Diseases Shared By Humans And Pets

(Picture Credit: Getty Images)

(Picture Credit: Getty Images)

Many people forget that we share more than our homes with our furry friends. Most of the medical conditions humans suffer from also affect our pets. Here are some of the more common diseases pets and people share.

Diabetes / Insulin Resistance

Humans- According to the American Diabetes Association, 23.6 million children and adults, 8.0% of the population, have diabetes.

  • Diagnosed: 17.9 million people
  • Undiagnosed: 5.7 million people
  • Pre-diabetes: 57 million people

Dogs and Cats – fastest growing hormonal disease in dogs and cats, related primarily to obesity

  • Prevalence in the USA has been increasing
  • Reported prevalence in 1970: 1 in 1250 cats
  • Reported prevalence in 1999: 1 in 81 cats
  • Reported prevalence in 1970: 1 case per 500 dogs
  • Reported prevalence in 1999: 1 case per 166 dogs
  • Overall incidence is probably about 1 in 150 to 200 dogs and cats

Clinical signs: increased thirst, urination and hunger, unexplained weight loss, increased fatigue, irritability, blurry vision

Diagnosis: blood and urine tests: elevated fasting blood glucose, presence of glucose in urine; other tests include fructosamine, glycosylated hemoglobin, glucose tolerance test

Treatment: change in diet (low carbohydrate, high-fiber, high-protein), weight loss and aerobic exercise, insulin injections (especially in dogs and cats, insulin pumps in humans), oral medications (Glucotrol, Glucophage, Precose, Prandin, Januvia, Avandamet, etc.)

High Blood Pressure

Humans – prevalence rate of 28.9% according to journal of Hypertension and American Heart Association

Dogs and Cats – exact prevalence is unknown, largely because veterinarians and pet owners lack awareness; hypertension is growing secondary to obesity

Clinical signs: most people and pets experience no clinical signs, hence the moniker “the silent killer.” Strokes, loss of vision (especially in dogs and cats), kidney and heart disease, headaches, fatigue, etc.

Diagnosis: blood pressure – same in humans, dogs and cats; we’re one of the few clinics in the US using high-definition oscillometric (HDO) blood pressure device

Treatment: increased aerobic exercise, weight loss, low-sodium diet, medication to lower pressure by relaxing arteries, lowering heart rate, reducing sodium or fluid, etc.


Humans – two-thirds (67%) of American adults are now obese or overweight (CDC), medical costs may be as high as $147 billion (CDC)

Dogs- an estimated 44% of us dogs are overweight or obese (APOP)

Cats – an estimated 57% of us cats are overweight or obese (APOP)

Veterinary Pet Insurance reported it paid $14 million in obesity-related claims

Treatment: increase aerobic exercise, low-calorie diet (high-protein, low-carbohydrate versus high-fiber diet strategies)

Irritable Bowel Syndrome – Inflammatory Bowel Disease

Humans – almost 2% of Americans have Irritable Bowel Syndrome (IBS)

Dogs and Cats – exact incidence unknown but number of affected pets seems to be increasing; may be related to high-carbohydrate diet, especially in cats

Clinical signs: diarrhea, abdominal pain and tenderness, bloating, gas, vomiting (in severe cases), weight loss

Diagnosis: medical history and clinical signs, intestinal biopsies

Treatment: dietary change, immunosuppressive medications

Heart Disease and High Cholesterol

Humans – heart disease most common cause of death in US

Dogs – high cholesterol is being diagnosed in obese dogs, heart disease affects approximately 1 in 10 dogs

Cats – exact incidence is unknown, most are genetically linked

Clinical signs: fatigue, exercise intolerance, shortness of breath, coughing, distended abdomen, weight loss, etc.

Diagnosis: physical examination, presence of a heart murmur, chest x-rays, echocardiography, ECG, MRI/CT, etc.

Treatment: based on specific type of heart disease, weight loss, aerobic exercise, etc.

Arthritis – Osteoarthritis and Rheumatoid Arthritis

Humans: incidence rate of osteoarthritis is about 7% (likely higher with increasing obesity rates), incidence rate of rheumatoid arthritis is about 1%

Dogs: up to 20% of all dogs may develop osteoarthritis; rheumatoid arthritis is rare but occurs

Cats – rarely are affected except in obese cats

Clinical signs: lameness, joint pain or swelling, decreased ability to walk, decreased range of motion

Diagnosis: medical history and clinical signs, x-rays

Treatment: weight loss and exercise, pain relief medications such as NSAIDs, supplements including glucosamine/chondroitin, omega-3 fatty acids (fish oils), etc.

Glaucoma (increased pressure in the eye)

Humans – approximately 1 in 136 or 0.74% or 2 million people in US are affected

Dogs and Cats – incidence unknown; more common in pure breeds:

Clinical signs: swollen, protruding eyeball, red, inflamed eye, sudden blindness, pain, head-pressing, etc.

Diagnosis: tonometry (measuring the pressure within the eyeball using a pen-like digital instrument)

Treatment: same in humans and pets, topical and/or oral medications to decrease pressure in the eye

Epilepsy (seizure disorders)

Humans –

  • Epilepsy and seizures affect almost 3 million Americans
  • Epilepsy costs an estimated $15.5 billion per year in direct and indirect costs
  • Approximately 200,000 new cases of seizures and epilepsy occur each year
  • Ten percent of the American population will experience a seizure in their lifetime
  • Three percent will develop epilepsy by age 75

Dogs and Cats – There are no epidemiologic studies of the general dog population to establish the true incidence of idiopathic epilepsy in dogs, but estimates range from 0.5% up to 5.7%. Pure-breed dogs more affected than mixed-breed dogs. Epilepsy is rare in cats.

Clinical signs: seizures, tremors, loss of consciousness

Diagnosis: clinical signs, MRI/CT scans

Treatment: anticonvulsant therapies – same in human and dogs

Gas (flatulence)

Humans, dogs and cats are all susceptible to excessive gas. The most common cause is diet. Treatments include change in diet (highly-digestible protein, lower fat, lower carbohydrate, change fiber source) to Yucca schidigera extract and more.

Cruciate Ligament Injury – Joint Injuries

Humans – knee injuries one of the most common sports-related injuries; incidence rate of 300 cases per 100,000 population and 2.1 per 1000 NCAA athletes

Dogs – Americans spent an estimated $1.32 billion dollars on treatment for ruptured cranial cruciate ligaments in dogs (2003); incidence is unknown but increasing with excess weight

Cats – rare but increasing due to obesity

Clinical signs: sudden lameness, pain in knee

Treatment: most cases in humans and dogs require some form of reconstructive knee surgery

Allergies – Hay Fever

Humans – incidence rate estimated to be 15 to 30% – “Hay fever”

Dogs and cats – incidence rate estimated to be 3 to 15% (Dogs and cats commonly have seasonal allergies, too!)

Clinical signs: itching (dogs and cats), red, runny eyes, sneezing, dermatitis

Diagnosis: intradermal skin testing, hypoallergenic food trials, IgE blood tests

Treatment: antihistamines, corticosteroids, immunosuppressants, etc.

Dementia – Alzheimer’s disease

Humans – Alzheimer’s disease affects nearly 5% of older Americans

Dogs – Dementia is called Cognitive Dysfunction Syndrome (CDS) in dogs and cats – 45% of dogs aged 11-12 years of age showed at least one positive category of CDS compared to 86% of dogs aged 15-16 years. Another analysis on the same data was performed examining the number of dogs that exhibited disorientation plus at least one other category. In this analysis 13% of 11 year-old dogs and 50% of 16 year-old dogs met the criteria.

Cats – exact incidence unknown – appears to be somewhat less common than in dogs

Clinical signs: disorientation, loss of housetraining, vocalizations, lack of responsiveness, lack of recognition, loss of greeting behaviors, walking to wrong side of door, etc.

Diagnosis: medical history and clinical signs, MRI/CT scans

Treatment: medications such as selegiline, supplements such as omega-3 fatty acids, SAMe, gingko, vitamin E, etc.

Bladder and Kidney Stones

Humans – most commonly get kidney stones

Dogs and Cats – most commonly get bladder stones with or without kidney stones

Clinical signs: painful urination, inability to urinate, blood in urine, frequent urinary tract infections, etc.

Diagnosis: medical history and clinical signs, bladder and kidney x-rays, abdominal ultrasound

Treatment: dietary change may succeed in dissolving stones until they can be passed, urethral hydropropulsion (a technique in which small stones are flushed from the bladder), lithotripsy (humans), surgical removal (most common in dogs and cats)

Hearing loss

Older humans, dogs and cats may all experience hearing loss. It is estimated that as many as 1 in 6 adult Americans will have some form of communication disorder. Government estimates state 28.6 million Americans suffer hearing loss. The exact incidence is unknown in dogs and cats.


Most people are surprised to learn that dogs and cats have a higher incidence of many tumors than humans.

Dogs have (all citations Texas A&M College of Veterinary Medicine)

  • 35 times as much skin cancer as do humans
  • 4 times as many breast tumors
  • 8 times as much bone cancer
  • Twice as high an incidence of leukemia.

The only types of cancer that are more frequently seen in humans than in small animals are:

  • lung cancer is 7 times higher in humans
  • stomach/intestinal malignancies are 13 times more frequent in man than in dogs and cats

Depression and Anxiety

Humans – The prevalence rate of depression in Americans is 5.30% according to various researches and studies by NIMH.

Dogs – as many as 15% of all dogs may experience some form of separation anxiety disorder making it the number one behavior-related disorder seen by veterinarians

Cats – less incidence of depression or anxiety than dogs and humans, likely due to their solitary nature

Diagnosis: based on clinical signs and medical history

Treatment: same for dogs and humans: anxiolytic drugs such as Prozac are commonly used; behavioral therapies including counter conditioning/desensitization, redirection, etc. are used in conjunction with medication in many cases.