Harkness and Wagner's Biology and Medicine of Rabbits and Rodents E-Book

Patricia V. Turner

• Herausgeber: John Wiley & Sons
• Kategorie: Fachliteratur
• Sprache: Englisch

Seitenzahl: 1366

Veröffentlichungsjahr: 2025

Beschreibung

Practical reference on small mammal husbandry and health, now with full-color clinical photographs throughout

The Sixth Edition of Harkness and Wagner’s Biology and Medicine of Rabbits and Rodents provides a thorough update to the classic reference on small mammal health and husbandry, now with full-color clinical photographs throughout. Part of ACLAM’s series of laboratory animal books, the book is a comprehensive, practical guide to caring for rabbits, guinea pigs, hamsters, gerbils, mice, rats, and chinchillas. Emphasizing biology, contemporary husbandry, diagnostics and clinical procedures, clinical signs, and diseases and conditions, the book is equally useful in the research, companion animal practice, or food animal setting.

New topics for the Sixth Edition include environmental monitoring for rodent health assessments, behavioral management considerations for optimizing animal health, enhanced pain assessment approaches, as well as considerations for creating a welfare-friendly small mammal practice. The Sixth Edition also updates common therapeutics, analgesics, anesthetics, and blood collection methodology, disease biology, husbandry, diagnostic modalities, and references, and covers new techniques for creating and modifying genetically engineered rodents.

Harkness and Wagner’s Biology and Medicine of Rabbits and Rodents includes information on:

• General husbandry and disease prevention, covering equipment needs, factors predisposing to disease, and occupational health and safety issues
• Clinical procedures, covering hematology, clinical chemistry, urinalysis, surgery, post-operative care, dentistry, ophthalmology, and imaging
• Clinical signs and differential diagnoses, covering astroviruses, hepatitis E and leporid herpesvirus-4 for rabbits and antimicrobial resistance for commercial rabbits
• Serologic testing and diagnostic sample submission, covering newer methodologies, environmental monitoring, and considerations for large rodent feeder-breeder operations

The Sixth Edition of Harkness and Wagner’s Biology and Medicine of Rabbits and Rodents is an essential reference for veterinary professionals dealing with small mammal species in research or practice settings, as well as veterinary students interested in small animals, comparative medicine, or laboratory animal medicine.

Leseprobe

Table of Contents

COVER

TABLE OF CONTENTS

TITLE PAGE

COPYRIGHT PAGE

DEDICATION PAGE

PREFACE

ACKNOWLEDGMENTS

PHOTOGRAPHY CREDITS

ABOUT THE AUTHORS AND ILLUSTRATORS

Chapter 1: Introduction, General Husbandry, and Disease Prevention

INTRODUCTION

SOURCES OF INFORMATION

TAXONOMY AND HISTORY

BEHAVIOR

REGULATORY CONSIDERATIONS

GENETICALLY MODIFIED ANIMALS

WELFARE‐FRIENDLY CLINICAL PRACTICES FOR RABBITS AND RODENTS

EQUIPMENT NEEDS

MAJOR HUSBANDRY CONCERNS

FACTORS PREDISPOSING TO DISEASE

ALLERGIES TO RABBITS AND RODENTS

REFERENCES

Chapter 2: Biology and Husbandry: Biology and Husbandry

THE RABBIT

THE GUINEA PIG

THE CHINCHILLA

THE HAMSTER

THE GERBIL

THE MOUSE

THE RAT

Chapter 3: Clinical Procedures

SAMPLE COLLECTION

HEMATOLOGY, CLINICAL CHEMISTRY, AND URINALYSIS

MEDICAL IMAGING

OPHTHALMOLOGY

ADMINISTRATION OF DRUGS AND FORMULARY

ANESTHESIA

ANALGESIA

SURGERY

DENTAL PROCEDURES IN RABBITS AND RODENTS

QUALITY ASSURANCE PROGRAMS FOR COLONY HEALTH SURVEILLANCE

OTHER SPECIAL TECHNIQUES

EUTHANASIA

Chapter 4: Clinical Signs and Differential Diagnoses

RECOGNIZING SIGNS OF ILLNESS AND PAIN IN RABBITS AND RODENTS

THE RABBIT

THE GUINEA PIG

THE CHINCHILLA

THE HAMSTER

THE GERBIL

THE MOUSE

THE RAT

Chapter 5: Specific Diseasesand Conditions

ACARIASIS (MITE INFECTIONS)

ANOREXIA AND REDUCED FOOD INTAKE

ASTROVIRUS INFECTIONS

BORDETELLA BRONCHISEPTICA INFECTIONS

CESTODIASIS (TAPEWORM INFECTION)

COCCIDIOSIS (HEPATIC) IN RABBITS

COCCIDIOSIS (INTESTINAL)

CORONAVIRUS INFECTIONS

CORYNEBACTERIUM KUTSCHERI INFECTIONS

CRYPTOSPORIDIOSIS

DERMATOPHYTOSIS (RINGWORM)

ENCEPHALITOZOONOSIS

ENTERITIS AND RELATED CONDITIONS

EPILEPSY IN GERBILS

FILOBACTER RODENTIUM INFECTIONS (CILIA‐ASSOCIATED RESPIRATORY BACILLUS)

GASTROINTESTINAL STASIS IN RABBITS

HANTAVIRUS INFECTIONS

HEART CONDITONS

HEAT PROSTRATION

HELICOBACTER INFECTIONS

HEMATURIA AND PIGMENTED URINE

HEPATITIS E INFECTIONS IN RABBITS

HERPESVIRUS INFECTIONS OF RABBITS

HYPOVITAMINOSIS C (SCURVY) IN GUINEA PIGS

LAWSONIA INFECTIONS (PROLIFERATIVE ILEITIS/ENTEROPATHY)

LISTERIOSIS

LIVER LOBE TORSION IN RABBITS

LYMPHOCYTIC CHORIOMENINGITIS VIRUS INFECTION

MALOCCLUSION AND DENTAL DISEASE

MASTITIS

MOUSEPOX (ECTROMELIA VIRUS)

MURINE ENCEPHALOMYELITIS

MURINE MYCOPLASMOSIS

MURINE NOROVIRUS INFECTIONS

MYIASIS (FLY STRIKE)—PRIMARY

MYIASIS (FLY STRIKE)—SECONDARY

MYXOMATOSIS

NASAL DERMATITIS (SORE NOSE) IN GERBILS

NEOPLASIA

NEPHROSIS

OXYURIASIS (PINWORMS)

PARVOVIRUS INFECTIONS

PASTEURELLA MULTOCIDA INFECTIONS

PEDICULOSIS

PNEUMOCYSTOSIS

PODODERMATITIS

PREGNANCY TOXEMIA

RABBIT VIRAL HEMORRHAGIC DISEASE

RABIES VIRUS INFECTION

RINGTAIL

RODENTIBACTER COMPLEX INFECTIONS

ROTAVIRUS INFECTIONS

SALMONELLOSIS

SENDAI VIRUS INFECTIONS

SPIRONUCLEOSIS

STAPHYLOCOCCOSIS

STREPTOCOCCUS PNEUMONIAE INFECTIONS IN RODENTS

STREPTOCOCCUS ZOOEPIDEMICUS INFECTIONS IN GUINEA PIGS

TRANSMISSIBLE COLONIC HYPERPLASIA IN MICE

TULAREMIA

TYZZER'S DISEASE (CLOSTRIDIUM PILIFORME INFECTION)

ULCERATIVE DERMATITIS (MOIST DERMATITIS)

UROLITHIASIS

VENEREAL SPIROCHETOSIS (TREPONEMATOSIS)

Chapter 6: Case Reports

THE RABBIT

THE GUINEA PIG

THE CHINCHILLA

THE HAMSTER

THE GERBIL

THE MOUSE

THE RAT

SUGGESTED SOLUTIONS

RABBITS

GUINEA PIGS

CHINCHILLAS

HAMSTERS

GERBILS

MICE

RATS

INDEX

END USER LICENSE AGREEMENT

List of Tables

Chapter 1

Table 1.1. Examples of some genetically modified mice (GMM) including produ...

Table 1.2. Special equipment needs for small mammal procedures.

Table 1.3. Temperature and relative humidity (RH) guidelines.

Chapter 2

Table 2.1. Minimum cage size requirements for rabbits used in biomedical re...

Table 2.2. Biodata: rabbits.

Table 2.3. Biodata: guinea pigs.

Table 2.4. Biodata: chinchilla.

Table 2.5. Examples of inbred strains of hamsters and their characteristics...

Table 2.6. Biodata: Syrian hamsters.

Table 2.7. Biodata: gerbils.

Table 2.8. Biodata: mice.

Table 2.9. Biodata: rats.

Chapter 3

Table 3.1. Approximate adult total blood volumes (TBV) and exsanguination v...

Table 3.2. Common sites and suggested equipment for use in blood collection...

Table 3.3. Common sites and suggested equipment for blood collection in rod...

Table 3.4. Reference hematology and clinical chemistry values for rabbits (...

Table 3.5. Reference hematology and clinical chemistry values for guinea pi...

Table 3.6. Reference hematology and clinical chemistry values for chinchilla...

Table 3.7. Reference hematology and clinical chemistry values for hamsters (...

Table 3.8. Reference hematology and clinical chemistry values for gerbils (S...

Table 3.9. Reference hematology and clinical chemistry values for mice (SI ...

Table 3.10. Reference hematology and clinical chemistry values for rats (SI...

Table 3.11. Drug formulary for rabbits, guinea pigs, and chinchillas. (Caut...

Table 3.12. Drug formulary for hamsters, gerbils, mice, and rats. (Caution:...

Table 3.13. Suggested drugs and dosages for rabbit preanesthetic medication...

Table 3.14. Various CRI protocols for rabbits.

Table 3.15. Suggested analgesic dosages for rabbits, guinea pigs, and chinc...

Table 3.16. Suggested analgesic dosages for hamsters, gerbils, mice, and ra...

Table 3.17. Dental formulas of rabbits and rodents.

Table 3.18. Summary of common rabbit and rodent diagnostic tests.

Chapter 4

Table 4.1. Common presenting skin conditions and differential diagnoses in ...

Table 4.2. Common presenting gastrointestinal conditions and differential d...

Table 4.3. Common presenting cardiorespiratory conditions and differential ...

Table 4.4. Common presenting nervous and musculoskeletal conditions and dif...

Table 4.5. Common presenting genitourinary conditions and differential diag...

Table 4.6. Common presenting skin conditions and differential diagnoses in ...

Table 4.7. Common presenting gastrointestinal conditions and differential d...

Table 4.8. Common presenting cardiorespiratory conditions and differential ...

Table 4.9. Common presenting nervous and musculoskeletal conditions and dif...

Table 4.10. Common presenting genitourinary conditions and differential dia...

Table 4.11. Common presenting skin conditions and differential diagnoses in...

Table 4.12. Common presenting gastrointestinal conditions and differential ...

Table 4.13. Common presenting cardiorespiratory conditions and differential...

Table 4.14. Common presenting nervous and musculoskeletal conditions and di...

Table 4.15. Common presenting genitourinary conditions and differential dia...

Table 4.16. Common presenting skin conditions and differential diagnoses in...

Table 4.17. Common presenting skin conditions and differential diagnoses in...

Table 4.18. Common presenting gastrointestinal conditions and differential ...

Table 4.19. Common presenting cardiorespiratory conditions and differential...

Table 4.20. Common presenting genitourinary conditions and differential dia...

Table 4.21. Common presenting skin conditions and differential diagnoses in...

Table 4.22. Common presenting cardiorespiratory conditions and differential...

Table 4.23. Common presenting nervous and musculoskeletal conditions and di...

Table 4.24. Common presenting genitourinary conditions and differential dia...

Table 4.25. Summary of zoonotic conditions reported for rabbits and rodents...

Chapter 5

Table 5.1. Coccidiostats commonly used in rabbits.

Table 5.2. Vitamin C content of some fruits and vegetables.

List of Illustrations

Chapter 1

FIGURE 1.1. DNA being injected into an embryonic nucleus by microinjection....

FIGURE 1.2. Two chimeric mice produced by knock‐out technology.

FIGURE 1.3. A: Example of suitable carrier for companion rabbit, B: Rabbit o...

FIGURE 1.4. A proposed umbrella model of research animal behavioral manageme...

FIGURE 1.5. Example of thoughtfully planned housing for gerbils.

FIGURE 1.6. Mice provisioned with a gel cup in a Shepherd Shack®, providing ...

FIGURE 1.7. Example of instrument used for ear punching of mice. Note that t...

FIGURE 1.8. A: Ear tag in a rabbit, B: Rabbit sedated and positioned for ear...

FIGURE 1.9. Tail tattoo in mouse. A: Mouse in tattoo cassette, B: Cassette i...

FIGURE 1.10. Standard ear notch punch codes for identification of rodents. T...

FIGURE 1.11. Generalized wheal‐and‐flare reaction on the arm of an individua...

Chapter 2

FIGURE 2.1. Typical appearance of several rabbit breeds, A: Dutch, B: Rex....

FIGURE 2.2. Normal rabbit incisors. Note the relative lengths of the maxilla...

FIGURE 2.3. Rabbit incisor malocclusion. A. Frontal view. B. Side view (arro...

FIGURE 2.4. A. Rabbit incisors following extraction. From left to right, pai...

FIGURE 2.5. Normal gastrointestinal anatomy of the rabbit in situ (A) and di...

FIGURE 2.6. Group‐housed mature rabbits (intact and neutered does and neuter...

FIGURE 2.7. Male rabbit with scrotal wound and exposure of testis following ...

FIGURE 2.8. Pair‐housed female New Zealand white rabbits. Pairing success ca...

FIGURE 2.9. Football hold used for carrying rabbits short distances. The rab...

FIGURE 2.10. Alternate methods for rabbit restraint, A: cradle hold for smal...

FIGURE 2.11. A–F: Instructions for performing the rabbit towel wrap. The tow...

FIGURE 2.12. Meat rabbit carcass demonstrating acute subcutaneous bruising a...

FIGURE 2.13. A: Typical suspended wire housing used for commercial rabbit op...

FIGURE 2.14. Stainless steel cage exercise for laboratory rabbit housing. Mu...

FIGURE 2.15. Group‐housed research rabbits in a biosafety level 2 infectious...

FIGURE 2.16. Two companion rabbits housed comfortably in a floor pen. Nonsli...

FIGURE 2.17. Pair‐housed mature pregnant does. Housing has elevated resting ...

FIGURE 2.18. Floor‐housed juvenile research rabbits.

FIGURE 2.19. Exercise pen for cage‐housed female laboratory rabbits composed...

FIGURE 2.20. Foot hygiene scoring system for rabbits, with scores ranging fr...

FIGURE 2.21. Coprophagy is a normal activity of a rabbit in which cecotropes...

FIGURE 2.22. A. External genitalia of the male rabbit (P, penis; * denotes p...

FIGURE 2.23. External genitalia of the female rabbit. Only the urogenital or...

FIGURE 2.24. Paired inguinal glands in a female rabbit (UG, urogenital orifi...

FIGURE 2.25. Body condition scores (BCS) for rabbits. Images depict scores b...

FIGURE 2.26. Equipment for artificial insemination of commercial meat rabbit...

FIGURE 2.27. Palpating the female rabbit for pregnancy. Rabbits are palpated...

FIGURE 2.28. Young rabbit with splayleg.

FIGURE 2.29. Typical appearance of several guinea pig breeds, A: English sho...

FIGURE 2.30. Normal guinea pig incisors. Note the relative lengths of the ma...

FIGURE 2.31. Normal guinea pig cheek teeth anatomy, as viewed with an otosco...

FIGURE 2.32. Malocclusion with overgrowth of lingual surface of molars, entr...

FIGURE 2.33. Palatal ostium (arrow) in a guinea pig taken at post mortem. In...

FIGURE 2.34. Adrenal gland (AG) and kidney (K) from a guinea pig. The normal...

FIGURE 2.35. Seminal vesicles from a mature boar.

FIGURE 2.36. Kurloff cells (white arrows) in a peripheral blood smear from a...

FIGURE 2.37. Guinea pig being restrained in an upright position for a nail t...

FIGURE 2.38. Pen housing for a pair of pet guinea pigs. The open top and pla...

FIGURE 2.39. Typical open‐topped guinea pig tub with tubes and hiding places...

FIGURE 2.40. Rack‐type group housing for laboratory guinea pigs with plastic...

FIGURE 2.41. Hiding places are important for guinea pigs and enhance feeling...

FIGURE 2.42. Guinea pig taking an orange‐flavored vitamin C tablet. Once acc...

FIGURE 2.43. A: Male genitalia of guinea pig with penis in prepuce (U, ureth...

FIGURE 2.44. The anus of the guinea pig is difficult to see in a conscious a...

FIGURE 2.45. A: Female genitalia of a mature sow during estrus phase (V, vag...

FIGURE 2.46. Pregnant sow shortly before parturition. The sow's abdomen is m...

FIGURE 2.47. Radiograph of a pregnant sow with two pups. The skulls (S) and ...

FIGURE 2.48. Five neonatal guinea pig pups within hours of birth. Pups are p...

FIGURE 2.49. Normal chinchilla incisors. Note the relative lengths of the ma...

FIGURE 2.50. A. Towel restraint for chinchilla*. B. Two‐handed restraint for...

FIGURE 2.51. Typical plastic‐coated wire multilevel cage for pet chinchilla....

FIGURE 2.52. Igloo shelter resource for chinchilla.

FIGURE 2.53. Running wheel for chinchilla.

FIGURE 2.54. Cardboard box resource for chinchilla. Courtesy of Glen and Reb...

FIGURE 2.55. Overheated chinchilla with marked bilateral aural vascular dila...

FIGURE 2.56. Examples of chinchilla dust bath, open (A) and closed* (B). Dus...

FIGURE 2.57. External genitalia of a mature female chinchilla (U, urethra; V...

FIGURE 2.58. External genitalia of a mature male chinchilla (P, penis; *, an...

FIGURE 2.59. Two week‐old chinchilla pups. Pups are born precocious.

FIGURE 2.60. Typical appearance of hamster species, A: Syrian, and B: Chines...

FIGURE 2.61. Flank gland on a Syrian hamster.

FIGURE 2.62. Syrian hamster with incisor malocclusion.

FIGURE 2.63. Syrian hamster with cheek pouches distended with food.

FIGURE 2.64. Hamsters are fastidiously groomed and a hamster with an unkempt...

FIGURE 2.65. Male hamsters are readily group housed, particularly when socia...

FIGURE 2.66. A. Towel restraint for examination of a hamster.* B. Firm restr...

FIGURE 2.67. A method for scooping a hamster out of its cage is demonstrated...

FIGURE 2.68. Male research hamsters group housed with running wheel, enrichm...

FIGURE 2.69. Hamsters appreciate having a shelter for resting undisturbed....

FIGURE 2.70. Typical plastic cage used for housing pet hamsters. A running w...

FIGURE 2.71. External genitalia of mature male hamster (U, urethral opening;...

FIGURE 2.72. External genitalia of mature female hamster. UO, urogenital ope...

FIGURE 2.73. Agouti gerbils (left)are most common, but solid coat colors...

FIGURE 2.74. Once out of its enclosure, a gerbil can be held in the hand wit...

FIGURE 2.75. An “over the back” grip for a gerbil.

FIGURE 2.76. Two examples of suitable housing and resources for gerbils. Ani...

FIGURE 2.77. A naturalistic shelter used to provide a hiding place for gerbi...

FIGURE 2.78. A sand bath will assist with grooming and maintaining the pelag...

FIGURE 2.79. External genitalia of an 11 day‐old female (left) and male (rig...

FIGURE 2.80. External genitalia of an adult female (left) and adult male (ri...

FIGURE 2.81. Numerous mouse strain variations exist with a variety of coat c...

FIGURE 2.82. Normal mouse incisors. Note the relative lengths of the maxilla...

FIGURE 2.83. Abnormal and overgrown incisors in a pair of mice. When breedin...

FIGURE 2.84. Moderate barbering seen in a cage of black (C57BL/6) mice. Alth...

FIGURE 2.85. Fighting injury seen in a CD‐1 male mouse.

FIGURE 2.86. Low‐stress handling refers to how the mouse is picked up from i...

FIGURE 2.87. Traditional scruffing restraint for mice can result in dyspnea ...

FIGURE 2.88. Small plastic containers may be used to accurately weigh mice....

FIGURE 2.89. Large shoebox mouse cage in research setting. Complexity is pro...

FIGURE 2.90. A variety of commercial enrichment devices are available for mi...

FIGURE 2.91. Housing for a companion mouse. The use of a shelter helps to im...

FIGURE 2.92. When given sufficient nesting materials, mice will rapidly crea...

FIGURE 2.93. Body Condition Scoring for mice. It is preferable to conduct th...

FIGURE 2.94. External genitalia of 5 day‐old female (left) and male (right) ...

FIGURE 2.95. External genitalia of a 10 week‐old (mature) female (left) and ...

FIGURE 2.96. Dam with nursing pups.

FIGURE 2.97. A Long–Evans rat.

FIGURE 2.98. Normal rat incisors. Note the relative lengths of the maxillary...

FIGURE 2.99. Gentling a rat. A. Holding newly acquired rats for at least 15 ...

FIGURE 2.100. Tail necrosis in an animal incorrectly restrained by the tip o...

FIGURE 2.101. Low‐stress handling techniques for rats. A. An adult rat being...

FIGURE 2.102. A. Over‐the‐back restraint of a rat. For larger animals, the h...

FIGURE 2.103. Various commercial restraint devices available for rats includ...

FIGURE 2.104. A rat being tickled.

FIGURE 2.105. Typical shoebox cage used for laboratory rat housing, cage lid...

FIGURE 2.106. Ringtail may occur in suckling and weanling rats and mice when...

FIGURE 2.107. Research rat housing is receiving additional attention. This f...

FIGURE 2.108. Nylon or wooden chew toys, such as this well‐used Nylabone®, c...

FIGURE 2.109. Rats will use tunnels for resting, chewing, and compartmentali...

FIGURE 2.110. Colony rats housed in a multilevel rat cage with hammocks, nes...

FIGURE 2.111. Exercise pen for rats containing climbing objects and other no...

FIGURE 2.112. Exercise pen for rats used at cage change or 2–3 times/wk for ...

FIGURE 2.113. External genitalia of an adult male rat. The paired scrotal sa...

FIGURE 2.114. External genitalia of a female rat. As in the other rodent spe...

Chapter 3

FIGURE 3.1. Habituation of rats to inhalant nose cones in their home cage. R...

FIGURE 3.2. A: Collection of blood from the jugular vein of the rabbit. To r...

FIGURE 3.3. A: Blood collection from the lateral saphenous vein of a guinea ...

FIGURE 3.4. A: Cranial vena cava approach for blood collection from an anest...

FIGURE 3.5. A: Collection of blood from the lateral saphenous vein of an awa...

FIGURE 3.6. Cranial vena cava puncture in an anesthetized hamster.

FIGURE 3.7. Large blood volumes can be collected terminally in an anesthetiz...

FIGURE 3.8. A: Both the mouse (depicted) and rat have ventral tail arteries ...

FIGURE 3.9. Vasodilatation of the tail vein may be accomplished by immersing...

FIGURE 3.10. Gingival blood collection from an anesthetized rat.

FIGURE 3.11. Facial vein bleeding in a conscious mouse. A: The mouse is firm...

FIGURE 3.12. Submental vein blood collection in a conscious mouse. A: The la...

FIGURE 3.13. A: Restraint for one‐handed jugular venipuncture in a conscious...

FIGURE 3.14. Rabbit urine frequently contains calcium crystals and the urina...

FIGURE 3.15. Ventrodorsal (A) and lateral (B) survey radiographs of the thor...

FIGURE 3.16. Cross‐sectional CT image of a rabbit at the level of the crania...

FIGURE 3.17. Lateral radiographic view of the skull of a normal rabbit with ...

FIGURE 3.18. Moderate‐to‐severe dental disease in a rabbit: Note the incisor...

FIGURE 3.19. Cross‐sectional CT view of a rabbit at the level of the osseous...

FIGURE 3.20. Lateral radiographic view of rabbit with moderate GI stasis. No...

FIGURE 3.21. Radiograph demonstrating severe dental disease in a chinchilla....

FIGURE 3.22. Intra‐abdominal abscess in a rabbit seen on abdominal ultrasoun...

FIGURE 3.23. Ovarian cysts in a guinea pig seen on abdominal ultrasound exam...

FIGURE 3.24. Conjunctivitis in a rabbit with prolapse of the nictitating mem...

FIGURE 3.25. Exophthalmos in a pet rabbit secondary to a retrobulbar abscess...

FIGURE 3.26. Epiphora and facial swelling secondary to rupture of the nasola...

FIGURE 3.27. Rabbit with glaucoma.

FIGURE 3.28. “Pea eye” in a guinea pig.

FIGURE 3.29. Cataract in a gerbil eye.

FIGURE 3.30. Corneal scarring and neovascularization in a rat as a sequela t...

FIGURE 3.31. Chamber induction of anesthesia in hamsters.

FIGURE 3.32. Monitoring of anesthesia maintenance in a rabbit following indu...

FIGURE 3.33. Technique for intraperitoneal injection into a mouse (A) and ra...

FIGURE 3.34. Sterile ophthalmic lubricant being placed in the eye of an anes...

FIGURE 3.35. Microwavable gel pack for maintaining rodent body heat during a...

FIGURE 3.36. Chinchilla anesthetized by isoflurane in oxygen, delivered by f...

FIGURE 3.37. Sequence of events to catheterize the central auricular artery ...

FIGURE 3.38. Lateral radiograph of a chinchilla with intraosseous catheter i...

FIGURE 3.39. A cephalic catheter may be placed in the rabbit for fluid admin...

FIGURE 3.40. The marginal ear vein is a convenient site to catheterize for f...

FIGURE 3.41. Fluids may be administered intravenously to rats using the late...

FIGURE 3.42. When possible, oxygen supplementation should be provided to sma...

FIGURE 3.43. Rat licking Ensure® from a syringe.

FIGURE 3.44. Facemask induction of a rabbit.

FIGURE 3.45. Blind endotracheal intubation in a rabbit.

FIGURE 3.46. Laryngeal mask airway (LMA) (inset) and restraint for LMA place...

FIGURE 3.47. Different sizes of the V‐gel, a laryngeal mask designed for rab...

FIGURE 3.48. Mask anesthesia with isoflurane in a guinea pig being prepared ...

FIGURE 3.49. Guinea pig intubated with a 2 mm uncuffed endotracheal tube for...

FIGURE 3.50. Chamber induction of a chinchilla.

FIGURE 3.51. Mice and rats may be intubated for research purposes. The techn...

FIGURE 3.52. The World Health Organization’s (WHO’s) Pain Relief Ladder for ...

FIGURE 3.53. Technique for closed castration of the rabbit. A: the surgical ...

FIGURE 3.54. Lateral survey radiograph of a closed tibial and fibular fractu...

FIGURE 3.55. Open technique for guinea pig castration. A: After incising the...

FIGURE 3.56. Urolith removed from a pet hamster via cystotomy.

FIGURE 3.57. Hamster with fractured femur.

FIGURE 3.58. Male gerbil with tibial fracture repaired by external fixation....

FIGURE 3.59. Elizabethan collar fitted for a rat.

FIGURE 3.60. Advanced dental disease in a pet rabbit, view of the left arcad...

FIGURE 3.61. Advanced dental disease in a guinea pig. The clinical crowns ar...

FIGURE 3.62. A: Stomatoscopy and dental examination in a companion rabbit. B...

FIGURE 3.63. Chinchilla teeth before (a) and after (b) molar trim.

FIGURE 3.64. Hamster voluntarily consuming medication.

FIGURE 3.65. Nasogastric tube in a rabbit. For chronic administration of flu...

FIGURE 3.66. Intranasal administration of substances can be accomplished rea...

FIGURE 3.67. The length of gavage needle to be inserted should always be mea...

FIGURE 3.68. Photomicrograph demonstrating characteristic appearance of cell...

Chapter 4

FIGURE 4.1. The hunched and withdrawn posture and behavior of this rabbit is...

FIGURE 4.2. Simplified facial grimace scoring for pain—Mouse. Body posture, ...

FIGURE 4.3. Simplified facial grimace scoring for pain—Rat. Body posture, ea...

FIGURE 4.4. Simplified facial grimace scoring for pain—Rabbit. Body posture,...

FIGURE 4.5. Subcutaneous swellings around the site of fracture repair of the...

FIGURE 4.6. Torticollis is a common presenting sign in rabbits and may be ca...

FIGURE 4.7. Congenital unilateral buphthalmia in a New Zealand white rabbit....

FIGURE 4.8. A: Swelling of the jaw in a guinea pig caused by a tooth root ab...

FIGURE 4.9. Lice eggs (nits) may be seen deep in the hair coat around the ni...

FIGURE 4.10. Bilateral pododermatitis in a Skinny pig that was housed in a c...

FIGURE 4.11. Moist cervical dermatitis or “slobbers” in a guinea pig (left) ...

FIGURE 4.12. Massive gastric dilatation in a guinea pig (arrows), diagnosed ...

FIGURE 4.13. Bilateral cystic rete ovarii (arrows) in an aged sow.

FIGURE 4.14. Prolapsed vagina in a guinea pig.

FIGURE 4.15. Cutaneous lymphosarcoma in a hamster. The condition causes irre...

FIGURE 4.16. Flank gland tumor in a male hamster.

FIGURE 4.17. Prolapsed rectum in a hamster at post mortem.

FIGURE 4.18. Nasal dermatitis in a gerbil.

FIGURE 4.19. Severe ulcerative dermatitis on the shoulders and back of a mou...

FIGURE 4.20. Necropsy photo of severe bilateral posterior cellulitis that ha...

FIGURE 4.21. Necropsy photograph of marked hydrometra in a female mouse. Thi...

FIGURE 4.22. Mammary gland fibroadenomas in aged sibling female rats.

FIGURE 4.23. Facial swelling in a Fischer 344 rat at necropsy (A). Mass open...

FIGURE 4.24. Bilateral chromodacryorrhea in a rat. This is a nonspecific sig...

FIGURE 4.25. Uroliths from the urinary bladder of an 8 week‐old female rat. ...

FIGURE 4.26. Vaginal prolapse in a female rat.

Chapter 5

FIGURE 5.1. Gravid female fur mite from a mouse collected using cellophane t...

FIGURE 5.2. Heavy infestation of

Psoroptes cuniculi

(arrows) in a rabbit ear...

FIGURE 5.3.

P. cuniculi

infestation in a rabbit before (left) and after (rig...

FIGURE 5.4.

Cheyletiella parasitovorax

infestation in a rabbit. Flaky, scali...

FIGURE 5.5. Liver and gall bladder from a rabbit with severe hepatic coccidi...

FIGURE 5.6. Section of small intestine from a mouse infected with mouse hepa...

FIGURE 5.7. Dermatophytosis (circular patch of alopecia) in a chinchilla, ca...

FIGURE 5.8. Chronic renal disease with pitting of the cortical surfaces (A) ...

FIGURE 5.9. Soiled hocks and perineum are a common presentation in rabbits w...

FIGURE 5.10. Coliform enteritis in a weanling rabbit. Note the flaccid, flui...

FIGURE 5.11. Section of opened intestine from a rabbit with mucoid enteropat...

FIGURE 5.12. Post mortem specimen from an anorectic rabbit with gastrointest...

FIGURE 5.13. Image of ciliated nasal epithelial cells from a rabbit infected...

FIGURE 5.14. Conjunctivitis and nasal discharge in a guinea pig with hypovit...

FIGURE 5.15. The nasal discharge has been transferred to the forepaws of thi...

FIGURE 5.16. Stifle joint of a guinea pig with hypovitaminosis C, demonstrat...

FIGURE 5.17. Hemorrhage and edema along the costochondral junctions of a gui...

FIGURE 5.18. Skull from a guinea pig that had presented with anorexia. There...

FIGURE 5.19. Chronic

Mycoplasma pulmonis

infection in a rat at necropsy. The...

FIGURE 5.20. Photomicrograph of a gravid female pinworm within the colonic l...

FIGURE 5.21. Pasteurellosis in a rabbit characterized by a mucopurulent rhin...

FIGURE 5.22. Lungs from a rabbit infected with

Pasteurella multocida

demonst...

FIGURE 5.23. Brain abscess in a rabbit secondary to

P. multocida

infection....

FIGURE 5.24. Multifocal ulcerations and swellings in a mouse infested by

P.

...

FIGURE 5.25. Bilateral pododermatitis of the metacarpals of a guinea pig.

FIGURE 5.26. Scoring system for pododermatitis in rabbits. Routine scoring o...

FIGURE 5.27. Rabbit hemorrhagic disease virus infections are often associate...

FIGURE 5.28. Conjunctivitis in a hamster. This condition may be seen with

Ro

...

FIGURE 5.29.

Spironucleus muris

trophozoites may be seen within clusters (ar...

FIGURE 5.30. Section of a kidney from a mouse with staphylococcal septicemia...

FIGURE 5.31. Severe ulcerative dermatitis in a C57BL/6 mouse.

FIGURE 5.32. Crusting and erosive lesions on the muzzle of a rabbit, charact...

Chapter 6

FIGURE 6.1. Ventrodorsal and lateral radiograph views of a guinea pig.

FIGURE 6.2. Severe bilateral pododermatitis of the hind feet in a guinea pig...

FIGURE 6.3. Intranuclear inclusions (white arrow) in salivary gland ductal e...

FIGURE 6.4. Ventrodorsal view of a chinchilla skull.

FIGURE 6.5. Echocardiogram image with color‐flow Doppler revealing valvular ...

FIGURE 6.6. Abdominal ultrasound of a rabbit demonstrating an enlarged hypoe...

FIGURE 6.7. Reduced color Doppler blood flow on an hepatic lobe suggestive o...

FIGURE 6.8. Lateral radiograph of the thorax of a rabbit with a large crania...

FIGURE 6.9. Sagittal view from a contrast CT scan of a rabbit with a thymoma...

FIGURE 6.10. Photomicrograph of brain from a rabbit with cerebral larval mig...

FIGURE 6.11. Ultrasound of the neck from a guinea pig displaying a partially...

FIGURE 6.12. Ventrodorsal view of a chinchilla skull showing indentation of ...

Guide

COVER PAGE

TABLE OF CONTENTS

TITLE PAGE

COPYRIGHT PAGE

DEDICATION

PREFACE

BEGIN READING

INDEX

WILEY END USER LICENSE AGREEMENT

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Harkness and Wagner's Biology and Medicine of Rabbits and Rodents

SIXTH EDITION

Patricia V. Turner, BSc, MS, DVM, DVSc, DACLAM, DABT, DECAWBM (AWSEL)

Charles River, Wilmington, MA, US & University of Guelph (University Professor Emerita), Guelph, Ontario, Canada

Colette L. Wheler, BSc, DVM, MVetSc

University of Saskatchewan Saskatoon, Saskatchewan, Canada

Hugues Beaufrère, DVM, PhD, DECZM, DABVP (Avian), DACZM

School of Veterinary Medicine University of California, Davis, CA, US

Niora Fabian, DVM, MS, DACLAM

Massachusetts Institute of Technology Cambridge, MA, US

John E. Harkness, DVM, MS, MEd, DACLAM

College of Veterinary Medicine (Professor Emeritus) Mississippi State University Mississippi State, MS, US

Illustrations by Gianni A. Chiappetta and Katie Sokolowski, PhD, DABT

Copyright © 2025 by John Wiley & Sons, Inc. All rights reserved including rights for text and data mining and training of artificial intelligence technologies or similar technologies.

Published by John Wiley & Sons, Inc., Hoboken, New Jersey.Published simultaneously in Canada.

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Library of Congress Cataloging‐in‐Publication Data Applied for

ISBN 9781119290476 (hardback)

Cover Design: WileyCover Images: Courtesy of Patricia V. Turner

This edition is dedicated to a devoted colleague and friend, Dr John Harkness, 1939–2020.

PREFACE

The Biology and Medicine of Rabbits and Rodents provides concise, up‐to‐date, reasonably comprehensive information to anyone concerned with the health, care, and management of rabbits and rodents. The book is intended for veterinarians, students, technicians, scientists, breeders, and those with a background in the biological sciences. A basic knowledge of biology and an interest in rabbits and rodents as pets, production animals, or laboratory animals are assumed. Beyond this, the emphasis throughout is on the practical aspects of rabbit and rodent care and health, and substantial detail is provided about many aspects of biology and husbandry, clinical signs and procedures, and specific diseases and their diagnoses. Distinctions between animals maintained for production, research or as companions are provided when relevant.

This book is intended to bridge the gap between the highly comprehensive hardcover reference works on various species of laboratory animals and a variety of class notes, handbooks, proceedings, autotutorial materials, and other publications used as references in practice or for teaching. The care and use of rabbits and rodents has changed considerably since the last edition of this text. The goal when writing this edition was to retain the easy‐to‐read practical style characteristic of previous editions, but to expand discussion of management and diseases that have evolved significantly since 1995.

Dr John Harkness, a close colleague and one of the original authors of this book, passed away during revision of this addition. We greatly appreciated his gentle but witty edits and corrections, as he challenged us to preserve the flavor and accessibility of previous editions. Every effort was made to correct errors and omissions from previous editions, and we welcome suggestions for improving and updating the next edition. Undoubtedly, despite our best intentions, errors will be discovered, and for these we apologize. We hope the new material added to this text will be helpful to new and seasoned readers of previous editions.

The major changes in this edition include revising certain disease descriptions under new taxonomic classifications; adding descriptions of new diseases, refined techniques such as quality assurance methods for rodent colony surveillance, conceptualization of research animal behavioral management programs, adding a section on welfare‐friendly clinical practices, updating clinical techniques including anesthesia, analgesia, and pain recognition and management, and revising husbandry practices. The following diseases and conditions have been given new or expanded coverage: anorexia and dental disease, various enteric conditions of rabbits and rodents, heart disease, and adding new information on astrovirus, rabbit herpesviruses, hepatitis E of rabbits, and rabbit viral hemorrhagic disease. In Chapter 6, some case reports have been deleted, others modified, and new ones added. Many, many references have been eliminated or updated and some web‐based resources have been included. Finally, over 150 images have been added to this edition, and almost all images are now in color.

We are humbled to have had the pleasure of working on the new edition of this classic text that has enjoyed such a loyal following over the decades. We can only hope that readers will be satisfied with our efforts, and that the information contained on the following pages will be used to improve the welfare of these interesting species that have contributed to human lives in countless positive ways.

Patricia V. Turner

Guelph, Ontario

Colette L. Wheler

Saskatoon, Saskatchewan

Hugues Beaufrère

Davis, California

Niora Fabian

Cambridge, Massachusetts

ACKNOWLEDGMENTS

Many portions of this sixth edition of Biology and Medicine of Rabbits and Rodents have been rewritten and updated, and we are grateful to our colleagues in veterinary practice and animal care facilities for advancing the knowledge underlying many of these changes. We feel very fortunate to have had the opportunity to work together during the preparation of this material, and we learned a tremendous amount from each other. We gained a true appreciation of the depth and variety of knowledge that we all acquire during our diverse experiences working with these species in different environments, and would encourage all readers to take advantage of their peers and colleagues when seeking answers to small mammal cases. We recognize that in spite of our best efforts, errors may be present in the text, and we invite your comments for future editions.

During the preparation of this book we experienced loss of a colleague, loss of family members, ill health, and other challenges that delayed finalization of the text. We especially wish to recognize the support given by our families and thank them for their unfailing patience throughout this project. We also thank our editors at Wiley for their support and suggestions throughout the preparation of this edition.

This project was undertaken by the American College of Laboratory Animal Medicine (ACLAM), and all proceeds from book sales will be used to support the educational mission of the ACLAM Foundation.

PHOTOGRAPHY CREDITS

Every effort has been made to attribute new photographs to their rightful owners, and we apologize in advance if we have inadvertently missed any contributor. We are deeply grateful to the following individuals and companies for providing permissions to use photographs in this edition of the book:

Amber Gold

BC SPCA, BC, Canada: Meghann Cant

Charles River Laboratories, Edinburgh, UK: Kerryanne Mooney, William Archibald; Laval, QC, Canada: Simon Authier; Mattawan, MI, US: Jennifer Kylie, April George, Brianna Harmsen, and Sarah Hoekwater; Shrewsbury, MA, US: Sera Perrotta; and Global Animal Welfare & Training: Elizabeth A. Nunamaker, Carly I. O'Malley.

Christina McMahon

Jackie Ranger

Jennie Lofgren, Novartis, MA, US

Leticia Materi, Calgary Avian & Exotic Pet Clinic

Michelle and Jeff Sanders, Brussels, ON, Canada

Minh Huynh, Arcueil, France,

Rachel Labitt, NIH, MD, US

Shepherd Specialty Papers, TN, US

ABOUT THE AUTHORS AND ILLUSTRATORS

Patricia V. Turner is a laboratory animal veterinarian and pathologist who works as Corporate Vice‐President, Global Animal Welfare for Charles River Laboratories. Turner is also a University Professor Emerita at the University of Guelph, where she worked previously as a tenured professor in the Department of Pathobiology overseeing teaching and graduate programs in laboratory animal science and managing the university's laboratory animal diagnostic pathology core. Turner is a Diplomate of the American College of Laboratory Animal Medicine (ACLAM), the American Board of Toxicology (ABT), and the European College of Animal Welfare and Behavioural Medicine (specialising in Animal Welfare Science, Ethics, and Law; ECAWBM). She is the President of the American College of Laboratory Animal Medicine, a member of AAALAC Council, and an author and co‐editor of many chapters, books and papers on animal welfare, laboratory animal science, and small mammal pathology.

Colette L. Wheler is a veterinarian and worked previously as an Associate Professor, Zoological Medicine at the Western College of Veterinary Medicine, University of Saskatchewan, teaching veterinary students, caring for exotic pets, supervising the wild bird clinic, and providing veterinary services to the Saskatoon Zoo. In 2002, Dr Wheler left her position to become Assistant Director of the Animal Resources Centre and was heavily involved with administering the University of Saskatchewan's animal care and use program and providing care for its many research animals. Subsequently, Dr Wheler worked for the Vaccine and Infectious Disease Organization (VIDO) in Saskatoon, where she continued to provide humane care and oversight to a diverse group of research animals as Program Manager of Veterinary Research Services. Dr Wheler retired from her position at VIDO in June 2023 and spends her time travelling, gardening, reading, and bird watching.

Hugues Beaufrère received his veterinary degree from the University of Lyon, France. Following veterinary school, he completed a small animal internship in a private practice in Belgium, an avian and exotic medicine internship at the Ontario Veterinary College at the University of Guelph, Canada, and a combined PhD/Zoological Medicine Residency program at the School of Veterinary Medicine, Louisiana State University and the Audubon Nature Institute in New Orleans. After the completion of his PhD, Beaufrère returned to the University of Guelph as an Assistant Professor in Clinical Studies. Beaufrère joined the School of Veterinary Medicine at the University of California, Davis in 2021 as an Associate Professor in Companion Zoological Medicine and Surgery. He is board certified by the European College of Zoological Medicine (Avian), the American Board of Veterinary Practitioners (Avian), and the American College of Zoological Medicine (subspecialty: Zoological Companion Animals).

Niora Fabian, DVM, MS, DACLAM, is a Research/Clinical Veterinarian at the Massachusetts Institute of Technology (Cambridge, MA). Fabian completed her postdoctoral training in laboratory animal medicine at the Division of Comparative Medicine at MIT in 2021. Prior to this, she completed an internship in avian and exotic animal medicine and surgery at Angell Animal Medical Center (Boston, MA) and has practiced avian and exotic medicine for several years. She currently coordinates and supports research in large and small animal models including biomedical device development, ingestible and implantable robotics, and novel/optimized drug delivery development. She also oversees zebra finches and other avian species used in research at MIT. Fabian's research interests include infectious diseases, animal model development, avian and exotic medicine, and animal welfare refinement. She also enjoys providing mentorship and training to residents and students within the veterinary field.

Gianni A. Chiappetta is an amateur illustrator and artist who works by day as Chief Technology Officer for Freshline. He lives with his family in Toronto, Ontario.

Katie Sokolowski, DVM, PhD, DABT is a freelance medical illustrator with a day job as Principal Toxicologist at Denali Therapeutics. At Denali, she is a project toxicologist and pharmacology technical team leader responsible for nonclinical safety assessment strategies and regulatory interactions for large and small molecules in the neurodegenerative disease therapeutic area. Previously, she worked as a senior toxicologist in the Division of Pharmacology/Toxicology for Neuroscience in the Center for Drug Development and Research, FDA.

Chapter 1Introduction, General Husbandry, and Disease Prevention

INTRODUCTION

Populations of rabbits, rodents, and other small mammal pets are difficult to estimate; however, a 2017 study conducted by the American Veterinary Medical Association (AVMA) estimated that more than 13% of US families keep these species as companion animals, including approximately 3.2 million rabbits, 1.4 million guinea pigs, 1.1 million hamsters, and 470,000 gerbils. However, only about 1.8% of these owners obtain annual veterinary care for their small mammal companions.

Numbers of animals used in research are also difficult to determine because of the limitations of applicable surveys and estimates where fixed data do not exist. Based on United States Department of Agriculture Animal and Plant Health Inspection Service (USDA‐APHIS) data, approximately 107,000 hamsters, 197,000 guinea pigs, and 144,000 rabbits were used in the United States in research, testing, and teaching in 2021, whereas many fewer numbers of gerbils and chinchillas were used. The numbers of rats and mice used are significantly more difficult to estimate because these data are not collected or reported by US federal agencies. Approximately 1.3 million mice were used in Canada in 2022, and this accounted for 38% of animals used in research (www.ccac.ca). Estimates of mice used in the United States in biomedical research range from 6 to 20 million mice per year. It is even more difficult to find accurate references for numbers of rats used annually in research, although estimates of up to four million have been suggested. Mice and rats are typically thought to account for up to 85% of all animals used in research in the United States, although significant numbers of fish, poultry, swine, and cattle are also used for food and fiber research. Availability of genetically characterized strains and stocks with increased relevance to the diseases being studied, sequencing of the mouse and rat genomes (completed in 2002 and 2004, respectively), development of new transgenic technologies, and ease and economy of housing large numbers of animals have significantly contributed to the popularity of rodents as models for many aspects of biomedical research.

Rabbits are the third most common farmed animal species in the world with almost one billion slaughtered annually, and global production increased by almost 10% between 2008 and 2018. In 2020, China accounted for ~38% of world production of rabbit meat with approximately 314 million rabbits produced annually, followed by Europe at 20% with 117 million rabbits (http://faostat.fao.org/en). Both the United States and Canada account for a negligible amount of world rabbit meat production. Production is by and large proportional to per capita consumption, as rabbit meat is rarely exported from North America; however, increasing amounts of rabbit meat are being incorporated into premium companion animal feeds, necessitating import of frozen rabbit meat from outside of North America. Specific legislation covering meat rabbit production and welfare is lacking in many countries, including the European Union and China, although a new rabbit code of practice was published in Canada in 2018.

With the exception of China, the number of rabbits used for fur, felt, and pelt production is much lower than the number raised for food consumption. Rabbit pelts harvested at slaughter for meat are typically of poor quality, as breed, age at harvest, time of year, and husbandry conditions differ significantly for optimal production of meat compared with pelts. Rex rabbits are the primary breed used for pelt harvest, whereas angora rabbit hair is brushed and shorn regularly for yarn production and weaving. China is the world's largest producer of rabbit pelts and angora fiber today, but the industry lacks national welfare oversight and standards, bringing into question the ethics of angora fur production.

Chinchillas have been used by humans as a source of pelts for clothing for centuries, a practice that drove them to near extinction in the wild in the early twentieth century. In 1983, it was estimated that the United States led production of chinchilla pelts, but by the late twentieth century, South American and eastern European suppliers significantly outpaced US and Canadian production. The industry is decreasing in size with a global estimated production of 80,000 pelts in 2023. Public perception about the use of animal pelts for fashion has led to development of specific industry husbandry guidelines as well as US state bans, and other country bans on fur farming.

While veterinary care is relevant for all the aforementioned reasons, the subjects of this book—rabbits, guinea pigs, chinchillas, hamsters, gerbils, mice, and rats—are becoming increasingly popular as companion animals. As a result, veterinary practitioners should expect to see them as patients, regardless of whether they work in exotic specialty practices or more traditional veterinary animal clinics.

Certainly, the human–animal bond applies regardless of animal size, and companion rabbit or rodent owners are often frustrated in their attempts to find veterinarians who are knowledgeable about their small mammal companions. Problems of management and husbandry are often at the root of several disease conditions and can often be addressed by appropriate client education. Small mammal practice does require a modicum of special knowledge; however, careful extrapolation of experiences from other small animals (i.e., dogs and cats) to rabbits and rodents is often useful and appropriate. Common disease conditions not encountered in dogs and cats must be understood though, before attending to small mammal species, such as specific gastrointestinal conditions, antimicrobial sensitivities, dentistry issues, and various infectious diseases, including some that are zoonotic. Small animal clinicians can become competent with most small mammal problems through continuing professional development, and practitioners inclined to develop a client base in this area should not be deterred because of a perceived lack of specialized veterinary training.

Veterinary clinicians are likely to encounter rabbits and rodents in a wide spectrum of situations, presenting a significant challenge when compiling literature regarding management of health and diseases of these species. For example, rabbits and rodents are produced by commercial breeders for the purposes of research and testing. Most animals raised in this manner are reared in specific pathogen‐free (SPF) barriers that preclude introduction of disease agents, and they are sold to research establishments that maintain highly controlled environments for housing these animals. Because of the sophisticated nature of some research, these animals are usually defined physiologically, genetically, and microbiologically. In contrast, rodents and rabbits in the retail pet trade have less certain genetic identification and health histories, and are often managed in ways that do not limit disease transmission among species and conspecifics, including mixing of species from different sources in large distribution centers. Commercial breeding operations for food and fiber production are intermediate between these two scenarios, emphasizing production as a goal, and employing management schemes that result in yet a third spectrum of disease issues. For example, in rabbits, the prevalence of certain diseases tends to be radically different between companion, laboratory, and meat animals. Therefore, medical challenges for private practitioners evaluating small mammal pets are substantially different from those seen by institutional laboratory animal veterinarians, and veterinarians treating animals in meat or fiber operations.

Early literature describing the attributes of these species originated from the laboratory animal and commercial breeder industry; however, more recent texts have been developed with the private practitioner in mind, adopting an individual animal approach versus a herd health approach to treatment. Although the biology, physiology, and disease susceptibility of animals reared and kept for research or as companion animals are similar, differences in purpose and management requirements should be kept in mind when reviewing the available literature on these animals. For example, housing requirements for mice held in a laboratory animal facility emphasize environmental and microbiological controls for the sake of experimental uniformity. These standards may exceed practical recommendations for owners rearing fancy mice for show or breeding rodent prey for reptile feeding. Diseases described in the laboratory animal literature are typically those seen in specific strains and ages most commonly used for research (i.e., SPF, genetically defined stocks of rodents, and New Zealand white rabbits) and are likely to differ substantially from common conditions of rodents purchased at the local pet store, chinchillas managed in a production setting or neutered geriatric house rabbits. Treatment of animals reared for food or fur production may be limited due to the impact of drug residues or damage to pelts. Thus, it is important to use professional judgment when evaluating the literature and to consider the differences in management and purpose when formulating an appropriate diagnostic and therapeutic plan for each case.

SOURCES OF INFORMATION

References for veterinarians who see rabbits and rodents in private practice are readily available. Web resources abound, but should be regarded with some caution if unreferenced or not evidence‐based. LafeberVet (lafeber.com/vet/) is a useful, free online resource for veterinarians that requires an initial registration and provides excellent articles and videos on treating exotic companion animals, including small mammals. General references related to the practice of rabbit and rodent medicine are listed at the end of this chapter. Species‐specific references are provided in the other chapters. This text emphasizes general references and indices of current literature rather than exhaustive literature reviews.

Knowledge about rabbits and rodents varies considerably among veterinarians. Even among the most knowledgeable and successful practitioners, recommendations for treatment vary, depending on personal experience and geographic area of practice, which may determine the nature of conditions seen as well as the general availability of therapeutics with which to treat different conditions. The Veterinary Information Network (VIN, www.vin.com) is a subscription‐only online network that supports dialogue among veterinary practitioners, including specialists in rabbit and rodent medicine. Membership in VIN also provides ready access to a searchable literature, webinar, and case database that includes many exotic species. Laboratory animal veterinarians have extensive training in these species, particularly in matters relating to biology, husbandry, and disease. Diagnostic laboratories specializing in rodent and rabbit diseases also can be helpful in suggesting appropriate work‐ups or providing necropsy and specialized diagnostic services. Companion animal veterinarians may need to seek diagnostic laboratories that specialize in research rodent or rabbit health monitoring for specific testing of certain infectious agents, because many laboratories geared to domestic animals do not provide these tests. Similarly, diagnostic expertise and availability of specific, validated assays for use in meat or fur‐bearing species is limited.

TAXONOMY AND HISTORY

Detailed taxonomy and history of domestication of rabbits and rodents can be found in Chapter 2. Until the early 1900s, rabbits and rodents were classified similarly; however, anatomic and physiologic studies indicated significant differences leading to reclassification of rabbits in their own distinct order. Rabbits are members of the family Leporidae in the order Lagomorpha, whereas rodents are members of the order Rodentia. Rats, mice, gerbils, and hamsters are in the suborder Myomorpha (“rat‐like,” a clade of Myodonta), while guinea pigs, degus, and chinchillas are classified in the suborder Hystricomorpha (“porcupine‐like,” a clade of Ctenohystrica). Differences in classification of rabbits and rodents relate to jaw musculature, dental anatomy and physiology, as well as to differences in nutrition, gastrointestinal function, reproduction, and molecular data. Rabbits and rodents belong to the monophyletic clade of the Glires.

Rabbits and guinea pigs have been used for food (and domesticated to the extent of captive production for this purpose) for centuries; however, during the last century, breeding of these species, as well as of chinchillas, commenced for other purposes. This included the widescale production of pelts (rabbits, chinchillas), use in biomedical research (primarily rabbits and guinea pigs), and as fancy show animals. Whereas mention is made of domestication of mice in Asia as long ago as 1100 B.C., modern fancy rats and mice were first domesticated in the late nineteenth century. Though rats were occasionally used for food in times of famine, their initial domestication was for the once popular sport of rat‐baiting, in which several rats were placed in a pit and bets collected on how long it would take a terrier to decimate the captives. Fancy rats and mice are relatively popular, and are judged in shows based upon size, color, and behavior. As discussed, rats and mice are the predominant mammals worked with in biomedical research; development of inbred and outbred stocks in the early twentieth century preceded the current explosion of genetically engineered strains (see below). Hamsters and gerbils were more recently domesticated and were introduced as companion and research animals in the 1950s. All these species became popular as small mammal companions starting in the 1960s, concurrent with their availability in pet stores and from private breeders, and with growth of urban and suburban communities.

BEHAVIOR

An understanding of the natural behavior of these animals is essential if provision of appropriate husbandry and veterinary care is to be made. All of the species described in this text are prey species, and as such, they are generally stressed in the presence of a perceived predator, such as a cat or dog, and have developed adaptive behaviors to avoid predation. One of the most prevalent of these is the propensity for active behaviors to be concentrated either during the dark phase of the daily cycle (nocturnal activity), or during dawn and dusk transitions (crepuscular activity). This is most apparent in hamsters, which exhibit significant resistance to arousal during the light cycle, and is least apparent in guinea pigs, which scatter their activities over a 24‐hour period. This fact may limit the ability of a clinician or owner to evaluate normal activity, in that the typical physical exam and evaluation will occur when the animal is less likely to be active, and may not be exhibiting evidence of pain. Behavioral evaluations are further complicated in that the “fight or flight” response initiated during an exam may override behaviors less conducive to overall survival. For this reason, evaluation during the dark phase and in the home cage can be beneficial for detecting subtle abnormalities. Evaluation in the home environment is often possible in a laboratory situation, and may be feasible when evaluating a colony‐wide problem at a commercial breeding establishment. If animals must be moved from their normal area to an examination area, it is helpful to have a small, darkened, secure transport cage and to minimize sudden and loud noises in the area of the cage. Many practices have developed procedures for specifically accommodating these small mammal companions; for example, restricting appointments to times when no predator species will be present or partitioning waiting rooms (see below for welfare‐friendly practice recommendations for small mammals).

Rabbits and rodents have highly developed senses of smell and hearing to aid in detection of predators. Therefore, it is likely less stressful to examine and house these animals outside the sight and smell of perceived predators. Prey species are often approached from above by predators, thus when picking up an animal, a slow, steady approach from the side will allow orientation to the movement. Rabbits and rodents are often calmed by a confident and encircling grasp, and by covering the eyes. This can be achieved by use of a towel or sleeve during the examination process.