Ferret Research Articles

Domestic ferrets (Mustela putorius furo) with cholecystitis commonly show hyperbilirubinemia and common bile duct dilation, gallbladder sludge, and gallbladder wall thickening on ultrasound.

To report clinical signs, biological anomalies, treatment, and outcome in domestic ferrets with cholecystitis, describe the ultrasonographic features of cholecystitis, and compare the ultrasonographic appearance of the hepatobiliary system between diseased and healthy ferrets. 11 ferrets with confirmed cholecystitis and abdominal ultrasonography were retrospectively included. Ten healthy ferrets were prospectively recruited to undergo hepatobiliary abdominal ultrasonography. Comparisons of explanatory variables (group, age, body weight, and sex) were performed. The most common clinical signs were nonspecific, and icterus was observed in 1/4 of diseased ferrets. Compared with healthy individuals, diseased ferrets showed a larger common bile duct (CBD; ≥ 2.8 mm), a thicker CBD wall (≥ 0.7 mm), a thicker gallbladder (GB) wall, more frequent echoic GB luminal content, visible intrahepatic bile ducts, and a greater GB volume. Bile culture was positive in 9/11 mostly for Escherichia coli (8/9). Bile cytology indicated septic purulent cholecystitis in 7/7 ferrets. Survival time after antibiotic treatment ranged from 6 to 104 weeks, with a median of 36 weeks. Ferrets with cholecystitis presented with nonspecific clinical signs and frequently showed hyperbilirubinemia. Ultrasonography findings such as enlarged CBD, thickened CBD wall, thicker GB wall, GB sludge, visible intrahepatic bile ducts, and enlarged GB may suggest cholecystitis. Escherichia coli was commonly isolated from bile. The medium-term mortality rate was high despite targeted antibiotherapy. This is the first study describing the clinical signs, biological anomalies, ultrasonographic findings, and outcomes after treatment in a series of domestic ferrets with cholecystitis.

Cancer Prevalence across Vertebrates.

Cancer is pervasive across multicellular species, but what explains the differences in cancer prevalence across species? Using 16,049 necropsy records for 292 species spanning three clades of tetrapods (amphibians, sauropsids, and mammals), we found that neoplasia and malignancy prevalence increases with adult mass (contrary to Peto's paradox) and somatic mutation rate but decreases with gestation time. The relationship between adult mass and malignancy prevalence was only apparent when we controlled for gestation time. Evolution of cancer susceptibility appears to have undergone sudden shifts followed by stabilizing selection. Outliers for neoplasia prevalence include the common porpoise (<1.3%), the Rodrigues fruit bat (<1.6%), the black-footed penguin (<0.4%), ferrets (63%), and opossums (35%). Discovering why some species have particularly high or low levels of cancer may lead to a better understanding of cancer syndromes and novel strategies for the management and prevention of cancer. Significance: Evolution has discovered mechanisms for suppressing cancer in a wide variety of species. By analyzing veterinary necropsy records, we can identify species with exceptionally high or low cancer prevalence. Discovering the mechanisms of cancer susceptibility and resistance may help improve cancer prevention and explain cancer syndromes.

Right cranial lung lobe torsion in a domestic ferret (Mustela putorius furo).

A 3-year-old male castrated domestic ferret presented with a 24h history of lethargy, weakness, and anorexia. The ferret was tachypneic, painful, dehydrated, pale, and obtunded on physical examination. Radiographs and thoracic CT were utilized to diagnose a 360° right cranial lung lobe torsion (LLT) with secondary pneumothorax and pleural effusion. This was confirmed on gross necropsy and histopathology. The LLT was suspected to be secondary to previous trauma based on chronic bilateral rib fractures. Lung lobe torsions are life-threatening conditions infrequently described in veterinary medicine. Based on our review of the literature, this is the first description of an LLT in a ferret.

Suspected encrusting cystitis in a domestic ferret (Mustela putorius furo)

BackgroundEncrusting cystitis diagnosis and medical management in domestic ferrets (Mustela putorius furo) has never been documented. Case descriptionA client-owned, 6.5-year-old, neutered, male domestic ferret was presented for lethargy, abdominal pain, straining to urinate for 12 days, and red, purulent urine. On physical examination, the ferret was quiet, alert, and responsive, had a distended and inexpressible bladder, large and firm kidneys, and was displaying signs of severe pain including vocalization on abdominal palpation and when attempting to urinate. Sonographic evaluation showed an irregular, layered, hyperechoic mass lesion present in the lumen of the urinary bladder with extensions of the layered luminal material into the urethra, and severely dilated renal pelves and ureters. These severe, urinary bladder changes were consistent with pseudomembranous, encrusting cystitis. Following a discussion with the owner about options for humane euthanasia versus exploratory surgery, euthanasia was elected. The remains were taken home with the owner and a necropsy was not performed. Conclusion and case relevanceTo the author’s knowledge, this paper reports the first known case of suspected encrusting cystitis in a domestic ferret including radiologic and ultrasonographic findings.

Expression of a Recombinant Cholesterol Esterase from Mustela putorius furo in Pichia pastoris and Its Applicability for γ-Oryzanol Hydrolysis.

Ferulic acid (FA) exhibits antioxidant and anti-inflammatory properties, making it valuable for numerous industrial applications. Traditionally, FA is produced by the alkaline hydrolysis of γ-oryzanol, which is typically associated with wastewater generation. Recently, an increasing demand of natural FA necessitates its green production via enzymatic hydrolysis of γ-oryzanol, a mixture comprising triterpene alcohol ferulates and phytosteryl ferulates. Thus far, γ-oryzanol can be hydrolyzed by only four commercial cholesterol esterases with low yields. Herein, we report a recombinant cholesterol esterase from Mustela putorius furo (MPFCE) for the enzymatic hydrolysis of γ-oryzanol. The enzyme yielded 25.5% FA, which is the highest reported through enzymatic means thus far. The hydrolysis profile revealed that the enhanced yield primarily resulted from the near-complete hydrolysis of phytosteryl ferulates, together with slight hydrolysis of triterpene alcohol ferulates. MPFCE serves as a potential candidate for the enzymatic production of FA through targeted hydrolysis of γ-oryzanol.

Pharmacokinetics of methadone after intravenous and subcutaneous administration in domestic ferrets (Mustela putorius furo)

ObjectiveTo determine the pharmacokinetic profile of methadone after intravenous (IV) and subcutaneous (SC) administration in domestic ferrets (Mustela putorius furo). Study designCrossover experimental study. AnimalsA group of eight healthy adult ferrets weighing 1.01 ± 0.23 kg (mean ± standard deviation). MethodsMethadone hydrochloride (0.3 mg kg–1) was injected IV or SC to each ferret with a 3 week washout period. Blood samples were collected via a jugular catheter before and 5, 10, 15, 20, 30, 45, 60, 90, 120, 180, 240, 360 and 480 minutes after drug administration. Liquid chromatography–tandem mass spectrometry was used to determine plasma methadone concentrations. A nonlinear mixed effects model was used to analyze the data. ResultsAfter IV injection, systemic clearance (Clss) and volume of distribution (Vdss) were 78.9 mL min–1 kg–1 and 9.8 L kg–1, respectively. Elimination half-life was 2.0 hours and SC bioavailability was fixed at 1. The maximum observed plasma concentration after SC injection was 92.1 ± 76.8 ng mL–1. Behavioral changes were observed after both routes. Conclusions and clinical relevanceThe pharmacokinetic profile of IV methadone was characterized by a high Clss and large Vdss, with high bioavailability and absorption rate after SC administration. Half-life was short and mean plasma methadone concentrations stayed above the minimum effective concentration (MEC) reported in humans only after SC administration for 5 minutes, but remained above that reported in dogs for 45 minutes following both routes. Further studies investigating the MEC and pharmacodynamics of methadone in ferrets are warranted.

Pharmacokinetics of Extended-release Buprenorphine and Clinical Efficacy for Postoperative Pain Management in the Domestic Ferret (Mustela putorius furo).

Buprenorphine hydrochloride (Bup-HCl) is a common injectable opioid analgesic. In ferrets, Bup-HCl must be administered every 8 to 12 h to maintain clinical efficacy. Extended-release analgesics offer multiple advantages, including reduced handling and injection frequency, improved compliance, and increased protection from end-of-dose failure. Although efficacy of extended-release buprenorphine formulations has been demonstrated in other species, their use in the domestic ferret has not been investigated. In this study, we evaluated the pharmacokinetics of a compounded polymeric formulation of buprenorphine (Bup-ER) and a pharmaceutical-grade, FDA-indexed liposomal suspension (Bup-XR). Two doses each of Bup-ER (0.12 and 0.2 mg/kg) and Bup-XR (0.2 and 0.6 mg/kg SC) were administered to young adult female ferrets and plasma concentrations were measured between 0 and 96 h (n = 4 animals per timepoint). All doses of both drugs achieved therapeutic plasma levels by 30 min. Furthermore, high-dose Bup-XR maintained therapeutic levels for 72 h, followed by high-dose Bup-ER (less than 48 h), low-dose Bup-XR (24 h), and low-dose Bup-ER (less than 24 h). In this study, we also developed a pain scoring system and utilized this to compare analgesic efficacy between single high-dose Bup-XR (0.6 mg/kg SC) and a standard postoperative course of Bup-HCl (0.02 mg/kg SC every 10 to 12 h for 8 doses) after ovariohysterectomy. Ferrets receiving Bup-XR had significantly lower respiratory rate and posture scores in the first 24 h postoperatively than did those that received Bup-HCl and were less likely to react to palpation of the surgical incision. Of note, ferrets that received high-dose Bup-ER had a significantly higher incidence of injection site reactions than ferrets that received Bup-HCl (P = 0.0137). This study demonstrates that a single dose of Bup-XR (0.6 mg/kg SC) is a safe and effective analgesic in female ferrets, with a duration of action up to 72 h and minimal side effects, offering a refinement to analgesia in this species.

Vaccine-induced distemper in domestic ferrets (Mustela putorius furo): 5 cases (2022)

BackgroundCanine distemper virus (CDV) is a highly contagious disease that has been reported in several mammals, including domestic ferrets (Mustela putorius furo). Vaccine-induced disease occurs when modified live virus (MLV) vaccines are used. MethodsA retrospective review of medical records and pathology reports from a single academic institution for 2022, was performed. All ferret cases that had CDV histopathology findings and positive CDV RT-PCR were included. ResultsFive cases were identified. Data was extracted from the available records/forms. Cases were presented between September to December of 2022 and included two castrated males and three unknown sex animals (11- to 29-week-old) from Oklahoma (n=4) and Virginia (n=1). All animals had clinical signs of CDV, originated from the same breeding facility, and were allegedly vaccinated with a commercially available MLV-CDV vaccine for mink. Histopathological findings were consistent with CDV, and brain and/or lung tissue was CDV positive by RT-PCR. H-gene sequencing identified America-1 strain/Lederle-CDV3-like genetic material with 99% identity with the vaccine. H-gene sequences showed that the CDV strains formed a separate clade in the tree within the Lederle group. The M-F regions were 100% identical to the MLV-CDV vaccine. Based on sequencing, ferrets were infected with a CDV Lederle-like strain, which is believed to be extinct in the wild. Conclusion and relevanceThe findings of these cases share several similarities to previous reports of vaccine-induced disease. MLV vaccines should be avoided for immunization of ferret kits, especially in settings like breeding facilities and pet stores, where epidemiologic risks are amplified.

Mycobacterium genavense detection in a blood smear from a domestic ferret

AbstractThe domestic ferret is sensitive to mycobacterial infections, which are likely underdiagnosed. There are limited reports of therapy for mycobacteriosis in ferrets and most have failed. A ferret in poor body condition revealed marked organomegaly on diagnostic imaging. The complete blood count revealed a mild pseudoeosinophilia, which might be attributed to negatively stained bacilli phagocytised by monocytes observed in the blood smear. Ziehl–Neelsen stain was performed and showed acid‐fast bacilli within monocytes. Fine‐needle aspirates of the spleen and liver revealed the same finding. Mycobacterium genavense was identified by PCR and DNA sequencing from peripheral blood. Treatment with rifampicin, clarithromycin and enrofloxacin was initiated. The disseminated mycobacteriosis was suspected from the observation of bacilli on the blood smear. After 16 months, the ferret is still undergoing treatment. To prevent recurrence, continued monitoring of drug toxicity and effective therapy will be maintained even after the resolution of clinical signs (mostly organomegaly).

Review of spontaneous lesions in the exocrine pancreas of domestic ferrets (Mustela furo).

Large-scale retrospective studies allow for identification of disease trends, such as predisposing factors, typical clinical signs, and range of histologic lesions, which cannot be determined in individual case reports. Lesions of the endocrine pancreas of ferrets are extensively reported; however, there are no in-depth investigations of lesions in the exocrine pancreas. This retrospective analysis presents the histologic features, clinical signs, and concurrent diseases of lesions in the exocrine pancreas of ferrets. Seventy-seven lesions were reported and included acinar cell hyperplasia (n = 32), chronic pancreatitis (n = 16), acute pancreatitis (n = 13), acinar cell adenoma (n = 5), acinar cell carcinoma (n = 4), acinar cell atrophy (n = 3), presumptive acinar cell hypoplasia (n = 2), and lymphoma (n = 2). Our results demonstrate that acinar cell hyperplasia and chronic pancreatitis can both cause grossly visible pancreatic nodules. Hyperplasia was not associated with neoplastic transformation. In addition, acinar cell adenoma was slightly more common than carcinoma, which is contrary to most reports of neoplasia in ferrets. Our findings also suggest that acute pancreatitis can be a sequela to pancreatic biopsy and that there may be an association between chronic pancreatitis and diabetes mellitus in ferrets. Finally, zinc toxicosis was found to be an unlikely cause of pancreatitis in these ferrets based on zinc tissue concentration testing in a subset of cases.

Ulcerative and pyogranulomatous pododermatitis due to Pseudomonas luteola infection in a domestic ferret (Mustela putorius furo): a case report with literature review of this emerging zoonotic disease in ferrets

Pseudomonas luteola (P.luteola), formerly called Chryseomonas luteola, is a strict aerobic gram-negative bacillus, 0.8 to 1.0 µm wide and 1.5 to 2.5 µm long, considered an opportunistic pathogen found ubiquitously in humid environments, both in soil and water. It sporadically causes disease in animals and immunosuppressed humans or those subjected to invasive procedures such us peritoneal dialysis or catheterization. In ferrets, this infection was first described in Spain in 2012 and since then, cases have appeared occasionally in Finland, Austria, Australia, France, the United States and also in Spain. This pathogen is considered an emerging zoonotic disease in ferrets, causing respiratory disease, panniculitis, and abscesses due to pyogranulomatous or suppurative inflammation predominantly of the pleura, lung, mediastinum, panniculus or salivary glands, frequently with lethal consequences. The clinical case of a ferret, infected by Pseudomona luteola, presenting with ulcerative suppurative pododermatitis and ipsilateral popliteal purulent lymphadenitis, is described. Together with a complete resolution of the clinical case by means of a non-invasive medical management likely due to the rapid detection, identification, and treatment of the infection.

Reference intervals for selected blood and urinary parameters related to renal function in clinically healthy ferrets (Mustela putorius furo)

BackgroundDiagnosis of chronic kidney disease can be challenging in ferrets. Physiological creatinine values are lower than in dogs and cats and marked elevations may only be detected in advanced disease. In canine and feline patients, specific staging, and treatment guidelines are available, based on serum creatinine, symmetric dimethylarginine (SDMA) levels, presence of proteinuria, and blood pressure measurement. No such guidelines exist for ferrets, and there is a lack of data concerning certain laboratory parameters. MethodsBlood and urine samples were taken from 60 clinically healthy pet ferrets to establish species-specific reference intervals for serum SDMA and urine protein/creatinine ratio (UPC ratio). Liquid-chromatography tandem mass spectrometry (HPLC-MS) was used for determination of serum SDMA, a colorimetric spectrophotometric method for urinary protein and an enzymatic method for urine creatinine. ResultsThe calculated reference interval for serum SDMA (2.78–7.66 µg/dL) was found to be lower than in dogs and cats, while the UPC ratio is similar to dogs (<0.5). Conclusions and clinical relevanceSerum SDMA reference intervals for ferrets may be lower than internals published for dogs and cats, while the UPC ratio appears to be similar to the ratio for dogs.

Widespread population of invasive ferrets Mustela furo (Carnivora: Mustelidae) on the island of Madeira, Macaronesia

Abstract Invasive mammalian predators are arguably the most damaging group of alien animals for global biodiversity and their impacts are particularly damaging in endemic-rich insular ecosystems. Ferrets (Mustela furo) are well-known for their potential to establish self-sustaining feral populations. Yet, knowledge about their distribution and trophic interactions is scarce. Here, we provide ample evidence of a well-established and widespread population of ferrets on the subtropical island of Madeira (Portugal). Ferrets are using natural and human-dominated habitats, where they are preying on both native (e.g., Cory’s shearwaters (Calonectris borealis) and the endemic and IUCN Endangered Zino’s petrel (Pterodroma madeira)) and non-native vertebrates.

Hypothermia, anemia, hyperglycemia, and severe hypoglycemia are significant prognostic indicators of death in client-owned ferrets (Mustela putorius furo).

To determine whether rectal temperature, Hct, or blood glucose at presentation were associated with all-cause mortality in ferrets (Mustela putorius furo). 321 client-owned ferrets. A medical record database was searched for ferrets from January 2012 through September 2022. Records from 1,189 individual examinations were evaluated. Inclusion criteria were rectal temperature, Hct, and/or blood glucose measured at presentation and data on survival status 7 days postpresentation. Data were included from 321 ferrets from 571 examinations. Rectal temperature in 244 ferrets from 346 examinations, Hct in 181 ferrets from 277 examinations, and blood glucose in 260 ferrets from 420 examinations were available. The odds of death for hypothermic ferrets (< 37.8 °C) were 3.72 times (OR, 3.72; 95% CI, 2.30 to 6.01) the odds of death for normothermic ferrets (37.8 to 40 °C). For every 0.56 °C below normal rectal temperature, the odds of death increased 1.49 times (OR, 1.49; 95% CI, 1.21 to 1.90). The odds of death for anemic ferrets (Hct < 33%) were 4.74 times (OR, 4.74; 95% CI, 1.70 to 13.21) the odds of death for ferrets with a normal Hct (33% to 57%). The odds of death for hyperglycemic ferrets (> 152 mg/dL) were 2.61 times (OR, 2.61; 95% CI, 1.29 to 5.30) the odds of death for normoglycemic ferrets (74 to 152 mg/dL). The odds of death for severely hypoglycemic ferrets (< 40 mg/dL) were 9.45 times (OR, 9.45; 95% CI, 3.18 to 28.12) the odds of death for normoglycemic ferrets. Hypothermia, anemia, hyperglycemia, and severe hypoglycemia were significant prognostic indicators of death in ferrets. Further investigation into the causes and management of these derangements is warranted.

Semen proteome and transcriptome of the endangered black-footed ferret (Mustela nigripes) show association with the environment and fertility outcome

The ex situ population of the endangered black-footed ferret (Mustela nigripes) has been experiencing declines in reproductive success over the past 30 years of human-managed care. A potential cause may be environmental-dependent inbreeding depression with diet being one of the contributing factors since ferrets are not fed their natural diet of prairie dogs. Here, we generated and analyzed semen proteome and transcriptome data from both wild and ex situ ferrets maintained on various diets. We identified 1757 proteins across all samples, with 149 proteins unique to the semen of wild ferrets and forming a ribosomal predicted protein–protein interaction cluster. Wild ferrets also differed from ex situ ferrets in their transcriptomic profile, showing enrichment in ribosomal RNA processing and potassium ion transport. Successful fertility outcomes documented for ex situ ferrets showed the strongest association with the semen transcriptome, with enrichment in genes involved in translation initiation and focal adhesion. Fertility also synergized with the effect of diet on differentially expressed transcriptomes, mainly affecting genes enriched in mitochondrial function. Our data and functional networks are important for understanding the causes and mechanisms of declining fertility in the ex situ ferret population and can be used as a resource for future conservation efforts.

Diagnostic challenge in veterinary pathology: Bony elbow mass in a domestic ferret.

Diagnostic challenge in veterinary pathology: Bony elbow mass in a domestic ferret.

A bilateral corneal descemetocele as a consequence of corneal dystrophy in a ferret (Mustela putorius furo)

AbstractThe purpose was to describe the clinical findings, surgery and outcome of a bilateral descemetocele in a ferret (Mustela putorius furo), resulting from corneal dystrophy. A female ferret was diagnosed with a descemetocele in the left eye, as a result of corneal dystrophy with crystalline deposits, which spontaneously detached. Surgery was performed with a corneal graft and a conjunctival flap. No systemic disease was correlated with the corneal dystrophy. After 3 months, the ferret was presented with a descemetocele of the right eye, still due to corneal dystrophy. The same surgery as previously described was performed. The ferret recovered uneventfully from both surgeries and maintained vision from both eyes. This is the first report of corneal dystrophy in a ferret, and the first report of successful surgery on a descemetocele in this species. Surgery is the treatment of choice, and if performed quickly and adequately, has a good outcome.

Abundance estimates of Gunnison's prairie dogs compared to the number of active burrows

AbstractReliable estimates of prairie dog (Cynomys spp.) population size and distribution are critical for assessing the status of prairie dogs and for selecting sites to reintroduce black‐footed ferrets (Mustela nigripes). The density of active prairie dog burrows has commonly been used as an index of prairie dog abundance. Indices derived from active burrow counts were developed for black‐tailed (C. ludovicianus) and white‐tailed (C. leucurus) prairie dogs, but their efficacy has not been evaluated for all prairie dog species and studies affirming their validity with robust abundance estimators are few. We indexed or estimated the abundance of Gunnison's prairie dogs (C. gunnisoni) in the Aubrey Valley, Arizona, USA, in 2006 at 2 different time periods using 4 different methods—maximum above ground counts (MAGC), minimum number known alive (MNKA), capture‐mark‐recapture (CMR), and mark‐resight—and compared these estimates to active burrow counts in 2005 and 2006. We found no positive relationship between active burrow counts and any abundance estimators. Mark‐resight estimates of abundance were greater than the MNKA and were positively correlated with both the MNKA (r2 = 0.30) and CMR estimates (r2 = 0.49). Both CMR estimates and MAGC were typically below the MNKA and therefore biased low. Our results indicated that more rigorous estimation methods may be necessary to accurately estimate prairie dog abundance and assess habitat quality for ferret conservation.

Markers of fertility in reproductive microbiomes of male and female endangered black-footed ferrets (Mustela nigripes)

Reproductive microbiomes contribute to reproductive health and success in humans. Yet data on reproductive microbiomes, and links to fertility, are absent for most animal species. Characterizing these links is pertinent to endangered species, such as black-footed ferrets (Mustela nigripes), whose populations show reproductive dysfunction and rely on ex-situ conservation husbandry. To understand microbial contributions to animal reproductive success, we used 16S rRNA amplicon sequencing to characterize male (prepuce) and female (vaginal) microbiomes of 59 black-footed ferrets at two ex-situ facilities and in the wild. We analyzed variation in microbiome structure according to markers of fertility such as numbers of viable and non-viable offspring (females) and sperm concentration (males). Ferret vaginal microbiomes showed lower inter-individual variation compared to prepuce microbiomes. In both sexes, wild ferrets harbored potential soil bacteria, perhaps reflecting their fossorial behavior and exposure to natural soil microbiomes. Vaginal microbiomes of ex-situ females that produced non-viable litters had greater phylogenetic diversity and distinct composition compared to other females. In males, sperm concentration correlated with varying abundances of bacterial taxa (e.g., Lactobacillus), mirroring results in humans and highlighting intriguing dynamics. Characterizing reproductive microbiomes across host species is foundational for understanding microbial biomarkers of reproductive success and for augmenting conservation husbandry.

Pharmacokinetics of hydromorphone hydrochloride after intravenous and subcutaneous administration in ferrets (Mustela putorius furo)

Pharmacokinetics of hydromorphone hydrochloride after intravenous and subcutaneous administration in ferrets (Mustela putorius furo)