Pet Disease Encyclopedia (A–Z Starter)

Disease encyclopedia

Contents

Pet Disease Encyclopedia (A–Z Starter) — A plain-English A to Z starter of common dog and cat diseases and conditions, each with a short description. Use it to understand what a diagnosis means and when to see a vet. Not a substitute for veterinary advice.

General guidance only — not a substitute for professional veterinary advice. When in doubt, call your vet.

How to use this encyclopedia

This is a starting reference to common pet health conditions, listed roughly A to Z, each explained in a line or two. It is meant to help you understand terms your vet may use, not to diagnose or treat your pet. If your pet shows signs of illness — changes in appetite, energy, thirst, breathing, or behavior — see your vet. Many conditions here are far easier to treat when caught early.

Conditions A–Z

Arthritis: painful swelling and stiffness of the joints, common in older and large-breed pets. Managed with weight control, gentle exercise, and vet-prescribed pain relief.
Bloat (gastric dilatation-volvulus): a sudden, life-threatening emergency in deep-chested dogs where the stomach fills with gas and twists. Needs immediate vet care.
Cushing's disease: the body makes too much cortisol, causing increased thirst, hunger, a pot-bellied look, and hair loss. Treated with medication.
Diabetes: the body cannot control blood sugar, leading to increased thirst, urination, and weight loss. Managed with insulin, diet, and monitoring.
Ear infections: red, itchy, smelly ears, common in floppy-eared dogs. Treated with cleaning and vet-prescribed medication.
Feline leukemia (FeLV): a contagious virus in cats that weakens the immune system and can cause cancer. Preventable with a vaccine; there is no cure.
Heartworm: worms spread by mosquito bites that live in the heart and lungs and can be fatal. Far easier to prevent with monthly medication than to treat.
Hip dysplasia: a poorly fitting hip joint, often inherited in larger breeds, causing pain and limping. Managed with weight control, medication, or surgery.
Hyperthyroidism: an overactive thyroid, common in older cats, causing weight loss, hunger, and a racing heart. Treatable with medication, diet, or other therapy.
Kennel cough: a contagious respiratory infection causing a harsh, honking cough. Usually mild and preventable with a vaccine.
Kidney disease: gradual loss of kidney function, common in older cats and dogs, causing increased thirst, urination, and weight loss. Managed with diet and fluids.
Obesity: excess body weight that strains the joints, heart, and organs and shortens life. Prevented and reversed with measured meals and exercise.
Parvovirus (parvo): a severe, often deadly virus in unvaccinated puppies causing bloody diarrhea and vomiting. Preventable with vaccination.
Pancreatitis: painful swelling of the pancreas, often triggered by fatty food, causing vomiting and belly pain. Needs vet care and a low-fat diet.
Rabies: a deadly virus spread through bites that affects the brain and is preventable only by vaccine. It is a legal requirement in many places and can infect people.
Ringworm: a contagious fungal skin infection (not a worm) causing circular patches of hair loss. Treatable and can spread to people.
Urinary tract disease: infections, crystals, or blockages in the bladder and urethra causing straining, accidents, or blood in the urine. A blocked male cat is an emergency.
Dental disease: buildup of plaque and tartar leading to gum infection, pain, and tooth loss. Prevented with brushing and cleanings.
Fleas and flea allergy: biting parasites that cause itching and, in allergic pets, severe skin irritation. Controlled with regular prevention.
Cataracts: cloudy lenses that blur vision and can lead to blindness, seen with age or diabetes. Sometimes correctable with surgery.

Some conditions here are emergencies — bloat, a urinary blockage in a male cat, parvo in a puppy, or trouble breathing. If your pet is in distress, do not wait; contact your vet or an emergency animal hospital right away.

Prevention is the best medicine

Most of these conditions are less likely, or easier to treat, with basic care: keep vaccines and parasite prevention current, feed a balanced diet, keep your pet at a healthy weight, brush the teeth, and see the vet for regular checkups. Early detection through routine exams and, for seniors, blood work catches many problems before they become serious.