Can Dogs Get Sick? Symptoms, Triage, Human Germs & Costs

Yes, Dogs Get Sick: What Usually Causes It and What to Do First

Yes, dogs can get sick from viruses, bacteria and parasites, as well as toxins, unsafe foods, heat, allergies and chronic conditions. Signs can range from a mild stomach upset to an emergency, such as difficulty breathing or collapse.

Dogs can also catch a few infections from people, though they don’t usually catch the viruses that cause human colds. COVID-19 and certain bacteria can pass from people to dogs; transmission of human flu to dogs appears uncommon.

If your dog is struggling to breathe, has pale or blue gums, collapses, has a swollen belly with repeated attempts to vomit, or may have eaten poison, go to an emergency veterinarian now. Call ahead if you can. If your dog has a single mild symptom but is otherwise acting normally, use the triage framework and home health check below to help decide what to do next.

This guide offers general education, not a diagnosis. Contact a veterinarian whenever you’re unsure, particularly if your dog is very young, elderly or has an existing medical condition.

Common Dog Illnesses in the US, in Plain Language

Common dog illnesses include ear infections, skin allergies, dental disease, intestinal parasites, kennel cough and arthritis. More serious conditions include parvovirus, heartworm disease and cancer. Symptoms often overlap, so treat the possible causes below as starting points for a conversation with your vet, not as diagnoses.

Contagious illnesses: kennel cough, parvo, distemper, canine flu

• Kennel cough: This contagious airway illness is associated with several germs. A dry cough, sometimes followed by gagging, is one of the common kennel cough symptoms. Germs spread through respiratory droplets, close dog-to-dog contact and contaminated items. Vaccines are available for some causes, including the bacterium Bordetella, but they don’t prevent every case.
• Parvovirus, or parvo: This potentially life-threatening infection is especially dangerous for puppies. It can cause lethargy, loss of appetite, vomiting and severe diarrhea, and it spreads through infected feces and contaminated surfaces. Vaccination is essential; treatment often requires intensive supportive care.
• Canine distemper: This viral disease can cause respiratory and digestive signs, and sometimes neurological problems. It spreads mainly through respiratory secretions. Vaccination is the main form of prevention.
• Canine influenza: Dogs can get the flu, but canine influenza is caused by viruses adapted to dogs. Signs may include coughing, nasal discharge, fever and tiredness. It spreads through respiratory secretions and contaminated objects; a vaccine is available for dogs at risk.
• Rabies: This deadly viral disease usually spreads through the bite of an infected animal. It can affect the nervous system and spread to people. Rabies vaccinations are essential and required by law in many jurisdictions. If a dog may have been exposed, contact a veterinarian and local public health authorities immediately.
• Leptospirosis: This bacterial infection can damage the kidneys or liver. Dogs can encounter the bacteria through infected animal urine or contaminated water or soil. It can also spread to people. Vaccination and avoiding suspect standing water help reduce the risk.
• Ringworm: Despite its name, ringworm is a fungal infection. It can cause patches of hair loss or scaly skin and spread between animals and people through direct contact or contaminated objects. A veterinarian can diagnose and treat it.

Tick-, flea-, and mosquito-borne illnesses: heartworm and Lyme disease

Heartworm disease spreads through mosquitoes and can damage the heart and lungs. A dog may have no obvious signs early on; later, coughing and reduced exercise tolerance can appear. Preventive medication and testing on a veterinarian’s schedule are important.

Lyme disease spreads through infected ticks. Some affected dogs develop shifting lameness, fever or lethargy. Tick control reduces exposure, and a Lyme vaccine may be appropriate for some dogs.

Fleas can cause intense itching or allergic skin disease, transmit tapeworms and, in heavy infestations, contribute to anemia. Dogs can pick up intestinal parasites such as roundworms, hookworms and Giardia from contaminated environments, feces or water. Some can also affect people. Fecal testing and treatment depend on the parasite.

Non-infectious causes: toxins, heatstroke, allergies, and chronic disease

Dogs can become ill without catching an infection. Chocolate, xylitol, grapes and raisins, medications and other household substances can be dangerous. A swallowed sock or toy can cause a blockage, while overheating can cause heatstroke.

Allergies often show up as itchy skin, paw licking or recurrent ear trouble rather than sneezing. Dogs can also develop diabetes, arthritis, dental disease and other chronic illnesses. A change in thirst, mobility, appetite or weight deserves veterinary attention, even when there’s no obvious infection.

Can Dogs Get Sick From Humans? Colds, Flu, COVID, MRSA, and Norovirus

A zoonotic disease is an infection that can pass between animals and people. Some infections can travel from a person to a dog, a process sometimes called reverse zoonotic transmission. Whether that happens depends on the germ and the exposure.

Which human illnesses can and can’t affect dogs

Human illness	Can dogs catch it?	How likely or typical signs in dogs	What owners should do
Common cold	Human cold viruses are not a usual cause of illness in dogs	A dog’s cough or sniffles are more often associated with other causes	Wash hands and have persistent respiratory signs checked rather than assuming your cold is responsible
Human flu	Occasionally reported, but uncommon	Dogs more commonly catch canine influenza from other dogs	Limit close face contact while sick; call a vet if your dog develops respiratory signs
COVID-19	Yes	Infection after close contact with a person has been documented; affected dogs often have mild or no signs	Limit close contact while ill and ask a vet about symptoms
MRSA	Yes, transmission between people and pets is possible	Dogs can carry the bacteria without signs or develop infections, including skin or wound infections	Wash hands, cover wounds and prevent licking of cuts or bandages
Strep throat	Not a typical household infection in dogs	A sore throat or cough has many possible causes	Use normal hygiene and seek veterinary advice for difficulty swallowing or persistent symptoms
Norovirus or a stomach bug	Human-to-dog transmission is not established as a common cause of canine illness	Vomiting and diarrhea have many other possible causes	Clean up promptly, wash hands and contact a vet if signs persist or worsen
Salmonella and some parasites	Some can move between people and animals	Infection may cause digestive signs or no obvious illness	Handle feces safely, wash hands and keep food and bowls clean

What to do if you’re sick and live with a dog

Wash your hands before and after handling your dog, food or bowls. While you’re ill, avoid face licking, sharing food and close face-to-face contact. If practical, ask another household member to provide care when you have COVID-19 or another potentially transmissible infection.

Don’t disinfect your dog with household cleaning products or put a mask on them. If your dog develops symptoms, call your veterinarian and mention any relevant household illness and exposures.

Signs Your Dog Is Sick vs. Normal Behavior

Your dog’s usual behavior is often the most useful point of comparison. A dog who naps after a long walk may simply be tired. One who is unusually lethargic, skips food and refuses a favorite activity needs closer attention.

Common signs of sickness include vomiting, diarrhea, loss of appetite, coughing, sneezing, limping, increased thirst or urination, and changes in breathing. Hiding, unusual irritability or reluctance to be touched can also signal discomfort. A warm or dry nose alone can’t tell you whether your dog has a fever.

A single skipped meal in an otherwise bright adult dog may be less concerning than a sudden change accompanied by vomiting or weakness. Consider how long a sign has lasted, whether it’s getting worse and whether other signs are appearing. Use the most urgent applicable tier in the next section.

Symptom-matching guide: kennel cough vs. allergies vs. pneumonia vs. heart disease

Use this table for orientation, not self-diagnosis. The sound of a cough alone can’t reliably distinguish these conditions.

Condition	Typical cough or breathing pattern	Other signs	Contagious?	Urgency level
Kennel cough	Often a dry, harsh cough, sometimes with gagging	Some dogs remain bright and eat normally	Often; respiratory droplets and contaminated objects can spread germs	Call a vet for a persistent cough; emergency care for breathing difficulty
Allergies	Sneezing or watery eyes may occur; coughing is not the main sign in many dogs	Itching, paw licking or ear irritation	No	Routine vet advice unless breathing is affected
Pneumonia	Coughing, fast breathing or increased breathing effort	Lethargy, poor appetite or fever may occur	Depends on the cause	Prompt veterinary care; emergency care for struggling to breathe
Heart disease	Cough or fast breathing; signs may appear at rest or with activity	Reduced stamina, weakness or fainting may occur	No	Prompt veterinary care; emergency care for collapse or breathing distress
Foreign object or throat irritation	Sudden coughing, gagging or repeated swallowing	Drooling, pawing at the mouth or distress	No	Emergency care for choking, distress or persistent symptoms

Quiet signs owners often miss

Watch for new bad breath, a lump, persistent sores, unexplained weight loss, changes in appetite or difficulty moving. These signs have many possible causes, including dental disease or cancer. If they persist, they deserve a veterinary assessment.

Emergency Now, Vet Within Days, or Monitor at Home? A Triage Framework

Start with breathing, gum color and responsiveness. If your dog is in distress, don’t delay the trip to measure vital signs. If more than one tier applies, choose the more urgent one.

Tier	Symptoms to look for	Why it matters	What to do
Emergency vet now	Trouble breathing; pale, white, blue or gray gums; collapse; prolonged or repeated seizures; a swollen or painful belly with unproductive retching; suspected poison; repeated vomiting or blood in vomit; heatstroke; inability to urinate; severe trauma	These signs can accompany life-threatening problems that worsen quickly	Go to an emergency vet now; call ahead if possible. For suspected poisoning, also contact a pet poison service
Vet promptly, generally within 24–48 hours	Vomiting or diarrhea lasting more than a day; not eating for more than 24 hours; a recurring cough; limping that does not improve; eye or ear discharge; drinking or urinating much more than usual	Dehydration, pain, infection or another condition may need treatment	Call for an appointment and ask whether your dog’s particular signs warrant faster care
Monitor closely at home	One vomit followed by normal energy; mild soft stool; brief sneezing; slightly reduced appetite with otherwise normal behavior	An isolated, mild sign may settle, but it can also be an early warning	Keep water available and watch closely; call a vet if signs repeat, combine, worsen or do not improve within about 24 hours

Red flags in puppies and senior dogs

Puppies, unvaccinated dogs, toy breeds, senior dogs and dogs with chronic illnesses can have less reserve when they become ill. Call sooner about vomiting, diarrhea, reduced appetite or a cough, even if the sign seems mild at first. Flat-faced dogs with breathing changes also need prompt assessment.

How to Do a Basic Dog Health Check at Home

A home check can help you describe what you see, but it can’t rule out illness. Check your dog while they’re calm, and stop if they’re in pain, frightened or likely to bite. Skip any step you can’t do safely.

Taking your dog’s temperature step by step

A dog’s normal temperature is roughly 101–102.5°F. Exercise, stress and measurement technique can affect the reading.

1. Prepare a thermometer

   Use a digital rectal thermometer with a little water-based lubricant. If needed, ask another person to help gently steady your dog.



2. Measure gently

   Lift the tail and gently insert the tip into the rectum, adjusting the depth for your dog’s size. Never force it or continue if your dog resists.



3. Record and clean

   Wait for the thermometer signal, record the reading and clean the device according to its instructions. Tell your veterinarian how and when you measured it.

Call your vet about a reading above approximately 103°F or below approximately 99°F, or sooner if your dog seems unwell. A very high temperature with heat exposure or distress is an emergency. Begin cooling and travel to a vet rather than repeatedly checking the reading.

Counting breaths and checking gum color

1. Count resting breaths. While your dog is asleep or resting quietly, count chest rises for 30 seconds and multiply by two. Many dogs take fewer than about 30 breaths per minute at rest. A repeatedly faster rate deserves a call; visible effort, gasping or blue gums means emergency care.
2. Look at the gums. Gently lift a lip. Gums are typically pink and moist, although some dogs have naturally dark pigment. If possible, check an unpigmented area and compare it with your dog’s usual appearance. Pale, white, blue or gray gums are an emergency; unusually bright red gums also need urgent advice.
3. Check capillary refill. Gently press an unpigmented area of gum for a second, then release. Color usually returns in about one to two seconds. A noticeably slow return can indicate a circulation problem; tell your vet, especially if your dog has other signs.
4. Look at overall comfort. Note dry or tacky gums, sunken eyes, a painful-looking abdomen, limping and changes in appetite or energy. A skin-tent check isn’t reliable enough to rule out dehydration, particularly in older or overweight dogs.

Write down the results and when symptoms began. Heart rate varies with a dog’s size and circumstances, so ask your vet what’s normal for your dog rather than relying on one universal number.

What You Can Safely Do at Home Before the Vet

Medications and remedies to avoid

Don’t give human fever reducers, painkillers or other over-the-counter medicines unless your veterinarian specifically directs you to. Ibuprofen, naproxen, acetaminophen and aspirin can be dangerous to dogs. A medication or dose that’s safe for a person may not be safe for a pet.

For suspected poisoning in the United States, the ASPCA Animal Poison Control Center and Pet Poison Helpline offer telephone consultations; fees may apply. Don’t wait for symptoms to appear before calling.

Comfort and monitoring checklist

• Offer water. For a dog with mild stomach upset, offer small amounts frequently. If your dog can’t keep water down, repeatedly vomits or seems weak, seek urgent veterinary care.
• Ask before changing food. A vet can advise whether an adult dog needs a short food pause or a bland diet. Don’t routinely withhold food from puppies, very small dogs or dogs with diabetes without veterinary direction.
• Keep your dog comfortable and separated. Provide a quiet place to rest. If an infection is possible, avoid contact with other dogs, wash your hands and clean bedding and bowls.
• Cool suspected heatstroke immediately. Move your dog into shade or air conditioning, wet the body with cool—not ice-cold—water, and use airflow if available. Offer small sips only if your dog is alert and able to drink. Travel to an emergency vet even if your dog seems better.
• Prepare for the visit. Record the symptom timeline, medications, possible exposures, recent travel, vaccination history and home-check results. Photos of vomit, stool or a suspected toxin can help.

Eating poop can expose dogs to parasites or germs. Cat food can upset a dog’s stomach, while garbage may contain spoiled food, toxins, bones or objects that cause an obstruction. Repeated vomiting, a swollen or painful belly, marked lethargy or a suspected toxin or swallowed object calls for urgent veterinary help.

Rain or cold weather alone doesn’t cause an infection. Prolonged cold exposure can still be dangerous, especially for small, young, older or short-coated dogs. Dry and warm a chilled dog gently; contact a vet if shivering persists or the dog seems weak or lethargic.

What Dog Illness Treatment Typically Costs in the US

Veterinary bills vary widely by region, clinic, dog size, severity and whether a dog needs testing, hospitalization or surgery. The source material for this guide doesn’t establish reliable national price ranges for these conditions. For a particular case, ask a clinic for an estimate rather than relying on an assumed average.

Estimated US vet costs for common dog illnesses

Condition or service	What’s typically involved	Estimated cost range	Prevention option
Basic sick visit	Examination and discussion; tests and medication may cost extra	Request a local estimate	Routine care and early attention to changes
Kennel cough	Examination, sometimes testing and medication	Request an outpatient estimate; complications can add costs	Risk-based vaccination and avoiding sick dogs
Ear infection	Examination, ear testing, medication and sometimes follow-up	Request an estimate; recurrent cases may need more care	Address allergies and follow your vet’s ear-care advice
Digestive upset	Examination, possible fecal testing, fluids or medication	Request an estimate based on tests and hydration needs	Secure garbage, introduce diet changes gradually and control parasites
Parvovirus	Testing, isolation, fluids, medications and sometimes hospitalization	Request an estimate for both hospitalization and any appropriate outpatient plan	Complete the recommended puppy vaccine series
Heartworm disease	Confirmatory tests, staged treatment, activity restriction and follow-up	Request an itemized estimate for the full treatment course	Year-round preventive medication and testing as advised
Swallowed foreign object	Imaging, anesthesia, possible endoscopy or surgery and monitoring	Request an estimate; complications and hospitalization can increase costs	Keep risky objects out of reach and supervise chewing

Ask for an itemized estimate and tell the clinic about financial limits early. A veterinarian may be able to explain which tests are most urgent, discuss medically appropriate alternatives or suggest a lower-cost clinic. Don’t delay emergency care while shopping for a price: call the emergency clinic on the way and discuss options there.

Preventing Illness and Staying Current: Vaccines, Parasite Control, Hygiene, and Outbreak Awareness

Vaccines and parasite prevention at a glance

Work with your veterinarian on a vaccination schedule suited to your dog’s age, health, location and activities. Core protection generally includes vaccination against rabies, distemper, parvovirus and canine adenovirus. A vet can also advise on leptospirosis, Bordetella, canine influenza and Lyme vaccines based on current professional guidance and your dog’s individual risk.

Use veterinarian-recommended heartworm prevention and flea and tick control on schedule. Ask about fecal testing and deworming, pick up waste promptly, provide clean water, and store medications, toxic foods and household chemicals securely. Avoid shared dog spaces when your dog is coughing or has diarrhea.

Reports of unusual canine respiratory illness have worried US dog owners. Respiratory signs can have several causes, and an outbreak report alone doesn’t establish a new pathogen or mean disease is widespread. For guidance relevant to your area in 2026, ask your veterinarian or check your state veterinary or animal health authority before boarding or attending dog events.

Your sick-dog action plan

1. Save the numbers for your regular vet, the nearest emergency clinic and a pet poison service.
2. Agree on a vaccination, parasite-prevention and testing schedule with your vet.
3. Learn your dog’s normal appetite, energy, gum appearance and resting breathing rate when healthy.
4. Keep a simple pet first-aid kit and your dog’s medication and vaccination records accessible.
5. If symptoms appear, use the triage table first. If your dog is stable, record what you observe and call your vet when signs persist, combine or worsen.

Key data

Condition Name	Category	Transmission Mode or Cause	Typical Symptoms	Contagious	Prevention Strategy	Veterinary Care Level
Kennel cough	Contagious	Associated with several germs (including Bordetella bacterium); spreads through respiratory droplets, close dog-to-dog contact, and contaminated items	Dry, harsh cough, sometimes followed by gagging; some dogs remain bright and eat normally	Yes	Vaccines available for some causes (risk-based, including Bordetella), avoiding sick dogs and shared dog spaces when coughing	Call a vet for a persistent cough; emergency care for breathing difficulty
Parvovirus (parvo)	Contagious	Parvovirus infection; spreads through infected feces and contaminated surfaces	Lethargy, loss of appetite, vomiting, and severe diarrhea	Yes	Complete recommended puppy vaccine series	Prompt Vet Care
Rabies	Contagious	Deadly viral disease; usually spreads through the bite of an infected animal	Affects the nervous system	Yes	Rabies vaccinations (essential/required core vaccinations in many jurisdictions)	Emergency
Canine distemper	Contagious	Viral disease; spreads mainly through respiratory secretions	Respiratory and digestive signs, and sometimes neurological problems	Yes	Vaccination (core vaccine)	Prompt Vet Care
Canine influenza (canine flu)	Contagious	Dog-adapted influenza viruses; spreads through respiratory secretions and contaminated objects	Coughing, nasal discharge, fever, and tiredness	Yes	Vaccine available for dogs at risk	Prompt Vet Care
Leptospirosis	Contagious	Bacterial infection from infected animal urine or contaminated water or soil	Kidney or liver damage	Yes	Vaccination and avoiding suspect standing water	Prompt Vet Care
Intestinal parasites (Roundworms, Hookworms, Giardia)	Contagious	Contaminated environments, feces (eating poop), or water	Digestive signs or stomach upset	Yes	Fecal testing, deworming, controlling parasites, and picking up waste promptly	Prompt Vet Care
Pneumonia	Contagious	Infectious germs or non-infectious causes affecting the lungs	Coughing, fast breathing, increased breathing effort, lethargy, poor appetite, or fever	Depends	Not in source	Prompt Vet Care
COVID-19	Contagious	Reverse zoonotic transmission from close contact with infected humans	Mild or no signs	Yes	Sick humans should limit close contact with dogs, wash hands, and have another household member provide care	Outpatient Management
MRSA	Contagious	Bacterial transmission between people and pets	Asymptomatic carriage or skin/wound infections	Yes	Wash hands, cover human wounds, and prevent dog from licking cuts or bandages	Prompt Vet Care
Salmonella	Contagious	Transmission between people and animals	Digestive signs or no obvious illness	Yes	Handle feces safely, wash hands, keep food and bowls clean	Outpatient Management
Ringworm	Contagious	Fungal infection; spreads through direct contact or contaminated objects	Patches of hair loss or scaly skin	Yes	Not in source	Outpatient Management
Heartworm disease	Tick/Flea/Mosquito-borne	Mosquitoes transmitting heartworms	No obvious signs early on; later coughing, reduced exercise tolerance/stamina, and damage to heart and lungs	No	Year-round preventive medication and testing on a veterinarian's schedule	Prompt Vet Care
Lyme disease	Tick/Flea/Mosquito-borne	Infected ticks	Shifting lameness, fever, or lethargy	No	Tick control/preventives and Lyme vaccine for at-risk dogs	Prompt Vet Care
Flea infestation / Flea allergic skin disease	Tick/Flea/Mosquito-borne	Fleas	Intense itching, allergic skin disease; can transmit tapeworms and cause anemia in heavy infestations	Depends	Year-round vet-recommended flea control	Outpatient Management
Toxins / Poisoning	Non-infectious	Ingestion of everyday substances like chocolate, xylitol, grapes, raisins, medications, or household chemicals	Vomiting, blood in vomit, distress, sudden collapse, or severe illness	No	Store medications, toxic foods, and household chemicals securely out of reach	Emergency
Heatstroke / Overheating	Non-infectious	Overheating / heat exposure	Distress, high body temperature	No	Cool dog immediately in shade/air conditioning with cool water; avoid excessive heat exposure	Emergency
Skin Allergies	Non-infectious	Allergens	Itchy skin, paw licking, recurrent ear trouble/irritation, sneezing or watery eyes (coughing is rare/not the main sign)	No	Address allergies and follow vet's advice	Outpatient Management
Foreign object ingestion / Swallowed object / Blockage	Non-infectious	Swallowing items like socks, toys, bones, or garbage	Sudden coughing, gagging, repeated swallowing, drooling, pawing at mouth, distress, choking, vomiting, swollen or painful belly, or blockage	No	Keep risky objects out of reach, secure garbage, and supervise chewing	Emergency
Ear infections	Non-infectious	Secondary to allergies or other causes	Ear irritation, discharge	No	Address underlying allergies and follow vet's ear-care advice	Prompt Vet Care
Dental disease	Non-infectious	Chronic dental decay / poor oral health	Bad breath	No	Routine dental care	Outpatient Management
Cancer	Non-infectious	Chronic non-infectious illness	Lumps, persistent sores, unexplained weight loss, changes in appetite	No	Early attention to changes	Prompt Vet Care
Heart disease	Non-infectious	Chronic cardiovascular condition/dysfunction	Cough or fast breathing (at rest or with activity), reduced stamina, weakness, or fainting	No	Not in source	Prompt Vet Care
Arthritis	Non-infectious	Chronic joint degeneration	Limping, difficulty moving, mobility changes	No	Not in source	Outpatient Management

FAQ

Can dogs get sick from ticks and fleas?

Yes. Ticks can transmit illnesses such as Lyme disease, while fleas can cause allergic skin disease, tapeworms, and anemia in heavy infestations. Year-round vet-recommended preventives greatly lower the risk.

Can dogs get the flu like humans do?

Dogs can get canine influenza, which is caused by dog-specific viruses rather than the usual human flu. It spreads between dogs and causes cough, fever, and lethargy, and a vaccine is available.

Can dogs get sick from being out in the rain or cold?

Weather alone doesn’t cause infections, but prolonged exposure can chill small, short-haired, young, or senior dogs and may worsen existing conditions. Dry them off and call a vet if they shiver, seem lethargic, or cough afterward.

Can dogs get sick from eating poop or garbage?

Yes. It can cause stomach upset, parasites, or bacterial infections, and garbage may contain toxins or objects that cause blockages. Seek prompt care for repeated vomiting, a swollen belly, or marked lethargy.

How long does it take for a dog to show signs after catching something?

It depends on the illness. Some infections show signs within a few days, while others, like heartworm, can take months to cause noticeable symptoms. A vet can advise based on the suspected exposure.