Millions of pets are treated by veterinarians every year for a variety of common canine and feline medical conditions. Some medical conditions are more likely to occur in certain breeds than others, but many are diagnosed within any breed. The following is a list of the ten most common conditions encountered by veterinarians in dogs and cats.
Allergies are the most common condition for which dogs and cats are treated in veterinary hospitals. They occur when the immune system reacts to substances that are usually harmless, but that an animal may have sensitivity to. Dogs can be allergic to grass, pollen, mold, dust mites, or other allergens and cats can be allergic to fleas and food ingredients. Symptoms may include scratching at the site of infection or hives on the head or body due to flea bites.
Dog parasites include fleas, ticks, mites and worms that live in or on dogs. Parasitic worms infect dogs by burrowing through the skin, causing it to become irritated and inflamed; some worms can also migrate to the lungs. Ticks are blood-sucking parasites that attach to dogs and cause severe irritation of the skin, leading to secondary bacterial infection; humans can be infected with tick-borne diseases as well. Mites are microscopic insects that live in or on a dog’s skin. There are three kinds of mites: scabies, sarcoptic mange, and itching. Mites that cause scabies infest the skin and hair of an animal; it is caused by a mite that burrows under the skin. Sarcoptic mange causes severe, intense itchiness that can persist for months after infection. Scabies does not cause itchiness but can weaken or kill some animals.
Urinary incontinence in dogs and cats is caused by a weakening of the sphincter muscles, which allows urine to leak out of the body when it shouldn’t. Urinary incontinence in dogs often occurs as a result of an enlarged prostate gland (benign prostatic hyperplasia), but it can also be caused by certain drugs or problems with the bladder or urinary tract. Symptoms include frequent urination, and the dog may have an odor on the coat from leakage of urine.
Diarrhea is a common dog and cat medical condition that can occur in a variety of forms. There are two main types: acute diarrhea (caused by food, alcohol, or medicines) and chronic diarrhea (caused by bad teeth or intestinal problems). Dogs and cats with acute diarrhea drink a lot of water to replace lost fluids; they may also have increased thirst and increase urinary output. Chronic diarrhea often causes dehydration because the dog or cat is drinking less fluid than normal. Dogs may also have increased appetite, loss of appetite, or a decrease in their ability to digest food. Chronic diarrhea can cause heartworm disease in dogs and “kennel cough” in cats (a form of bacterial infection).
Urinary tract infections occur when bacteria from the environment get into the bladder and irritate it; this causes an infection within the urinary tract. The bladder of a dog or cat can be infected by bacteria that enter the urinary tract through the urethra, but it can also be caused by bacteria that enter through the anus (anal) or vagina. Infections can occur in dogs and cats of any age. Dogs may have increased thirst, urination, frequency, urgency, foul-smelling urine (although some dogs may not notice a strong odor), change in personality or behavior (especially acting more frisky than usual), blood in their urine, and/or an increase in appetite. Cats may have increased thirst, urination, increase in frequency or urgency of urination; an increase in appetite; and/or depression due to loss of appetite (anorexia). Cats can also develop cystitis.
Allergic dermatitis (skin allergies) is one of the most common skin conditions in dogs and cats and is characterized by rashes, redness, inflammation, hair loss, and itchiness of the skin. Dandruff in dogs is an example of allergic dermatitis. Allergies cause allergic dermatitis because the immune system overreacts to substances that are usually harmless (allergens). Common allergens include: grass; pollen; house dust; perspiration from people or animals; food ingredients (digestive enzymes or proteins); flea saliva; and some types of mites like scabies. Allergic dermatitis is the most common skin condition in dogs.
Hypothyroidism and hyperthyroidism are the most common endocrine (hormone) disorders in dogs and cats, respectively, and account for about half of all endocrine diseases in these pets. Hyperthyroidism is a condition in which the dog’s or cat’s thyroid gland makes too much thyroid hormone. Thyroid hormones cause the body to convert food into energy, and regulate metabolism. Signs of hyperthyroidism in dogs include restlessness, increased panting, excessive drooling, vomiting, diarrhea (especially on waking), and weight loss. Cats may have increased thirst, urination, change in behavior (especially aggression), lethargy (lack of energy), changes in coat color and pattern (including hair loss), jaundice (yellowing of skin tissues), and/or recumbency among senior pets. This condition can be very dangerous if not closely monitored by a veterinarian.
When the ureters become blocked by stones or tumors and bacteria lodge in the ureters, this condition is called urinary tract neoplasia. Dogs may have increased thirst, increased urine output, blood in the urine (hematuria), size of the prostate or bladder, change in behavior (especially depression), anorexia (decreased appetite), and change in coat pattern. Cats may have increased thirst, urination, blood on the urine (hematuria), an increase in appetite and weight loss.
FeLV-positive cats are also at risk for developing hyperthyroidism due to immune suppression caused by concurrent infection with FeLV.
Crohn’s disease is a chronic disorder of the digestive system, usually affecting the digestive tract of dogs and cats and characterized by inflammation, ulcers, and strictures. Dogs with Crohn’s disease may have a dry, scaly skin (hyperkeratosis). Cats may have increased thirst, urination, loose stools (diarrhea), blood in the urine (hematuria), an increase in appetite and weight loss.
Dogs with uterine problems experience an increase in urine volume because of strictures or abscesses in the bladder or urethra. Cats with uterine problems may experience an increase in thirst, blood in the urine (hematuria), loss of appetite, and weight loss.
Cats with hepatobiliary disease may have increased thirst, decreased appetite, and weight loss. They also may exhibit an increase in frequency of urination and a change in coat pattern. Dogs affected by hepatobiliary disease may have a dry skin (hyperkeratosis). In addition to having signs of mild liver disease (such as depression and anorexia), the affected pets may present with a fever. If your pet has a persistent fever, this is often accompanied by signs of jaundice (yellowing of skin tissues).