The prevalence and pathogenicity of Chorioptes bovis (Hering, 1845) and Psoroptes cuniculi (Delafond, 1859) (Acari: Psoroptidae) infestations in feral goats in New Zealand

Between October 1976 and January 1980 a total of 368 feral goats was examined in New Zealand for the presence of Chorioptes bovis and 434 for the presence of Psoroptes cuniculi. The seasonal pattern of C. bovis infestation in feral goats was similar to that seen in sheep and cattle. The prevalence of infestation reached 100% in July and August (winter) and declined to 27% in February and March (summer). Fewer goats were infested with P. cuniculi and prevalence of infestation reached a maximum of 41% in July. No goats were found infested in the December and January samples. Chorioptes bovis infestation was independent of the age and sex of hosts. Infestation with P. cuniculi was independent of the sex of the hosts, but older goats were more frequently infested (16%) than younger goats (8.6%). Unilateral infestation with P. cuniculi was more common (74.5%) than bilateral infestation. No severe lesions were associated with C. bovis, but 21.3% of goats with P. cuniculi had the external auditory meatus blocked by waxy material and 12.8% had scabby encrustations on the ears. The importance of goats as a possible source of infestation to domestic animals is discussed.     

Some observations on the sero-prevalence of heartwater and tick infestation in Zambian goats

A survey was carried out to define the distribution of heartwater in goats that originated from six districts in communal grazing semi-arid areas of Zambia. A total of 181 samples (40.1%) out of 451 serum samples from adult goats were positive for Ehrlichia ruminantium antibodies after screening using indirect MAP-1B antigen ELISA technique with statistically significant differences (P < 0.01) between the six districts. Out of 1 036 adult goats examined for tick infestation, 105 were infested by ticks, with Amblyomma species being the most dominant tick encountered. Amblyomma variegatum, which is the vector for heartwater transmission in Zambia constituted 42.4% of the tick species, identified. The overall tick infestation rate was 10% while the tick:goat ratio was 2.1:1. Amblyomma variegatum appears to be widespread throughout the study area, as are antibodies to E. ruminantium.     

Immunohistochemical detection of <Emphasis Type="Italic">Mannheimia (Pasteurella) haemolytica</Emphasis> antigens in goats with natural pneumonia

Pneumonia is a leading cause of loss to ruminants throughout the world. Mannheimia (Pasteurella) haemolytica is one of the most important etiological agent of pneumonia in cattle, sheep, and goats. This study was carried out to determine the incidence of M.haemolytica antigens using immunohistochemistry labelling of formalin-fixed, paraffin-embedded tissues in pneumonic lungs of goats slaughtered at abattoir, and then to compare these immunohistochemistry results with the results of bacterial isolation. For these objectives, a total of 1505 goat lungs slaughtered in slaughterhouse were grossly examined and pneumonia was detected in 74 cases (4.91%). Of these, with the exception of verminous pneumonia observed in 32 cases, on 42 pneumonic lungs immunohistochemical examinations were performed. Formalin-fixed and paraffin-embedded lung tissue samples were immunohistochemically stained by the avidin-biotin-peroxidase complex (ABC) procedure using polyclonal antibodies to detect M.haemolytica antigens. Pneumonic lesions were more frequently encountered in cranioventral lobes than caudal lobes, and characterized by irregular lobular foci of atelectasis or lobar pneumonia. The presence of M.haemolytica antigens was detected in 19 (45%) out of 42 pneumonic lungs. Bacterial antigens were found most frequently in the cytoplasm of bronchial and bronchiolar epithelial cells, in the swirling degenerating leukocytes in the alveoli, and in the degenerating leukocytes in the area of coagulation necrosis, less frequently in the epithelial cells of bronchial glands, and lymphoid cells. Conclusionly, immunohistochemical detection of M.haemolytica antigens in pneumonic lungs appear to be more reliable compared to bacterial isolation.     

Economic impact of <Emphasis Type="Italic">Przhevalskiana silenus</Emphasis> infestation in native goats of Northern India

Economic losses incurred by Przhevalskiana silenus in goats of Jammu province of Jammu and Kashmir (North India) were assessed from July 2005 to June 2006. Abattoir studies revealed holes in hides for 112 days (mid-December 2005 to first week of April 2006) and trimming of carcass for 243 days (July 2005 to February 2006) during a lifecycle, leading to annual losses of Rs. 7,391,432 and Rs. 10,510,837, respectively. An effect on production traits (weight gain and milk) was assessed on naturally P. silenus-infested Beetal goats. The mean body weight loss of warbled goats was 2.40 kg (equal to 1.096 kg of meat, assuming 45.7% dressing percentage of goat) leading to an annual loss of Rs. 35,473,265. The mean milk yield loss per warbled goat per day was 101.7 g resulting in losses to the tune of Rs. 19,879,012. It can be concluded that P. silenus infestation resulted in an overall loss of Rs. 73,254,547, i.e. 73.26 million annually (equivalent to US 1.62 million; US1.62 million; US 1 = Rs. 45.24), where reduced growth alone contributed 49% of the total losses. A study recommends that a control scheme against P. silenus infestation in goats using an effective insecticide should be followed to prevent huge economic losses in hide, milk and meat production. Economic losses associated with P. silenus infestation in goats were estimated for the first time from India.     

Survey of tick infestation in small ruminants of Miesso district,West Harergie,Oromia Region,Ethiopia

A survey was conducted to identify tick species and determine the prevalence of tick infestation in small ruminants of Miesso District, West Harergie Zone. Collection and identification of the ticks were undertaken from November 2007 to April 2008. All visible individual adult ticks were collected from the body of 328 goats and 40 sheep. The prevalence of tick infestation in goats and sheep was found to be 89.9% and 87.5%, respectively. In this study, ten species of ticks which grouped under four genera were identified. The most abundant species found in this study were Boophilus decoloratus (60%), Rhipicephalus pulchellus (25.1%), and Amblyomma gemma (11%). Hyalomma dromedarii was the minor species observed on goats. The difference in the prevalence of tick infestation between sheep and goats was not statistically significant (Χ ²   = 0.22, p = 0.63) but found to be statistically significant between male and females (Χ ²  = 9.8, p = 0.003). Attention should be given to the control and prevention of ticks, since they cause sever damage to the skins of small ruminants and thereby reduce the foreign exchange of the country; they also transmit some diseases which can cause sever loss to the productivity of these animals.     

Cross-transmission studies with Hypoderma lineatum de Vill. (Diptera: Oestridae): attempted infestation of goats (Capra hircus)

The potential for cross-transmission of Hypoderma lineatum from cattle to domestic goats (Capra hircus) was examined using artificial infestation techniques. Two routes of infestation, subcutaneous injection and dermal penetration, were used to expose goats to newly hatched first instars. Presence of antibodies and appearance of circulating antigen (hypodermin C) were evaluated at selected intervals for up to 40 weeks post-infestation. In addition, immunoblots against H. lineatum first-instar proteins were conducted using sera taken at 10 weeks post-infestation. Goats were palpated for the presence of developing larvae at sub-dermal sites beginning at week 30 pi. No developing larvae were palpated at any time, regardless of the route of infestation nor was circulating antigen detected in any infested goats. Antibodies were present at weeks 6 and 10 and week 27 pi in both infested groups. Immunoblots indicated all infested goats produced antibodies to first instar H. lineatum antigens. H. lineatum appears to be incapable of completing development in domestic goats although the transient appearance of ELISA detectable antibodies and the presence of bands on immunoblots suggests that at least some larvae survive long-enough to engender a humoural response. The host specificity of H. lineatum is discussed in light of the general concepts of host-parasite relationships of oestrids.     

Experimental transmission of sarcocysts from cattle to mice

Summary A survey of sarcosporidiosis made in healthy cattle slaughtered at Omdurman Central Abattoir gave an infestation rate of 98 per cent. Transmission of sarcocysts from cattle to mice was accomplished thus confirming the absence of host specificity.     

Evaluation of newly developed ‘six recombinant secretary proteins based ‘cocktail ELISA’ and ‘whole cell lysate’ based ‘indigenous ELISA’ and tissue microscopy’ with ‘Gold standard’ histo-pathology for the diagnosis of Johne’s disease in slaughtered goats and buffaloes

Three screening tests {(newly developed, six recombinant secretory proteins based 'cocktail ELISA', in-house robust 'indigenous ELISA' based on semi-purified protoplasmic antigens and tissue microscopy were evaluated with 'Gold standard', histo-pathology for the diagnosis of Johne's disease in goats and buffaloes. Serum and tissues {mesenteric lymph nodes and intestines) were driven from farmer's goats (n = 77) and buffaloes (n = 40) slaughtered for harvesting meat and farm goats (n = 77), died and necropsied. Twenty seven (35%) goats and 23 (57.5%) buffaloes were positive in all the four tests. Of 134 tissues screened by histo-pathology, 79.8% MLN and 76.8%, intestines, were positive for MAP infection. In tissue microscopy, 55.2 and 52.3%, goats and buffaloes were positive, respectively. Of 117 sera screened by i_ELISA, 58.4 and 70.0%, goats and buffaloes were positive, respectively. Whereas, c_ELISA detected 55.8 and 62.5%, goats and buffaloes, positives, respectively. Twelve tissues (70.5%) of goats necropsied were positive, both in tissue microscopy and histo-pathology. Most significant gross findings were serous atrophy of the fat and mild to moderate, diffuse thickening of terminal ileum, especially at ileo-caecal junction with or without transverse / longitudinal corrugations. In histo-pathology grade III and IV lesions were significantly low as compared to grade I and II. Of the four tests used for screening 268 samples, histo-pathology was most sensitive (78.3%), followed by i_ELISA (62.3%), c_ELISA (58.9%) and tissue microscopy (58.9%). Between two ELISA tests, c_ELISA using six recombinants secretory proteins, had higher specificity as compared to i_ELISA.     

Failure to protect goats following vaccination with soluble proteins of Sarcoptes scabiei: evidence for a role for IgE antibody in protection

Developing an anti-scabies vaccine is thought to be a feasible alternative to chemical control, since animals which have recovered from sarcoptic mange become resistant against mite reinfestation. The purpose of this study was to evaluate the protective value of immune responses developed in animals after immunisation with soluble mite proteins. Soluble proteins from Sarcoptes scabiei were extracted then subjected to ion exchange chromatography, and proteins from the column were eluted step-wise with 0%, 10%, 25% and 50% of 1 M solution of NaCl in a Tris buffer. Each protein fraction was concentrated and dialysed against PBS. To evaluate the immunogenicity of the fractions, 36 goats were allocated into six groups, group1 goats were unvaccinated, group 2 were vaccinated with intact soluble mite proteins, and groups 3-6 were vaccinated respectively with the fractionated proteins. Vaccinations were conducted four times with 1 mg protein/dose and 4-week intervals between vaccinations. One week after the last vaccination, all goats were challenged with approximately 2000 live mites on the auricles and infestations were allowed to progress for 6 weeks. The severity of lesions caused by the infestation was assessed throughout the study. The challenge caused mange or encrustation dermatitis in all animals and no differences in severity of lesions were observed between vaccinated and unvaccinated control goats. Vaccination with each fraction of the mite proteins invoked high levels of scabies-specific IgG in the serum of all animals but failed to induce specific IgE as determined by Elisa. In contrast, goats challenged experimentally with a primary or repeated mite challenge developed strong serum IgE and IgG antibody responses to Sarcoptes antigens. The latter animals were shown in a previous study to be resistant to reinfestation. The lack of immune protection in the vaccinated animals may be attributed to the absence of protective levels of IgE antibody, and the present findings indicate that allergens and IgE antibody is important in immunity to S. scabiei infection.     

Biological, seasonal and environmental factors associated with Pulex irritans infestation of dairy goats in Greece

The objectives of the present study were to study the fauna of fleas infesting dairy goats in Greece, the spectrum of hosts each flea species infests, identify risk factors in the environment, and goat management practices that favour flea infestation of goats, and describe the seasonal variation of infestation in goats. For this purpose, a total of 64 herds, with a history of flea infestation in goats, were visited during June and July of 2002 for data collection on flea burdens, species of fleas on goats, and other farm or pet animal species in the farm. Also data were collected on herd characteristics and management along with the flea infestation status of the village where it was located through a questionnaire survey. Data on elevation and climatic characteristics of the villages where the herds were located were also used in the study. All fleas collected from goats, sheep, pigs, and cattle were identified as being Pulex irritans. All fleas collected from cats were identified as being Ctenocephalides felis. Dogs were infested either with P. irritans, C. canis, or C. felis, or with both C. canis and C. felis. Kids had a significantly higher flea burden than goats and the Skopelos breed had the highest flea burden of all breeds followed in diminishing order by the breeds Capra prisca, Saanen cross mix, and Alpine cross mix (p < 0.05). The gender of the animal had no significant effect on flea burden. Factors significantly affecting the flea burden of goats were duration of flea infestation in the herd, type of flea control, and manure imported prior to the appearance of fleas in the herd (p < 0.05). The flea burden of goats was highest during summer and lowest during winter (p < 0.01), with complete an absence of infestation in January and February. Finally, a significant difference (p < 0.05) was found between the average annual temperature of villages with flea infestation (15.59 degrees C) and villages without flea infestation (17.14 degrees C). It was concluded that P. irritans was a true infestation of goats in Greece.     

Survey of ixodid ticks in domestic ruminants in Bedelle district,Southwestern Ethiopia

A survey aimed at determining the status of ticks in cattle, sheep and goats in Bedelle district (Southwestern Ethiopia) was carried out from November 2007 to April 2008. Out of the total 330 animals examined, 314 (95.2%) were found to be infested (harbouring of at least a single tick). High rates of infestations were recorded across all three host species. Factors like month of collection, age and sex of host species did not show significant association with infestation rates. A total of 5,507 ticks belonging to three genera (i.e. Amblyomma, Boophilus and Rhipicephalus) were collected during the study period of which six species were identified. The species of ticks encountered comprise of Amblyomma cohaerens (44.1%), Amblyomma variegatum (13.8%), Amblyomma lepidum (1.2%), Boophilus decoloratus (24.9%), Rhipicephalus evertsi evertsi (14.3%) and Rhipicephalus lunulatus (1.7%). As about 86.7% (4,772) of the ticks were collected from cattle, it was recognised that this could be an evidence of host preference where cattle are serving as principal host while sheep and goats serve as alternative hosts. The role of ecological factors and little attention paid by livestock owners for treatment of animals against ticks are suggested to result in the abundance of ticks. Acaricide spraying should be strategically applied to control ticks. Better result could be achieved if an emphasis is being put on spraying cattle. Studies on tick-borne diseases, involvement of wildlife species as well as related factors are recommended as they may provide a valuable basis for designing and launching an all-round control programme in the country.     

Host preference of the sheep scab mite,Psoroptes ovis

Sheep scab mites, Psoroptes ovis, collected from a Merino donor sheep, were used to infest Merino and Dorper sheep, and Angora and Boer goats. Mites were placed on the sheep on 1 or 2 occasions and on 5 occasions on the goats. All the animals were examined at regular intervals for the presence of scab lesions and living mites. Both sheep breeds developed lesions, but those on the Merino sheep were always larger than those on the Dorper sheep at the same intervals after infestation. None of the goats developed lesions or showed signs of irritation, or harboured any mites.     

Seasonal occurrence of Karoo paralysis in Angora goats in relation to the infestation density of female Ixodes rubicundus.

The seasonal occurrence of Karoo paralysis in relation to the infestation density of female Ixodes rubicundus was investigated in an enzootic area of the southwestern Orange Free State, South Africa. Young and adult Angora goats were exposed to infestation during two paralysis tick seasons. Only the young goats became paralysed and their infestation densities (female ticks kg-1 host body weight) were significantly higher than those of healthy animals. The infestation densities on paralysed goats varied between 0.64 and 3.56 ticks kg-1. During the 1988 season, 30% of the naive young goats became paralysed compared with 67% the following season. Twenty-nine percent of previously paralysed goats were paralysed again during the same season. Paralysis occurred during periods of peak tick activity (April-June).     

A severe case of contagious ecthyma in Tswana goats

The first severe case of caprine contagious ecthyma (parapox) in Tswana goats is described from Botswana. Affected animals were indigenous adult Tswana goats. The case involved a flock of 12 goats of which 4 (33.3%) were very severely affected but none died. The lesions were confined to the head and included swollen lips, swollen submandibular lymph nodes, gingivitis, glossitis, ulceration on lip and gum mucosae and scab formation on ulcerated areas. No lesions were found on other parts of the body. This case was clinically indistinguishable from bluetongue.     

Transabdominal ultrasonographic findings in goats with paratuberculosis

This study describes the transabdominal ultrasonographic findings in 54 goats with confirmed Johne’s disease (JD). Compared with the control group (0.8 ± 0.4 mm thick), the test group presented with mild (2.8 ± 0.2 mm), moderate (4.2 ± 0.4 mm), and severe (6.9 ± 1.1 mm) thickening of the intestinal wall. The most outstanding ultrasonographic findings were pronounced enlargement of the mesenteric lymph nodes in 49 goats. In 36 goats, the enlarged lymph nodes showed a hypoechoic cortex and a hyperechoic medulla. In 7 goats, the cortex and medulla were hypoechoic. In 5 goats, the cortex and the medulla could not be differentiated. In the remaining cases, the cortex and medulla contained small hypoechoic lesions. Necropsy findings included enlarged mesenteric lymph nodes in 52 goats and thickening of the small intestinal wall in 30 goats. Compared with the postmortem results, the antemortem ultrasound sensitivity in detecting intestinal wall thickness and enlarged mesenteric lymph nodes was 80% and 94%, respectively.     

Contagious caprine pleuropneumonia in Beetal goats

Seroprevalence, clinical findings, and lesions of contagious caprine pleuropneumonia (CCPP) in Beetal goats were recorded during an outbreak. The overall seroprevalence of CCPP was 32.50%. Confirmation of Mycoplasma mycoides in serum was carried out using counter immunoelectrophoresis (CIE) technique. The highest CIE-positive cases were recorded in the older goats (51.72%) as compared to young ones. Nasal swabs collected from 39 goats showing respiratory signs were found positive for M. mycoides. The most consistent clinical findings were mild to severe cough, purulent nasal secretion, emaciation, dyspnea, increased respiration rate, and pyrexia. Mortality due to CCPP was 9.17%. Consolidation of lungs exhibited the highest frequency (100%), followed by alveolar exudation (90.90%) and pleural adhesion (72.72%). Among the microscopic lesions, septal peribronchiolar fibrosis exhibited the highest frequency (81.81%), followed by fibrinous pleuritis (63.63%) and peribronchiolar cuffing of mononuclear cells (54.54%) in lungs. From these results, it was concluded that CCPP under subtropical conditions has high prevalence in Beetal goats and leads to significant mortality.     

Incidence of Oestrus ovis infestation in Borno-white Sahel goats in the semi-arid zone of Nigeria

Research conducted on the incidence of Oestrus ovis in Maiduguri showed that 53.8% of the 4,000 Borno-White Sahel goats examined were parasitised. The mean year-round infestation per goat was 2.03 larvae. Adult goats had a higher infestation rate than younger ones (60 versus 47.5%). Infestation rates for the females and males were 55.2 and 52.2%, respectively. Nevertheless there was no statistical significance between values for the different age and sex groups studied. Different larval stages were encountered throughout the year with a 3rd instar peak between May and September and a first instar peak from June to October suggesting a fly period between June and October.     

Experimental infection of dexamethasone-treated goats with Pasteurella haemolytica A2.

Sixteen goats either subjected to transport stress or without transport stress were treated with dexamethasone for 3 days prior to infection with P. haemolytica serotype A2 intranasally. The transport-stressed and dexamethasone-treated goats in the first group had various degrees of pulmonary lesions and the organism was re-isolated from the nasal cavity, lymph nodes and lungs. None of the goats treated with dexamethasone only were infected with P. haemolytica and had no lesions of pneumonic pasteurellosis. Treatment with dexamethasone alone failed to induce experimental infection by P. haemolytica except in combination with another stress factor.     

Observations on the potential for natural transfer of Psoroptes cuniculi and Chorioptes bovis (Acari: Psoroptidae) between goats and sheep

Goats and sheep were pastured together and held in close contact in yards twice a month for 21 months. The goats had a high prevalence of both the rabbit ear canker mite, Psoroptes cuniculi and the chorioptic mange mite, Chorioptes bovis. The sheep were not infested with P. cuniculi at the beginning of the study and viable C. bovis could not be detected. At no time during the study did P. cuniculi establish in the ears of sheep, despite a maximum prevalence of >95% P. cuniculi in goats. This may have been related to the viscous nature of sheep cerumen. Levels of cerumen in goats' ears increased with increasing prevalence of the mite in the flock. The prevalence of C. bovis in the sheep flock did not exceed 10%, despite a maximum prevalence of >90% infested goats. The difficulty of detecting light infestations of mites means that it was not clear whether the C. bovis infestation of sheep was derived from goats or was present when the study began. Whatever the source, close contact with goats with an active and extensive C. bovis infestation seems unlikely to seriously influence populations of the ectoparasite in sheep. Psoroptes cuniculi was found to he established in goats as young as five days and post-mortem examination of goats' ears was more successful at revealing P. cuniculi than was use of an otoscope during life.     

Proliferation and transmission patterns of <Emphasis Type="Italic">Pasteurella multocida</Emphasis> B:2 in goats

This report describes the proliferation and transmission patterns of Pasteurella multocida B:2 among stressful goats, created through dexamethasone injections. Thirty seven clinically healthy adult goats were divided into three groups consisted of 15 goats in group A, 11 goats in group B and the remaining 11 in group C. At the start of the study, all goats of group A were exposed intranasally to 1.97 × 10¹⁰ CFU/ml of live P. multocida B:2. Dexamethasone was immediately administered intramuscularly for 3 consecutive days at a dosage rate of 1 mg/kg. The exposed goats were observed for signs of HS for a period of 1 month. At the end of the 1-month period, 11 goats from group B were introduced into and commingled with the surviving goats of group A before all goats from both groups were immediately injected intramuscularly with dexamethasone for 3 consecutive days. The treatment with dexamethasone was then carried out at monthly interval throughout the 3-month study period. Goats of group C were kept separately as negative control. Three surviving goats from each group were killed at 2-week interval for a complete post-mortem examination. Two (13%) goats of group A were killed within 24 hours after intranasal exposure to P. multocida B:2 while another two (13%) goats from the same group were killed on day 40, approximately 10 days after the second dexamethasone injection. All four goats showed signs and lesions typical of haemorrhagic septicaemia. Bacteraemia was detected in 3 goats of group A that were having rectal temperature higher than 41°C. The P. multocida B:2 isolation pattern was closely associated with dexamethasone injections when significantly (p < 0.05) higher rate of isolations from both groups were observed after each dexamethasone injection. Transmission of P. multocida B:2 from goats of group A to group B was successful when P. multocida B:2 was isolated from goats of group B for a period of 28 days. There was a strong correlation between dexamethasone injections, rate of bacterial isolation and serum cortisol level. The IgG level showed an increasing trend 2 weeks after exposure to P. multocida B:2 and remained high throughout the study period.