Veterinary Dermatology & Antimicrobial Drugs: Key Concepts and Treatments

Dermatologic conditions?

Conditions related to the skin that are common in veterinary practice.

Epidermal turnover rate?

The time it takes for cells of the deepest part of the epidermis to reach the outermost part, approximately 3 weeks.

Functions of skin?

Barrier to physical and chemical insults, sense (hot, cold, pain), body temperature regulation, immunologic defense, and reservoir for electrolytes.

Piloerection?

The process of hair standing on end, caused by arrector pili muscles associated with hair follicles.

Comedome?

A blackhead that results when a hair follicle loses hair and becomes plugged with sebaceous secretions and keratin.

Hair cycle control factors?

Factors that control the hair cycle include day-night length (photoperiod), environmental temperature, hormones, and nutritional status.

Aluminum acetate solution (Burow's solution)?

An astringent solution and an antipruritic agent useful for treating superficial skin problems.

Colloidal Oatmeal?

An anti-inflammatory and antipruritic agent, safe for use in products like DermAllay Oatmeal Spray.

Essential Fatty Acids (EFA)?

Used for antipruritic and anti-inflammatory properties, helping to create healthy skin.

Phytosphingosine?

Useful in treating localized inflammatory and pruritic cases such as Atopy.

Topical Corticosteroids?

Used for localized itching or inflammatory conditions; should not be used in pregnant animals.

Hydrocortisone?

Useful in treating localized pruritis and inflammatory conditions.

Triamcinolone Acetonide?

Useful in the adjunct treatment of pruritis, best for small lesions needing short-term treatment.

Gels?

Used for treating pyodermas, chin acnes, and localized Demodex lesions.

Shampoos?

Used for pyodermas, furunculosis, generalized demodicosis, and Schnauzer comedo syndrome.

OxyDex Gel?

An example of a gel used for treating skin conditions.

Benzoyl Peroxide Shampoo?

An example of a shampoo used for treating skin conditions.

SulfOxyDex Shampoo?

An example of a shampoo used for treating skin conditions.

Clindamycin?

Used in the treatment of feline acne.

ClinzGard?

May be used in the treatment of anal sac and other abscesses and puncture wounds.

Clindagel?

An example of a topical antimicrobial.

Gentamicin Sulfate?

Used to treat primary or secondary bacterial infections and can be used to treat 'hot spots'.

MoMetaMax Otic Suspension?

An example of an otic treatment.

Mupirocin?

FDA-approved for treating pyoderma, interdigital cysts, draining tracts, acne, and pressure point pyodermas.

Nitrofurazone?

Used to treat/prevent superficial infections.

Silver Sulfadiazine?

Used for second and third degree burns and to treat skin infections caused by Pseudomonas spp.

Acetic Acid/Boric Acid?

Used to treat skin infections caused by Staphylococcus spp., Pseudomonas spp., and Malassezia.

Chlorhexidine?

May be used on patients unable to tolerate benzoyl peroxide and can remain on the skin after rinsing.

Ketoconazole?

Used against dermatophytes and yeast.

Lime Sulfur?

Used in the treatment of dermatophytosis, Malassezia, Cheyletiellosis, chiggers, and mange.

Miconazole?

Used to treat dermatophytes and yeast.

Nystatin?

Used to treat topical yeast lesions.

Selenium Sulfide?

Used to treat seborrheic disorders and Malassezia.

Salicylic Acid?

Used to treat seborrheic disorders with antipuritic, antibacterial, keratoplastic, and keratolytic actions.

Amitraz?

Used in the treatment of generalized demodicosis.

Fipronil?

Used to treat fleas, ticks, and chewing lice, also chiggers and sarcoptic mange.

Imidacloprid?

Used to treat fleas in dogs and cats.

Permethrin?

Used as a flea treatment but is toxic to cats.

What are the two main categories of antimicrobial drugs based on their action?

Bactericidal (kill bacteria) and bacteriostatic (inhibit bacterial growth).

What is the Minimum Inhibitory Concentration (MIC)?

The lowest concentration of a drug that macroscopic inhibits the growth of an organism.

What is a common side effect of aminoglycosides?

Nephrotoxicity and ototoxicity.

Which aminoglycoside is FDA-approved for use in dogs?

Amikacin.

What is the mechanism of action for carbapenems?

They inhibit bacterial wall synthesis and are usually bactericidal.

What are the adverse effects associated with imipenem-cilastatin?

Gastrointestinal issues, CNS toxicity, pruritis, anaphylaxis, and seizures if given too quickly.

What distinguishes first-generation cephalosporins from later generations?

First-generation cephalosporins are mainly active against gram-positive bacteria.

What is CEFOVECIN (Convenia) used for?

Treatment of skin infections in dogs and cats, with effects lasting 2 weeks.

How do macrolides inhibit bacterial growth?

By penetrating the cell wall and binding to the 50S ribosome subunits.

Which macrolide is used to treat Bordetella in canines?

Azithromycin.

What is the action of penicillins?

They are bactericidal and inhibit mucopeptide synthesis in the cell wall.

What is the purpose of clavulanic acid in amoxicillin/clavulanate?

It irreversibly bonds to beta-lactamases and penicillinases produced by bacteria.

What is a significant side effect of tetracyclines in young animals?

Yellow to brown discoloration of bones and teeth.

What is the primary use of doxycycline in small animals?

Treatment of Borrelia burgdorferi, leptospirosis, and other infections.

What are lincosamides effective against?

Anaerobes, gram-positive aerobic cocci, and Toxoplasma parasites.

What is a critical contraindication for using quinolones?

They are contraindicated in growing animals due to potential cartilage abnormalities.

What is the mechanism of action for sulfonamides?

They are bacteriostatic agents that prevent bacterial replication.

What is the primary use of metronidazole?

Treatment of Giardia in dogs and cats, and anaerobic infections in horses.

What is the main use of rifampin?

Treatment of Rhodococcus equi in young horses.

What is the mechanism of action for antifungal agents like amphotericin B?

Systemic antifungal medication that must be given IV through a dilution.

What are some common adverse effects of ketoconazole?

GI disturbances and hepatic toxicity.

Which antiviral agent is used to treat feline herpes?

Famciclovir.

What is the role of disinfectants and antiseptics in veterinary medicine?

To reduce or eliminate pathogens on surfaces and skin.

Desquamation?

Continual shedding of skin cells.

Epidermis?

Normal microorganisms that help prevent overgrowth of pathogenic microorganisms.

Dermis?

Thick layer that is made up of collagen fibers, blood vessels, nerves, lymphatics, hair follicles, sebaceous glands, & sweat glands.

Hypodermis?

Deepest layer composed of fat & connective tissues, functions to provide padding & insulation & stores energy.

Eccrine gland?

One type of sweat gland found only in footpads, & plays a role in body temp regulation.

Functions of the skin?

Barrier to physical and chemical insults, Sense (hot, cold, pain, etc.), Body temperature regulation, Immunologic defense, Reservoir for electrolytes.

Hair growth location?

From follicles in the dermis.

Hairs per follicle?

Cats & dogs = multiple, humans = only 1.

Infections in hair follicles?

Bacterial, fungal, & demodectic.

Comedones formation?

If the hair follicle loses hair & becomes plugged with sebaceous secretions and keratin.

Hair growth stages?

Anagen (growth), telogen (rest), & catagen (intermediate).

Hair cycle control?

Day-night length (aka photoperiod), environmental temperature, hormones, & nutritional status.

Excessive shedding causes?

General illness, skin disorders, poor nutrition, overbathing, & stress.

Wound?

Created when an insult, either purposeful (such as surgery) or incidental (such as trauma), disrupts the normal integrity of the tissue.

Stages of wound healing?

Inflammatory, debridement, repair, & maturation.

Inflammatory stage?

First stage of wound healing, that usually begins with hemorrhage & is limited by vessel contraction & constrictions.

Debridement stage?

Second stage of wound healing, begins about 6 hours after injury & is facilitated by the appearance of neutrophils & monocytes that migrate to the wound.

Repair stage?

Third stage of wound healing, formation of a blood clot, is usually active for 3 to 5 days post injury, & form granulation tissue.

Repair stage specifics?

Fibroblasts produce collagen & connective tissue proteins, then capillaries infiltrate the wound to provide blood supply & oxygen, forming granulation tissue, where epithelial cells proliferate beneath the scab, & the wound begins to contract.

Maturation stage?

Final stage of wound healing, period of remodeling.

Granulation tissue?

Both have healthy beds of granulation tissue & is part of normal wound healing.

Proud flesh?

Granulation tissue called in horses.

Burrow's solution?

A non-steroidal, astringent, & antipruritic agent.

Aluminum acetate solution?

Useful for the treatment of superficial skin problems (such as skin fold dermatitis).

Aluminum acetate solution precautions?

Avoid contact with eyes & wear gloves or wash hands after administration.

Colloidal oatmeal?

A non-steroidal, anti-inflammatory, & anti-pruritic agent that helps create healthy skin.

Diphenhydramine HCl?

Aka Benadryl; non-steroidal, antihistamine (also anti-inflammatory & anti-pruritic).

Diphenhydramine HCl application caution?

Should not be applied within 2 weeks before allergy testing.

Lidocaine or Lidocaine & prilocaine combo?

Non-steroidal anesthetics that also help with pruritus; eg. EMLA Cream.

EMLA Cream usage?

Can be used before IV catheter placement to ease discomfort.

Phytophingosine?

May cause skin redness & irritation.

Pramoxine HCl?

Non-steroidal used in equine patients for overexertion, soreness, or stiffness.

Phenol or Menthol or Camphor?

Used in conjunction with other treatments for localized itching or inflammatory conditions; eg. Cool Gel, Scarlet Oil.

Topical corticosteroids?

Do not use in pregnant animals & do not allow the animal to lick the application site for at least 30 minutes.

Diphenhydramine & topical Corticosteroids caution?

Should not be used within 2 weeks before allergy testing.

Topical corticosteroid drugs?

Otomax, MalOtic, GentaSpray, Betagen, Betamethasone, & Lotrisone.

Hydrocortisone (topical)?

Useful in treating itching & inflamed skin that may be associated with bacterial or yeast infections; eg. Zymox, Malacetic wipes, Cortispray, & Chlorhexidine 4% HC shampoo.

Mometasone Furoate?

May delay wound healing when used for more than 7 days; eg. MoMetaMax Otic.

Triamcinolone acetonide?

Topical corticosteroid useful in the adjunct treatment of pruritus, & is best suited for small lesions that only need to be treated for a short amount of time; eg. Genesis spray, Derma-Vet, Panalog, Animax, Quadritop, & Dermalone.