Critical Care of Ferrets, Rabbits, and Rodents · 2016-04-12 · Critical Care of Ferrets, Rabbits,...

Critical Care of Ferrets, Rabbits,and RodentsLisa Harrenstien, DVM

Becauseof the acute and rapidly progressive nature ofdisease in small exotic mammals, veterinarians mustbe able to recognize signs of serious illness and actquickly to stabilize, diagnose, and definitively treatthese patients. Keeping various species' particularphysiologic and behavioral characteristics in mind, thebasic principles of small animal medicine and surgeryare applicable to the critical care of ferrets, rabbits, androdents. Basicrecommendations are presented in tableformat and several of the more common supportivecare procedures and diseasesare described in detail inthe text.Copyright © 1994 by W.B. Saunders Company

KeyWords: Critical care, supportive care, ferrets, rab-bits, rodents.

Critically-ill small mammals are challengingpatients to manage. Collection of diagnos-

tic information can be difficult and stressfulfor the patient (as well as the veterinarian), andthe progression of disease is often too rapid toallow time for in-depth research and labora-tory analysis. Their rapid metabolic rates andsensitive gastrointestinal physiology (especiallyin rabbits and rodents) merit careful consider-ation of antibiotic types and dosages. Theirhigh surface area-to-volume ratios and naturalecological position as "prey" require appropri-ate caging, including hide spaces and effectivetemperature controls (especially if the patientis semi-conscious).

Tables 1,2, and 3 list recommendations forinitial treatment and diagnostic plans for thepresenting signs of critically ill ferrets, rabbits,and rodents. Fluid and nutritional support andother empirical treatments are extremely im-portant. Maintenance fluid needs range be-tween 50 mLlkg/day for gerbils to 200 mLlkglday for hamsters"; other species' needs can beinterpolated between 50 and 200 mLlkg/day,in a ranking that roughly follows body size(larger species require smaller fluid volumesper kg than would smaller species). Subcuta-neous lactated Ringer's solution or 0.9% so-dium chloride solution (which may include upto 5% dextrose) are appropriate for subacutepatients, but intravenous (in ferrets, guinea

pigs, or rabbits) or intraosseous (in all smallmammals) routes are necessary if immediatefluid replacement is desired. Intravenous cath-eterization is possible in the cephalic, saphen-ous, or jugular veins of ferrets, and the cephal-ic, saphenous, or caudal auricular veins of rab-bits; they can be maintained for up to 48hours. Caution should be noted when access-ing rabbit ears because ear tip necrosis can oc-cur. Intraosseous catheters are usually insertedinto the femur at the trochanteric fossa, andmay be tolerated well and maintained for up to72 hours; the same site of catheterization maybe re-used 24 hours after removal of a priorcatheter.f Caloric support is provided by sy-ringe-feeding a blenderized form of the pa-tient's regular diet. For ferrets, AID diet (Hill'sPet Products, Topeka, KS) is convenient anduseful at approximately 50 mLlkg/day. In rab-bits and rodents experiencing diarrhea, oraladministration of feces from a healthy animalof the same species is useful to help re-establishnormal gut flora, although it is unknownwhether the microbes survive the stomach's ex-treme acidity.

Although sick or sedated small mammalsdo require supplemental heat, most are alsoprone to heat stress at environmental temper-atures greater than 80° F. For this reason, it isnot appropriate to house small mammals in thesame hospital ward as tropical birds and rep-tiles, unless separate thermostatic controls canbe maintained. Animals undergoing heat stressmay show hypersalivation, dyspnea, cyanosis,and seizures. They should be removed to acool environment, given fluid support, and (ifpossible) their rectal temperature monitored

From Exotic Animal, Wildlife, and Zoo Animal MedicineService, Department of Clinical Sciences, College of VeterinaryMedicine, Kansas State University, Manhattan, KS.

Address correspondence to Lisa Harrenstien, DVM, Depart-ment of Pathology, College of Veterinary Medicine, University ofTennessee, PO Box 1071, Knoxville, TN 37901-1071.

Copyright © 1994 by W.B. Saunders Company1055-937X/94/0304-0003$5 .00/0

Seminars in Avian and Exotic Pet Medicine, Vol 3, No 4 (October), 1994: pp 217-228 217

218 Lisa Harrenstien, DVM

Table 1. Recommendations for the Critical Care of Ferrets

Initial DiagnosticSign Treatment Differential DX Plan References

Constipation Parenteral fluids GI foreign body* Abdominal palpation 16, 18,32,33Do not administer Secondary to dehydration Abdominal radiographs

enema until (after diarrhea episode) with or without contrastdiagnosis is made media

PCVITS

Cyanotic oral Oxygen Respiratory compromise (see Dyspnea, below)mucosa (see Dyspnea, below)

Diarrhea Parenteral fluids Proliferative bowel Fecal examination (direct 16, 18,32,(LRS) disease :t H elicobacter smear and flotation) 33, 38-42

sppGI foreign body CBCSalmonella Fecal culture/sensitivityAleutian disease virus Aleutian disease virusEosinophilic serologyt

gastroenteritisGI parasitism

Dyspnea Oxygen Pleural edema due to Radiographs of thorax 6-9, 10-15,cardiomyopathy* or and abdomen 32, 33, 35,trauma Thoracocentesis 37, 44

Pleural effusion due to Electrocardiogramcardiomyopathy, * EchocardiogramIymphosarcoma,* or Abdominocentesisheartworm disease CBC

Pneumonia due to human Occult heartworm testinfluenza virus, TrachealB ordetelLa bronchiseptica, culture/sensitivityblastomycosis, Tracheal wash forhistoplasmosis, cytology andcocciodiomycosis culture/sensitivity

Heat stress+HyperadrenocorticismMegaesophagusAbdominal

enlargement due toascites or masses

Organomegaly Wait until diagnosis is Idiopathic hypersplenism Abdominal radiographs 10-16,18,made Adrenal mass and ultrasonography 32, 33, 35,

Lymphosarcoma* Fine needle aspirate of 36GI foreign body mass for cytologicUrinary obstruction examinationMetastasis of other

neoplasiaBarbiturate

administrationTuberculosisHistoplasma

Pale mucous Warmth Anemia due to History 3-5, 14, 32,membranes Oxygen hyperestrogenism* or Signalment 33

Do not administer ectoparasitism Rectal temperaturefluids until packed Hypothermia PCV/TS*cell volume is Adrenal disease:j: Abdominal palpation toknown detect adrenal mass

Paraparesis onspecific (also see Weakness listing, (also see Weakness listing, 41,42below) above)

Trauma Spinal radiographsMyelitis Aleutian disease virusBotulism serologytAleutian diseaseTuberculosisRabies

(Continued)

Critical Care of Ferrets, Rabbits, and Rodents 219

Table 1. Recommendationsfor the CriticalCare of Ferrets (Cont'd)

Sign ReferencesInitial

Treatment Differential DXDiagnostic

Plan

Seizures and otherCNS signs

Vomiting orhypersalivation

Weakness

Glucose POConsider use of

diazepam orphenobarbital IV

Parenteral fluids(LRS)

Consider nutritionalsupport (glucose IVor PO, AID or PIDdiet§)

Consider antiemeticmedication(metoclopramide)

Consider GIprotectantmedications(sucralfate,cimetidine)

Oral glucose, followedby AID or PID diet

(also see Weakness listing,below)

Canine distemper virusTraumaListeriosisBotulismCryptococcus

Insulinoma*GI foreign body*

(including hairballs)Gastric ulcer* ±H elicobacter spp

Eosinophilicgastroenteritis

Heat stress*Rabies (rare)

Hypoglycemia due toinsulinoma* or sepsis

Adrenal-associatedendocrinopathy

Secondary to diarrhealdisease (see above)

HistoryPhysical examinationBlood glucoseSkull radiographsConjunctival scraping

(distemper)

Blood glucoseAbdominal palpation to

detect GI foreign bodyCBCSerum electrolyte panelBlood gas to assess

acid-base statusAbdominal radiographs

with or without contrastmedia

Exploratory laparotomy

10, 14-18,32-34, 38

Ferrets

closely for the next 12 hours because hypotha-lamic regulation of body temperature recoversrelatively slowly after heat stress, and reboundhypothermia is possible.

Female ferrets are seasonally polyestrus in-duced ovulators. Estrus ensues in spring (un-der natural light cycles)and can continue for 6months if the jill is not bred. High estrogenconcentrations cause bone marrow suppres-sion, however, and the resulting pancytopeniamay be fatal after just 2 months or more du-ration of estrus." Although gonadotropin re-leasing hormone (GnRH) and human chorion-ic gonadotropin (HCG) are useful to induceovulation and thus end the estrus phase, they

HistoryBlood glucose level

before oralsupplementation

CBCAbdominal palpation for

adrenal massAbdominal radiographs

and ultrasonography

10, 14, 15,32-35

* Discussed in detail in the text.t ADV Indirect Immunofluorescence Antibody Assay, Division of Comparative Medicine, Massachusetts Institute ofTechnology, Cambridge, MA, and Counterelectrophoresis test, United Vaccines (Harlan Sprague Dawley, Inc), Madison,WI.:j: Packed cell volumeltotal solids.§ AID and PID canned diets (Hill's Pet Products, Topekar KS).

are not effective once anemia has been noted.An estrous intact female with anemia shouldbe treated with whole blood transfusion (ap-proximately 6 to 10 mL, administered at therate of 0.25 to 0.5 mUmin) and given nutri-tional and parenteral fluid support until itspev is 11% or greater and its vital signs arestable; an emergency ovariohysterectomy isthen performed.v" Additional transfusion(s)may be necessary postoperatively until the pa-tient's bone marrow becomes more productive.

Both dilatative and hypertrophic cardiomy-opathy have been noted in ferrets.P" Pleuraledema and/or effusion, cardiomegaly, ascites,and hepatosplenomegaly may be seen on ra-diographs, and an electrocardiogram mayshow premature ventricular complexes, talland wide QRS complexes, A-V block of vary-


Table 2. Recommendations for the Critical Care of Rabbits

Initial DiagnosticSign Treatment Differential DX Plan References

Abdominal Nonspecific until Intestinal disorders* Abdominal radiographs 2,23,26, 31,enlargement, diagnosis is made including obstruction, and ultrasonography 43, 47acute/subacute trauma, foreign bodies CBC

(also see Diarrhealisting)

Coccidiosis (hepatic)Metritis/pyometraUterine adenocarcinoma

Anorexia Supportive care, until Malocclusion of incisors Oral examination, using 2,21-23,26,diagnosis is made or molars otoscope to assess 30,31,43,

Forcefeed blenderized Tooth root abscess molars 48,49,51alfalfa pellets Hairball* Abdominal palpation

Parenteral fluids Pneumonia* Abdominal radiographs(LRS) Coccidiosis (hepatic or with or without contrast

Offer yellow-colored intestinal) mediababy foods Pain Thoracic radiographs

Upper respiratory disease

Diarrhea Parenteral fluids History of inappropriate History 23,25,26,Forcefeed alfalfa antibiotic Signalment 43,47,51,

pellets if anorectic administration* Fecal examination (gross 52Chloram phenicol Mucoid enteropathy appearance, direct

Tyzzer's disease* smear, flotation)Pseudomonas aeruginosa Rectal temperatureEnterotoxemiaColibacillosisCoccidiosis (intestinal)Low «18%) dietary fiber

Dyspnea Oxygen Pneumonia* due to Thoracic radiographs 21-23,26,Low stress Pasteurella, Klebsiella, Thoracocentesis 45, 54

environment Bordetella CBCMetastasis of neoplasia Abdominal radiographs

such as uterine and ultrasonographyadenocarcinoma

Fever Antibiotic Mastitis Physical examination 21-23,25,administration Pneumonia* CBC 27, 28, 43,(enrofloxacin or Pregnancy toxemia* Thoracic radiographs 52chloramphenicol) Enterotoxemia Abdominal radiographs

Parenteral fluids ColibacillosisNutritional support Septicemia due to

Pasteurella orPseudomonas

Rabbit poxBacterial cellulitis

Paraplegia Dexamethasone 4 Vertebral fracture at L6 Physical examination 23,26,43,45mg/kg 1M space Spinal radiographs (both

Evacuate urinary (other DDx much less lateral and VD views)bladder likely)

Enema

Seizures Nonspecific Cerebral trauma Skull radiography 23Consider use of Heat stress* CBC

diazepam IV Abscesses in brain due to Rectal temperatureConsider use of Pasteurella Consider CSF tap

chloramphenicol Encephalitozoonosis

(Continued)


Table 2. Recommendations for the Critical Care of Rabbits (Cont'd)



Plan

Skeletal trauma(other thanvertebralfracture)

Superficial mass

Testicular swelling

Torticollis

Vulvar Discharge

Analgesic medicationAerobic and anerobic

culture/sensitivity ofwound

Clean woundsConsider application

of bandage andElizabethan collar*

Parenteral fluids

Nonspecific untildiagnosis is made

Enrofloxacin 5 mg/kgSQ q 12 hours ortwice daily

Castration



Considerovariohysterectomy

Long bone fractureSoft tissue trauma

Abscess (most commonlydue to Pasteurella)

MyxomatosisRabbit poxLymphosarcoma

PasteurellosisInterstitial cell tumorRabbit pox

Otitis media due topasteurellosis,listeriosis,encephalitozoonosis

Otitis externa due to earmite or yeast infection(rarely causes torticollis,however)

Trauma to cranial nerveVIII

Pyometra due toPasteurella

Abortion due toPasteurella, Listeria orBrucella

MetritisUterine adenocarcinoma

RadiographsCulture/sensitivity testing

(of swab collectedbefore woundcleansing)

Fine needle aspirate forcytologic examinationand culture/sensitivity

Excision andhistopathologicexamination

Histopathology of excisedtestes

Physical examinationOtoscopic examinationSkull radiographs

Rectal temperaturePhysical examinationAbdominal radiographs

and ultrasonographyUrine sediment analysisCulture/sensitivity of

aborted fetusCBC.

23, 43, 50

23,45

23, 43

23, 26, 45, 46

23, 28, 54

* Discussed in detail in text.

ing degree, and depressed ST segments.P'"Echocardiography is useful to differentiatewhether the dilatative or hypertrophic form(or a mixed form) is present." Thoracocentesis,abdominocentesis, oxygen therapy, furose-mide (1 to 4 mg/kg intramuscularly [1M] thenorally [PO] twice daily [BID]), digoxin elixir(0.01 mg/kg PO every 12 to 48 hours), en ala-pril (0.5 mg/kg PO every 8 to 48 hours), nitro-glycerine, and dietary sodium restriction maybe used for treatment of heart failure associ-ated with cardiomyopathy''; long-term prog-nosis is guarded.

Lymphosarcoma (LSA) in ferrets is a multi-systemic disease, with signs referable to the sys-tem(s) affected. Peripheral and/or mesenteric

lymphadenopathy, hepatosplenomegaly, pal-pably roughened kidneys, and lymphocytosis(lymphocytes comprising greater than 60% oftotal white blood cell count, or absolute lym-phocyte count greater than 3,500)10 are allconsistent with LSA. The mediastinal form ofLSA is also fairly common in younger ferrets,and results in dyspnea secondary to pleural ef-fusion. Thoracic radiography is useful for di-agnosis, and cytologic examination of thoracicfluid or of a fine needle aspirate of the massmay show large numbers of lymphocytes withmitotic figures. Thoracic ultrasonographycould initially be useful in diagnosis, if there isa large amount of pleural fluid present (pro-viding an acoustic window to the anterior me-


Table 3. Recommendations for the Critical Care of Rodents



Plan

Abdominalenlargement

Abortion andstillbirths

Anorexia

Anuria, dysuria orhematuria

Ataxia

Constipation orvomiting

Diarrhea

Nonspecific

Nonspecific

Blenderized foodadministered byorogastric tube

Vitamin C [P]

Nonspecific

onspecificNutritional support

Nonspecific

Parenteral fluidsDiscontinue any

medications untilmedication-induceddiarrhea has beenruled out

Ascites due to amyloidosisor pericarditis (Strepzooepidemicus )

Organomegaly due topolycystic disease [H]or cystic ovaries [G]

PregnancyObesityNeoplasia

Secondary to systemicdisease

Malocclusion of incisorsor molars

Salmonellosis (Styphimurium or Senteritidis)

Tyzzer's disease(Clostridiumpiliformis) [G]

Sepsis (Streptococcus)Urolithiasis [P]Trauma

"Guinea pig paralysis"TraumaPregnancy toxemia*Toxin exposureToxoplasmosis

Tapeworm infection(Hymenolepis nana or Hdiminuta)

GI torsionGI intussusceptionCecal impactionGastric or colonic

calcification [P]GI neoplasia

Antibiotic- ind uced *[especially in P]

GI parasitism (coccidiosis[P], Cryptosporidium,giardiasis [C]

Subacutepseudo-tuberculosis(Yersiniapseudotuberculosis) [P]

Mucoid enteritisTyzzer's disease [H, G]E coli [H, P]Salmonellosis [P]Corynebacteriumpyogenes [P]

(Continued)

UrinalysisAbdominocentesisAbdominal radiographs

and ultrasonographyFine needle aspirate offluid or mass, with

ultra sono graphicguidance

Thoracic radiographsExploratory laparotomy

SignalmentHistoryPhysical examinationCBCWhole body radiographs

Physical examinationOral examination, using

otoscope to assessmolarsFecal culture/sensitivity

HistoryUrinalysis

Physical examinationWhole body radiographs

Fecal examinationAbdominal palpationAbdominal radiographs

with contrast media(iohexol)

Exploratory laparotomywith biopsy collection

SignalmentHistoryFecal examination (gross

appearance, directsmear, flotation)

Fecal culture/sensitivity

29, 54

28

48

58

27,28,50,56, 59

23,27,29,56

23, 24, 55, 56


Table 3. Recommendations for the Critical Care of Rodents (Cont'd)



Plan

Dyspnea

Dystocia

Facial mass (deep)

Hypersalivation

Melena

Neonatecannibalism orlitter desertion

Neonatal diarrhea

OxygenAntibiotic

administration(chloramphenicol asfirst choice)

Increase humidity ofenvironment, ornebulize

Palpate pubicsymphysis

Consider oxytocin0.2-0.3 mg/kg 1Mor Cesarean section

Nonspecific

Nonspecific

Parenteral fluidsSucralfate 50 mg/kg

POCimetidine

Low stressenvironment fordam

Make more freshfoods available todam

Usually unsuccessful

Cervical lymphadenitis(Streptococcuszooepidemicus )

Allergic (dry bedding)*Foreign body in

respiratory tractPneumonia due to

mycoplasma, *Streptococcus, Pasteurella,B ordetella, Klebsiella,Sendai virus

Hypovitaminosis C [P]*Heat stress* [C, P]Pregnancy toxemia

[especially in P]*

Feti too large relative topelvic canal diameter[especially in Rand P]*

Uterine torsionDam is compromised or

weakened due tomalnutrition, illness orobesity

Tooth abscess (sequela ofperiodontitis)

Dental malocclusionHypovitaminosis C [P]*Adrenocortical

insufficiencyOral foreign bodyRectal impactionHeat stress* [C, P]

Gastric ulcer [H]

Environmentaldisturbance 2 days pre-to 10 days postpartum

Primiparity (maternalinexperience)

Mastitis

Epidemic diarrhea ofinfant mice (EDIM)(rotavirus)

Lethal intestinal virus ofinfant mice (LIVIM)(coronavirus)

Transmissible murinecolonic hyperplasia

Sendai virus [M]

(Continued)

Culture/sensitivity of anydischarge

Thoracic radiographsNasal cavity radiographs

SignalmentHistoryAbdminal radiographs

Oral examination,including use ofgingival probe

Oral examination, usingotoscope to assessmolars

Abdominal palpationAbdominal radiographs

HistoryVisual examination of

damPhysical examination of

dam if above optionswere not informative

Postmortem virusisolation

23, 24, 27,28, 56, 59

23, 28, 29, 56

48

24, 48, 56

23, 55

23



.lnitial DiagnosticSign Treatment Differential DX Plan References

Paralysis or Nonspecific "Guinea pig paralysis" Physical examination 23, 29, 50, 56reluctance to Nutritional support Orthopedic disease Whole body radiographsmove (fracture, luxation, CBC

arthritis); arthritis may Urinalysisbe due tohypovitaminosis C [P],*Corynebacterium,Mycoplasma,Streptobacillusmoniliformis

Pseudotuberculosis(Corynebacteriumpyogenes) [R]

Hypovitaminosis EUrinary calculiProstatitisLate pregnancyToxoplasmosisImbalance of calcium and

phosphorus

Polydipsia/polyuria Nonspecific Interstitial nephritis [G] Urinalysis

Seizures Nonspecific Idiopathic epilepsy [G] Signalment 23,56,59Low stress Heat stress* [C, P] History

environment Lymphocyticchoriomeningitis [M]

Pregnancy toxemia*EnterotoxemiaRabies

Superficial mass Excision of mass is Bacterial lymphadenitis Cytology of fine needle 23, 29, 56best treatment due to Staphylococcus aspirate or excised massoption aureus, B-hemolytic Culture/sensitivity of

Antibiotics Streptococcus Lancefield aspirate or excised mass(chloramphenicol is Group C, Strepfirst choice) zooepidemicus [P],

Streptobacillusmoniliformis,salmonellosis [H, P],Corynebacterium pyogenes[P], Yersiniapseudotuberculosis [P]

Abscess due toCorynebacterium kutscheri[R], Strep zooepidemicus

Lymphosarcoma (viraletiology)

Reticulum cell sarcoma oflymph nodes

MyiasisMastitis

Torticollis Nonspecific Otitis media due to Skull radiographs 23, 56Nutritional support Streptococcus

zooepidemicus orMycoplasma pulmonis

Otitis internaEncephalitisTrauma

(Continued)



SignInitial


Plan References

Thrombosis [H]Calcifying vasculopathy

[H]; may be secondaryto hypervitaminosis D

Leptospiraicterohemorrhagica

Sepsis due to StrepLancefield Group C,Mycoplasma pulmonis,Corynebacterium pyogenes,secondary to pyometra

Pregnancy toxemia*

Bite woundsTrauma from cageSelf-mutilation after 1M

injections (neuritis)Draining abscessBurn (thermal!chemical!

caustic)

Vascular signs(petechiation,edema)

Nonspecific Whole body radiographyDark field microscopy of

unne

55

CBCAbdominal palpationAbdominal radiographs

and ultrasonography

27, 28, 56, 59Weakness Nonspecific

History 56Wounds Culture/sensitivity ofwound

Antibiotics(chloramphenicol isfirst choice)

Wound cleansingConsider surgical

closureConsider application

of Elizabethancollar*

Abbreviations: H, hamsters; G, gerbils; P, guinea pigs; R, rats; M, mice; C, chinchillas.* Discussed in detail in text.

teaspoon BID in food).14,15 Definitive diagnosisrequires exploratory laparotomy and excisionalbiopsy of pancreatic nodule(s); metastatic lesions(or other neoplasia such as adrenal adenoma!adenocarcinoma or lymphosarcoma) may also benoted at time of surgery. Surgical treatmentserves to increase the survival times of insulino-ma patients, but rarely constitutes a total curedue to early metastasis of insulinomas; the needfor postoperative chemotherapy should be ex-pected.

Young ferrets that exhibit signs of nauseahave likely ingested foreign items from theirenvironment. In contrast, gastrointestinal ob-structions of older ferrets are more commonlycaused by hairball accumulation. Presentingsigns usually include anorexia, weight loss andnausea, and occasionally the offending massmay be palpated.l? Further diagnostic confir-mation is made with abdominal radiography;administration of barium (2 to S mLlkg viaoro gastric tube) or iohexol (10 mLlkg via oro-gastric tube; use iohexol diluted 1: 1 with tapwater) provides useful contrast. Standard gas-trotomy and enterotomy techniques are appro-priate for resolution of the problem. 16

Gastric ulcers have been associated with

diastinum). After initial thoracic drainageand oxygen therapy, chemotherary of medias-tinal LSA may be considered.U" '

Insulinorna, or pancreatic beta-cell adeno-ma/adenocarcinoma, is common in middle-aged and older ferrets. Inappropriately highinsulin levels result and ferrets become hypo-glycemic, with signs of nausea (hypersalivation,pawing at the mouth) and weakness (some-times progressing to seizures). Ferrets withthese presenting signs should have their bloodglucose measured immediately, and should re-ceive nutritional support (SO% dextrose 3 mLPO, then S to 10 mL A/D or feline PID canneddiet) without delay. Presumptive diagnosis ofinsulinoma is made using signalment and his-tory information along with the presence of hy-poglycemia (blood glucose less than or equal to60 mg/mL); researchers question the diagnos-tic value of serum insulin measurements andinsulin/glucose ratios. 14Chemotherapy may bebegun once a presumptive diagnosis has beenmade; current protocols include frequent feed-ings, prednisone or prednisolone (O.S to 2.0mg/kg PO BID), diazoxide (Proglycem; BakerNorton Pharmaceuticals, Miami, FL) (S to 20mg/kg PO BID), and brewer's yeast (118 to 114


signs of vague abdominal pain, nausea, halito-sis, hemoptysis, and melena. Although Helico-bacter (formerly Carmpylobacter) spp have beenimplicated in their etiology, 17 the cause isprobably multifactorial, including the effect ofenvironmental stress. 18 If suspected, gastric ul-cers can be treated with amoxicillin (20 mg/kgPO or subcutaneously [SQ] every 8 to 12hours) or metronidazole (20 mg/kg PO BID),PeptoBismol (Proctor and Gamble, Cincinnati,OH) (0.25 mLlkg PO every 4 to 6 hours), ci-metidine (10 mg/kg or intravenous [IV] threetimes a day [TID]), and sucralfate (125 mg POfour times daily [QID]).

Rabbits and Rodents

Pneumonia is a common primary or second-ary problem in rabbits and rodents. Dusty cag-ing, wood resin fumes (as from cedar shav-ings), Pasteurella spp, Streptococcus spp, Bordetellaspp, and Mycoplasma (especially in conjunctionwith high ammonia levels, as would be foundin unsanitary cages) have been implicated ascauses of fatal pneumonia. 19 In addition, lungand liver tissues are considered the "shock or-gans" of rabbitsf" and rodents. Patients withdyspnea or hyperpnea should be assumed tohave severe cardiopulmonary disease (with aguarded prognosis) and treated empiricallywith antibiotics (enrofloxacin 5 mg/kg SO BIDfor rabbits21,22 or chloramphenicol sodiumsuccinate 30 mg/kg 1M once a day [SID] forrodents/"), furosemide 1 to 4 mg/kg 1M every4 to 6 hours, and dexamethasone 2.6 mg/kg1M, and placed into a dark cage with 40% oxy-gen concentration.

As mentioned previously, the types and dos-ages of antibiotics must be chosen carefully forsmall mammals, or antibiotic-associated diar-rhea will likely result. Medications especiallydisruptive to the normal gut flora of rabbitsand rodents include penicillins, erythromycin,clindamycin, and lincomycin, particularly ifgiven via the oral route. E coli24 and ClostridiumSpp25 overgrow and cause enterotoxemia that isoften fatal. As is the case for any diarrheal dis-ease in rabbits or rodents, treatment shouldinclude discontinuation of any offending med-ication, intravenous or intraosseous fluid sup-

port, and oral administration of feces from ahealthy animal. If specific anticlostridial ther-apy is desired, metronidazole, bacitracin, orvancomycin are available.f" but dosages havenot been fully described for small mammals.

Clostridium (formerly Bacillus) pilifor-mis causes acute hemorrhagic typhlocolitis inyoung rabbits ("Tyzzer's disease"), anorexia ingerbils, and vague clinical signs in other spe-cies. Part of the normal intestinal flora, it over-grows in times of stress or its spores are trans-mitted by the fecal-oral route in unsanitaryconditions. Definitive diagnosis can only bemade by Giemsa or Periodic acid-Schiff stainsof intestinal biopsies. Although treatment ofsuspected Tyzzer's disease patients may be at-tempted using tetracycline 50 mg/kg PO BIDor oxytetracycline 15 mg/kg 1M TID, it is usu-ally unsuccessful. Reduction of environmentalstress and improvement of sanitation (by dis-infection with 0.5% sodium hypochlorite solu-tion)26 should prevent clinical disease from oc-curring in other animals of the same house-hold.

Pregnancy toxemia is fairly common inheavily gravid rabbits, guinea pigs, and color-dilute rats. The large volume of the uterus pre-cludes adequate filling of the stomach, result-ing in inadequate caloric intake, mobilizationof the body's fat stores, and acetonerniai";uterine ischemia or obesity also may cause thiscondition.i" Lipemia, acidic ketonuria, hyper-kalemia, and CNS signs ensue, sometimes pro-gressing to death. Treatment is directed to-ward correction of ketoacidosis, but is usuallyineffective. If treatment is attempted, it shouldinclude administration of 0.9% sodium chlo-ride solution IV or intraoperatively (IP), so-dium bicarbonate IV or IP (approximately 2mEq/kg), 50% dextrose IV or IP (1 to 2 mL forrats and guinea pigs), 10% calcium gluconate0.5 to 1 ml/kg IV or IP, and continued nutri-tional support. It should be mentioned thatguinea pigs require exogenous vitamin C daily,and treatment of anorexia (regardless of etiol-ogy) of guinea pigs should always include vita-min C supplementation (10 to 30 mg/kg 1M orPO SID).

Primiparous guinea pigs are prone to dys-tocia if first bred after 7 months of age, thedate of closure of the pubic symphysis.23,28

The precocious young have large heads and


can weigh up to 100 g at birth, necessitating alarge pelvic canal in the dam. Dystocia may alsobe caused by concurrent toxemia or obesity.Cesarean section (using isoflurane anesthe-sia)29or oxytocin 0.2 to 0.3 U/kg 1M (if sym-physeal dilation is at least 20 mm)28 may beused to resolve the dystocia.

Gastric trichobezoars ("hairballs") are acommon cause of anorexia in rabbits.P" Occa-sionally, a doughy mass may be palpable in thecranial abdomen, but radiography (with con-trast media) is a more reliable diagnostic tool.(Fig 1). For patients with severe and acute ab-dominal signs, aggressive medical and surgicaltherapy should be pursued immediately. Forpatients whose clinical signs have persistedfewer than 72 hours, a treatment protocol ofintravenous lactated Ringer's solution (6 mUkg/hr), metoclopramide 0.5 mg/kg SQ every 4to 8 hours, and forcefeeding vegetable babyfood or blenderized high-fiber food such asalfalfa pellets (to guard against hepatic lipido-sis) may be effective in promoting passage ofthe trichobezoar; after 72 hours of clinical ill-ness or unsuccessful medical treatment, gastro-tomy is indicated.v''! Offer water soon aftersurgery and force feed (if anorexia persists) 24hours postoperatively.

Wounds and surgical sites can be difficult tomanage in rabbits and rodents (Ferrets, in con-trast, seem to tolerate sutures well). Near-constant grooming behavior and sharp incisorsmake bandages and exposed sutures veryshort-lived; skin staples (in rabbitsj'' and bur-ied subcuticular suture patterns (in rodentsl/"are suggested to resolve these problems. Re-striction of head movements by Elizabethan

Figure 1 Radiograph of 22-gauge spinal needleplaced into the femur of a Dutch Rabbit.

collar or "straightjacket" -type bandaging onlyserves to cause anorexia and extend recoverytime.

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