The gastrointestinal, urinary and reproductive systems perform essential functions that support an assistance animal’s overall health, wellbeing and ability to work safely. Together, these systems are responsible for digesting food, absorbing nutrients, maintaining hydration, eliminating waste products, regulating fluid and electrolyte balance, and supporting reproduction. Although these systems perform different physiological functions, disease affecting any one of them can have significant consequences for an animal’s energy levels, comfort, behaviour and capacity to perform assistance work.

For occupational therapists, an understanding of these body systems assists in recognising changes that may indicate illness or reduced welfare. Assistance animals often continue working despite feeling unwell, meaning subtle changes in appetite, body condition, toileting habits or behaviour may be the first indication that veterinary assessment is required.

While occupational therapists do not diagnose or treat medical conditions, they are well positioned to observe changes during routine interactions with assistance animal teams and facilitate timely referral to veterinary professionals.

The Gastrointestinal System

The gastrointestinal (digestive) system is responsible for breaking down food into nutrients that provide energy, support growth and repair tissues. It also absorbs water and essential vitamins and minerals while eliminating indigestible waste.

Digestion begins in the mouth, where food is mechanically broken down through chewing and mixed with saliva. Food then passes through the oesophagus into the stomach, where gastric acids and digestive enzymes begin further digestion. The partially digested material moves into the small intestine, where most nutrient absorption occurs. Nutrients enter the bloodstream and are transported throughout the body to support normal physiological function.

The large intestine absorbs water and electrolytes before compacting waste into faeces for elimination through the rectum and anus. Several accessory organs, including the liver, pancreas and gallbladder, also play essential roles in digestion by producing enzymes, bile and hormones that assist nutrient metabolism.

A healthy gastrointestinal system ensures assistance animals receive adequate nutrition to support physical activity, immune function, wound healing and cognitive performance.

Common Gastrointestinal Conditions

Digestive disorders are among the most common reasons companion animals require veterinary care. While many conditions are mild and self-limiting, others require urgent treatment.

Acute gastroenteritis commonly presents with vomiting, diarrhoea or both and may result from dietary indiscretion, infectious disease, parasites, toxins or food intolerance. Even relatively mild gastrointestinal illness may rapidly affect an assistance animal’s hydration status and ability to work safely.

Chronic gastrointestinal disorders, including inflammatory bowel disease, food allergies and gastrointestinal malabsorption syndromes, may result in recurrent vomiting, diarrhoea, weight loss or poor body condition. These conditions often require lifelong dietary management and veterinary monitoring.

Constipation may also occur, particularly in older animals, animals receiving certain medications or those with neurological disease. Straining to defecate, reduced faecal output or discomfort during toileting should prompt veterinary assessment.

Because assistance animals frequently accompany their handlers into public places, episodes of vomiting or diarrhoea not only indicate illness but may also temporarily prevent the animal from safely undertaking public access activities.

The Urinary System

The urinary system maintains the body’s fluid balance while removing waste products generated during normal metabolism. It consists of the kidneys, ureters, bladder and urethra.

The kidneys continuously filter blood, removing toxins and waste products while regulating water balance, electrolyte concentrations and blood pressure. They also play important roles in hormone production and red blood cell regulation.

Urine produced by the kidneys travels through the ureters to the bladder, where it is stored until voluntarily emptied through the urethra.

Normal urinary function is essential for maintaining hydration, electrolyte balance and overall health. Even mild impairment may affect an assistance animal’s comfort, endurance and wellbeing.

Common Urinary Conditions

Urinary tract disease may occur at any age but becomes increasingly common in older animals.

Urinary tract infections may cause increased frequency of urination, discomfort, blood in the urine or urinary accidents. Bladder stones may produce similar signs and, in some cases, may obstruct urine flow.

One of the most serious emergencies is urinary obstruction, particularly in male animals. Complete obstruction prevents normal urination and rapidly becomes life-threatening without immediate veterinary treatment.

Chronic kidney disease is particularly common in ageing dogs and cats. Early disease may present only as increased thirst and urination before progressing to reduced appetite, weight loss, lethargy and declining quality of life.

Occupational therapists should recognise that increased water intake, frequent requests to toilet or unexpected urinary accidents may indicate underlying medical disease rather than behavioural problems.

The Reproductive System

The reproductive system enables breeding and the continuation of the species. In assistance animal practice, however, reproductive health is more commonly considered in relation to preventative healthcare, responsible breeding programmes and desexing.

Female reproductive organs include the ovaries, uterus, cervix and vagina, while the male reproductive system includes the testes, epididymis, prostate gland and penis.

Although occupational therapists are unlikely to work directly with breeding programmes, an understanding of reproductive health remains important because reproductive disease can significantly affect an animal’s welfare and working capacity.

Desexing

Desexing, also referred to as spaying or castration, is commonly performed in companion animals and many assistance animal programmes. Desexing prevents unwanted breeding and may reduce the risk of several reproductive diseases.

In females, desexing eliminates the risk of pyometra, a life-threatening infection of the uterus, and substantially reduces the risk of mammary tumours when performed before the first few oestrous cycles. In males, castration prevents testicular disease and may reduce the incidence of certain prostate disorders.

The timing of desexing remains an area of ongoing research. While early desexing offers population control benefits, some evidence suggests that delaying desexing in certain large and giant breeds may reduce the risk of specific orthopaedic conditions. Decisions regarding the timing of desexing should therefore be individualised and made collaboratively between breeders, handlers and veterinarians.

Assistance animal breeding programmes often retain selected breeding animals until they have contributed to carefully managed breeding programmes before desexing and transitioning into working or retirement roles.

Common Reproductive Conditions

Although reproductive disease is less frequently encountered in desexed assistance animals, occupational therapists should be aware of several important conditions.

Pyometra is a serious bacterial infection of the uterus affecting entire females. Animals often present with lethargy, reduced appetite, vomiting, fever, excessive thirst and, in some cases, vaginal discharge. Without urgent surgery, pyometra can rapidly become fatal.

Mammary tumours are among the most common tumours affecting older entire female dogs. Testicular tumours and benign enlargement of the prostate may occur in entire males.

Pregnancy, lactation and reproductive hormones also influence nutritional requirements, behaviour and physical capacity. Consequently, actively breeding animals are generally unsuitable for assistance work during pregnancy and early lactation.

Nutrition, Hydration and Body Condition

The gastrointestinal and urinary systems work together to maintain adequate nutrition and hydration. Appropriate nutrition supports muscle development, immune function, tissue repair, cognitive performance and physical endurance, while adequate hydration is essential for circulation, temperature regulation and kidney function.

Obesity is one of the most common health problems affecting companion animals and can significantly reduce an assistance animal’s working longevity. Excess body weight increases stress on joints, reduces exercise tolerance, contributes to cardiovascular disease and predisposes animals to diabetes and osteoarthritis.

Conversely, poor body condition may indicate inadequate nutrition, chronic disease, gastrointestinal dysfunction or other underlying health concerns.

Regular monitoring of body weight and body condition score forms an important component of preventative healthcare for all assistance animals.

Recognising Gastrointestinal, Urinary and Reproductive Disease

Because assistance animals often continue working despite illness, occupational therapists should remain alert to changes that may indicate underlying disease.

Reduced appetite, weight loss, vomiting, diarrhoea, constipation, excessive drinking, increased urination, urinary accidents, blood in urine or faeces, abdominal discomfort, changes in body condition or altered behaviour should all prompt veterinary assessment. Similarly, lethargy, fever, unexplained pain or reproductive discharge require immediate veterinary investigation.

Changes in toileting behaviour may be particularly noticeable during community access activities and should never be dismissed simply as behavioural problems without considering possible medical causes.

Occupational Therapy Considerations

The gastrointestinal, urinary and reproductive systems influence an assistance animal’s health, comfort and ability to participate safely in everyday occupations. Illness affecting these systems may reduce endurance, alter behaviour, impair concentration and compromise an animal’s capacity to work effectively.

Occupational therapists should be attentive to changes in appetite, hydration, body condition, toileting habits and general wellbeing when observing assistance animal teams. Recognising these early indicators of disease and facilitating timely veterinary referral supports both animal welfare and client safety.

Therapists should also appreciate the importance of appropriate nutrition, hydration and preventative healthcare in maintaining long-term working capacity. When planning community access activities or extended outings, consideration should be given to opportunities for regular toileting, access to fresh water, environmental conditions and the individual health needs of the assistance animal. Through collaboration with veterinarians, handlers and other animal professionals, occupational therapists can contribute to holistic care that supports the health and longevity of the assistance animal partnership.