Impact of baiting on feral swine behavior in the presence of culling activities

We studied the effects of baiting on feral swine (Sus scrofa) movements and corresponding likelihood of disease spread under real and simulated culling pressure. Our objectives were to determine the proportion of feral swine that used the bait station site, and if baiting of feral swine altered areas of utilization, distances from location centroids to treatment location (control or bait station), and movement rates by survivors during culling activities. We hypothesized that the bait station would increase the sedentary nature of feral swine, thus reducing the potential for dispersal and hence disease dispersal. Our experiment was conducted between February and May 2011 on the Rob and Bessie Welder Wildlife Foundation (WWF) in San Patricio County, Texas. We trapped 83 feral swine and placed GPS collars on 21 animals. We established and maintained a centralized bait station on one side of the WWF from 13 March to 27 April. We conducted population-wide culling activities, including trapping, controlled shooting, drive shooting, and aerial gunning, from 3 to 27 April and removed 143 feral swine (4.6feral swine/km(2)). Areas of utilization did not differ between treatments (control or bait station). However, we found location centroids of bait station site feral swine to be closer to the treatment location than those of control site animals and daily movement rates of bait station site feral swine to be 39% greater than movement rates of control site animals. Based on our observation that only 62% of feral swine trapped in proximity to the bait station used it, we cannot recommend baiting as an alternative to fences for containing animals during culling activities. However, there is value in using bait stations to describe patterns of feral swine movements, facilitate observation, and improve efficacy when conducting removals.     

家畜伊氏锥虫病的根治研究

以开放血脑屏障药甘露醇(20％,50～150ml)配合抗锥虫药那加诺(Naganol,12mg/kg体重)、贝尼尔(5mg/kg体重),对12例人工感染锥虫马(骡)和42例自然发病的锥虫病水牛分组进行治疗(重症者先静注葡萄糖钙)试验。结果,试验组马(骡)和水牛(除7号骡因继发肾炎,以可的松治疗而导致复发外)均获治愈,经6～12个月观察、复查,确认其完全康复,无一复发。本疗法简便、安全、经济、有效。     

A SURVEY OF MYCOBACTERIOSIS OF FERAL PIGS IN THE NORTHERN TERRITORY

Seven hundred and fifty-one feral pigs from the subcoastal plains of the Northern Territory were examined. The sample population consisted of 52.4% females and 47.6% males. They ranged in age from newborn piglets to mature animals of over 72 months. Of the pigs examined 47.7% had macroscopic abscesses and of these 80.2% were probably caused by mycobacteria. Tissues from 193 pigs were examined bacteriologically and 93 strains of mycobacteria were isolated. These were typed as M. bovis (37 strains); M. avium serotype 2 (1); M. intracellulare serotypes 6 (2), 7 (3), 9 (1) and 18 (1); M. intracellulare double serotypes 6 + 12 (1), 8 + 12 (1) and 11 + 25 (1); M. intracellulare unclassified serotype (4); M. scrofulaceum serotype 41 (1); M. scrofulaceum unclassified serotype (7); M. gordonae (2); M. kansasii (1); M. simiae (2); M. szulgai (2); M. vaccae (1); and M. xenopi (2). Additionally, 3 strains were unidentifiable members of the M. avium-M. intracellulare-M. scrofulaceum (MAIS) complex, one strain was a Runyon's group IV and 4 strains were typed as members of the genus Rhodococcus. Five strains were non-viable on subculture and 10 did not conform to any currently recognised species of mycobacteria. Of the 93 strains, 3 were isolated from tissue that did not contain macroscopic lesions, viz. M. simiae, Runyon's group IV and an unidentifiable member of the MAIS complex. It was concluded that the feral pig is probably an end host for both M. bovis and atypical mycobacteria and not a significant source of infection for cattle. M. bovis is not a significant cause of mortality in feral pigs but mycobacterioses are a significant cause of morbidity. With increasing age, the proportion of pigs having lesions increased whereas the proportion of lesions from which mycobacteria could be isolated decreased.     

HYDATID DISEASE OF ANIMALS IN AUSTRALIA

SUMMARY: Echinococcus granulosus is maintained in a dog-sheep cycle in Australia and other infections, such as those in cattle, pigs and man, can be regarded as aberrant. The knowledge on infection rates in these species is summarised. The dog is the only definitive host in Australia and infection rates are correlated with areas of high sheep density, the area with the highest prevalence being the South-eastern Statistical Division of New South Wales. A dingo-wallaby feral cycle exists throughout the eastern States and can serve as a source of infection for grazing animals and man. The threat posed by the possible introduction of the equine strain is discussed.     

STUDIES OF FERAL DONKEYS IN THE VICTORIA RIVER-KIMBERLEYS AREA

SUMMARY One hundred and ninety-seven feral donkeys were shot and examined for reproductive status, age and sex distribution. Limited observations on behaviour and habitat were made. Breeding was markedly seasonal and the reproductive rate was high. Evidence of territoriality and harem groups was observed. Some aspects of possible strategies to control donkeys are discussed.     

SONOGRAPHIC EVALUATION OF THE CRANIAL MEDIASTINUM IN SMALL ANIMALS

Clinical records, radiographs, and sonograms of 17 animals presented for possible cranial mediastinal disease were reviewed. Radiographs were evaluated for accuracy in detection of mediastinal masses. Sonography of the mediastinum was performed using a parasternal approach with the animals in sternal or lateral recumbency. The mediastinum was evaluated for the presence of a mass or other disease. Masses were characterized by echogenicity, size, number, and margination. Mediastinal vessels were studied to determine if there was vascular invasion or compression. A comparison of radiographic and sonographic assessment in cranial mediastinal disease indicates sonography adds valuable information in the diagnosis of mediastinal disease. Results of ultrasound-guided, fine-needle aspirate were documented and found to be advantageous in establishing a diagnosis in mediastinal masses.     

Epidemiology of Mycobacterium bovis infection in feral ferrets (Mustela furo) in New Zealand: I. Pathology and diagnosis

Necropsies from 228 ferrets captured from eight areas in the North and South Islands provided material for an investigation into the epidemiology of tuberculosis in feral ferrets. Mycobacterial culture of pooled lymph nodes (retropharyngeal, respiratory and jejunal) identified the prevalence of infection to be much higher than that estimated from gross lesions only. Seventy-three of the 228 animals examined (32%) were diagnosed as tuberculous. Fifty-three culture-positive ferrets and 18 seemingly uninfected animals were subjected to detailed histopathological examination. The outcomes of these investigations, including the characteristics of the disease, distribution of lesions and aids to diagnosis, are presented. Of the feral carnivores found in New Zealand, the disease persists at high prevalence only in ferrets, and is probably the maintained principally by ingestion of tuberculous carrion. The course of the disease may be prolonged in some ferrets, but tuberculosis eventually causes death of many infected animals. Microscopic hepatic granulomas may be considered pathognomonic of the disease, and have potential to be used as a rapid diagnostic tool in ferrets with no gross lesions.     

PATHOPHYSIOLOGICAL EFFECTS OF RENAL ALLOGRAFTS IN THE DOG

Seven dogs with renal allografts were studied to: (1) determine the practicality of the procedure for the treatment of end stage kidney disease in small animal medicine, and (2) measure allograft function to permit evaluation of immunosuppressive drug dosage to prevent rejection. Infection (bacterial nephritis, pneumonia, pleuritis), drug toxicity (bone marrow depression, liver degeneration and/or necrosis), and rejection of the transplants were the consistent problems. No objective measurement which would permit accurate determination of immunosuppressive drug dosage was found. Polyuria in the transplanted animals was attributed to failure to develop the interstitial osmotic gradient essential for the allografts to respond to antidiuretic hormone. Polydipsia probably was compensation for the polyuria. The results would indicate that until a major immunological breakthrough occurs in tissue transplantation, the clinical placement of a renal allograft in the dog for long term function is not practical. Prolonged function of the renal allograft has been accomplished in the dog using immunosuppressive drugs, suggesting that the procedure can be utilized for the treatment of end stage renal disease in this animal.¹⁸ Immunosuppressive drugs have inherent toxicities, of which bone marrow depression, liver and gastrointestinal tract damage are most notable.^5,18,23 Ideally, minimal immunosuppression is desired to avoid drug toxicity, maintain some degree of immune competence to reduce chances of serious, if not fatal infection, and yet allow the transplanted kidney to survive in a hostile immune environment.²² There are no good measurements to determine the immunological status of patients on immunosuppressive therapy,²² consequently, such treatment is emperic; based on experimental and clinical experience. ^13,18 Although the dog is a common model for renal allograft investigations, ^15,18 there is limited information in the veterinary literature 3.5.6,11,14 concerning the experience of veterinary clinicians and their attempts to maintain the renal homograft. This report summarizes the author's experiment with renal transplants in the dog.     

THE RADIOGRAPHIC APPEARANCE OF THE PULMONARY VASCULATURE IN THE CAT

The purpose of this study was to determine the dimensions of the pulmonary arteries and veins in the cat, both in normal animals and those with evidence of intrathoracic disease. The radiographs of 50 normal cats, 35 cats with hypertrophic cardiomyopathy (HCM), and 15 cats with other intrathoracic disease were assessed. The normal range for the right cranial lobar artery compared with the proximal third of the fourth rib was 0.5-1.0, with a mean artery-to-rib ratio of 0.70 (standard deviation +/- 0.13). Normal cats had a mean vein diameter of (0.20 +/- 0.03 cm) (P = 0.034) compared with cats with HCM, which had a significantly greater mean vein diameter (0.22 +/- 0.04 cm).     

Efficacy of the Boar-Operated-System to deliver baits to feral swine

Feral swine (Sus scrofa) pose a significant disease threat to livestock and humans. Emerging technologies to reduce feral swine disease transmission risks include fertility control, vaccination, and toxicants. However, for these technologies to be appropriate for field application, a feral swine-specific oral delivery system is needed. We used two field trials to generate information related to appropriate field application of the Boar-Operated-System (BOS?), an oral delivery system designed to provide bait access only to feral swine. Our objectives were to determine whether pre-baiting BOS? units increased bait removal and to evaluate the proportion of feral swine and non-target animals that ingest baits designed to deliver pharmaceuticals through the BOS?. During both trials we used baits housed within 10 BOS? units. We monitored wildlife visitation, bait removal, and ingestion using motion sensing digital photography and baits containing the bait marker tetracycline hydrochloride (TH). During trial 1 we found three of five pre-baited BOS? units were used by feral swine only. Additionally, we found the five BOS? units that were not pre-baited were not used by feral swine or non-target wildlife. During trial 2 we determined bait removal from the BOS? to be reduced by only 10% for feral swine when activated, whereas bait removal from the BOS? by all other wildlife was reduced by 100% when activated. We captured 81 feral swine and 23 raccoons and found 90% and 13% to have TH-marked teeth, respectively. With minor modifications, the BOS? should be considered a valuable tool to be used in feral swine disease management in conjunction with existing technologies.     

THE KANGAROO ISLAND STRAIN OF PIG IN BIOMEDICAL RESEARCH

The feral pig from Kangaroo Island, South Australia, has descended from British breeds released onto the Island by early explorers approximately 180 years ago. It has developed into a smaller pig than the modern commercial equivalent, with distinctive and reproducible physical characteristics and a physiology which appears to bestow on it some advantages in terms of fitness and vigour. It has adapted easily to laboratory and intensive piggery conditions where it has reproduced satisfactorily. It has a higher erythrocyte count and PCV than the equivalent Large White and a lower white blood cell count. Plasma Na, K and glucose were significantly higher and HCO₃ urea and creatinine lower in the Kangaroo Island strain. It represents a useful strain of pig for biomedical research, approaching in size the miniature pigs used overseas. A useful approach to routine bleeding of pigs is described.     

THE CONTROL OF BLUETONGUE IN AN ENZOOTIC SITUATION

On account of the wide host range of bluetongue virus and its biological transmission by insects, control of the disease in an enzootic situation is based primarily on the active immunisation of susceptible animals as well as on the prevention of contact between the insect vectors and the susceptible hosts. In spite of their unquestionable value, the egg attenuated vaccines which are currently employed for prophylactic immunisation, have certain shortcomings. The existence of 16 known serotypes of bluetongue virus makes it difficult to achieve a very wide spectrum of immunity in sheep vaccinated once or twice only. The problems which are experienced with the immunisation of lambs born in spring are indicated. The present vaccine can also present problems when used in breeding animals. Furthermore, the costs involved in the annual vaccination of large numbers of animals are considerable. The need for a vaccine for cattle is indicated. Work is also being conducted at present on the development of an inactivated vaccine for use in sheep. The use of novel virological techniques may aid in the future development of absolutely safe and highly efficient vaccines against bluetongue.     

Endocrine diseases of rodents.

The frequency of documented endocrine diseases in rodents and other small mammals varies considerably among the species maintained as pets, biomedical research animals, or display animals in zoos. The clinical diagnosis of endocrine diseases almost never occurs in free-ranging animals in their native habitat. Feral animals that have clinical endocrine disease, such as neoplasia, adrenal cortical hyperplasia, or diabetes, would exhibit clinical signs of altered behavior that would result in their removal by predators. The diagnosis of endocrine disease thus takes place in the relatively protective environment of captivity. This observation should forewarn pet owners and clinicians caring for these animals that the environment contributes to the development of endocrine diseases in these animals.     

Causes of death and illness in the native sheep of North Ronaldsay, Orkney. I. Adult sheep

Post-mortem examinations on 71 native sheep found dead on the island of North Ronaldsay, Orkney in four visits between April 1983 and July 1985 were carried out. The sheep in this almost feral flock have access to a small area of unmanaged moorland pasture but are otherwise restricted to the foreshore where they subsist largely on Laminaria spp. and other seaweeds. Young adult animals died largely of heavy parasite burdens combined with inadequate nutrition, while the older sheep often starved because of severe dental disease precipitated by heavy deposits of tartar on the cheek teeth--rarely seen in sheep on a more conventional diet. Other underlying metabolic conditions, such as the extensive mineralization of the kidney medulla in many mature sheep, may be debilitating. The pathological findings suggest that adaptation to the peculiar environmental rigours and dietary restrictions on North Ronaldsay is less complete than has previously been assumed.     

Epidemiology of Mycobacterium bovis infection in feral ferrets (Mustela furo) in New Zealand: I. Pathology and diagnosis

Necropsies of 228 ferrets captured from eight areas in the North and South Islands provided material for an investigation into the epidemiology of tuberculosis in feral ferrets. Mycobacterial culture of pooled lymph nodes (retropharyngeal, respiratory and jejunal) identified the prevalence of infection to be much higher than that estimated from gross lesions only. Seventy-three of the 228 animals examined (32%) were diagnosed as tuberculous. Fifty-three culture-positive ferrets and 18 seemingly uninfected animals were subjected to detailed histopathological examination. The outcomes of these investigations, including the characteristics of the disease, distribution of lesions and aids to diagnosis, are presented.

Of the feral carnivores found in New Zealand, the disease persists at high prevalence only in ferrets, and is probably maintained principally by ingestion of tuberculous carrion. The course of the disease may be prolonged in some ferrets, but tuberculosis eventually causes the death of many infected animals. Microscopic hepatic granulomas may be considered pathognomonic of the disease, and have potential to be used as a rapid diagnostic tool in ferrets with no gross lesions.     

口蹄疫病毒2c基因的克隆及表达

从O型口蹄疫病毒China98株病毒材料中克隆到了非结构蛋白2C的基因，并成功地将该基因在大杆菌中进行了表达，为建立以基因工程产品为抗原，能区分人工免疫和自然感染动物的检疫方法提供也技术和材料条件。 sri     

A review of feral cat control

Animal overpopulation including feral cats is an important global problem. There are many stakeholders involved in the feral cat debate over 'what to do about the problem', including those who consider them a nuisance, the public at risk from zoonotic disease, people who are concerned about the welfare of feral cats, those concerned with wildlife impacts, and the cats themselves. How best to control this population is controversial and has ranged from culling, relocation, and more recently 'trap neuter return' (TNR) methods. Data support the success of TNR in reducing cat populations, but to have a large impact it will have to be adopted on a far greater scale than it is currently practised. Non-surgical contraception is a realistic future goal. Because the feral cat problem was created by humans, concerted educational efforts on responsible pet ownership and the intrinsic value of animals is an integral part of a solution.     

CONTROL OF BLUETONGUE IN AN EPIZOOTIC SITUATION: AUSTRALIAN PLANS

Epizootics of BT outside Africa have occurred in the Middle East, Indian subcontinent, Spain and Portugal, and the United States of America. The disease has only been eradicated from a major region once, this being Spain and Portugal in 1956-60 when it was achieved by quarantine, compulsory vaccination and slaughter of some infected animals. Because of the serious economic effect that BT would have on the Australian sheep industry the policy in this country is to attempt eradication, if at all feasible. The prospects of eradication will be greatly enhanced if the disease can be diagnosed quickly, when the outbreak is still localised. The laboratory diagnosis of BT involves inoculation of blood samples, collected from febrile animals on the suspect property, into groups of susceptible sheep in insect-proof quarters. The diagnosis would be confirmed at the reference laboratory in South Africa by serological and other identity tests. The diagnosis of an outbreak that originated in the northern cattle areas might be very difficult, because of the probable mild clinical nature of the disease in cattle. It is suggested that sentinel sheep flocks be maintained in these areas in strategic places near likely points of entry. Control measures, based on current knowledge of the epizootiology and pathogenesis of bluetongue; are discussed. The disease is transmitted by Culicoides that ingest infected blood from viraemic ruminants. Control is based on reducing the number of viraemic ruminants in the infected area, reducing the population density of Culicoides, and reducing the availability of susceptible ruminants. It is vital to prevent the movement of potentially infected ruminants to new localities. Contingent plans for the eradication of an epizootic of BT in Australia have been prepared. These call for the creation of two control zones. In the inner infected area, which extends for about five miles around known infected farms, there would be an intensive disinsection programme with aerial and ground spraying. Ruminants in the infected area would probably be slaughtered. The quarantine zone would extend for another 50 miles and in this area there would be prohibition of the movement of ruminants from farms. Regular clinical inspections and serological surveys would be carried out to detect secondary outbreaks. If control measures failed, it might be necessary to mount urgently a massive vaccination campaign to prevent disastrous losses to the Australian sheep industry. The difficulties in obtaining sufficient quantities of monovalent vaccine from overseas at short notice are discussed. Plans have been made to produce BT vaccine in Australia, in a specially designed high security laboratory, should the need arise.     

SONOGRAPHIC APPLICATION IN THE DIAGNOSIS OF PYELONEPHRITIS IN CATTLE

Nineteen cattle with pyelonephritis were examined sonographically. A 3.5- and 5.0-MHz convex transducer was used for percutaneous and a 5.5-MHz linear scanner for transrectal examination. Ultrasonographic changes included enlarged kidneys, echogenic material, and flocculent fluid within a dilated and deformed renal sinus and a poor cortical medullary differentiation. Azotemia was detected in 10 and hematuria and proteinuria in all animals. Microbial culture revealed Corynebacterium renale in eight and Escherichia coli in five cattle. Sonography supplemented the clinical examination and clinicopathological analysis by providing additional information on renal disease in these patients.