Assistance animals are susceptible to the same diseases and health conditions as any other companion animal. However, because they undertake demanding physical and cognitive roles while accompanying their handlers into a wide variety of public environments, even relatively minor health conditions may have a significant impact on their welfare, performance and ability to work safely.

Many diseases develop gradually and initially present with subtle changes in behaviour, activity levels or task performance rather than obvious clinical signs. An assistance animal may appear less enthusiastic during training, tire more quickly on familiar routes or become reluctant to perform previously well-established tasks before more recognisable signs of illness emerge. Occupational therapists, who regularly observe animals in functional contexts, are therefore well placed to identify early changes that warrant veterinary assessment.

This section provides an overview of common health conditions affecting assistance animals. It is not intended to enable occupational therapists to diagnose disease but rather to develop awareness of common presentations, understand how these conditions may influence occupational performance and recognise when referral to a veterinarian is appropriate.

Skin Conditions

The skin is the body’s largest organ and provides an essential protective barrier against injury, infection and environmental hazards. Healthy skin also contributes to temperature regulation, sensory perception and immune function.

Skin disorders are among the most common reasons companion animals are presented to veterinarians. Allergic skin disease, bacterial infections, fungal infections and parasite infestations may all cause discomfort that affects an assistance animal’s ability to concentrate and work effectively.

Animals experiencing chronic itching often become distracted, restless or irritable. Repeated scratching, licking or chewing may result in secondary skin infections, hair loss and significant discomfort. Occupational therapists should appreciate that behavioural changes associated with chronic skin disease may reflect pain or irritation rather than poor training or reduced motivation.

Regular grooming, parasite prevention, prompt treatment of skin wounds and routine veterinary care all contribute to maintaining healthy skin.

Ear Disease

Healthy hearing is essential for many assistance animals, particularly those that rely on verbal cues or environmental sound awareness. Ear disease can impair hearing, cause pain and alter behaviour.

Otitis externa, or inflammation of the external ear canal, is one of the most frequently diagnosed ear conditions in dogs. Allergies, moisture, parasites and bacterial or yeast infections commonly contribute to its development.

Affected animals may shake their heads frequently, scratch at their ears, display sensitivity around the head or produce an unpleasant odour from the ears. Chronic ear disease may eventually impair hearing if left untreated.

Because some assistance tasks rely heavily on auditory information, even mild hearing impairment may influence occupational performance and should prompt veterinary assessment.

Eye Conditions

Vision plays an important role in navigation, obstacle avoidance and environmental awareness. Although some assistance animals can continue working successfully with visual impairment depending on their role, many tasks require normal visual function.

Common eye conditions include conjunctivitis, corneal ulcers, cataracts, glaucoma and progressive retinal degeneration. Clinical signs may include squinting, excessive tearing, redness, cloudiness of the eye, discharge or apparent difficulty navigating familiar environments.

Eye injuries should always be treated as veterinary emergencies because delays in treatment may result in permanent vision loss. Occupational therapists should encourage immediate veterinary assessment whenever ocular abnormalities are observed.

Dental Disease

Oral health is often overlooked despite its importance to an assistance animal’s overall wellbeing. Dental disease is one of the most prevalent chronic conditions affecting adult dogs and cats, with periodontal disease becoming increasingly common as animals age.

Pain associated with dental disease may significantly reduce quality of life while remaining difficult to detect. Animals may continue eating despite severe oral pain, masking the severity of disease.

Clinical signs may include bad breath, difficulty chewing, dropping food, excessive salivation, facial swelling or reluctance to hold or retrieve objects. Because many assistance animals perform retrieval tasks, oral pain may directly affect occupational performance.

Routine dental examinations, appropriate dental hygiene and professional veterinary dental care play important roles in maintaining long-term oral health.

Obesity

Obesity is one of the most common preventable health conditions affecting companion animals and has significant implications for assistance animal welfare.

Excess body weight increases stress on joints, reduces exercise tolerance, impairs cardiovascular fitness and increases the risk of osteoarthritis, diabetes mellitus and reduced lifespan. Obesity may also compromise an assistance animal’s ability to perform physically demanding tasks safely.

Maintaining an ideal body condition through appropriate nutrition, portion control and regular exercise is one of the most effective strategies for promoting long-term working longevity.

Occupational therapists should encourage healthy lifestyle practices for both handlers and assistance animals, recognising that daily routines often influence the health of both members of the partnership.

Arthritis and Chronic Pain

Osteoarthritis has been discussed previously within the musculoskeletal system but warrants further emphasis because of its high prevalence in ageing working animals.

Chronic pain frequently develops gradually and may initially present as subtle behavioural changes rather than obvious lameness. Reduced willingness to work, slower movement, difficulty rising, reluctance to jump into vehicles or decreased enthusiasm during training may all indicate chronic discomfort.

Modern veterinary pain management adopts a multimodal approach incorporating medication, weight management, rehabilitation, exercise modification and environmental adaptations. Early intervention improves both welfare and functional outcomes.

Occupational therapists should remain alert to changes in functional performance that may indicate chronic pain and facilitate appropriate veterinary referral.

Cancer

Cancer is increasingly common in ageing companion animals and represents one of the leading causes of retirement and death in older assistance animals.

Many forms of cancer are treatable, particularly when detected early. Depending on the tumour type, treatment may include surgery, chemotherapy, radiation therapy or palliative care.

Early warning signs include unexplained weight loss, persistent swellings, wounds that fail to heal, chronic coughing, reduced appetite, lethargy or changes in behaviour.

Occupational therapists should recognise that an assistance animal undergoing cancer treatment may require temporary workload modification, extended recovery periods or eventual retirement depending on prognosis and quality of life.

Infectious Diseases

Despite routine vaccination and preventative healthcare, assistance animals remain susceptible to infectious diseases caused by viruses, bacteria, fungi and other microorganisms.

Common infectious diseases affecting dogs include canine parvovirus, canine distemper, canine infectious respiratory disease complex and leptospirosis, while cats may develop conditions such as feline calicivirus, feline herpesvirus and feline panleukopenia.

Vaccination has substantially reduced the prevalence of many serious infectious diseases and remains an important component of preventative healthcare. Nevertheless, vaccinated animals may occasionally develop illness or require temporary withdrawal from work while recovering from infection.

Animals displaying signs of infectious disease should not undertake public access activities until cleared by a veterinarian, both to support recovery and to minimise disease transmission.

Parasites

Internal and external parasites remain important causes of disease despite the availability of highly effective preventative treatments.

Internal parasites include roundworms, hookworms, whipworms, tapeworms and protozoal infections such as Giardia. These organisms may cause diarrhoea, weight loss, poor body condition or gastrointestinal disturbance.

External parasites include fleas, ticks, lice and mites. In addition to causing discomfort, some parasites transmit serious infectious diseases or produce severe allergic reactions.

Routine parasite prevention should be tailored to the animal’s geographical location, lifestyle and veterinary recommendations. Occupational therapists should encourage handlers to maintain preventative healthcare schedules, particularly because assistance animals regularly visit public environments where parasite exposure may occur.

Zoonotic Diseases

Zoonotic diseases are infections that can be transmitted between animals and humans. While the overall risk associated with healthy, well-managed assistance animals is low, occupational therapists should understand basic zoonotic principles to support safe practice.

Examples include ringworm, salmonellosis, campylobacteriosis, leptospirosis and certain intestinal parasites. Good hygiene practices, routine veterinary care, appropriate parasite prevention and prompt treatment of illness substantially reduce transmission risks.

Hand hygiene before and after interacting with animals, appropriate waste disposal and avoiding contact with bodily fluids are simple but effective infection prevention measures. These practices are particularly important when working with clients who are immunocompromised, very young or older adults.

Recognising Early Warning Signs

Many illnesses initially present with subtle changes that may easily be attributed to ageing, training issues or temporary fatigue. Occupational therapists should therefore consider an animal’s overall pattern of function rather than focusing on isolated behaviours.

Persistent changes in appetite, body weight, thirst, toileting habits, activity levels, mobility, breathing, behaviour, coat condition or task performance warrant veterinary assessment. Similarly, vomiting, diarrhoea, coughing, unexplained pain, seizures, wounds, abnormal swellings or signs of distress should never be ignored.

Importantly, assistance animals are often highly motivated to continue working despite discomfort. A reduction in performance or enthusiasm may therefore represent a significant indicator of underlying disease.

Occupational Therapy Considerations

Occupational therapists working alongside assistance animal teams should recognise that health and occupational performance are closely interconnected. Many common medical conditions affect not only an animal’s physical function but also its ability to learn, concentrate, tolerate environmental demands and safely perform trained tasks.

Routine observation during therapy sessions provides valuable opportunities to identify subtle changes that may otherwise go unnoticed. Therapists should remain alert to alterations in gait, posture, endurance, behaviour, appetite, grooming, body condition and task performance, recognising that these may be early indicators of illness rather than training difficulties.

Occupational therapists should never attempt to diagnose or treat veterinary conditions. Instead, their role is to recognise potential concerns, recommend timely veterinary assessment and collaborate with veterinarians, trainers and handlers to ensure that assistance animals remain healthy, comfortable and able to participate safely in their occupational role. By promoting preventative healthcare, early intervention and interdisciplinary collaboration, occupational therapists contribute to the long-term welfare, effectiveness and longevity of assistance animal partnerships.