NAVLE Integumentary

Feline Decubitus Ulcer Study Guide

📅 March 28, 2026 ⏱ 25 min read

Overview and Clinical Importance

Decubitus ulcers (also known as pressure ulcers, pressure sores, or bed sores) are localized injuries to the skin and underlying tissue resulting from prolonged pressure, typically over bony prominences. In feline patients, these lesions are most commonly encountered in recumbent, paralyzed, or critically ill cats unable to reposition themselves. Understanding the pathophysiology, staging, prevention, and treatment is essential for the NAVLE.

While decubitus ulcers are more commonly tested in canine contexts due to higher incidence in large breed dogs, feline patients present unique challenges due to their smaller size, thinner skin, and tendency to hide illness. Cats recovering from spinal trauma, orthopedic surgery, or systemic diseases are particularly at risk.

High-YieldPrevention is always superior to treatment for decubitus ulcers. NAVLE questions often focus on identifying risk factors, implementing preventive measures, and recognizing early-stage lesions before progression.

Layer	Clinical Significance in Pressure Injuries
Epidermis	Outermost protective layer; first to show pressure damage (erythema, blister). Avascular - relies on diffusion from dermis.
Dermis	Contains blood vessels, nerves, hair follicles. Pressure-induced ischemia begins here. Stage 2 ulcers involve partial dermis loss.
Hypodermis	Subcutaneous fat providing cushioning. Stage 3 ulcers extend into this layer. Cats with poor body condition have reduced protection.
Fascia/Muscle/Bone	Stage 4 ulcers involve these deep structures. Osteomyelitis is a severe complication when bone is exposed.

Anatomy and Pathophysiology

Skin Anatomy Review

Understanding skin structure is fundamental to appreciating the progression of pressure injuries:

Pathophysiology of Pressure Injury

Decubitus ulcer formation is multifactorial but follows a common pathway to ischemia and necrosis:

Primary Mechanism: Pressure-Induced Ischemia

Arterial capillary pressure: External pressure exceeding 32 mmHg impedes arterial blood flow
Venous capillary closing pressure: Pressure greater than 8-12 mmHg impairs venous return
Sustained pressure above these thresholds leads to tissue hypoxia, accumulation of metabolic waste products, and cellular death
Ischemia-reperfusion injury: When pressure is relieved, reperfusion generates reactive oxygen species (ROS), causing additional cellular damage

NAVLE TipMuscle tissue is MORE susceptible to pressure damage than skin. This explains the "tip of the iceberg" phenomenon where visible skin damage may mask much deeper underlying tissue destruction.

Contributing Factors

Factor	Mechanism	Clinical Relevance
Shear Force	Parallel forces cause tissue layers to slide, stretching blood vessels	Occurs when patient slides down in cage or during repositioning
Friction	Mechanical abrasion damages epidermis; increases susceptibility	Rough bedding, improper patient handling during turning
Moisture	Softens/macerates skin, reducing tensile strength	Urine/fecal soiling, wound exudate
Temperature	Elevated temperature increases metabolic demand	Heating pads can cause burns in immobile patients

Risk Factors in Feline Patients

Intrinsic (Patient-Related) Factors

Immobility/Recumbency: Paralysis (IVDD, FCE, spinal trauma), severe weakness, prolonged anesthesia, coma
Poor Nutritional Status: Hypoproteinemia, vitamin deficiencies (A, C, zinc), cachexia
Altered Sensory Perception: Neurological conditions preventing patient from feeling discomfort
Circulatory Compromise: Cardiovascular disease, hypotension, anemia, diabetes mellitus
Body Condition: Both obesity (increased pressure) and emaciation (reduced cushioning) increase risk
Age: Geriatric cats have thinner, less elastic skin with reduced subcutaneous fat
Incontinence: Urinary or fecal soiling leads to skin maceration and infection risk

Extrinsic (External) Factors

Inadequate bedding or support surface
Infrequent repositioning (greater than 4 hours in same position)
Improper bandaging or cast application causing localized pressure
Medical devices (catheters, oxygen masks) creating pressure points

Common Anatomical Locations in Cats

Exam Focus: The greater trochanter is the most commonly affected site in laterally recumbent patients. Research shows that the scapulohumeral articulation, greater trochanter, and 13th rib are the most consistent high-pressure zones in lateral recumbency.

Position	High-Risk Areas	Clinical Notes
Lateral Recumbency	Greater trochanter (most common), scapulohumeral joint, lateral malleolus, 13th rib, olecranon	Alternate sides every 2-4 hours; pad bony prominences
Sternal Recumbency	Sternum, point of shoulder, carpal joints, chin/mandible	Preferred position for feeding; reduces aspiration risk
Dorsal Recumbency	Sacrum, spinous processes, occiput, calcaneus	Less common in cats; primarily during surgery/recovery

Staging of Decubitus Ulcers

The National Pressure Injury Advisory Panel (NPIAP) staging system classifies pressure injuries based on tissue depth and appearance. This system guides treatment decisions.

Stage	Description	Clinical Findings
Stage 1	Non-blanchable erythema of intact skin	Skin intact; localized redness that does not blanch; area may be painful, firm, soft, warmer or cooler. Difficult to detect in darkly pigmented skin.
Stage 2	Partial-thickness skin loss with exposed dermis	Shallow open ulcer with red-pink wound bed; no slough. May present as intact or ruptured blister.
Stage 3	Full-thickness skin loss	Adipose visible; granulation tissue and rolled wound edges often present. Bone/tendon NOT visible. May include undermining.
Stage 4	Full-thickness skin and tissue loss	Exposed or palpable fascia, muscle, tendon, ligament, cartilage, or bone. Risk of osteomyelitis.
Unstageable	Obscured full-thickness loss	Wound bed covered by slough or eschar preventing depth assessment. Will be Stage 3 or 4 once debrided.

Clinical Diagnosis

Clinical Signs

Early Signs (Stage 1):

Localized hair loss over bony prominences
Hyperemia that does not blanch with digital pressure
Skin may feel warmer, cooler, firmer, or softer than surrounding tissue
Easily epilated hair when parted
Patient may lick, chew, or guard the area (if sensation present)

Progressive Signs (Stage 2-4):

Open wounds ranging from shallow ulcers to deep craters
Serosanguinous to purulent discharge
Necrotic tissue (eschar - black/brown; slough - yellow/tan)
Foul odor indicates bacterial infection
Systemic signs if infected: fever, lethargy, anorexia, leukocytosis

Stage	Approach	Interventions
Stage 1	Conservative - relieve pressure and prevent progression	Strict repositioning, padded bedding, moisture barriers, transparent film dressing, offload affected area
Stage 2	Wound care with moist healing environment	Gentle saline cleansing, hydrocolloid or foam dressing, topical antimicrobials if colonized, E-collar if needed
Stage 3	Debridement + advanced wound care	Surgical/mechanical debridement, honey/sugar dressings, alginate for exudative wounds, culture if infected, systemic antibiotics if cellulitis
Stage 4	Surgical intervention often required	Extensive debridement, negative pressure wound therapy, flap reconstruction, rule out osteomyelitis, long-term antibiotics if bone involved

Prevention Strategies

Prevention is the cornerstone of decubitus ulcer management. Implement these evidence-based strategies for all at-risk feline patients:

Pressure Redistribution

Repositioning Protocol

Frequency: Turn patient every 2-4 hours
Positions: Rotate between left lateral, right lateral, and sternal recumbency
Documentation: Record position, time, and skin assessment on treatment sheet
Nighttime: Turning schedule must continue overnight - decubitus ulcers can develop within hours

Support Surfaces and Bedding

Memory foam: Distributes pressure more evenly; convoluted "egg-crate" foam is effective
Fleece/sheepskin: Provides soft surface and wicks moisture away from skin
Padding prominences: Use foam or rolled towels to offload pressure points
Avoid: Donut-shaped cushions (can concentrate pressure at edges)

High-YieldSimple test for adequate padding: if your knees hurt when kneeling on the bedding, the patient needs more cushioning. Layer blankets on top of orthopedic beds for easy cleaning.

Skin Care and Hygiene

Keep skin clean and dry: Wash soiled skin with mild soap and water, dry thoroughly
Moisture barriers: Apply barrier cream to perineal area for incontinent patients
Inspect skin frequently: Every 2 hours, part hair over bony prominences to check for erythema
Change bedding immediately: When soiled with urine, feces, or wound exudate

Agent	Mechanism/Benefits	Notes
Medical-Grade Honey	High osmolality draws fluid, acidic pH inhibits bacteria, methylglyoxal provides antimicrobial activity	Use in inflammatory phase; discontinue once granulation tissue present
Sugar	Hyperosmotic effect reduces edema, inhibits bacterial growth	Apply 1 cm thick layer; cover with absorbent dressing. Inexpensive alternative to honey.
Silver Sulfadiazine	Broad-spectrum antimicrobial including Pseudomonas; bactericidal	Apply thin layer on non-adherent dressing. Discontinue once clean granulation bed.
Calcium Alginate	Absorbs exudate, forms gel maintaining moist environment, hemostatic	Best for exudative wounds. Can leave in place 3-7 days.

Treatment by Stage

Topical Agents and Dressings

NAVLE TipHoney-treated wounds showed bacterial elimination within 7 days versus 32+ days with silver sulfadiazine in clinical studies. Honey is particularly effective for infected wounds and those with necrotic tissue.

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