SYMPTOM
Recurrent infections
Owners may observe recurrent infections in their pet.
Various conditions
This symptom can occur in multiple conditions and warrants further assessment.
Retroviral Immunosuppression
Feline immunodeficiency virus and feline leukaemia virus both weaken the immune system's ability to clear routine pathogens, leaving affected cats prone to repeated skin, respiratory, or oral infections. FIV is most often transmitted through bite wounds, so outdoor, unneutered male cats that roam and fight carry a higher exposure risk. Infections in these cats tend to respond to treatment initially but recur once the course finishes.
Endocrine Disease
Diabetes mellitus alters glucose availability in tissues and impairs white blood cell function, creating conditions that favour recurrent bacterial and fungal infections, particularly of the skin and urinary tract. Overweight, middle-aged to older cats are most commonly affected. Infections in a diabetic cat often improve only once blood glucose control is achieved alongside treatment of the infection itself.
Chronic Allergic Skin Disease
Atopic dermatitis disrupts the normal skin barrier, allowing resident bacteria and yeast to overgrow and cause repeated superficial skin infections in the same areas, especially the face, ears, and ventral abdomen. Cats with this pattern usually show intermittent itching and overgrooming between infection episodes. Onset is typically in young to middle-aged cats, and while some cases follow a seasonal pattern, many affected cats show signs all year round.
Latent Viral Reactivation
Many cats carry feline herpesvirus from kittenhood in a dormant state, and stress, boarding, or concurrent illness can reactivate it, producing recurring bouts of sneezing, ocular discharge, or conjunctivitis. This pattern is common in cats from multi-cat households or rescue backgrounds and reflects a normal feature of herpesvirus biology rather than a genuinely new infection each time. Episodes usually settle on their own within one to two weeks.
Anatomical Predisposition
Breed conformation, such as the narrowed ear canals of some pedigree cats or the deep facial skin folds of flat-faced breeds, creates pockets where moisture and debris accumulate, favouring recurrent otitis externa or localised skin infection. This structural tendency does not change over a cat's lifetime, so the same site tends to flare repeatedly. Regular hygiene routines usually reduce, though do not eliminate, the frequency of episodes.
Why timing matters
Early observation
Early recognition allows prompt assessment and intervention if needed.
Later presentation
Persistent or worsening signs may indicate progression requiring attention.
The significance of this symptom depends on its context, duration, and associated findings.
Conditions commonly associated
Feline Immunodeficiency Virus (FIV)
Increased susceptibility to infections is a hallmark of immunodeficiency when it develops.
Cushings Disease in Dogs
Excess cortisol production in Cushing's disease can suppress normal immune function, rendering dogs more susceptible to bacterial skin infections, urinary tract infections, and other recurring infectious processes. The metabolic and immune changes associated with this hormonal imbalance often mean that infections take longer to resolve and may return after treatment.
Diabetes Mellitus in Dogs
Diabetes mellitus in dogs can impair white blood cell function and alter the tissue environment in ways that favour bacterial growth, particularly in the urinary tract and skin. Recurrent urinary tract infections and skin infections are commonly observed in diabetic dogs, particularly when blood glucose control is suboptimal.
Atopic Dermatitis in Dogs
Atopic dermatitis involves chronic inflammation and disruption of the skin barrier, creating an environment where bacterial and yeast infections can establish more readily. Secondary skin infections in atopic dogs may recur frequently, often coinciding with flare-ups of the underlying allergic condition.
Otitis Externa in Dogs
Otitis externa often involves underlying factors such as allergies, anatomical features, or moisture retention that predispose the ear canal to repeated episodes of bacterial or yeast overgrowth. Dogs with recurrent ear infections may have one or more persistent contributing factors that allow the condition to return despite treatment of individual episodes.
Colour Dilution Alopecia
The fragile hair follicles and altered skin barrier make the affected areas more prone to low-grade bacterial folliculitis, which can return even after treatment.
When to explore further
When the symptom is persistent or worsening
When other signs are present alongside
When daily activities or quality of life are affected
When there is uncertainty about the cause
Noting when this symptom occurs, any triggers, and how it changes over time can provide useful information for veterinary discussions.
Last reviewed: 24 April 2026 · Dr Alastair Greenway MRCVS