Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Ferrets”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 91 records · Page 5Linked to original sources

Coronavirus-associated epizootic catarrhal enteritis in ferrets.

OBJECTIVE: To characterize clinical signs and lesions and identify the etiologic agent associated with epizootic catarrhal enteritis in domestic ferrets. DESIGN: Cross-sectional study. ANIMALS: 119 ferrets with epizootic diarrhea of presumed viral cause and 5 control ferrets. PROCEDURE: Clinical records and biopsy or necropsy specimens of ferrets with presumed epizootic catarrhal enteritis were reviewed. Immunohistochemical staining for coronavirus antigen was performed on paraffin-embedded tissues from approximately 10% of affected ferrets to identify viral antigen and determine its distribution. Transmission electron microscopy was performed on fecal samples and sections of jejunum. Virus isolation studies as well as immunofluorescent tests for other similar viruses were performed. RESULTS: Characteristic microscopic lesions consistent with intestinal coronavirus infection (vacuolar degeneration and necrosis of villus enterocytes; villus atrophy, fusion, and blunting; and lymphocytic enteritis) were consistently detected in affected ferrets. Coronavirus particles were identified in feces and jejunal enterocytes by use of transmission electron microscopy. Immunohistochemical staining of jejunal sections revealed coronavirus antigens. Antigen staining was not detected in healthy ferrets or ferrets with other gastrointestinal tract diseases. Virus isolation was unsuccessful, and other similar viruses were not detected. CONCLUSIONS AND CLINICAL RELEVANCE: Results strongly implicate a coronavirus as the causative agent of epizootic catarrhal enteritis in ferrets. Diagnosis may be made on the basis of a combination of historical, clinical, and microscopic findings.

Animals↗

Factors associated with aggression between pairs of domestic ferrets.

OBJECTIVE: To identify factors (eg, familiarity, sex, neutering status, and time of year) associated with aggression between domestic ferrets and test a method for reducing aggression when introducing ferrets. DESIGN: Prospective trial. ANIMALS: 56 healthy domestic ferrets. PROCEDURE: To identify variables associated with aggression, pairs were placed in an enclosed area and observed. To test whether increasing familiarity would decrease aggression when introducing ferrets, pairs of ferrets were housed in separate cages next to each other or in separate rooms for 2 weeks prior to introduction. RESULTS: 49 of 82 pairs of strangers fought, but 31 cage mate pairs did not. Time of year had no apparent effect. Pairs consisting of 2 neutered females or 2 sexually intact males were significantly more likely to fight than were pairs consisting of a neutered female and a sexually intact male. Pairs caged next to each other for 2 weeks prior to introduction were no less likely to fight than were control pairs. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that familiarity, sex, and neutering status are important determinants of aggression between ferrets. If unfamiliar neutered ferrets are introduced, then pairing 2 males or a male and female would likely result in the lowest levels of aggression. However, neutered females and sexually intact males are not indiscriminately aggressive, as a neutered female can be paired with a sexually intact male without resulting in aggression. Caging ferrets next to each other for 2 weeks does not decrease aggression when the ferrets are introduced.

Aggression↗

Effect of field capture on the measurement of cellular immune responses in wild ferrets (Mustela furo), vectors of bovine tuberculosis in New Zealand.

Ferrets are recognised as significant wildlife vectors of bovine tuberculosis (Tb) in New Zealand. Disease management strategies, such as the development of a protective wildlife vaccine, could be assisted by the ability to measure pertinent cellular immune responses among wild animals. In the present study, we investigated whether it is possible to measure in vitro lymphocyte reactivity in wild-caught ferrets, and also determined levels of physiological stress in these animals, and we compared these responses to those observed in laboratory-maintained domesticated ferrets. Over a 12-month period, 80 ferrets were live-captured from a Tb-endemic region (Otago, southern New Zealand); cardiac blood was withdrawn on-site, and mononuclear cell cultures were successfully established from 75 of these animals. Lymphocyte transformation (LT) responses to T cell and T/B cell mitogens (Concanavalin A [Con A] and pokeweed mitogen) were measured via uridine incorporation assay. The magnitude of these responses did not differ significantly between animals that had been captured in wire-framed cage traps and those captured using soft-jawed leg-hold traps. Levels of serum cortisol and glucose (as indicators of physiological and oxidative stress, respectively) were highest in animals captured using leg-hold traps. In comparison to domesticated ferrets, wild-caught ferrets had lower overall LT responses to Con A, but significantly higher levels of serum cortisol. Finally, 10/80 animals captured from the wild were severely diseased (Tb+), as evidenced by gross tuberculous lesions at autopsy. Successful mononuclear cell cultures were established from nine of these animals; LT responses to Con A were significantly lower in Tb+ ferrets than in either wild-caught/non-diseased (Tb-) or domesticated ferrets. These results demonstrate that it is possible to measure cellular immune responses from the blood of wild-caught ferrets, but that field capture and disease status may have detrimental effects on in vitro T cell function, possibly due to the influence of physiological stress.

Animals↗

Partial protection against oral challenge with Mycobacterium bovis in ferrets (Mustela furo) following oral vaccination with BCG.

SETTING: Ferrets (Mustela furo) are important wildlife vectors of bovine tuberculosis (TB) in New Zealand. Protective vaccination of ferrets may limit the potential of transmission to livestock. OBJECTIVE: To determine whether orally-delivered Mycobacterium bovis BCG can confer protection against oral challenge with virulent M. bovis. DESIGN: Ten ferrets were vaccinated by feeding measured doses of live BCG, and subsequently challenged with virulent M. bovis via the oral route. Ten non-vaccinated (control) ferrets were similarly challenged. Live body weights and lymphocyte reactivity were monitored longitudinally, and ferrets were killed 20 weeks following challenge. Necropsy, histological examination and bacterial culture of alimentary tract lymphatic tissues were undertaken. RESULTS: There was a significant reduction in the incidence of gross tuberculous lesions among vaccinated ferrets compared to control animals, and fewer vaccinated ferrets had histologically-detectable acid-fast organisms in mesenteric lymph node (LN) tissues. There were significantly fewer vaccinated ferrets with culture-positive retropharyngeal LNs, and the mean bacterial burden was significantly lower for retropharyngeal LNs isolated from vaccinated animals than from controls. CONCLUSION: These results demonstrate that oral BCG vaccination of ferrets can confer partial protection against M. bovis, and suggest that systemic immune responses may be less important in mediating this degree of protection than local immunity.

Animals↗

Craniofacial morphology and growth in the ferret: effects from alteration of masticatory function.

INTRODUCTION: Our hypothesis is that any effects on craniofacial growth and morphology induced by altering the masticatory function will vary according to the species involved. The general aim of this thesis was to test the possible effects of altering the masticatory function on craniofacial growth and morphology, as well as features of masticatory muscles in ferrets. To better elucidate these mechanisms involved, the anatomy of the skull, craniofacial growth pattern and development of occlusion in the ferret were investigated to serve as baseline data. MATERIALS AND METHODS: The description of the anatomy and the radiographic features of the skull was based on observations of 100 skulls of adult ferrets of both sexes. The craniofacial growth pattern was studied in 16 young ferrets of both sexes using serial cephalograms taken on 5 occasions according to age: 25 days, 35 days, 55 days, 80 days and 300 days. To follow the development of occlusion, these animals underwent dental examinations every other day. Forty male ferrets were divided into two groups from the age of 5 weeks. One group was fed hard pellets (hard-diet group), and the other the same diet but softened with water (soft-diet group). After six months, specimens of masticatory muscles were dissected and analysed histochemically, and cephalograms were analysed cephalometrically. RESULTS: The ferret skull is relatively elongated with a short facial region, being longer and broader in males than in females. The viscero- and neurocranium follow an orderly pattern of expansive growth. The growth of the mandible is mainly characterized by an anteroposterior body elongation, and enlargement of the coronoid process. Craniofacial growth in ferrets ceases earlier in female than in male animals. The deciduous teeth erupted between the 19th and 31st postnatal day, and exfoliated approximately between days 51 and 76. The time of eruption of the permanent teeth ranged from 42 to 77 days. The female ferrets were generally ahead of the males regarding the eruption age of permanent teeth. The alteration of the masticatory function by feeding the animals a soft diet caused a hard palate plane more distant from the cranial base plane, smaller inter-frontal and inter-parietal widths, and a slenderer zygomatic arch, as well as a generally shorter and narrower coronoid process. Variations of most variables are greater in animals fed on soft diet. The mean cross-sectional area of type I and type II fibres in the temporalis and the masseter, and type II fibres in the digastricus, as well as the number of capillaries per fibre were significantly smaller in the soft-diet animals. CONCLUSION: Altered masticatory function has induced changes in masticatory muscles and certain effects on craniofacial growth in ferrets. These changes are not the same as those reported in other species (e.g. rats). It appears that reduced masticatory function leads to smaller fibres in the elevators and transverse skull dimensions. The different effects are presumably related to the differences in craniofacial anatomy and growth pattern, as well as the masticatory system, in the various species studied previously.

Animals↗

The role of cellular susceptibility in the declining severity of respiratory influenza of ferrets with age.

A comparison was made, both in vivo and in organ culture, between newborn (1-day-old) and suckling (15-day-old) ferrets of lower respiratory tract tissue infected with a virulent strain (clone 7a) of influenza virus. Newborn ferrets were killed by influenza virus following intranasal inoculation but suckling ferrets were almost as resistant as adult ferrets. In newborn ferrets there was a rapid, severe and progressive infection of lung tissue with infection of alveolar cells as well as those of bronchial and bronchiolar epithelium (assessed by monitoring virus infectivity and by fluorescent antibody staining). In suckling ferrets, as previously shown for adult animals, the lung infection was less severe, less persistent and confined to the epithelium of bronchi with only a small bronchiolar involvement and even less alveolar cell infection. These differences observed in vivo were repeated in organ cultures obtained from various areas of the lung. i.e. alveolar and airway epithelial cells of newborn ferrets exhibited a greater susceptibility than those of older ferrets. Thus, it appears that one factor determining the greater susceptibility of the lower respiratory tract of newborn ferrets is a greater inherent susceptibility of alveolar and airway epithelial cells to infection with influenza virus. Other factors may also be involved and have yet to be investigated.

Aging↗

The role of lung development in the age-related susceptibility of ferrets to influenza virus.

Newborn (I-day-old) ferrets died following intranasal inoculation of influenza virus (clone 7a) but suckling (15-day-old) ferrets were almost as resistant as adult ferrets. Many of the deaths in newborn ferrets were consequent upon an increased lower respiratory tract infection. One reason for the latter was an increase in susceptibility of both ciliated epithelium and alveolar cells in newborn ferret lungs when compared with the corresponding cells in adult and suckling ferrets (Coates et al. 1984). Work reported here shows that the lungs of newborn ferrets possess a greater proportion of ciliated epithelium-lined airway in comparison with the lungs of suckling and adult ferrets. This situation might also contribute to the increased susceptibility of the lower respiratory tract although the difficulties of assessing this influence precisely are discussed. In addition, the occlusion of the narrower airways of the immature lung in the infected newborn ferret contributes to the increased respiratory complications.

Age Factors↗

Transmission of a chronic lymphoproliferative syndrome in ferrets.

BACKGROUND: Lymphomas and leukemias are caused by transmissible viruses in a wide variety of species, including humans, cattle, and cats. Features of lymphoma in ferrets suggest that it, too, may have an infectious etiology. No agent has been identified. EXPERIMENTAL DESIGN: Cells or cell-free inocula from a ferret with spontaneous malignant lymphoma were administered i.p. to six recipient ferrets. Two ferrets received fresh cells, two received frozen cells, and two received cell-free culture supernatant. The recipients were monitored routinely clinically and hematologically, and lymphoma was confirmed histologically. The lymphomas were characterized using cytology, cytochemistry, immunophenotyping, and histology. Cultivated cells from the donor and recipients were examined using reverse transcriptase assay, microscopy, and electron microscopy. RESULTS: All of the six recipient ferrets developed mild sustained lymphocytosis within 6 weeks of the inoculation. Two of six were euthanized 14 to 18 months after inoculation. Lymphoma was later diagnosed in three of the four remaining ferrets at 24 to 36 months after inoculation. All developed a chronic indolent syndrome featuring profound splenomegaly, lymphocytosis with atypia, and histologically polymorphous lymphoma. Two of the three who developed lymphoma had received fresh donor lymphoma cells, and the third had received supernatant from donor cell cultures with elevated reverse transcriptase activity. Cultivated cells from the affected ferrets demonstrated reverse transcriptase activity and retrovirus-like particles. CONCLUSIONS: This study demonstrates horizontal transmission of malignant lymphoma in ferrets using cell or cell-free inocula. Clinical and pathologic features of this syndrome in ferrets resembled virally induced lymphomas in other species.

Animals↗

Pancreatic beta cell tumor in ferrets: 20 cases (1986-1994).

OBJECTIVE: To characterize survival times, disease-free intervals, and prognostic variables in ferrets with pancreatic beta cell neoplasia. DESIGN: Retrospective study. ANIMALS: 20 ferrets with histologically confirmed pancreatic beta cell tumors. PROCEDURE: Medical records of ferrets with pancreatic beta cell tumors were reviewed. Variables such as age, sex, duration of clinical signs, existence of other neoplasia, single versus multiple masses in the pancreas, benign or malignant histologic features, and the type of treatment used at redevelopment of clinical signs were examined to determine their relationship to survival times and disease-free intervals. RESULTS: Duration of clinical signs prior to diagnosis and initial surgery was inversely correlated with survival time and disease-free interval. Overall median survival time for all ferrets with pancreatic beta cell tumors was 483 days. Median disease-free interval for ferrets that had abdominal surgery for pancreatic beta cell tumor removal was 240 days. Distant tumor metastasis was not found in this group of ferrets, but local tumor recurrence was common. In 4 ferrets that had a second celiotomy, removal of recurrent pancreatic tumors did not prolong survival but did result in a second disease-free interval. CLINICAL IMPLICATIONS: Pancreatic beta cell tumors should be considered in ferrets over 2 years of age that have clinical signs of seizures, episodic lethargy, ptyalism, ataxia, and hind limb weakness. In the study reported here, complete surgical excision of the tumor resulted in temporary resolution of clinical signs in ferrets; however, redevelopment of clinical signs at a later time was common.

Animals↗

Protective vaccination of ferrets against canine distemper with recombinant pox virus vaccines expressing the H or F genes of rinderpest virus.

OBJECTIVE: To investigate the ability of rinderpest virus (RPV) antigens, expressed in pox virus vectors, to protect against canine distemper virus (CDV) infection in ferrets. ANIMALS: Ferrets (Mustela putorius; n = 27) with no previous exposure to CDV. PROCEDURE: Ferrets were inoculated intradermally with recombinant vaccinia viruses expressing the H gene of RPV, the F gene of RPV, the H and F genes of RPV, or fowlpox virus recombinant expressing both genes. Two ferrets were vaccinated s.c. with CDV vaccine as positive controls, and 1 group was left unvaccinated as a negative control. Blood was obtained from ferrets biweekly; antibody titer to RPV was detected by ELISA, and CDV antibody titer was measured by serum neutralization testing and ELISA. RESULTS: Partial protection was seen in all groups, with vRVFH vaccination being the most protective (60%). CONCLUSIONS AND CLINICAL RELEVANCE: A single inoculation with a vaccinia virus expressing the H and F genes of RPV was able to protect 60% of the vaccinated ferrets challenge exposed with a high dose of CDV. These results indicate the ability of RPV antigens expressed by vaccinia virus to protect ferrets against a related morbillivirus. Further, they document the safety and efficacy of a recombinant vaccinia virus vaccine for ferrets. Such vaccines may be useful given the susceptibility of ferrets to CDV and the problem of maternal antibody interfering with vaccination of young animals.

Animals↗

Immunity to influenza in ferrets. V. Immunization with inactivated virus in adjuvant 65.

Ferrets infected with influenza virus A2/Hong Kong/3/68 responded with a febrile reaction; the temperature was elevated by 1.0 degrees C. or greater to a level of 40 degrees C. or more. In addition, relatively high titres of virus were recovered from nasal washings taken 3 days after virus infection, serum antibody was produced, increased nasal protein was detected and nasal washings contained both HI and neutralizing antibody. Of four ferrets immunized with 400 CCA units of inactivated influenza virus A2/Aichi/2/68 in saline, only one produced detectable serum HI antibody, and none produced detectable nasal antibody. These ferrets were subsequently found to be susceptible to intranasal infection with influenza virus A2/Hong Kong/3/68. Thus, the temperature response, the titre of virus recovered from nasal washings and the serum HI antibody response found after virus infection was similar to that found after infection of non-immunized ferrets. However, the increase in protein concentration and the titre of HI and neutralizing antibody found in nasal washings after virus infection was detectably less than that found after virus infection of non-immunized ferrets.Four ferrets were immunized with 400 CCA units of inactivated A2/Aichi/2/68 virus in adjuvant 65, and these ferrets produced relatively high titres of serum HI antibody but no detectable nasal antibody. After subsequent virus infection with influenza virus A2/Hong Kong/3/68, these ferrets showed a modified temperature response, reduced titres of virus in nasal washings compared to that found in nasal washings from non-immunized ferrets, no increase in nasal protein and no detectable nasal HI antibody. Thus, immunization with inactivated virus in adjuvant 65 resulted in a significant modification of the response of ferrets to challenge virus; however, the immunity was not complete, and appreciably less than that found after infection with live homologous virus.

Adjuvants, Immunologic↗

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<mu<3.6 at 95% CI), 17.9% for ferrets (n=.548, 14.9<mu<21.5), and 1.6% for stoats (n=62, 0.04<mu<8.95). Bovine tuberculosis was not found in any of the four weasels examined. A statistically significant association (p=0.019) was shown between the prevalence of tuberculosis in ferrets from infected properties compared to uninfected properties. High prevalences of bovine tuberculosis in ferrets, the geographically widespread nature of bovine tuberculosis infections in ferrets, and the association of tuberculous ferrets with infected cattle herds suggest that ferrets may transmit infection to domestic stock.

Journal Article↗

Quantitative light and scanning electron microscopy of ferret sperm.

Sperm were obtained via electroejaculation from Domestic ferret, (Mustela putorius furo), Siberian ferret (M. eversmanni), Black-footed ferret (M. nigripes), and a hybrid between Siberian and Domestic, called the Fitch ferret (M. sp.). Comparisons of sperm were made by four different microscopy techniques to determine whether differences exist among species. First, Nomarski differential interference microscopy could be used to distinguish domestic ferret sperm from the others on the basis of the structure of the posterior part of the acrosome. Second, both silver staining, which demonstrates argentophilic protein distribution, and scanning electron microscopy (SEM), revealed differences among the morphology of sperm for each species; variation in the unique appearance of the acrosome in ferret sperm was detected especially well by SEM. To quantify differences in morphology, five sperm head parameters were measured using image analysis; light microscopy produced significantly larger values than did SEM (all parameters and all species but Fitch), and there were significant differences owing to species for all parameters but one. Generally, our data demonstrate the value of complementary techniques to distinguish among sperm of closely related species and more specifically may help establish evolutionary relationships among the ferret species studied. In addition, they provide baseline data important for the captive breeding of the endangered Black-footed ferret.

Acrosome↗

Identification of genotypes of Cryptosporidium parvum isolates from ferrets in Japan.

Recent molecular studies show that Cryptosporidium parvum is composed of at least eight genotypes including zoonotic genotypes. Therefore, it is important to screen the genotypes of the isolates harbored in animals for the control of human cryptosporidiosis. The ferret is a popular pet, but also a reservoir of Cryptosporidium. Since the infectivity of zoonotic genotypes in ferrets remains unclear, there is a possibility these hosts harbor zoonotic genotypes. In the present study, we examined the genotypes of C. parvum isolates from ferrets in Japan using polymerase chain reaction direct sequencing. The sequences of the isolates examined clustered with the ferret-adapted genotype (ferret genotype). Our study suggests that ferrets harbor the ferret genotype which is conserved across geographical areas. Further study is required to determine whether ferrets are a significant reservoir for human cryptosporidiosis.

Animals↗

Helicobacter mustelae-associated gastritis in ferrets. An animal model of Helicobacter pylori gastritis in humans.

Gastric Helicobacter mustelae was present in 100% of 11 adult female ferrets (Mustela putorius furo). The high immunoglobulin G antibody levels to H. mustelae in all ferrets showed a significant immune response to the organism. Urease mapping of the ferret stomach indicated that the bacteria heavily colonized the proximal duodenum and antrum and, to a lesser extent, the corpus. The histological gastritis observed coincided with presence of H. mustelae. Superficial gastritis was noted in the oxyntic gastric mucosa, whereas in the distal antrum the chronic inflammatory response occupied the full thickness of the mucosa. In the proximal antrum and transitional mucosa, focal glandular atrophy and regeneration were observed. Seven control specific-pathogen-free ferrets were not colonized with the bacteria, did not have detectable levels of immunoglobulin G H. mustelae antibody, and did not have H. mustelae-associated gastritis. The ferret lacks the polymorphonuclear-cell response seen in active chronic gastritis typically described with Helicobacter pylori gastritis in humans. However, the lesion in ferrets does closely resemble the diffuse antral gastritis seen in a subset of adults with H. pylori gastritis as well as children infected with H. pylori. Like H. pylori, H. mustelae adheres tightly to gastric mucosa. The ferret infected with H. mustelae, in addition to specific-pathogen-free uninfected control ferrets, will make longitudinal studies possible, enabling dissection of multiple host and environmental variables that influence the effect of H. mustelae colonization on progression and severity of gastroduodenal disease.

Animals↗

Neoplasia in ferrets: eleven cases with a review.

Records from a veterinary diagnostic laboratory in south Florida, U.S.A. were reviewed for cases of neoplasia in pet ferrets. Twelve ferret tumours were received over a four-year period; one case, a ferret with lymphocytic leukaemia and multi-organ involvement, had been reported previously. The other eleven tumours were: two chordomas of the tail, two sebaceous adenomas of the skin, a sebaceous epithelioma of the skin, a cutaneous mastocytoma, a malignant fibrous histiocytoma from the eyelid, a malignant mesenchymoma and an undifferentiated sarcoma from the dorsal abdominal cavity, a leiomyosarcoma found unattached in the abdominal cavity and an interstitial cell tumour of the testicle. A review of the literature yielded reports of 83 other tumours in domestic ferrets, black-footed ferrets and European polecats. Of the 95 ferret tumours, 46 were considered malignant. Tumours occurred in all organ systems except the respiratory tract and central nervous system. Affected ferrets ranged in age from 209 days to 12 years. The most frequently occurring tumours were ovarian stromal tumours (24 of 95), haemangiomas/haemangio-sarcomas (15 of 95). This information indicates that, contrary to previous opinion, ferrets appear to be subject to a similar incidence and variety of tumours as other animals.

Animals↗

Malignant lymphoma in ferrets: clinical and pathological findings in 19 cases.

The clinical and pathological findings in 19 ferrets (Mustela putorius furo) with malignant lymphoma are reviewed. Peripubescent ferrets had rapidly progressive stage IV high grade immunoblastic or small non-cleaved cell lymphoma. Adult ferrets had stage II or IV low grade diffuse small lymphocytic (DSL) lymphoma, stage IV high grade small non-cleaved cell lymphoma, or stage IV high grade immunoblastic polymorphous (IBP) lymphoma. Three ferrets had concurrent IBP and DSL lymphoma involving different organs. The IBP admixture of immunoblasts, large atypical lymphocytes, Reed-Sternberg-like cells, lymphoblasts and small lymphocytes has been associated with certain retrovirally associated lymphomas and nodal hyperplasias in man, non-human primates and cats. Aleutian disease, a parvovirus-induced lymphoproliferative disease, also involves clinical and histological features similar to certain lymphomas in ferrets. Seven ferrets tested were seronegative for feline leukaemia virus antigen. Only one of eight ferrets was positive for Aleutian parvovirus antibody. The clinical and pathological findings are suggestive of a viral aetiology for certain lymphomas in ferrets.

Animals↗

Retinal decussation patterns in pigmented and albino ferrets.

The decussation patterns of retinal ganglion cells in adult pigmented and albino ferrets were determined from the distribution of cells labelled after large unilateral injections of horseradish peroxidase into the visual pathway, involving the lateral geniculate nucleus and fibres of passage to the superior colliculus. About 6000 retinal ganglion cells project ipsilaterally in pigmented ferrets compared with only about 1500 in albino ferrets. In both strains, the vast majority of these cells (99 and 87% in pigmented and albino animals, respectively) are located in the temporal crescent, although we describe one albino ferret in which an aberrant uncrossed projection arises from nasal retina. In pigmented ferrets, there is a sharp nasotemporal division that runs through the area centralis; a small proportion of the ganglion cells in temporal crescent (less than 10%) does project contralaterally. In albinos, however, the majority of cells in temporal retina project contralaterally. There is no clear nasotemporal division in the albino retina; the density of uncrossed ganglion cells is reduced throughout temporal crescent and at no location exceeds the comparable density of the crossed projection. The peak density within the reduced uncrossed projection is also displaced away from the area centralis into temporal retina. Analysis of cell type on the basis of soma size indicates that whereas large horseradish peroxidase injections into the visual pathway of pigmented ferrets label all types of ganglion cell in the crossed projection, injections restricted to the superior colliculus label only those ganglion cells with large or small somata. The distribution of cell sizes in the crossed projection from temporal retina is biased towards small cells in the pigmented ferret but in albinos resembles that seen in the crossed projection from nasal retina. Thus the adult pigmented ferret has both a well developed nasotemporal division in which decussation lines are obvious in the crossed and uncrossed pathways and also, unlike rodents but like cats, a class of ganglion cell that does not project to the superior colliculus. The albino mutation both reduces the uncrossed projection throughout temporal retina, although the reduction is greatest close to the area centralis, and also commensurately increases the crossed projection from temporal retina.

Albinism↗