SYMPTOM
Non-healing wounds
Owners may observe non-healing wounds in their pet, which can present in various ways depending on the underlying cause.
Metabolic
Conditions such as diabetes mellitus or hyperadrenocorticism can impair the body's capacity to repair tissue, slowing collagen formation and reducing the efficiency of immune cells involved in wound closure. Nutritional deficiencies may similarly compromise the availability of substrates needed for healing.
Immune-mediated
Disorders in which the immune system is overactive or misdirected can disrupt normal tissue repair, sometimes creating inflammation that perpetuates rather than resolves. Conversely, immunosuppressive conditions or treatments may leave wounds vulnerable to infection and delay healing through reduced cellular defence.
Infectious
Bacterial, fungal, or protozoal colonisation of a wound can sustain inflammation and prevent the progression from one phase of healing to the next. Some organisms produce enzymes or biofilms that actively resist clearance and tissue closure.
Neoplastic
Tumours arising within or adjacent to wounded tissue can disrupt the local architecture and blood supply, interfering with the normal sequence of repair. In some cases, malignant cells may directly invade healing tissue or produce factors that inhibit closure.
Vascular
Inadequate blood flow, whether from generalised circulatory compromise or localised vessel damage, can deprive tissue of the oxygen and nutrients required for effective healing. Poor venous drainage may lead to oedema that further impairs the local environment.
Behavioural
Persistent licking, chewing, or scratching can mechanically disrupt the early stages of wound repair, preventing the formation of stable tissue and reintroducing surface contamination. This behaviour may be driven by discomfort, habit, or responses to the wound itself.
Why timing matters
Early observation
When a wound is first observed not to be healing as might be expected, the picture often reflects either the nature of the original injury or the immediate local environment. Minor wounds in healthy animals typically show signs of contraction and surface coverage within days, so early stalling may indicate contamination, ongoing trauma, or an underlying factor affecting tissue repair. The initial phase offers a window in which local factors tend to dominate.
Later presentation
If healing remains stalled over weeks, the pattern often shifts towards consideration of systemic influences—metabolic, immune, or nutritional conditions that may not have been apparent at the outset. Chronic wounds can develop a persistent inflammatory state in which normal repair mechanisms become dysregulated, sometimes establishing a cycle that resists simple intervention. The longer a wound remains open, the more likely it is that secondary infection or tissue changes have become part of the picture.
Wounds may show initial improvement before stalling, or they may fail to progress from the start, and these trajectories can suggest different underlying mechanisms. Some animals experience fluctuating patterns in which partial healing is followed by breakdown, often reflecting intermittent interference—mechanical, behavioural, or physiological. Individual variation in healing capacity is influenced by age, general health, and the specific tissue involved, and these factors can shape the timeline in ways that are difficult to predict for any single animal.
Conditions commonly associated
Diabetes Mellitus in Dogs
Diabetes mellitus can impair the body's ability to heal wounds through several mechanisms, including reduced blood flow to peripheral tissues, altered immune cell function, and the effects of persistently elevated blood glucose on tissue repair. Wounds in diabetic dogs may heal more slowly and can be more prone to secondary infection.
Cushings Disease in Dogs
Cushing's disease causes chronic elevation of cortisol, which suppresses immune function and interferes with collagen production and tissue repair. Skin in affected dogs often becomes thin and fragile, and wounds that would typically heal in a predictable timeframe may remain open or break down repeatedly.
Osteomyelitis
Osteomyelitis involves infection within bone tissue, and when it develops near the skin surface or follows a penetrating injury, it can prevent overlying wounds from healing. The persistent infection and inflammation disrupt the normal stages of tissue repair, and the wound may continue to drain or fail to close despite initial treatment.
Transitional Cell Carcinoma
Transitional cell carcinoma can occasionally extend to involve surrounding soft tissues or skin, particularly in the perineal region, and tumour-associated tissue may ulcerate or form wounds that do not follow the expected course of healing. The abnormal tissue structure and local immune environment can interfere with repair processes.
Alabama Rot (CRGV)
Alabama rot typically presents with skin lesions—often on the lower limbs or face—that begin as localised areas of redness or swelling and may progress to ulceration. The underlying damage to small blood vessels can prevent these wounds from healing normally, and in some cases the condition progresses to affect the kidneys.
When to explore further
If a wound shows no measurable change in size or character over a period of two to three weeks, despite basic wound care, this may warrant a closer look at both local and systemic factors.
If the wound is accompanied by changes in drinking, urination, appetite, or weight, these patterns can sometimes reflect metabolic or endocrine conditions that affect healing capacity.
If there is progressive swelling, discharge with an unusual odour, or darkening of surrounding tissue, this may suggest infection or compromise of local blood supply.
If the animal is persistently interfering with the wound despite attempts to limit access, understanding the source of that behaviour can be part of addressing the underlying problem.
If the wound appeared minor initially but has expanded or deepened over time, this evolution may reflect an underlying process that was not evident at the outset.
Non-healing wounds gain meaning through the broader context—what else is happening with the animal, how the wound originated, and how it has changed over time. These observations, alongside physical examination and sometimes laboratory or tissue sampling, help build a picture of what may be influencing repair. Conversations that include the full history and any accompanying signs tend to be the most informative, particularly when a wound has not responded to straightforward measures.
Last reviewed: 24 April 2026 · Dr Alastair Greenway MRCVS