Chinchillas by liaoqinmei

VIEWS: 14 PAGES: 4

									Chinchillas
              2                                      Blackwell’s Five-Minute Veterinary Consult

                  Alopecia
Chinchillas




                                                                 Physical Examination Findings                    Multifocal to Focal Alopecia
                                                                 r Alopecia with or without scaling,               r Lack of proper dust bath—may cause poor,
                                                                 crusting—distribution may help differentiate     unkept coat that may become matted and
                       BASICS                                    disease process.                                 shed abnormally; may cause alopecia and
                                                                  r Broken hair shafts—suggestive of barbering    accumulation of scale in matted areas
              DEFINITION                                                                                           r Trauma
              Alopecia is common in chinchillas and is           (self-inflicted or conspecifics)
                                                                  r Ptyalism—associated with dental               ◦ Bite wounds—alopecia with or without
              characterized by complete or partial lack of
              hair in expected areas. It may be multifactorial   malocclusion; a thorough oral examination is     erythema, can abscess—secondary
              and can be either a primary or secondary           critical for evaluating for premolar/molar       Staphylococcus spp. or Streptococcus spp.
              disorder. As many as 60 hairs grow from a          malocclusion                                     infections can occur
                                                                  r Epiphora—associated with dental               ◦ Fur slip—alopecia with or without
              single hair follicle in the healthy chinchilla.
                                                                 malocclusion; a thorough oral examination is     erythema, no scaling
              PATHOPHYSIOLOGY                                    critical for evaluating for premolar/molar       ◦ Ear trauma, including frost-bite alopecia
              r Multifactorial causes
              r All disorders represent a disruption in          malocclusion                                     with erythema, scaling, necrosis of pinnae
                                                                                                                   r Fur chewing—may chew on fur constantly
              growth of the hair follicle due to infection,      CAUSES
                                                                 r Normal shedding pattern—some chinchillas       or intermittently and fur may regrow in
              inflammation, trauma, or blockage of the                                                             between episodes. Usually chew dorsal flanks
              receptor sites for stimulation of the cycle.       may lose hair in patches when shedding
                                                                  r Behavioral—barbering-dominant cagemates       and sides, pregnant females may chew
              SYSTEMS AFFECTED                                   may chew or pull out hair of submissive          temporarily.
              r Skin/exocrine                                                                                      r Dental disease—facial moist dermatitis
              r Behavioral—may cause self-inflicted               chinchilla
                                                                  r Parasitic—ectoparasites (fleas, lice,          associated most commonly with ptyalism or
              chewing, biting                                    mites)—because of the dense coat of the          epiphora; alopecia; with or without erythema,
               r Gastrointestinal—especially dental                                                               scale, or ulceration. Staphylococcus spp. or
                                                                 chinchilla, ectoparasites are uncommon
              disease—may cause anorexia, dysphagia,              r Infectious—dermatophytosis, bacterial         Streptococcus spp. infections can occur
              ptyalism                                           pyoderma                                         secondary to moist dermatitis.
               r Hemic/lymphatic/immune                                                                            r Dermatophytosis—Trichophyton
                                                                  r Trauma—fur slip due to excessive restraint;
               r Ophthalmic—ophthalmic or dental disease                                                          mentagrophytes most common but
                                                                 self- or conspecific-inflicted barbering, bite
              may cause epiphora, conjunctivitis resulting       wounds                                           Microsporum canis and M. gypseum have been
              in alopecia surrounding one or both eyes.           r Neoplastic—cutaneous lymphoma,                identified; partial or complete alopecia with
                                                                 trichofolliculoma, mast cell tumor               scaling and pruritis; with or without
              GENETICS
               r Dental disease: avoid breeding these animals     r Nutritional—especially protein and fiber       erythema, not always ring-shaped; may begin
                                                                 deficiencies                                      as alopecia around eyes, nose, then spreads to
              as inheritance of dental disease is suspected.
               r Fur chewing: avoid breeding animals that                                                         feet, body, genitals. May be first identified on
                                                                 RISK FACTORS                                     the “grooming claw” (medial first digit) of
              fur chew.                                          Poor husbandry: lack of dust baths, proper       hind limbs.
              INCIDENCE/PREVALENCE                               ventilation, and sanitation; nutritional          r Cheyletiella sp.—reported in chinchillas,
              Common condition in chinchillas                    deficiencies such as low-fiber diets leading to    lesions usually located in the intrascapular or
                                                                 fur chewing and other deficiencies allowing       tail-base region and associated with large
              GEOGRAPHIC DISTRIBUTION                            for immunosuppression; traumatic handling
              N/A                                                                                                 amounts of white scale. Mites readily
                                                                 leading to fur slip                              identified on skin scrapes or acetate tape
              SIGNALMENT                                                                                          preparations on low power.
              No specific age or sex predilection                                                                   r Urinary tract infection—perineal moist
              SIGNS                                                                                               dermatitis; alopecia; with or without
               r The pattern and degree of hair loss is                                                           erythema, scale, or ulceration
                                                                         DIAGNOSIS                                 r Arthritis of hind limbs—perineal moist
              important for establishing a differential
              diagnosis.                                         DIFFERENTIAL DIAGNOSIS                           dermatitis; alopecia; with or without
               r Multifocal patches of alopecia—most             Differentiating Causes                           erythema, scale, or ulceration
              frequently associated with folliculitis from       Pattern and degree are important for              r Lumbar spinal spondylosis—perineal moist
              mycotic or bacterial infection                     differential diagnoses.                          dermatitis; alopecia; with or without
               r Large, diffuse areas of alopecia—indicate       Symmetrical Alopecia                             erythema, scale, or ulceration
                                                                  r Barbering—broken fur shafts identified on       r Pododermatitis of hind limbs—perineal
              follicular dysplasia or metabolic
              component—not reported in chinchillas but          close inspection; most commonly on dorsal        moist dermatitis; alopecia; with or without
              should be considered                               flanks, around face and ears; can have a          erythema, scale, or ulceration
               r May be acute or slowly progressive in onset     “moth-eaten” appearance to the coat. Owners       r Abscesses—anywhere on body alopecia with
                                                                 may or may not observe barbering between         or without erythema, scale, ulceration
              Historical Findings                                                                                  r Ear mites—alopecia around base of ear; may
               r Inappropriate diet—fiber deficiency, other        animals.
                                                                  r Fur chewing—very common in chinchillas;       extend to head, neck, abdomen, perineal
              nutritional deficiencies
               r Inappropriate frequency or complete lack of     may chew on fur constantly or intermittently     region, intense pruritis; brown beige crusty
                                                                 and fur may regrow in between episodes.          exudate in ear canal and pinna
              dust bath; use of inappropriate dust bath                                                            r Fleas—patchy alopecia; flea dirt will help
                                                                 Usually chew dorsal flanks and sides, pregnant
              materials
               r Inappropriate sanitation, ventilation           females may chew temporarily. Coat may have      differentiate; secondary pyoderma sometimes
               r Self-inflicted or conspecific barbering           moth-eaten appearance.                           seen
                                                                  r Matted fur associated with high                r Contact dermatitis—alopecia with or
               r Drooling, dysphagia
               r Ocular or nasal discharge                       environmental temperature (>80◦ F), humid        without erythema; scale on ventral abdomen
               r History of fur slip, fur                        environment, or if dust baths are inadequate     and other contact areas
                                                                 or not provided.                                  r Moist dermatitis—alopecia; with or without
              chewing
                                                                                                                  erythema, scale, or ulceration associated with
                                                                  Chinchillas                                                                         3

  (Continued)                                                                                                                  Alopecia




                                                                                                                                                            Chinchillas
urinary disease (urine scald), diarrhea,            NURSING CARE                                        successfully—is odiferous and can stain;
uneaten cecotrophs, arthritis, pododermatitis,      Subcutaneous fluids can be administered              antifungal shampoos (ketoconazole/
spinal spondylosis                                  (50–100 mL/kg) as needed; IV access is              chlorohexiderm) and antifungal sprays
 r Neoplasia—cutaneous lymphoma,                    difficult in the chinchilla; lateral saphenous       (miconazole, enilconazole) are available but
cutaneous epitheliotrophic lymphoma                 vein catheters often kink; consider                 toxicity information not available for
(mycosis fungoides), trichofolliculoma, mast        intraosseous (IO) catheterization if                chinchillas.
cell tumors; focal or diffuse alopecia; scaling     intravascular fluids are needed. Base fluid            r 0.5%–1% chlorohexidine solution for
and erythema; may see crust formation—not           selection on the underlying cause of fluid loss.     cleansing of affected areas
reported in chinchillas but should be               In most patients, Lactated Ringers solution or       r Antihistamines (diphenhydramine,
considered.                                         Normosol crystalloid fluids are appropriate.         hydroxyzine) for severe pruritis—may cause
CBC/BIOCHEMISTRY/URINALYSIS                         Maintenance fluids are estimated at                  drowsiness
                                                    100 mL/kg/day.                                       r Nonsteroidal antiinflammatory medications
To identify evidence of infection,
inflammation, and organ function for                 ACTIVITY                                            (meloxicam 0.2–0.5 mg/kg PO, SC q24h;
underlying disease, especially with urine           Dust baths should be administered at least          carprofen 2–5 mg/kg PO q12h) may be
scald, perineal dermatitis, infectious              2–3 times weekly—minimize during                    helpful with inflammatory conditions,
organisms                                           treatment for infectious organisms (especially      analgesia for dental disease
OTHER LABORATORY TESTS                              dermatophytes); do not reuse dust bath. Use         CONTRAINDICATIONS
                                                    only good-quality dust bathing materials.            r Oral administration of antibiotics that select
Fungal cultures: especially DTM for
dermatophytes; two negative cultures should         DIET                                                against gram-positive bacteria (penicillins,
be obtained after diagnosis to ensure clearance      r Some chinchillas will develop inappetence.       cephalosporins, macrolides, lincosamides) can
of infection.                                       Be certain the chinchilla is eating, or provide     cause fatal enteric dysbiosis and
                                                    assisted syringe feeding of an herbivore critical   enterotoxemia.
IMAGING                                                                                                  r Metronidazole toxicosis has been previously
 r Skull radiographs: to identify underlying        care diet if anorectic to prevent the
                                                    development, or exacerbation of,                    reported in chinchillas.
dental disease in chinchillas with ptyalism,                                                             r Potentially nephrotoxic drugs (e.g.,
epiphora                                            gastrointestinal dysmotility/GI stasis.
                                                     r Increasing water content in foods or via oral    aminoglycosides, NSAIDs) should be avoided
 r Whole body radiographs: to identify
                                                    or parenteral fluids may increase fluid intake.       in patients that are febrile, dehydrated, or
orthopedic, spinal, gastrointestinal, renal,                                                            azotemic or that are suspected of having
reproductive diseases associated with perineal      Provide multiple sources of fresh water,
                                                    including supplementing fresh water with            pyelonephritis, septicemia, or preexisting
dermatitis or urine scald                                                                               renal disease.
 r Abdominal ultrasound: to identify                small amounts of pure fruit juice (no added          r Glucocorticoids or other
gastrointestinal, renal, reproductive diseases      sugars), high water content vegetables, or
                                                    soaking or misting fresh vegetables before          immunosuppressive agents should be used
associated with perineal dermatitis or urine                                                            only when no alternative is available and
scald.                                              offering.
                                                                                                        should be used with precaution.
                                                    CLIENT EDUCATION                                     r Do not use fipronil or flea collars as toxicity
DIAGNOSTIC PROCEDURES                                r Do not breed animals with malocclusion, or
r Skin scraping—micro-spatula with                                                                      in chinchillas is not known.
                                                    that chew their own fur, as both traits are          r Do not use organophosphate-containing
flat-ended blade preferable; dull edge of
scalpel blade                                       potentially hereditary.                             products in chinchillas.
                                                     r Disinfect caging and cage materials if
 r Acetate tape preparation—
                                                    infectious organisms; for dermatophytes 10%         PRECAUTIONS
evaluate on low power field for ectoparasites                                                             r Flea-control products are off-label use in
 r Trichogram—cytology of epilated hairs to         bleach solution
                                                     r Discard wooden cage materials if infectious      chinchillas; safety and efficacy have not been
examine for lice or parasite eggs                                                                       evaluated in this species.
 r Skin biopsy—especially with suspicion of         organisms                                            r Topical flea products such as permethrins
                                                     r Remove conspecifics if barbering is
neoplasia, infectious organisms                                                                         and pyrethrins may be toxic in chinchillas.
 r Woods lamp ultraviolet evaluation of             identified.                                           r Prevent chinchillas and cagemates from
Microsporum canis lesions; but T.                   SURGICAL CONSIDERATIONS                             licking topical spot-on products until dry.
mentagrophytes does not fluoresce                    N/A                                                  r Toxicity—if any signs are noted, the animal
PATHOLOGIC FINDINGS                                                                                     should be bathed thoroughly to remove any
Gross and histopathologic findings will differ                                                           residual products and treat appropriately.
                                                                                                         r Griseofulvin—bone marrow suppression
depending upon the underlying condition.
                                                           MEDICATIONS                                  reported in dogs, cats as idiosyncratic reaction
                                                                                                        or with prolonged therapy; not reported in
                                                    DRUG(S) OF CHOICE                                   chinchillas but may occur; weekly or
                                                    r Varies with specific cause
                                                    r Fleas, mites (including Cheyletiella spp.),       bi-weekly CBC should be performed.
                                                                                                        Neurological effects reported in dogs and cats,
       TREATMENT                                    other ectoparasites—ivermectin 1% (0.4              monitor chinchillas for these signs.
                                                    mg/kg SC q10–14d × 3–4 doses); selamectin           Teratogenic in first two trimesters of
APPROPRIATE HEALTH CARE                             (Revolution 6–12 mg/kg applied topically
 r Patients that appear otherwise normal are                                                            pregnancy.
                                                    q30d); flea shampoos for kittens without              r Immunosuppressive agents should be
typically managed as outpatients; diagnostic
                                                    permethrins, pyrethrins can be used. Treat all      avoided.
evaluation may require brief hospitalization.
 r Diseases associated with systemic signs of       affected animals and clean the environment.
                                                     r Dermatophytes—itraconazole (5 mg/kg PO           POSSIBLE INTERACTIONS
illness (e.g., pyrexia, depression, anorexia, and                                                       None
                                                    q24h) for 6–8 weeks; fluconazole (16 mg/kg
dehydration) or laboratory findings of
                                                    q24h) × 14 days; or griseofulvin (25 mg/kg          ALTERNATIVE DRUGS
azotemia and or leukocytosis warrant an
                                                    PO q24h) for 4–6 weeks for refractory cases;        Ketoconazole has been utilized for
aggressive diagnostic evaluation and initiation
                                                    lime sulfur dips q7d has been used                  dermatophytes in other species—safety and
of supportive and symptomatic treatment.
              4                                      Blackwell’s Five-Minute Veterinary Consult

                  Alopecia                                                                                                             (Continued)
Chinchillas




              efficacy are unknown in chinchillas.            AGE-RELATED FACTORS                               INTERNET RESOURCES
              Hepatopathy reported in cats and dogs can be   N/A                                               N/A
              severe.                                        ZOONOTIC POTENTIAL                                Suggested Reading
                                                             Dermatophytosis and Cheyletiella can cause        Donnelly TM. Disease problems of
                                                             skin lesion in people.                              chinchillas. In: Quesenbery KE, Carpenter
                                                             PREGNANCY/FERTILITY/BREEDING                        JW, eds. Ferrets, Rabbits, and Rodents
                      FOLLOW-UP                               r Do not breed animals with malocclusion or        Clinical Medicine and Surgery, 2nd ed. St
              PATIENT MONITORING                             that fur chew, as both traits are potentially       Louis: WB Saunders, 2006:255–265.
              Varies with cause                              hereditary.                                       Harkness JE, Turner PV, Vande Woude S, et
                                                              r Griseofulvin contraindicated in pregnant         al. Biology and husbandry of the chinchilla.
              PREVENTION/AVOIDANCE                                                                               In: Harkness JE, Turner PV, Vande Woude
               r Provide good-quality dust baths several     animals during first two trimesters as it can be
                                                             teratogenic.                                        S, et al, eds. Harkness and Wagner’s Biology
              times weekly to maximize coat quality.          r Avoid ivermectin in pregnant animals.            and Medicine of Rabbits and Rodents, 5th
               r Feed diets with balanced protein and fiber
                                                                                                                 ed. Ames, IA: Wiley-Blackwell,
              for chinchillas.                               SYNONYMS                                            2010:58–64.
               r Separate animals that barber or fur chew    Ringworm (dermatophytes)                          Harkness JE, Turner PV, Vande Woude S,
              from other animals.                            Fur chewing (self-inflicted barbering)               et al. Specific diseases and conditions. In:
              POSSIBLE COMPLICATIONS                         SEE ALSO                                            Harkness JE, Turner PV, Vande Woude S,
              N/A                                            Dermatophytosis                                     et al, eds. Harkness and Wagner’s Biology
                                                                                                                 and Medicine of Rabbits and Rodents, 5th
              EXPECTED COURSE AND PROGNOSIS                  ABBREVIATIONS                                       ed. Ames: Wiley-Blackwell, 2010:249–396.
              r Treatment times for dermatophytosis are      DTM = dermatophyte test medium
                                                                                                               Longley L. Rodents: dermatoses. In: Keeble E,
              long (4–8 weeks); treatment diligence          GI = gastrointestinal
                                                                                                                 Meredith A, eds. BSAVA Manual of
              necessary to clear infection; continue until
                                                                                                                 Rodents and Ferrets. Gloucester: BSAVA,
              two negative cultures are obtained.
                                                                                                                 2009:107–122.
                                                                                                               Author Michelle G. Hawkins, VMD DABVP
                                                                                                               (Avian)

                     MISCELLANEOUS
              ASSOCIATED CONDITIONS
              r Dental disease
              r Musculoskeletal disease

								
To top