Given the wide scope of canine capabilities, the list of disabilities that qualify people for service dogs is seemingly endless. From pulling wheelchairs to fetching telephones, or even comforting war veterans, these well-trained dogs can help people in a wide variety of situations. Essentially, anyone with a diagnosable condition who would tangibly benefit from a companion dog may qualify.
Physician's Approval Required
Service dog organizations virtually always require a written letter from a medical doctor. This means that an undefined number of conditions can qualify a person to use a service dog, as long as the dog can perform tasks that directly benefit the person in light of the condition. For instance, old age does not qualify a person for an assistance animal, but osteoporosis can.
ADA Rights Protection
It's possible to obtain a service dog for a condition not protected by the assistance animal provisions of the Americans with Disabilities Act of 1990, even if the condition itself is otherwise covered by ADA laws. This means that the dog may not have open access to businesses that do not allow regular pets. Post-traumatic stress disorder, social anxiety disorder and various levels of depression are conditions that frequently qualify people for service dogs but are not covered by the ADA.
Service dogs can help those in wheelchairs or using other mobility devices, but there's a wider range of physical limitations that qualify for service dog use. Diabetes, asthma, arthritis, multiple sclerosis and other conditions that can result in occasional or frequent episodes of physical impairment also qualify for service dog use. Patients with neurological problems such as spina bifida, muscular dystrophy or conditions that result in sciatica can also benefit from service dogs.
Guide dogs are perhaps most famous for helping the blind, but other visual impairments can be treated with the companionship of an animal. If poor eyesight, lack of depth perception or another visual impairment prevents a person from taking care of certain tasks or navigating public spaces, a trained dog can potentially assist and protect him.
Those with hearing loss or deafness are prime candidates for service animals. The ADA generally allows dogs for the purpose of alerting their owners to "the presence of people or sounds." Guide dogs can protect people from dangers that they cannot hear, or simply help them through daily tasks by keeping them aware of people and moving objects near them.
Mental and Emotional Conditions
Service animal organizations often provide guide dogs to people facing mental and emotional disorders in spite of the sometimes vague laws surrounding their public rights. Former soldiers and others with post-traumatic stress disorder often qualify for dogs, as do those with social anxiety disorder, major depression and related issues.
Seizures and Allergies
Specially trained dogs can assist people with the risk of seizures from epilepsy or other conditions. In some cases the dogs alert their owners to oncoming seizures before they begin, although it's not fully understood why this happens. The dogs can also call for help or awaken owners during seizures. People with severe allergies can also benefit from service dogs' keen senses, being alerted by the dogs to trace amounts of allergens that may be present nearby.