Transmission of Mycobacterium bovis from experimentally infected ferrets to non-infected ferrets (Mustela furo)

AIMS: To demonstrate the transmission of Mycobacterium bovis infection from experimentally infected ferrets (Mustela furo) to non-infected ferrets in a laboratory setting, using three different isotypes of M. bovis, and to observe ferret behaviour that might be implicated in disease transmission. METHODS: Three female ferrets, each experimentally infected with a unique strain of M. bovis, were housed together with six female and two male non-infected ferrets in an isolation facility. Transmission of infection was monitored clinically, serologically (using an ELISA test), bacteriologically, histologically, and by isotype analysis of M. bovis isolates using spoligotyping to determine whether or not transmission of each strain occurred. Ferret behaviour was observed using a time-lapse video recorder. RESULTS: Transmission of M. bovis infection was confirmed in two male and four female ferrets. Isotype analysis showed that of the experimentally infected females, one did not infect any other ferret, another transmitted M. bovis to one ferret before it died prematurely 49 days post-infection, and the third, which was cannibalised, appears to have transmitted M. bovis to both males and three females. However, two of these latter three females had died before the event of cannibalism took place. One female was infected with two strains. Several behavioural interactions were observed that could have resulted in M. bovis transmission, including den sharing, sniffing of orifices and faeces, cannibalism and aggressive breeding behaviour. CONCLUSIONS: Horizontal transmission of M. bovis infection was demonstrated in ferrets under experimental housing conditions. Routes of transmission may involve cannibalism and factors such as den sharing, playing, fighting, mating, and sniffing of faeces.     

Surveillance of wildlife for Mycobacterium bovis infection using culture of pooled tissue samples from ferrets (Mustela furo)

AIM: To compare culture results of homogenates of pooled lymph nodes from individual ferrets with and without macroscopic lesions of bovine tuberculosis for the presence of Mycobacterium bovis, and to determine whether homogenates from 10-30 ferrets could be combined and cultured without loss of sensitivity as a possible method for improving cost-effectiveness of surveillance for M. bovis infection in wildlife populations. METHODS: Numbers of colony forming units (cfu) of M. bovis present in cultures of homogenates of pooled lymph nodes from individual ferrets known to be infected and having no visible lesions (NVL) or macroscopic lesions consistent with bovine tuberculosis were determined. Prevalences of M. bovis infection in populations of ferrets in the Marlborough region of the South Island of New Zealand were determined by culturing homogenates of pooled lymph nodes from individual animals. Samples from homogenates from North Canterbury were combined to form pools representing 10, 20 and 30 animals and also cultured for M. bovis. RESULTS: Fewer M. bovis cfu were isolated from ferrets with NVL (mean=0.77 log10) compared with ferrets with macroscopic lesions (mean=3.22 log10; p<0.05). The mean prevalence of infection in eight different surveys involving 427 ferrets from the Marlborough region was 18% (range 8-44%), which included a small number of animals with macroscopic lesions of tuberculosis. Pooling of samples from up to 30 different ferrets with NVL did not reduce the sensitivity of detecting M. bovis infected populations. CONCLUSION: Culturing of pools of lymph node samples detected a significant proportion of M. bovis-infected ferrets that would otherwise have gone unnoticed based on samples that had only macroscopic lesions. Culturing of samples pooled from up to 30 different ferrets could provide significant cost savings in surveys of wildlife for the presence of M. bovis infection without any apparent loss of sensitivity.     

The distribution of gross lesions of tuberculosis caused by Mycobacterium bovis in feral ferrets (Mustela furo) from Otago, New Zealand

The distribution of gross lesions of Mycobacterium bovis was examined in 94 tuberculous feral ferrets (Mustela furo) collected from 1992 to 1995 from areas of Otago endemic for bovine tuberculosis. Overall, 56.4% of tuberculous ferrets had single-site lesions, 24.5% had multiple infections and 19.1% had generalised infections. The mesenteric lymph node was the most common site of infection (34.5% of all lesions), with the retropharyngeal (17%) and the prescapular lymph nodes (16.4%) also frequently infected. Only 2.9% of lesions involved the respiratory tract. Of single-site lesions, 60.4% were in the mesenteric lymph node. The high proportion of lesions in the alimentary tract suggests that the ingestion of infectious material, possibly carrion or prey, is an important source of infection. Peripheral lymph nodes contributed to 24.5% of all infections, suggesting that within species transmission by social contact such as fighting and mating also occurs. Open and respiratory lesions were found in 11.7% of tuberculous ferrets, which suggests that ferrets are potentially infectious and therefore may be involved in the transmission of bovine tuberculosis to domestic stock and other mammals. The distribution of gross M. bovis lesions in ferrets is compared to those observed in possums (Trichosurus vulpecula) and badgers (Meles meles).     

Susceptibility of ferrets (Mustela putorius furo) to experimentally induced rabies with European Bat Lyssaviruses (EBLV)

Twenty ferrets (Mustela putorius furo) were inoculated by intramuscular (i.m.) injection with European Bat Lyssaviruses (EBLV) type-1 and 2 using 10(4.0) foci-forming units (FFU) EBLV-2 (n = 6), 10(4.0) FFU EBLV-1 (n = 7) and 10(6.0) FFU EBLV-1 (n = 7). Furthermore, 15 mice received 10(2.5) FFU EBLV-2 (n = 5), 10(2.5) FFU EBLV-1 (n = 5) and 10(4.5) FFU EBLV-1 (n = 5) by i.m. inoculation. All ferrets and mice receiving the higher dose of EBLV-1 succumbed to infection. In contrast, only three of seven ferrets and two of five mice inoculated experimentally with the lower EBLV-1 dose died. By comparison, all of the EBLV-2 infected ferrets and four of five mice survived infection. All 20 infected ferrets seroconverted. Using sensitive molecular tools, the virus was detected in different tissues, but it could not be found in any saliva samples taken during the 84-day observation period.     

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.     

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.     

Epidemiology of Mycobacterium bovis infection in feral ferrets (Mustela furo) in New Zealand: II. Routes of infection and excretion

Detailed 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 wild ferrets. Seventy-three of the 228 (32%) animals examined were diagnosed as tuberculous, by culture of pooled lymph nodes and detailed histopathological examination. The prevalence of bovine tuberculosis was 96% in 24 ferrets taken from areas in which tuberculous possums were common. None of 35 animals under 4 months of age were found to be infected, and the prevalence of infection was shown to rise with age, such that for each 6 month age increment there was a 2.8 times greater risk of becoming infected. The most common route of infection appeared to be via the alimentary tract, as 79% of 38 animals, in which the initial lesions could be reasonably determined, had these lesions associated with the digestive tract. Samples from potential sites of excretion from infected ferrets were submitted for culturing. The most common route of excretion was via the oral cavity, with M. bovis recovered from 15 of 64 (23%) oral swabs. Mycobacterium bovis was also isolated from four of 64 (6%) tracheobronchial lavage samples, ten of 63 (16%) faecal samples, two of 29 (7%) urine samples and one of 8 (12.5%) mammary glands. The disease in ferrets appears to be principally maintained by ingestion of tuberculous carrion. Although a moderate number of ferrets excrete M. bovis orally, there appears to be only minor intraspecific transmission by bite wounding. The findings provided no evidence to support the occurrence of pseudo-vertical transmission.     

Phimosis and paraphimosis in two ferrets (Mustela putorius furo)

Cases of paraphimosis are rarely described in ferrets. Phimosis has not been reported in the ferret. Two castrated ferrets with abnormalities of the prepuce were presented separately. Case 1 had a 4-month duration of a non-reducible paraphimosis. A shortening of the sheath prevented complete covering of the penis. Case 2 had dermatitis around the prepuce of a month's duration. The foreskin was distended by urine which could be eliminated through a barely visible opening by the application of manual pressure. The penis could not be extruded under general anesthesia. Surgery was performed in both cases. In case 1, parts of the skin of the prepuce, and mucosa of the sheath were resected to create an enlarged opening correcting the constriction of the penis. In case 2, a circular incision was made along the periphery of the skin with dermatitis, and the skin of the prepuce. The skin was resected to enlarge the preputial orifice. Surgical treatment was successful in both cases, did not present any technical difficulties, and was of a short duration. Surgical treatment of paraphimosis and phimosis have not been reported in ferrets and should be considered in cases of scalding of the prepuce not responding to medical treatments.     

Adrenal teratoma in four domestic ferrets (Mustela putorius furo)

Teratomas are histologically complex neoplasms that are composed of structures derived from multiple germ cell layers (ectoderm, mesoderm, and endoderm). These neoplasms are uncommon in domestic animals and are usually found in the gonads. This paper describes teratomas of the adrenal gland in four domestic ferrets (Mustela putorius furo). Three of four of the neoplasms contained tissues from ectodermal, mesodermal, and endodermal germ cell layers; two of four contained rudimentary teeth. In one case, malignant epithelial cells had metastasized to local lymph nodes. Teratomas, although uncommon, should be included in the differential diagnosis for adrenal neoplasms in domestic ferrets.     

Electrocardiographic values from clinically normal, anesthetized ferrets (Mustela putorius furo)

Electrocardiograms were recorded from 25 clinically normal male ferrets anesthetized with ketamine and xylazine and from 7 ferrets anesthetized with ketamine alone. Ferrets anesthetized with ketamine alone had excessive salivation, open eyes, muscle tremors, muscle twitching, paddling motions, attempts to stand, and an unstable ECG baseline. Because ketamine/xylazine combination resulted in induction and good muscle relaxation, the ECG had little interference resulting from muscular movement.     

A congenital Toxoplasma-like disease in ferrets (Mustela putorius furo)

Approximately 30% of 750 neonatal farmed ferret kits died without observed clinical signs. The presence of multifocal necrosis associated with Toxoplasma-like organisms in the liver, lung and heart suggested a diagnosis of toxoplasmosis. Surviving animals from affected litters were stunted but showed no histological or serological evidence of Toxoplasma infection, nor could infection be demonstrated by mouse inoculation. The involvement of animals at one day of age indicated congenitally acquired disease.     

Outbreak of canine distemper in domestic ferrets (Mustela putorius furo)

In 2006 an outbreak of canine distemper affected 14 young domestic ferrets in Barcelona, Spain. Their clinical signs included a reduced appetite, lethargy, dyspnoea, coughing, sneezing, mucopurulent ocular and nasal discharges, facial and perineal dermatitis, diarrhoea, splenomegaly and fever. Late in the course of the disease, general desquamation and pruritus, and hyperkeratotic/crusting dermatitis of the lips, eyes, nose, footpads, and perineal area were observed. None of the ferrets developed neurological signs. Non-regenerative anaemia and high serum concentrations of alpha- and beta-globulins were the most common laboratory findings. Most of the animals died or were euthanased because of respiratory complications. Postmortem there were no signs of lung collapse. Distemper was diagnosed by direct immunofluorescence of conjunctival swabs or pcr of several organs, and histology revealed the characteristic eosinophilic intracytoplasmic and intranuclear inclusion bodies of canine distemper virus in several organs. The minimum incubation periods calculated for six of the ferrets were 11 to 56 days, and in 13 of the ferrets the signs of disease lasted 14 to 34 days. Inclusion bodies compatible with infection by herpesvirus were found in the lungs of one of the ferrets.     

Extrahepatic biliary tract obstruction in two ferrets (Mustela putorius furo)

This report describes extrahepatic bile duct obstruction in two ferrets, which were presented with anorexia, chronic weight loss and general weakness. Physical examination revealed lethargy, cachexia, dehydration, abdominal pain and icterus. Marked haematological, serum chemistry and urinalysis abnormalities included hyperbilirubinaemia (65·5 and 114·2 μmol/L), high concentrations of alanine transaminase (1327·53 and 2578·88 IU/L) and biluribinuria. Abdominal ultrasonography revealed thickening of the bile duct together with the gall bladder wall. The common bile duct was obviously distended. Choledochotomy revealed inspissated bile with fragile green gelatinous plugs that was removed to allow the bile to flow into the duodenum. Cytology and culture of the biliary tract contents were negative for bacteria. Laboratory analyses of biliary plugs showed presence of only protein substances, without detectable mineral composition. Histopathological examination of the liver showed diffuse steatosis and non-specific cholangiohepatitis in both cases.     

Excretion of Mycobacterium bovis by experimentally infected cattle

Three groups, each of five calves, four to seven months old, were inoculated intranasally with different numbers of Mycobacterium bovis. Infection was established readily in the calves which received an inoculum containing either 10(6) or 10(4) colony forming units (cfu). After every infection there was a lag period during which the organisms could not be isolated from specimens of nasal mucus. All the animals excreted M bovis and the time of commencement, quantity and duration of excretion appeared to be related to the inoculation dose. Excretion continued for many weeks, and for two calves excretion became intermittent over many months. All the calves which were given inocula of 92 cfu failed to develop the disease and no immunological responses were detected; however, M bovis was isolated from nasal secretions from one of these animals 100 days after inoculation.     

Hepatic hemangiosarcoma in two ferrets (Mustela putorius furo).

Two ferrets were presented to the authors' clinic. Hemoperitoneum was diagnosed in one ferret, and an abdominal mass was palpated in the other. One ferret was euthanized and necropsied, and one ferret underwent exploratory laparotomy and liver lobectomy. In both cases, the histopathologic diagnosis was hepatic hemangiosarcoma.     

The prevalence of bovine tuberculosis (Mycobacterium bovis) infections in feral populations of cats (Felis catus), ferrets (Mustela furo) and stoats (Mustela erminea) in Otago and Southland, New Zealand

Twenty-one properties in the Otago region of the South Island of New Zealand were surveyed for the presence of gross lesions due to Mycobacterium bovis infection in feral cats (Felis catus), ferrets (Mustela furo) and stoats (Mustela erminea) during 1993 and 1994. In total, 1293 cats, ferrets, stoats and weasels (Mustela nivalis) were examined for the presence of tuberculous lesions. The properties surveyed were selected according to the history and incidence of bovine tuberculosis infection in their cattle herds. Sixteen infected cattle properties were trapped in areas of Otago that were endemic for bovine tuberculosis and five properties were trapped in non-endemic areas that were considered to be free from tuberculosis infection in the cattle. No tuberculous cats, ferrets, stoats or weasels were found in non-endemic areas, and prevalence rates in the endemic areas were 0.9% for cats (n=215, 0.12相似文献