ALAT Chapter 32 Ferrets.pdf

ALAT Chapter 32 Ferrets Ferrets are commonly used in studies of viral and respiratory diseases, as well as in dental research and in the study of the reproductive and digestive systems. They are also used as a model in safety testing of drugs and chemicals, and as an alternative to the cat for pharm...

ALAT Chapter 32 Ferrets Ferrets are commonly used in studies of viral and respiratory diseases, as well as in dental research and in the study of the reproductive and digestive systems. They are also used as a model in safety testing of drugs and chemicals, and as an alternative to the cat for pharmacological studies. Males are more often used as laboratory animals due to problems associated with persistent estrus in females. General Latin Name : Mustela putorious furo Mustela "a weasel" Putorius “evil smelling” furo "a thief" Taxonomic order Carnivora, and is in the same family as otters, weasels, and minks. Ferrets are basically called an evil smelling thief weasel!!  Closer to biologically & physiologically to humans than mice & rats.  Lungs are nearly identical to humans in regards to function & disease susceptibility.  Oestrous cycle very similar to women’s.     Influenza/SARS/COVID Reproductive physiology Anatomy Neurobiology  Development of visual pathways  Replacement for cats  Pediatric intubation clinical laboratories  Neuroendocrinology  Neuroanatomy  Cardiology Anatomy & Physiology • Ferrets vary in coloration. Research ferrets typically have the fitch coloration (which is a wildtype with tawny and brown markings, Figure 32.1) or are albino (Figure 32.2). • Ferrets are characterized by their long, flexible torso and relatively short legs. The neck is thick, and the area where the head ends and the neck begins can sometimes be difficult to distinguish. They have very prominent canine teeth which may be visible even when the mouth is closed. • Ferrets have sizable claws on their toes. • Seasonal Weight Change: Ferrets undergo large seasonal changes in weight, losing weight during the mating season (approximately March to August) and gaining it again later in the fall. For example, a male weighing 2,700 grams in January may weigh only 1,800 grams at the end of July. • Scent glands: Ferrets naturally have a musky odor due to their normal skin secretions, and also have anal scent glands from which secretions are released at will. The scent glands are commonly removed from laboratory ferrets surgically once they are old enough. • Their body temperature often drops when they sleep; they may shiver for several minutes after they awake while their temperature is returning to normal. Sexing & Reproduction • Most animal facilities purchase ferrets from commercial sources and are not concerned about their reproduction, except when ferrets are used in reproductive studies. • Males are called hobs, and are larger than the females, which are called jills. The young are called kits. • The testes of immature males are small and firm; in older males, they are longer and somewhat fleshy. The testicles are quite close to the anus. The male has a ventrally situated penis that possesses a bony structure known as the baculum, or os penis. • The vulva of a female that has been in estrus usually retains some trace of having been swollen (a slight protrusion) and has a wrinkled appearance. • Like the rabbit and the cat, ferrets are induced ovulators. Jills may remain in estrus for prolonged periods of time if they are not bred. For reproductive studies, jills may be injected with hormones to induce ovulation. This treatment is also useful to terminate perpetual estrus which, if not treated, can lead to bone marrow problems and possibly death. Reproductive Data • Terms: • Male = hob • Female = jill • Babies = kits • Sexual maturity: 4-12 months • Gestation period: • 41 if primiparous • 42 days if multiparous • Average litter size: 8 • Weaning: 6-8 weeks • INDUCED OVULATORS Most animal facilities purchase ferrets from commercial sources and are not concerned about their reproduction, except when ferrets are used in reproductive studies. For reproductive studies, jills may be injected with hormones to induce ovulation. This treatment is also useful to terminate perpetual estrus which, if not treated, can lead to bone marrow problems and possibly death. Sexing • Male: • Prepuce on ventral abdomen • Os penis palpable • Greater anogenital distance Male • Female: • Single urogenital opening near anus • Smaller anogenital distance Female Biological Data • Body weight • Adult male: 1–2 kg • Adult female: 0.5–1 kg • Newborn: 6–12 g • Normal body temperature 37.8–40°C (100–104 °F) • Heart rate (beats per minute) 200–400 • Respiration rate (breaths per minute) 33–36 • Life span (years) 5–11 • Daily consumption Feed: 50–75 g per animal • Water: 75–100 ml per animal • Puberty age (months) • Male: 6–12 • Female: 6–12 • Sexual cycle duration (days) Continuous until bred • Sexual cycle type • Monoestrous (continuous estrus until bred); seasonal; • induced ovulator • Gestation period (days) 41–43 • Litter size/# of young 1–18 • Begins eating solid feed (weeks) 3 • Age at weaning (weeks) 6–8 Biological Data Weight @ maturity: 8001200gms Life span 5-11 years Body temperature 100-104F Heart rate: 200-400bpm Respiratory rate: 33-36 per minute Biological Data Water Consumption 75-100 ml/day Food Consumption High protein Low carb Low fiber 50-75gm/day Urine output 26-28ml/day Behavior • Ferrets are playful and mischievous. They are very social animals and prefer to be housed in pairs or groups. They are escape artists, however, so they must be housed in escape-proof caging. • An interesting characteristic of ferrets is the difficulty they have waking up from sleep. If approached, a ferret may take up to 30 seconds to awaken. Do not mistake this for poor health unless the time for the ferret to awaken far exceeds 30 seconds. Another unique behavior of the ferret is the shivering that often occurs when it awakens or becomes excited. This is normal. • When the ferret is held by the scruff of the neck, it often yawns and relaxes its body. • Ferrets produce several distinct vocalizations that can alert a watchful technician to different conditions. Kits make a cheeping sound when hungry. Older ferrets chuckle or hiss when they are playing or excited, and hiss or screech in stressful situations. Handling & Restraint • Ferrets have been described as aggressive and difficult to handle, but with appropriate handling and socialization, they can be easily managed. • Regular handling is necessary to maintain the well-being of ferrets. • Caution should be exercised when handling ferrets from a new shipment or when working with jills with kits. Jills are protective mothers and may bite if they feel threatened. • After adjusting to their new environment, ferrets can usually be handled without difficulty, and usually without restraint gloves. The adult ferret is best held by grasping it just behind the forelimbs with one hand, and supporting the hindquarters with the other hand. Holding the hind legs of a ferret will cause it to struggle. An alternative method of restraint is to place one hand across the animal’s shoulders, with the thumb and forefinger around the neck and the other fingers around the chest behind the forelimb. Ferrets can also be scruffed. When held in this manner, the animal will generally relax, allowing simple procedures such as nail trims and intramuscular injections to be performed. Scruffed ferrets may also yawn, making it easier to perform oral examinations. Identification Methods • Individual identification of ferrets is typically accomplished by the use of ear tags or microchips. Ferrets may also be tattooed, but the technique is made difficult by the thickness of their hair coat and their small ears. Husbandry • Heat Sensitive: Ferrets are sensitive to heat, and should be kept in rooms less than 27 °C (81 °F); they seem to prefer temperatures between 13 °C and 18 °C (55 °F and 64 °F). • Coat shedding: Ferrets generally shed their coats twice a year; temperature fluctuations and day length are likely to influence when they shed. • Scruffing: In group housing, one might see ferrets carrying other ferrets by the nape of the neck. This is normal behavior, and no action is needed unless it becomes excessive. • Group sleeping: Ferrets tend to sleep together in groups; the rest area should be large enough to accommodate all the animals. • Escape artists! Ferrets can be kept in cat or rabbit cages if the door is close-fitting and the bar spaces narrow. As mentioned before, they are known to be escape artists, and can pass through spaces just larger than an inch in diameter. If a rabbit cage is used, the lower part of the opening inside the door must be fitted with a strip of metal to retain the bedding material and prevent escapes. Top-filled feed hoppers without covers (J-type) cannot be used in ferret caging because a ferret can easily crawl through one when it is empty. Diet • Ferrets require a high protein diet. Their diet should be at least 35% protein and should be animal-based, as they are obligate carnivores. Laboratory ferrets are generally fed a commercial ferret diet, which fulfills their nutritional needs. • Ferrets have a short digestive tract, and must eat frequently. Hypoglycemia may occur if they are fasted or feed-restricted; ad libitum feeding is the standard practice. • Ferrets, particularly kits, are avid chewers, so you must be cautious of what else they could be ingesting in their microenvironment. Gastrointestinal obstructions, caused by hairballs or fragments of enrichment materials, are common in ferrets. The most common clinical signs of obstruction are weight loss, tooth grinding, loss of appetite, and bloody stool. Report these symptoms to your supervisor or veterinary staff for appropriate diagnosis and treatment. • To prevent hairballs, laxatives may be given during active shedding seasons Environmental Enrichment • Ferrets are intelligent, curious, and social animals and need a complex and stimulating environment. Tubes, hammocks, boxes, and even paper bags can provide an opportunity to crawl and burrow. Ferrets like water, and enjoy an occasional water bath. • In choosing toys for enrichment, the ferret’s propensity to chew should be taken into consideration. Only hard, durable toys should be used; toys should be checked often for signs of chewing. Enrichment https://nationalzoo.si.edu/animals/news/caring-for-black-footed-ferrets-stories-real-life-zoo-guardian “We also provide the ferrets with different types of play enrichment, which encourages them to stay active. Most of the toys are a product of keeper creativity since you cannot always buy items appropriate for endangered species. One popular enrichment is a paper bag filled with shredded paper. When a ferret approaches the bag to investigate, the bag will “respond” with a crinkle or fall over. We also have weeble-wobble toys and create bouncy tubes by upcycling old materials that our team no longer uses. By far, our black-footed ferrets’ favorite enrichment seems to be live prey. In the wild, 90 percent of a black-footed ferret’s diet is prairie dogs. At SCBI, they receive rats. It is particularly important for a reintroduction animal to know how to hunt so they can survive without relying on humans. Female ferrets with kits typically get live prey so the kits learn to hunt from their mom just as they would in the wild.” Signs of Pain, Distress, or Illness • Ferrets usually arch their backs. If a ferret’s back is straight, it is a sign of an underlying illness, neurological disease, or fatigue. An uncomfortable ferret will not curl into its normal relaxed sleeping position, and may be lethargic and anorexic. • Aggressive behavior in a normally gentle animal is often a sign of pain, as is rapid breathing. If the animal is hurt or angered in any way, a foul-smelling substance is sometimes emitted (not sprayed) from the scent glands located on either side of the anus. Ferrets also vocalize; they will chuckle, hiss, or screech in situations of discomfort or stress. An animal that grinds its teeth may suffer from abdominal pain. • Ferrets vomit very infrequently; observation of active vomiting or of yellow foamy liquid in the cage should be immediately reported to the veterinary staff. Any kind of sneezing, breathing difficulty, nasal discharge, or eye discharge should also be reported immediately, as ferrets are susceptible to some human respiratory infections. • Female ferrets may also develop estrogen toxicity if they are intact, or if some reproductive tissue was accidentally left behind when they were spayed. The presence of a persistently swollen vulva may be an indication of this condition. Fur loss may be another sign of estrogen toxicity, or it may be caused by other hormonal conditions. Euthanasia • Ferret euthanasia is usually accomplished by the use of sedation or anesthesia followed by an injection of a lethal dose of barbiturate. If the ferret is to be euthanized whilst under anesthesia, an adjunctive method such as exsanguination or bilateral thoracotomy may be performed. • As with other laboratory animal species, death must be verified. • Your institution’s SOPs may require an additional procedure to be performed for this verification. Carcass disposal should be according to the facility’s guidelines.