Full text loading...
Laboratory evaluation of skin and ear disease
/content/chapter/10.22233/9781910443255.chap26
Laboratory evaluation of skin and ear disease
- Author: Tim Nuttall
- From: BSAVA Manual of Canine and Feline Clinical Pathology
- Item: Chapter 26, pp 492 - 510
- DOI: 10.22233/9781910443255.26
- Copyright: © 2016 British Small Animal Veterinary Association
- Publication Date: March 2016
Abstract
Very few skin disorders have an unequivocally pathognomonic appearance and almost all require some form of laboratory investigation to confirm the diagnosis. Fortunately, the skin is readily accessible. Most tests are straightforward and can be accessed in a practice laboratory. This chapter considers the investigation of skin disease and otoscopes and examination of the ears. Case examples are also considered.
/content/chapter/10.22233/9781910443255.chap26
Figures
/content/figure/10.22233/9781910443255.chap26.ch26fig2
26.2
(a) Adhesive tape strip preparation from a dog with Malassezia dermatitis stained with the ‘one-stain’ method. (Rapi-Diff II® stain; original magnification X400). (b) Adhesive tape strip preparation from the same dog as (a) stained with the ‘two-stain’ method. (Rapi-Diff II® stain; original magnification X400) © 2016 British Small Animal Veterinary Association
10.22233/9781910443255/fig26_2_thumb.gif
10.22233/9781910443255/fig26_2.png
26.2
(a) Adhesive tape strip preparation from a dog with Malassezia dermatitis stained with the ‘one-stain’ method. (Rapi-Diff II® stain; original magnification X400). (b) Adhesive tape strip preparation from the same dog as (a) stained with the ‘two-stain’ method. (Rapi-Diff II® stain; original magnification X400)
/content/figure/10.22233/9781910443255.chap26.ch26fig4
26.4
Anagen hairs from a German Shepherd Dog. (Original magnification X40) © 2016 British Small Animal Veterinary Association
10.22233/9781910443255/fig26_4_thumb.gif
10.22233/9781910443255/fig26_4.png
26.4
Anagen hairs from a German Shepherd Dog. (Original magnification X40)
/content/figure/10.22233/9781910443255.chap26.ch26fig5
26.5
Telogen hairs from a crossbred dog with hyperadrenocorticism. (Original magnification X40) © 2016 British Small Animal Veterinary Association
10.22233/9781910443255/fig26_5_thumb.gif
10.22233/9781910443255/fig26_5.png
26.5
Telogen hairs from a crossbred dog with hyperadrenocorticism. (Original magnification X40)
/content/figure/10.22233/9781910443255.chap26.ch26fig6
26.6
Follicular casts from a dog with sebaceous adenitis. (Courtesy of Dr Bob Kennis) © 2016 British Small Animal Veterinary Association
10.22233/9781910443255/fig26_6_thumb.gif
10.22233/9781910443255/fig26_6.png
26.6
Follicular casts from a dog with sebaceous adenitis. (Courtesy of Dr Bob Kennis)
/content/figure/10.22233/9781910443255.chap26.ch26fig7
26.7
Ectothrix spores on a damaged hair from a cat with a Microsporum canis infection. © 2016 British Small Animal Veterinary Association
10.22233/9781910443255/fig26_7_thumb.gif
10.22233/9781910443255/fig26_7.png
26.7
Ectothrix spores on a damaged hair from a cat with a Microsporum canis infection.
/content/figure/10.22233/9781910443255.chap26.ch26fig8
26.8
Microsporum canis on dermatophyte test medium. Note that the red colour change coincides with early fungal growth. © 2016 British Small Animal Veterinary Association
10.22233/9781910443255/fig26_8_thumb.gif
10.22233/9781910443255/fig26_8.png
26.8
Microsporum canis on dermatophyte test medium. Note that the red colour change coincides with early fungal growth.
/content/figure/10.22233/9781910443255.chap26.ch26fig9
26.9
Microsporum canis macroconidia from in vitro culture; these are not produced in vivo. (New methylene blue stain; original magnification X400) (Courtesy of Professor Susan Dawson) © 2016 British Small Animal Veterinary Association
10.22233/9781910443255/fig26_9_thumb.gif
10.22233/9781910443255/fig26_9.png
26.9
Microsporum canis macroconidia from in vitro culture; these are not produced in vivo. (New methylene blue stain; original magnification X400) (Courtesy of Professor Susan Dawson)
/content/figure/10.22233/9781910443255.chap26.ch26fig11
26.11
Ectoparasite identification key for (a) insects and (b) mites and ticks. This figure was produced with the assistance of Merial Animal Health. © 2016 British Small Animal Veterinary Association
10.22233/9781910443255/fig26_11_thumb.gif
10.22233/9781910443255/fig26_11.png
26.11
Ectoparasite identification key for (a) insects and (b) mites and ticks. This figure was produced with the assistance of Merial Animal Health.
/content/figure/10.22233/9781910443255.chap26.ch26fig12
26.12
Flea faecal pellet. (Original magnification X100) (Courtesy of Peter Forsythe) © 2016 British Small Animal Veterinary Association
10.22233/9781910443255/fig26_12_thumb.gif
10.22233/9781910443255/fig26_12.png
26.12
Flea faecal pellet. (Original magnification X100) (Courtesy of Peter Forsythe)
/content/figure/10.22233/9781910443255.chap26.ch26fig13
26.13
Tape strip cytology. (a) Tape-stripping from the skin. (b) Forming a loop on a microscope slide. (c) Staining in a Diff-Quik® stain. © 2016 British Small Animal Veterinary Association
10.22233/9781910443255/fig26_13_thumb.gif
10.22233/9781910443255/fig26_13.png
26.13
Tape strip cytology. (a) Tape-stripping from the skin. (b) Forming a loop on a microscope slide. (c) Staining in a Diff-Quik® stain.
/content/figure/10.22233/9781910443255.chap26.ch26fig14
26.14
Impression smear from a pustule. (a) Rupture the pustule with a sterile needle. (b) Absorb the contents on to a swab. (c) Gently make a thin impression by rolling the swab on a microscope slide. Too much smearing will rupture the cells. © 2016 British Small Animal Veterinary Association
10.22233/9781910443255/fig26_14_thumb.gif
10.22233/9781910443255/fig26_14.png
26.14
Impression smear from a pustule. (a) Rupture the pustule with a sterile needle. (b) Absorb the contents on to a swab. (c) Gently make a thin impression by rolling the swab on a microscope slide. Too much smearing will rupture the cells.
/content/figure/10.22233/9781910443255.chap26.ch26fig15
26.15
Algorithm for interpreting cutaneous cytology preparations. © 2016 British Small Animal Veterinary Association
10.22233/9781910443255/fig26_15_thumb.gif
10.22233/9781910443255/fig26_15.png
26.15
Algorithm for interpreting cutaneous cytology preparations.
/content/figure/10.22233/9781910443255.chap26.ch26fig16
26.16
Inflammation. (a) Acute inflammation in a sample from a dog with otitis externa; note the preponderance of degenerate neutrophils. The insert shows a close-up of degenerate neutrophils containing phagocytosed rod-shaped bacteria. (Diff-Quik® stain; original magnification X400; inset X1000). (b) Chronic inflammation in a dog with deep pyoderma; there is a mixture of neutrophils and macrophages. (Diff-Quik® stain; original magnification X400) © 2016 British Small Animal Veterinary Association
10.22233/9781910443255/fig26_16_thumb.gif
10.22233/9781910443255/fig26_16.png
26.16
Inflammation. (a) Acute inflammation in a sample from a dog with otitis externa; note the preponderance of degenerate neutrophils. The insert shows a close-up of degenerate neutrophils containing phagocytosed rod-shaped bacteria. (Diff-Quik® stain; original magnification X400; inset X1000). (b) Chronic inflammation in a dog with deep pyoderma; there is a mixture of neutrophils and macrophages. (Diff-Quik® stain; original magnification X400)
/content/figure/10.22233/9781910443255.chap26.ch26fig17
26.17
Neutrophils. (a) Degenerate cells in a staphylococcal pyoderma; note the swollen, fragmented nuclei (karyorrhexis), nuclear rupture and streaming, and swollen cytoplasm. There are numerous bacteria seen associated with neutrophils and extracellularly. (Diff-Quik® stain; original magnification X1000). (b) Non-degenerate neutrophils admixed with squamous epithelial cells; note the shrunken, hypersegmented intact nuclei. (Diff-Quik® stain; original magnification X1000) (b, © Tim Nuttall) © 2016 British Small Animal Veterinary Association
10.22233/9781910443255/fig26_17_thumb.gif
10.22233/9781910443255/fig26_17.png
26.17
Neutrophils. (a) Degenerate cells in a staphylococcal pyoderma; note the swollen, fragmented nuclei (karyorrhexis), nuclear rupture and streaming, and swollen cytoplasm. There are numerous bacteria seen associated with neutrophils and extracellularly. (Diff-Quik® stain; original magnification X1000). (b) Non-degenerate neutrophils admixed with squamous epithelial cells; note the shrunken, hypersegmented intact nuclei. (Diff-Quik® stain; original magnification X1000) (b, © Tim Nuttall)
/content/figure/10.22233/9781910443255.chap26.ch26fig18
26.18
Acanthocytes and neutrophils in a smear from a pustule in a dog with pemphigus foliaceus. (Diff-Quik® stain; original magnification X400) © 2016 British Small Animal Veterinary Association
10.22233/9781910443255/fig26_18_thumb.gif
10.22233/9781910443255/fig26_18.png
26.18
Acanthocytes and neutrophils in a smear from a pustule in a dog with pemphigus foliaceus. (Diff-Quik® stain; original magnification X400)
/content/figure/10.22233/9781910443255.chap26.ch26fig19
26.19
Performing a punch biopsy. (a) Draw a circle around the biopsy site and then bisect the circle with a line in the direction of hair growth. (b) Infiltrate the skin with local anaesthetic, introducing the needle outside the circle to avoid trauma to the biopsy site. (c) Press a 6 mm biopsy punch against the skin and rotate in one direction. (d) Dissect free from the underlying tissues, taking care not to damage the biopsy specimen. (e) Blot any excess blood away using a swab and fix in a 10X volume of 10% neutral buffered formalin. Note the line indicating the direction of hair growth. © 2016 British Small Animal Veterinary Association
10.22233/9781910443255/fig26_19_thumb.gif
10.22233/9781910443255/fig26_19.png
26.19
Performing a punch biopsy. (a) Draw a circle around the biopsy site and then bisect the circle with a line in the direction of hair growth. (b) Infiltrate the skin with local anaesthetic, introducing the needle outside the circle to avoid trauma to the biopsy site. (c) Press a 6 mm biopsy punch against the skin and rotate in one direction. (d) Dissect free from the underlying tissues, taking care not to damage the biopsy specimen. (e) Blot any excess blood away using a swab and fix in a 10X volume of 10% neutral buffered formalin. Note the line indicating the direction of hair growth.
/content/figure/10.22233/9781910443255.chap26.ch26fig20
26.20
Multiple positive reactions to house dust mites and pollens in an atopic Shar Pei. Positive reactions are identified by erythema and swelling. © 2016 British Small Animal Veterinary Association
10.22233/9781910443255/fig26_20_thumb.gif
10.22233/9781910443255/fig26_20.png
26.20
Multiple positive reactions to house dust mites and pollens in an atopic Shar Pei. Positive reactions are identified by erythema and swelling.
/content/figure/10.22233/9781910443255.chap26.ch26fig21
26.21
(a) Schematic representation of a typical ELISA test for allergen-specific serum IgE. The sensitivity and specificity of the test depends on the efficiency with which the IgE detection reagent detects the allergen-bound IgE. (b) Monoclonal anti-IgE antibodies specific for certain IgE epitopes are highly specific (i.e. there are few false positives) but may be less sensitive if they fail to detect allergen-specific IgE without that particular epitope (i.e. there may be more false negatives). Polyclonal antibodies or oligoclonal antibody mixes recognize a greater range of epitopes and may therefore be more sensitive. However, if some epitopes are shared with IgG these tests may be less specific, with more false positive results. © 2016 British Small Animal Veterinary Association
10.22233/9781910443255/fig26_21_thumb.gif
10.22233/9781910443255/fig26_21.png
26.21
(a) Schematic representation of a typical ELISA test for allergen-specific serum IgE. The sensitivity and specificity of the test depends on the efficiency with which the IgE detection reagent detects the allergen-bound IgE. (b) Monoclonal anti-IgE antibodies specific for certain IgE epitopes are highly specific (i.e. there are few false positives) but may be less sensitive if they fail to detect allergen-specific IgE without that particular epitope (i.e. there may be more false negatives). Polyclonal antibodies or oligoclonal antibody mixes recognize a greater range of epitopes and may therefore be more sensitive. However, if some epitopes are shared with IgG these tests may be less specific, with more false positive results.
/content/figure/10.22233/9781910443255.chap26.ch26fig22
26.22
Contact reaction to an adhesive bandage in a dog. © 2016 British Small Animal Veterinary Association
10.22233/9781910443255/fig26_22_thumb.gif
10.22233/9781910443255/fig26_22.png
26.22
Contact reaction to an adhesive bandage in a dog.
/content/figure/10.22233/9781910443255.chap26.ch26fig23
26.23
A normal tympanic membrane seen through a video otoscope. Note the taut and translucent pars tensa (pt), the dorsal, fleshy pars faccida (pf) and the C-shaped manubrium (m) of the malleus. (© Karl Storz Endoscopy UK Ltd, Dundee, UK) © 2016 British Small Animal Veterinary Association
10.22233/9781910443255/fig26_23_thumb.gif
10.22233/9781910443255/fig26_23.png
26.23
A normal tympanic membrane seen through a video otoscope. Note the taut and translucent pars tensa (pt), the dorsal, fleshy pars faccida (pf) and the C-shaped manubrium (m) of the malleus. (© Karl Storz Endoscopy UK Ltd, Dundee, UK)
/content/figure/10.22233/9781910443255.chap26.ch26fig24
26.24
Oval and budding Malassezia yeasts overlying pale-staining, angular keratinocytes. (Diff-Quik® stain; original magnification X400) © 2016 British Small Animal Veterinary Association
10.22233/9781910443255/fig26_24_thumb.gif
10.22233/9781910443255/fig26_24.png
26.24
Oval and budding Malassezia yeasts overlying pale-staining, angular keratinocytes. (Diff-Quik® stain; original magnification X400)
/content/figure/10.22233/9781910443255.chap26.ch26fig26
26.26
(a) Numerous extracellular and intracellular staphylococci, (b) Pseudomonas aeruginosa and degenerate neutrophils. Note the nuclear streaming from ruptured nuclei. (Diff-Quik® stain; original magnification (a) X400, (b) X1000) © 2016 British Small Animal Veterinary Association
10.22233/9781910443255/fig26_26_thumb.gif
10.22233/9781910443255/fig26_26.png
26.26
(a) Numerous extracellular and intracellular staphylococci, (b) Pseudomonas aeruginosa and degenerate neutrophils. Note the nuclear streaming from ruptured nuclei. (Diff-Quik® stain; original magnification (a) X400, (b) X1000)
/content/figure/10.22233/9781910443255.chap26.ch26fig27
26.27
3-year-old crossbred dog exhibiting pruritus and alopecia. © 2016 British Small Animal Veterinary Association
10.22233/9781910443255/fig26_27_thumb.gif
10.22233/9781910443255/fig26_27.png
26.27
3-year-old crossbred dog exhibiting pruritus and alopecia.
/content/figure/10.22233/9781910443255.chap26.ch26fig28
26.28
Close-up of the affected skin on the ventrolateral abdomen. © 2016 British Small Animal Veterinary Association
10.22233/9781910443255/fig26_28_thumb.gif
10.22233/9781910443255/fig26_28.png
26.28
Close-up of the affected skin on the ventrolateral abdomen.
/content/figure/10.22233/9781910443255.chap26.ch26fig29
26.29
Palmar aspect of an affected forefoot. © 2016 British Small Animal Veterinary Association
10.22233/9781910443255/fig26_29_thumb.gif
10.22233/9781910443255/fig26_29.png
26.29
Palmar aspect of an affected forefoot.
/content/figure/10.22233/9781910443255.chap26.ch26fig30
26.30
Adhesive tape cytology from the ventral abdomen. (Modified Wright–Giemsa stain; original magnification X400) © 2016 British Small Animal Veterinary Association
10.22233/9781910443255/fig26_30_thumb.gif
10.22233/9781910443255/fig26_30.png
26.30
Adhesive tape cytology from the ventral abdomen. (Modified Wright–Giemsa stain; original magnification X400)
/content/figure/10.22233/9781910443255.chap26.ch26fig31
26.31
Indirect impression smear cytology from an affected foot. (Modified Wright–Giemsa stain; original magnification X400) © 2016 British Small Animal Veterinary Association
10.22233/9781910443255/fig26_31_thumb.gif
10.22233/9781910443255/fig26_31.png
26.31
Indirect impression smear cytology from an affected foot. (Modified Wright–Giemsa stain; original magnification X400)
/content/figure/10.22233/9781910443255.chap26.ch26fig32
26.32
Stained needle core cytology smear from a popliteal lymph node. (Modified Wright–Giemsa stain; original magnification X400) © 2016 British Small Animal Veterinary Association
10.22233/9781910443255/fig26_32_thumb.gif
10.22233/9781910443255/fig26_32.png
26.32
Stained needle core cytology smear from a popliteal lymph node. (Modified Wright–Giemsa stain; original magnification X400)
/content/figure/10.22233/9781910443255.chap26.ch26fig33
26.33
Hair pluck from ventral neck. (Original magnification X100) © 2016 British Small Animal Veterinary Association
10.22233/9781910443255/fig26_33_thumb.gif
10.22233/9781910443255/fig26_33.png
26.33
Hair pluck from ventral neck. (Original magnification X100)
/content/figure/10.22233/9781910443255.chap26.ch26fig34
26.34
9-year old Bichon Frise exhibiting alopecia. © 2016 British Small Animal Veterinary Association
10.22233/9781910443255/fig26_34_thumb.gif
10.22233/9781910443255/fig26_34.png
26.34
9-year old Bichon Frise exhibiting alopecia.
/content/figure/10.22233/9781910443255.chap26.ch26fig35
26.35
Close-up of the flank skin. © 2016 British Small Animal Veterinary Association
10.22233/9781910443255/fig26_35_thumb.gif
10.22233/9781910443255/fig26_35.png
26.35
Close-up of the flank skin.
/content/figure/10.22233/9781910443255.chap26.ch26fig36
26.36
Close-up of lesional skin from the flank. © 2016 British Small Animal Veterinary Association
10.22233/9781910443255/fig26_36_thumb.gif
10.22233/9781910443255/fig26_36.png
26.36
Close-up of lesional skin from the flank.
More like this
/content/chapter/10.22233/9781910443255.chap26
dcterms_title,dcterms_description
-contentType:Journal
5
5