis with varying clinical respiratory signs. The disturbance caused to small ruminants while grazing and the effects during development of larvae can have severe consequences on livestock production. The evolution of O. ovis depends on the weather; the parasite is very well-adapted to their environment, being able to undergo hypobiosis either inside or outside the host, according to the climatic environmental conditions and seasonality. Understanding the epidemiology and life cycle of O. ovis is crucial to design effective control measures of this myiasis. Moreover, O. ovis infestation is considered a zoonosis; it causes ophthalmomyiasis in man in many parts of the world. The present article focuses on describing the main information about this parasite gathered in the last 20 years.

Failure of ivermectin efficacy against Psoroptes ovis infestation in cattle: Integrated pharmacokinetic-pharmacodynamic evaluation of two commercial formulations

Psoroptic mange is an important parasitic disease that mainly affects beef cattle producing marked economic losses. Ivermectin (IVM) is considered one of the most effective treatments against psoroptic mange and is used worldwide to control both endo and ectoparasites in different species. The current work assessed the relationship between pharmacokinetic behavior of IVM and its efficacy against Psoroptes ovis after the subcutaneous administration of two commercial formulations in a cattle feedlot. Aberdeen Angus and Hereford steers were selected based on the presence of active mite infestations. Animals were allocated into 4 experimental groups and treated with a single (day 0) or repeated subcutaneous injection (days 0 and 7) of one of two commercial formulations of IVM (1%) at 0.2 mg/kg. Blood and skin samples were taken from 8 randomly selected animals of each experimental group to measure IVM concentrations by HPLC. Skin scrapings were also collected from six different sites in each animal, mites were counted and ranked based on a density score. Equivalent plasma concentrations of IVM were measured after the administration of IVM formulations under study. The repeated administration of both IVM formulations at day 0 and 7 accounted for a greater plasma drug availability compared with the single administration (P < 0.05). IVM was well distributed from the plasma to the skin without significant differences between both IVM formulations. There was a positive correlation between IVM concentrations in skin and plasma (r: 0.73 P < 0.0001). The mean ratios between IVM availabililty (measured as AUC) in the skin and in plasma were between 1.2 and 2.1. The repeated administration of IVM increased significantly the IVM concentrations in the skin of areas affected by mange. IVM failed to obtain a parasitological cure in the different groups affected by mange. The failure was observed with both formulations administeredat single or repeated doses. Based on the number of animals cured, the range of efficacy was between 0% on day 7 and 60% on day 28 post-treatment. No significant differences in the P. ovis density scores were observed after the IVM treatment at single or repeated doses. Additional studies are needed to confirm the presence of resistant strains of P.ovis and to establish the appropriate measures to control these parasitic infestations in feedlot cattle.

Hematological Profile of Sheep Experimentally Infested with Bovicola ovis

Changes in some haemotological parameters (erythrocyte count, hematocrit values and leukocyte counts) in animals with lice infestation had been reported previously. In this regards, information on the effect of Bovicola ovis (B. ovis) infestation on hematological values under experimental condition in Ethiopian sheep is not available. A total of 12 animals divided into two groups of six animals each were used in the experiment. Animals in one group were infested with 500 lice (Bovicola ovis) per sheep collected from different donor animals and the other group served as a non-infested control. Each group was observed for a period of eight consecutive weeks. The present findings demonstrated that the mean parasite burden/10 cm2 of skin was 16 in infested group whereas the control group did not have any lice. Packed cell volume was not significantly different between the two groups and values were in the normal range. On the other hand total RBC count was significantly lower for the infested group (P<0.05). Comparison of the leukocyte counts between the two groups indicated that the total count and eosinophil levels were significantly elevated in the infested group (P<0.05). In conclusion, B. ovis infestation results not only skin damage but also causes systemic changes that may significantly alter the physiological and health status of infested animals.

Prevalence of Melophagus ovinus and Bovicola ovis infestation in sheep in Wogera District, North Gondar Zone, Ethiopia

The study was conducted from October, 2015 to May, 2016 in Wogera district, North Gondar zone, Ethiopia with the objectives of identifying and estimating the prevalence of sheep ked and lice infestation and to appraise potential risk factors of their attachment to sheep. Out of 423 sheep examined, 71.6% were infested either by Melophagus ovinus (M. ovinus) or Bovicola ovis (B. ovis) or both. The prevalence of M. ovinus and B. ovis were 33.57% and 12.07% respectively. Mixed infestation of M. ovinus and B. ovis (25.53%) were also recorded. The overall prevalence of M. ovinus and B. ovis infestation were significantly varied among the age (χ2=56.52; P=0.00), sex (χ2=14.71; P=0.00) and body condition (χ2=22.52; P=0.00) categories of sheep. The prevalence of M. ovinus in sheep of poor (70.1%) and medium (64.5%) body condition was significantly (χ2=23.29; P=0.00) higher as compared to those of good body (40.5%) condition. Furthermore, the prevalence of M. ovinus was significantly varied with age (χ2=99.26; P=0.00). Similarly, B. ovis prevalence was significantly (χ2=16.56; P=0.00) highest in poor (52.9%) and medium (38.2%) than in good (25%) body condition score group. Moreover, the prevalence of B. ovis was significantly (χ2=7.44; P=0.008) higher in rams (46.5%) than in ewes (33%) but, did not significantly varied with age (p>0.05). Significant differences were noted in harboring mixed B. ovis and M. ovinus infestations among the age (χ2=23.42; P=0.00), sex (χ2=18.41; P=0.00) and body condition (χ2=21.74; P=0.00) groups. In conclusion, further studies on prevalence and economic impacts of infestation of sheep with M. ovinus and B. ovis are recommended.

Seasonal Prevalence of Myiasis Causing Fly (Oestrus ovis) Diptera Oestridae in Goats in Kaduna State Nigeria

The survey was carried out for two consecutive dry and wet seasons to determine seasonality of Oestrus ovis (Diptera: Oestridae) infestation in goats in five Local Govemment Areas (LGAs) of Kaduna State, Nigeria. A total of 893 goat heads were bought from slaughter houses and market places. The heads were hand sawn vertically through the nasal cavity; forceps and pen knife were used to expose the nasal cavities, and turbinate bones and frontal sinuses. The larvae collected were preserved in 10% formalin and kept in appropriately labelled sample bottles. The average prevalence of O. ovis in goats was 18.7%; the distribution of prevalence by LGAs was 22.9%, 19.8%, 14.1%, 17.0% and 18.8% for Sabon Gari, Zaria, Kudan and Makarfi LGAs, respectively. The seasonal prevalence showed a bi-modal peak during the two year periods, each occurring between June and July of each year. There was a significant difference (P&lt;0.05) in the prevalence during the dry season of November to April(14.7%) and wet season of May to October (22.7%).

Seasonal prevalence and mean intensity of Psoroptes ovis infestation in goats in the Brazilian semiarid region.

To determine the prevalence and seasonal variation of Psoroptes ovis (Delafond, 1858) mange in goats in the semiarid region of Paraíba, 541 crossbred goats of both sexes and different ages were examined between June 1999 and May 2001 and between August 2011 and December 2012, by washing their ear canals.The monthly prevalence of the infestation varied between 66.66% and 100% without significant differences (p = 0.10) among months and years. The intensity of infestation was higher between 2011-2012 (p < 0.05), with an annual rainfall of 123 mm, than between 1999-2000, which had an annual rainfall of 614.9 mm. By the Spearman test there was a negative correlation between the relative humidity and the rainfall of the intensity of the P. ovis infestation. It is concluded that parasitism by P. ovis occurs at a similar prevalence rate during the entire year but increases during dry years.

Treatment and control of bovine sarcoptic and psoroptic mange infestation with ivermectin long-acting injectable (IVOMEC(®) GOLD).

The efficacy of ivermectin long-acting injection (IVM LAI, IVOMEC® GOLD, Merial; 3.15 % ivermectin w/v) formulation was evaluated in cattle with induced Sarcoptes scabiei var. bovis or Psoroptes ovis infestations. A total of 64 cattle were included in this series of four studies, with 16 animals per study. Approximately, 8 weeks following initial induced mite infestation, cattle were allocated to treatment groups based on decreasing pre-treatment bodyweights. Treatments (saline (control) or IVM LAI (630 mcg ivermectin/kg bodyweight) at 1 mL/50 kg bodyweight) were administered by a single subcutaneous injection in front of the right shoulder on Day 0. Skin scrapings were collected prior to treatment and at approximately weekly intervals for 8 weeks thereafter to establish live mite counts. Character and extent of skin lesions were evaluated at each sampling. Animals were weighed before treatment and at the end of the studies. Mite counts of the IVM LAI-treated animals were significantly (p < 0.05) lower than those of the controls in all four studies at all occasions post-treatment. In the two Sarcoptes studies, IVM LAI-treated cattle were free of mites at 14 days after treatment and in the Psoroptes studies at 13 or 28 days post-treatment. All IVM LAI-treated cattle remained free of mites to the end of the studies while all control animals remained infested. Mange lesions of the IVM LAI-treated animals improved significantly (p < 0.05) compared to those of the controls from Day 21 (Sarcoptes studies) and from Days 28 or 34 (Psoroptes studies). In all studies, mean weight gain over the 8 week post-treatment period was significantly (p < 0.05) higher for the IVM LAI-treated animals than for the controls: Sarcoptes studies, 64.1 and 68.6 kg vs. 46.9 and 48.6 kg, respectively; Psoroptes studies, 43.0 and 43.4 kg vs. 20.8 and 34.9 kg, respectively. All animals accepted the treatment well, and no treatment-related health problems and adverse events were observed throughout the studies. These studies demonstrated the high efficacy of IVOMEC® GOLD against sarcoptic and psoroptic mange in cattle.

Impact of sheep and goats ectoparasites on the tanning industry in Tigray Region, Ethiopia

A study was carried out to assess the effect of ectoparasites on the quality of processed skin and defects that cause downgrading and rejection of skins in pickled sheep and wet blue goat-skins at Wukro Sheba tannery in Tigray region. A total of 120 sheep and 120 goat pelts with known infestation by ectoparasites and ectoparasite free control pelts were purchased and processed in Sheba tannery and the corresponding skin defects were analyzed. Accordingly, three groups of 40 sheep pelts each (one group infested with M. ovinus, one group infested with Damalina ovis and a control group of ectoparasite free sheep pelts) and three groups of 40 goat pelts each (one group infested with sarcoptic mange, one group infested with Linognathus spp. and a control group of ectoparasite free goat pelts) were used. Defects observed at pickled stage include cockle, scratch, scar, technical defects due to flaying and old age. A strong association (P<0.001) was observed between cockle lesion and infestation of sheep pelts with D. ovis and Mellophagus ovinus and infestation of goat pelts with sarcoptic mange. Further more, the severity of infestation of sheep pelts with M. ovinus and D. ovis and infestation of goat pelts with sarcoptic mange were found to correlate significantly (P<0.001) with severity of cockle defect. Further investigation on 1000 pickled sheep and 1000 wet blue goat skins revealed that scratch defect was the dominant (43.4 % and 53 %), followed by cockle (35 % and 21.5 %), scar (7 % and 6.8 %) and knife cut (3.4 % and 6.2 %) in pickled sheep and wet blue goat skins, respectively. There was a significant difference (P<0.001) in proportion of cockle between pickled sheep and wet blue goat skins. In addition, a strong association (P<0.001) was observed between cockle and scratch, and cockle and scars on both pickled skins. The economic loss due to quality deterioration of exported skin in the study tannery was estimated to be 778,199.41 USD for pickled sheep and 247,677.61 USD for wet blue goat skins per annum. The growing threat of ectoparasites to small ruminant production and to the tanning industry needs well coordinated and urgent control intervention.Keywords: Ectoparasites, Goat, Sheep, Skin defects, Tigray Region, Ethiopia.