Integumentary System

Jr / Sr Vet Science

Cancer

•Three types in horses:– 1. Melanoma

–2. Squamos cell carcinoma

–3. Sarcoid

Cancer

• Not much internal organ cancer in horses

• Common: –Sinus tumors

–Intestinal

Cancer Signs

In horses:Nasal dischargeSwelling between eyes or right in front

of an eye. Be careful of diagn. Because could be

a tooth root prob. in an older horse.If antibiotics don’t work for two weeks,

usually a tumor

Cancer Treatment

• Cancer treatment:• Surgical incision through the sinus bone• Only a few vet schools do radiation, they are:

• North Carolina State• Ohio State• Auburn Univ.?• Cost usually @ $2,000-3,000 and 4-5,000

for radiation

Melanoma

• Can occur in dark skinned horses but mostly in gray.

• Over age 15 most common

• Young horses usually higher incidence of malignant

Melanoma• Usually see:

• Under tail, vulva, anus, sheath, or penis. • Lumps, or masses, may be under the skin.• Spreads, check for changes reg.• Earlier they are cut out the less chance of

them metastasizing.• Small surgeries often, better than large

growths.

Melanoma Treatment

• Cimetidine: used for human digestice tract upsets.

• Possible future vaccine

Squamos Cell Carcinoma

• Usually quite visible

• Often appears around genitalia, anus, eyes or eyelids.

• Most common in unpigmented skin.

Sarcoid

Squamous cell carcinoma

NEOPLASIA OF THE EYE AND ASSOCIATED STRUCTURES

An extensive sarcoid involving the majority of the upper eyelid which has penetrated the lid skin. Courtesy of Dr.

Kirk N. Gelatt

NEOPLASIA OF THE EYE AND ASSOCIATED STRUCTURES

Sarcoid of the medial upper eyelid which is still beneath the skin.

Courtesy of Dr. Kirk N. Gelatt

TUMORS OF THE SKIN AND SOFT TISSUES(Tumors of Melanocytic Origin)Malignant melanoma. The flank scent glands on the lateral trunk of the hamster are pigmented glands that are occasional sites of melanoma formation.

Courtesy of Dr. Louise Bauck

Squamos Cell Carcinoma

• Can affect the third eyelid called the nictitating membrane.

• May mean eye removal

• Will save horse

Squamos Cell Carcinoma

• Signs:

–May start as small bump on inside of eyelid, raw surface, runny sore, may get worse quickly.

–This type of cancer spreads more rapidly than melanoma.

Squamous cell carcinoma in a dog

Squamos Cell Carcinoma

• Treatment:– Removal by surgery, burning,

cryosurgery (freezing).

– Can be treated with anti-inflammatory drugs:

–Pyroxicam: prevents recurrence.

–Can cause stomach ulcers, diarrhea from long term use.

Squamos Cell Carcinoma

• Treatment cont.:

• Chemotherapy: Injectable in places like eye where other methods could injure the eye.

• Most difficult: Penis

Squamous cell carcinoma in cow

Sarcoids

• Don’t usually spread internally

• Don’t travel through the blood stream

• If not removed may disable the horse due to size.

Sarcoids

• Signs• Looks like proud flesh

• Warty area

• Weepy and bleeding

• Nasty red lump

Sarcoids

• Two forms:

1. Flat hairless: This form may grow if

irritated

2. Large uncontrolled mass:

Grow in areas that are repeatedly

rubbed or injured.

Sarcoids

• Cause:

• Combination of a virus and genetic susceptibility.

• Different breeds react differently. QH more prone.

TUMORS OF THE SKIN AND SOFT TISSUES(Connective Tissue Tumors)

Fibrosarcoma, parakeet. This mass shows the typical ulcerated surface.

Courtesy of Dr. Louise Bauck

Sarcoids

• Treatment:–Surgical w/ 50% recurrence–Chemo–Lazer–Freezing–Less risk for coming back due to killing

cells underneath. –U of Minn: working with cream that is

currently usd on human genital warts.»Aldara

TUMORS OF THE SKIN AND SOFT TISSUESFibrosarcoma on the right metatarsal of a geriatric

Maine Coon cat.

Courtesy of Dr. Alice Villalobos

• Cutaneous histiocytomas

• These comprise a group of poorly defined skin diseases all characterized by a proliferation of histiocytes (tissue macrophages) in the absence of any known stimulus.

TUMORS OF THE SKIN AND SOFT TISSUES

Multifocal nodules involving the dermis and subcutaneous tissues in a 6-year-

old Boxer.

The lesions responded to treatment but a large mass developed in the

retropharyngeal area 1 month later.

Courtesy of Dr. Alice villalobos

EXUDATIVE EPIDERMITISExudative epidermitis.

This young pig shows the characteristic greasy lesion on the

ventral abdomen. Courtesy of Dr. Louise Bauck

EXUDATIVE EPIDERMITISChronic exudative epidermitis over the entire body in

weaner pig approximately 5 weeks old. Courtesy of Dr.

Ranald D. A. Cameron

PYODERMASuperficial pyoderma, dog.

Courtesy of Dr. Stephen White

Sweet itch, Urticaria

CONTAGIOUS ECTHYMAContagious ecthyma, goat.

Courtesy of Dr. Robert Dunstan

Consists of:

• Skin and appendages:• Hair Beaks

• Skin Wool

• Nails Fur

• Feathers Claws

• Horns

Skin:

• Role in:• Immunology• Waterproofs the body• Prevents fluid loss• Species specific color• Vit. D synthesis

What else is Skin?

• Hair and Nails!!

• Hair: Controls body heat loss and is a

sense receptor.

• Nails: Protect the dorsal surface of the

distal phalanx

Skin

• Covers external surfaces of body

• Composed of epithelial tissue

• Dermatology is the study of Skin

Skin• Three Layers:

1. Epidermis: Outermost, no blood vessels

» Avascular layer» Varies from region to region: Thicker in

areas of greatest exposure ie: foot pads and teats.

» Made of squamous epithelium, flat, plate like arrangement thus called stratified squamous epithelium

Skin

2. Dermis:

» Directly deep to the epidermis

» Also called the corium

» Composed of blood and lymph vessels, nerve fibers and accessory organs of the skin

Skin

• Dermis contains connective tissue which is composed of the following 5 cells:

• Fibroblasts: Produce fiber. • Collagen: Tough, flexible fibrous protein

found in skin, bone, cartilage ligaments and tendons.

• Histiocytes: Phagocytic cells that engulf foreign substances

• Mast cells: Respond to insult by producing and releasing histamine and heparin

• Perception: Ability to recognize sensory stimuli

Skin

3. Subcutaneous layer:

Also called hypodermis

Deep to or under the dermis

Composed of connective tissue

Contains a large amount of fat

Adipocytes: fat cells that produce

lipid

Skin Glands:

Exocrine Glands:

• 1. Sebaceous

• 2. Sweat

Skin• Sebaceous:

• Lubricates Skin• Bacterial growth due to slight acidity.• Secrete oily substance called sebum.• Found in anal sacs, glands that produce musk and circumoral and supracaudal, which cats use to mark their territory when they groom and rub their tail respectively.

Skin

•Sweat Glands:

• Regulate body temp

• Excrete wastes

http://en.wikipedia.org/wiki/Image:Skin.jpg

Sweat ducts can be easily seen.

Do Dogs Sweat?• Dogs have a dermal skin layer: Two types of

glands that produce fluids. • The apocrine glands, which produce sweat in

humans, have two other functions in dogs —• Seal the outer layer of the epidermis • Secrete pheromones that give dogs a distinctive

body odor.• The eccrine glands in the pads of the paws do

produce a watery secretion similar to human perspiration. This secretion leaves damp pawprints behind nervous or stressed canines and may also improve traction for a quick getaway.

Glands

• Eccrine glands:

•Produce and secrete water, salt and waste

•Tiny, Coiled

Glands

• Apocrine:–Produce and secrete a strong smelling substance to the hair follicle.

–

Hair

• Rod like fibers

• Made of dead protein cells filed with keratin

Hair• Composed of:

–Cuticle: One cell layer, scaly–Cortex: Main component,

several layers thick, coat color

–Medulla: Innermost component

Hair

• Follicles:– Sacs that hold hair fibers

– Arrector pili: Tiny muscle that causes hair shaft to stand in response to cold or stress.

– Piloerection:

– Condition of hair standing up straight

Nails, Claws and Hooves

• Distal phalanx is covered by nails.

• All have a wall, sole and pad

Nails, Claws and Hooves

• Walls: Located dorsal and lateral to distal phalanx

• Sole: Ventral to the distal phalanx and usually flaky

Nails, Claws and Hooves

• Foot pads, also called tori:• Cushioning• Protection for bones of foot• Thick and composed of keratinized

epithelium• Subcutaneous layer containing large

numbers of adipose cells and elastic connective tissue.

• Sweat glands are found in most mammal foot pads

Antlers and Horns

• Horns:• Protective structures• Horns are permanent• Grow continuously• Orig. from keratinized epithelium• From frontal skull bones• Cornification: conver. from epithelium to

keratinized cells

Antlers and Horns

• Antlers:• Not permanent• Shed and regrown annually• Initially covered with skin called velvet• Rubbed off after skin dies• Bone exposed after, lose blood supply and

antlers are shed.

The End