Ferret urogenital diseases

An Update on Key Nutritional Factors in Ferret Nutrition

It is understood that ferrets are obligate carnivores. Constraints of manufacturing and cost make it difficult to align a single commercial diet to meet all physiological needs of ferrets. Thus, a combination of dietary formats should be offered. Ferret diets should be high in protein and fat and low in carbohydrates. Emphasis should be placed on fat concentrations and protein-to-fat ratios, which can be targeted at 2:1. Plant-based ingredients do not have a place in ferret diets and could unbalance diets, particularly in amino acids. Items such as fruits, while highly palatable to ferrets, should be avoided.

Development of renal adenocarcinoma in a ferret with renal cortical cysts (Mustela putorius furo)

CASE DESCRIPTION

A 5.5-year-old 0.929-kg spayed female domestic ferret (Mustela putorius furo) underwent serial abdominal ultrasonographic and clinicopathologic examinations after multiple renal cysts were detected bilaterally during a routine examination.

CLINICAL FINDINGS

The ferret was apparently healthy at the start of the monitoring period and had no clinical signs for > 20 months. Four months after the initial examination, the largest cyst became increasingly mineralized; 17 months after detection, it had increased in size and become amorphous, and the ferret's plasma BUN concentration was mildly high. Within 21 months after the first visit, a nodule was detectable, and hydronephrosis developed in the kidney with the largest cyst. Findings for fine-needle aspirates from the nodule were consistent with renal carcinoma.

TREATMENT AND OUTCOME

Contrast-enhanced CT revealed severe unilateral nephromegaly with no contrast uptake in the affected ureter. Following surgical removal of the affected kidney, histologic examination identified renal adenocarcinoma replacing the entire renal cortex and medulla. The ferret was euthanized postoperatively because of declining condition. On necropsy, metastasis to a mesenteric lymph node was identified; comorbidities included 2 other neoplasms and acute, severe injury of the contralateral kidney.

CLINICAL RELEVANCE

Neoplastic transformation of a renal cyst was suspected in the ferret of this report on the basis of observed ultrasonographic changes over time and extensive infiltration of the neoplasm throughout the affected kidney. Renal cysts are linked to renal neoplasia in other species, and the findings for this patient supported the need for periodic monitoring of renal cysts in ferrets.

Variation in mineral types of uroliths from ferrets (Mustela putorius furo) submitted for analysis in North America, Europe, or Asia over an 8-year period

OBJECTIVE

To compare mineral types of naturally occurring uroliths in ferrets (Mustela putorius furo) from North America, Europe, and Asia and to identify potential risk factors associated with cystine urolithiasis in ferrets.

SAMPLES

1,054 laboratory submission records of uroliths obtained from ferrets between January 1, 2010, and December 31, 2018.

PROCEDURES

For this cross-sectional study, the medical records databases at 4 diagnostic laboratories were searched for records of submissions of uroliths obtained from ferrets. Data collection included submission date; ferret sex, neuter status, and age; receiving laboratory and continent; and urolith mineral type. Regression analyses were performed to identify variables associated with cystine uroliths.

RESULTS

Of the 1,054 urolith submissions, 1,013 were from North America, with 92.6% (938/1,013; 95% CI, 90.8% to 94.1%) cystine uroliths, and 41 were from Europe and Asia, with only 26.8% (11/41; 95% CI, 15.7% to 41.9%) cystine uroliths. Median age was 2.0 years for ferrets with cystine urolithiasis versus 4.0 years for those with other types of uroliths. Submissions were more likely cystine uroliths for ferrets in North America versus Europe and Asia (adjusted OR [aOR], 59.5; 95% CI, 21.4 to 165.6), for ferrets that were younger (aOR, 0.67; 95% CI, 0.58 to 0.77), or for submissions in 2018 versus 2010 (aOR, 21.1; 95% CI, 5.1 to 87.9).

CONCLUSIONS AND CLINICAL RELEVANCE

Results indicated that the proportion of submissions that were cystine uroliths dramatically increased in North America between 2010 and 2018. There is an urgent need to determine underlying causes and mitigate cystine urolithiasis in ferrets.

Managing the Health of Captive Herds of Exotic Companion Mammals

Common medical problems diagnosed and treated in individual companion exotic mammals are relevant in a herd-health setting. Many of these problems are often associated with poor husbandry and/or inappropriate nutrition. Rabbits, ferrets, chinchillas, and rodents have been domesticated alongside humans and an understanding of their ethology gives veterinarians a base knowledge in making recommendations for animals in their care. This article briefly reviews the ethology and husbandry in such species, but detailed needs are beyond the scope of this article.

Familial disease history and fur color type are associated with urinary tract disease in farmed mink (Neovison vison)

Mink urinary tract disease (MUTD) and mink fatty liver disease (MFLD) constitute two important disease entities in the mink production associated with sudden mortality and economic loss. Genetic factors or heritability of the diseases have not previously been investigated. Since mortality associated with MUTD and MFLD mainly occurs in the young immature mink, a potential genetic predisposition would rarely be passed on by the mink itself but potentially by relatives. This study aimed to investigate familial aggregation of MUTD and MFLD based on data from four generations of mink on a research farm. The study included a total of 27,511 mink of brown and black color type with a post mortem prevalence of 0.8% for MUTD (n = 221) and 0.5% for MFLD (n = 138) within a year from birth. The prevalence in the color types brown and black were 0.6% and 1.6% for MUTD and 0.5% and 0.7% for MFLD. Family history of MUTD in breeding animals was found to be associated with a significantly higher probability of MUTD leading to mortality in offspring (p = 0.012, RR = 1.7; CI [1.1-2.4]), however this association was not significant for MFLD (p = 0.163, RR = 1.5; CI [0.9-2.7]). Mink of the color type black showed significantly higher risk of MUTD (RR = 2.6; CI [2.0-3.3]) and MFLD (R = 1.6; CI [1.1-2.2]) compared to brown mink. The results indicate that genetic factors may play a role in understanding MUTD and that selective breeding may contribute to reduce mortalities associated with this disease.

Cystine Urolithiasis in Ferrets

Urolithiasis in captive domestic ferrets has previously been predominantly struvite uroliths, although more recent laboratory submissions show a shift to predominantly cystine uroliths. Genetic mutations for cystinuria have been identified in dogs, and it is suspected that underlying genetic mutations are partly responsible for this disease in ferrets. Currently, surgery remains the only definitive treatment of cystine urolithiasis in ferrets, since dietary dissolution protocols have not been thoroughly explored. Despite this, medical management with dietary and urinary manipulation should be considered for use in ferrets postoperatively based on principles of cystine urolithiasis management in dogs adapted for ferrets.

Diagnostic Imaging of the Renal System in Exotic Companion Mammals

Radiographs can be used to easily visualize common types of urinary calculi in all parts of the urinary tract. Positive-contrast excretory urography and cystourethrography are sensitive to diseases within the ureters and urethra, most commonly obstruction. Ultrasound is widely available and noninvasive and can be used to evaluate renal architecture, ureteral dilation, urinary bladder wall disease, and urolithiasis. Computed tomography is increasing in availability and provides a large amount of cross-sectional information quickly and noninvasively. Multiple imaging modalities can be used to estimate or quantify glomerular filtration rate.

Characterisation of the French ferret population, husbandry, reported medical care and feeding habits

Ferrets have become a common companion animal. But no data are available on the French population of ferrets. The goal of the survey was to characterise this population, including demographic characteristics, husbandry, reported medical care and feeding habits. Complete data were available for 1205 pet ferrets in 709 households. Most ferrets (86·1 %) lived indoors, 1 % received only artificial lighting, and 47 % chewed their cage. For 60 % of the ferrets, body weight was higher in winter and lower in summer. Neutered ferrets (58·5 % of males and 62·9 % of females) appeared lighter than intact ferrets of comparable age. A majority (52·4 %) of ferrets received a mix of commercial foods and fresh foods, but 28·6 % were offered no commercial foods. Data were analysed using several multivariable logistic regression models including age, sex, castration, food type and artificial lighting developed for four clinical outcome (lethargy and/or insulinoma, dental problems, diarrhoea and/or bird-seed stools and alopecia). Predictors of four clinical outcomes (lethargy, dental disease, diarrhoea and alopecia) were examined using multivariable logistic regression, with age, sex, neuter status, food type and artificial lighting as the exposure variables. Aged ferrets were more likely to have lethargy, insulinoma, dental problems and alopecia. Ferrets with artificial lighting were more likely to show alopecia. Additionally, ferrets fed commercial food only or a mixed diet (both commercial food and fresh food) were more likely to have lethargy, insulinoma, dental problems, diarrhoea and/or bird-seed stools compared with ferrets fed fresh food only. We also found a significant association between neutering and alopecia. It is to our knowledge the first description of the French population of the ferret as a companion animal.

Reproductive Medicine in Ferrets

In the United States, desexing is performed routinely in ferrets at the age of 6 weeks, therefore reproductive tract diseases are not so common. However, in Europe most ferrets are desexed when they are several months old, or they are kept as intact animals. For this reason, diseases of the reproductive organs and a prolonged estrus are far more frequent in Europe than in the United States. This article summarizes and reviews the anatomy, reproductive physiology, management of reproduction (including surgical and hormonal contraception) and reproductive tract diseases in male and female ferrets.

Ferret nutrition

The domestic ferret (Mustela putorious furo) is a strict carnivore, also referred to as an obligate carnivore. Its dentition and gastrointestinal tract are adapted to a carnivorous diet. Its ancestor, the European polecat (Mustela putorius), feeds on birds and other small vertebrates. Domesticated ferrets have been fed mink feeds, cat foods, and now mostly subsist on commercial ferret diets formulated specifically to meet their needs.

Radiographic kidney measurements in North American pet ferrets (Mustela furo)

OBJECTIVES

The purpose of the current study was to determine normal radiographic kidney -measurements in pet ferrets.

METHODS

Kidney length and width dimensions and the length of the second lumbar vertebra (L2) were determined from survey ventrodorsal radiographs in 53 neutered ferrets of various ages, weight and sex, with no evidence of urogenital disease. Kidney dimensions were expressed as a ratio to the body length of L2.

RESULTS

All ferrets in this study had six lumbar vertebrae. The median length of L2 was 13·3 mm, and was longer in males than females (P=0·0001). The 95% confidence interval for kidney-length-to-L2 ratios was 2·21 to 2·31 for the right and 2·15 to 2·25 for the left. For the kidney-width-to-L2 ratios these intervals were 1·09 to 1·14 for the right and 1·07 to 1·12 for the left kidney. There was a significant association between kidney size and weight or sex but not with age.

CLINICAL SIGNIFICANCE

The results of this radiographic study may allow practitioners to have a more -objective clinical radiographic evaluation of kidney size of pet ferrets based on individual traits.

Urine specific gravity values in clinically healthy young pet ferrets (Mustela furo)

OBJECTIVES

To determine urine specific gravity values in clinically healthy pet ferrets and explore possible associations with sex, sampling techniques, hydration status and urine analytes.

METHODS

Sixty-nine entire ferrets of both sexes, under one year of age, were included in this study. Physical examination, complete blood count, blood biochemistry, urine microscopy, urine dipstick and urine specific gravity were performed on all ferrets. Urine specific gravity was determined using a handheld urine refractometer. Statistical analysis was performed to determine urine specific gravity value intervals and to test for associations with sex, sample collection method, packed cell volume, plasma total protein concentrations and urine analytes.

RESULTS

Urine specific gravity differed by sex in ferrets as females exhibited a lower urine specific gravity (P<0·001). There was no significant correlation between urine specific gravity, sampling method, packed cell volume/total protein and urine dipstick analytes. Mean urine specific gravity reported in this study was 1·051 for entire males (sd ±9; range 1·034 to 1·070) and 1·042 for entire females (sd ±8; range 1·026 to 1·060).

CLINICAL SIGNIFICANCE

Results of this study may allow clinicians to have a more accurate evaluation of the ability of those animals to concentrate urine by comparing their urine specific gravity results to those obtained from this cohort of clinically healthy animals.

Ovariohysterectomy in ferrets

Surgical sterilization of ferrets is a relatively common surgical procedure. It is usually done as a method of contraception and to prevent diseases associated with the reproductive system. This column will describe the anatomy, principles, possible complications and outcomes of surgical ovariohysterectomy in ferrets.

The senior ferret (Mustela putorius furo)

Ferrets are an increasingly popular pet in the United States. They are active, gregarious pets that delight their owners with playful antics. One of the issues that ferret owners and veterinarians have had to deal with is their shortened life span. Although literature cites the life span of the ferret as 8 to 10 years, most veterinarians see ferrets as "old" at as early as 3 years of age. Most information on senior ferrets has focused on neoplastic diseases. This article discusses husbandry and nutritional issues of the aging ferret, more commonly seen geriatric diseases, and diagnostic and treatment options.

FERRETS

This chapter familiarizes veterinarians with basic knowledge of ferret biology, medicine, surgery, and care. Ferrets have a long, slender body with short muscular legs, a long thin tail, small eyes, and short ears. The life span of the ferret is 5 to 8 years. Ferrets may be housed singly or in groups, inside or outside of a house. When kept outdoors, however, they must be protected from extreme weather. Ferrets have difficulty tolerating temperatures above 90°F or below 20°F, and appropriate precautions must be taken to prevent their exposure to these extremes. Ferrets are carnivorous and require a suitable diet. A diet that is high in good-quality animal protein and fat and low in complex carbohydrates and fiber is recommended. Ferrets are routinely immunized against canine distemper virus (CDV) and rabies virus. Ferrets are quite susceptible to CDV, and there is a 100% mortality rate in unvaccinated ferrets infected with CDV. When a new ferret is brought into the household, a quarantine period is recommended before introducing it to other animals, particularly other ferrets. The purpose of the quarantine period is to identify and prevent transmission of infectious disease potentially carried by the new ferret. The duration of this period allows for the development of any clinical signs in a seemingly healthy ferret following entrance into the new household.

Mixed urolith (struvite and calcium oxalate) in a ferret (Mustela putorius furo)

Urolithiasis has been reported in veterinary literature in some species of the Mustelidae family, including ferrets. In this species, the most common form of urolithiasis is that caused by struvite. The current study examined the case of mixed urolith in an 8-month-old female ferret (Mustela putorius furo) with antecedents of strangury and hematuria. A cystotomy was carried out to remove the urolith, which had a rough surface and a homogeneously porous interior and was formed by a mixture of struvite (60%) and calcium oxalate dehydrated (40%).

Issues to consider for preparing ferrets as research subjects in the laboratory

The domestic or European ferret (Mustela putorius furo) has been domesticated for thousands of years. Ferrets have been used for hunting and fur production, as pets, and as models in biomedical research. Despite the relatively small numbers used in the laboratory, ferrets have some unique applications including study of human influenza and severe acute respiratory syndrome (SARS)-associated corona virus. They have served as models for peptic ulcer disease, carotenoid metabolism, cystic fibrosis, and drug emesis screening, among others. Most research ferrets are males, due to estrus-related health problems in females. They may be housed conventionally and are easy to care for when their biology and behavior are understood. Due to the small number of ferret suppliers, animals are often shipped long distances, requiring air transport and intermediate handlers. It is important to minimize shipment stress, especially with weanling and pregnant animals. Additional expertise is required for success with pregnant and whelping ferrets and for rearing of neonates. The animals have specific dietary requirements, and proper nutrition is key. Successful housing requires knowledge of ferret behaviors including social behavior, eating habits, a general inquisitive nature, and a species-typical need to burrow and hide. Regular handling is necessary to maintain well-being. A ferret health care program consists of physical examination, immunization, clinical pathology, and a working knowledge of common ferret diseases. Various research methodologies have been described, from basic procedures such as blood collection to major invasive survival surgery. Ferrets have a distinct niche in biomedical research and are hardy animals that thrive well in the laboratory.

Exotic mammal renal disease: diagnosis and treatment

Knowledge of the renal anatomy and clinical pathology associated with renal disease can help the practitioner with interpretation of imaging procedures and urine, blood, and serum biochemical values. This article discusses specimen collection techniques, along with species variables in several clinical pathology parameters. Diagnostic tools and interpretations are discussed for the more common renal maladies affecting exotic mammals. Treatment guidelines are offered for general as well as specific exotic mammal renal diseases.

Exotic mammal renal disease: causes and clinical presentation

Renal disease is not uncommon in exotic mammals, with degenerative,infectious (bacterial, viral, parasitic), metabolic, nutritional,neoplastic, anatomic, and toxic causes all represented. This article discusses the clinical presentation for the various renal diseases affecting exotic mammals. Anatomic pathology at the gross and microscopic level is reviewed, as is disease pathophysiology unique to the species under discussion.

Ferret care and husbandry

Convivial and playful, the ferret has cohabited with humans for hundreds of years. Maintenance of this mustelid's health and quality of life is paramount for the endurance of the human-animal bond. This review article for veterinary care givers, veterinarians, and staff, encompasses discussions on: husbandry, clinical techniques, prevalent diseases, history taking, physical examination, vaccination, and pain recognition. This article also enables the veterinary community to contribute to the care and welfare of ferret patients by offering facts to distinguish these animals from dogs and cats.