Why Are Dogs Dying

Veterinarians can provide bereaved owners support because some conditions are frequent in cats and dogs.

The situation might be as follows: When pet owners get home, they discover their cat or dog has unexpectedly passed away with no indication of what specifically went wrong.

In this circumstance, pet owners frequently consult their veterinarian. They might switch to an emergency practice instead, depending on the situation.

A veterinarian may occasionally be able to identify the cause of death with relative ease. In other situations, the owners of the animal might decide to have a necropsy.

There isn’t much information regarding abrupt unexpected death in cats and dogs in veterinary literature. In 2000 and 2001, two studies from the University of Saskatchewan Western College of Veterinary Medicine were published in The Canadian Veterinary Journal: “Causes of sudden and unexpected death in dogs: a 10-year retrospective study” and “Causes of sudden and unexpected death in cats: a 10-year retrospective study.”

The researchers looked at records of older dogs and cats that had been thought to be healthy but had been brought to the veterinary college for a postmortem investigation. Heart disease, toxicosis, gastrointestinal disorders, trauma, and hemorrhage unrelated to trauma were the top five reasons of sudden unexpected death among 151 dogs, in that order. There were 79 cats, and the top five causes of death were, in no particular order, trauma, heart disease, intestinal disease, respiratory disease, and urinary tract disease.

Experts were consulted by AVMA News to discuss how practitioners might approach these situations, what to look for, and why it’s crucial to provide pet owners with as much information as possible.

Finding an answer

There aren’t many experiences that are more upsetting for a pet owner than discovering a dead animal in their house, yard, or neighborhood, according to Dr. Stalker. One of the main reasons companion animals are sent to the Animal Health Laboratory for postmortem testing is to identify the cause of sudden unexpected death.

Dr. Stalker compiled reasons of sudden unexpected death for the Ontario Animal Health Network, a disease surveillance network, from September 2015 to September 2019. Top causes among 150 dogs included underlying hidden neoplasia, primarily hemangiosarcoma, heart illness, pulmonary disease—more than half of which were brought on by inhaled food—trauma, and gastrointestinal mishaps.

The most frequent causes of sudden unexpected death in 71 cats were underlying heart illness, with cardiomyopathy accounting for nearly all instances, trauma, various inflammatory conditions, cases with no obvious cause of death, and various infectious diseases.

In an interview, Dr. Stalker stated that veterinarians frequently advise pet owners to visit the Animal Health Laboratory to ascertain the reason for a sudden unexpected death. When pet owners leave an animal behind, they are typically very upset. Some animals are delivered by courier or by the doctor who referred them. The necropsy results are discussed by the laboratory with the referring veterinarian.

The animal frequently has an underlying ailment. Hemangiosarcoma in dogs kills quickly and exhibits oblique clinical symptoms. Cardiomyopathies in cats can be clinically silent or extremely subtle.

The most common causes of trauma death in pets include being struck by cars or being attacked by predators like coyotes. Dr. Stalker did discover five cases of canine rodenticide poisoning, but she doesn’t think those were done on purpose.

Prior to her pathology studies, Dr. Stalker spent a few years working in clinical practice. She uttered: “I recognize that you deal with these intensely emotional circumstances, so I think it’s important to let you know that you can get in touch with your neighborhood diagnostic lab. In most cases, an answer is found, though it almost certainly costs money and may or may not be worthwhile to the owner.

She went on, “We can never guarantee that, but if there is something there, we’ll try our best to locate it. In this small case series, 5 to 8% were indeterminate.

Dead on arrival

Findings from the University of Saskatchewan and later the University of Guelph were comparable to these findings. From January 1, 2007, to May 31, 2012, there were 112 cases of sudden, unexpected death in dogs, with the cardiovascular system being most frequently involved. Other major contributing factors included lung disease, gastrointestinal disorders, trauma, and toxicosis.

When a pet passes away unexpectedly after regular business hours, pet owners may travel to an emergency hospital, according to Dr. Erick Mears, an internal medicine specialist and the medical director of Tampa Bay, Florida-based BluePearl Specialty and Emergency Pet Hospitals.

Unfortunately, the main problem with our veterinary patients is that they frequently won’t necessarily exhibit symptoms of illness, according to Dr. Mears. Pet owners frequently don’t become aware that their animals are ill until the animal passes away suddenly from a tumor, an irregular cardiac rhythm, or a blood clot in the lungs.

In some instances, a pet owner may have been treating a pet’s underlying ailment when the pet passed very suddenly due to the condition’s catastrophic progression. Other famous causes of sudden unexpected death in Florida, but not unexplained death, include alligator attacks and drowning in swimming pools.

According to Dr. Mears, a necropsy is a technique to determine what happened in cases of inexplicable death. However, even the postmortem examination may not be able to detect, for example, a clot that dissolves. If the circumstances permit, BluePearl might offer pet owners the choice of a necropsy and, in Florida, perhaps collaborate with veterinary pathologists at the University of Florida College of Veterinary Medicine.

Do we always receive a response? Dr. Mears stated that we don’t. However, they can undoubtedly help eliminate out a number of possibilities. And occasionally they can recall what actually occurred.

The pet owner and the animal will be delivered to the university by BluePearl, and the institution will inform BluePearl of its initial findings. Depending on the circumstance, either the institution will work directly with the client or BluePearl will interact with them to assist in interpreting the results.

In general, BluePearl will also contact the pet owner’s regular veterinarian in cases of sudden death via phone, email, or both to share information with them, such as the outcome of a necropsy.

Giving closure

Necropsy Services Group, a three-person business in Davis, California, specializes in performing necropsies on cats and dogs. Dr. Taylor Spangler, Dr. Mai Mok, and their colleague, Dr. Bill Spangler, assist in running NSG. They are all veterinarians and pathologists.

Considering the region’s low capacity for professional necropsies

Necropsies on instances from outside the University of California-Davis School of Veterinary Medicine are not typically performed.

In 2008, Dr. Spangler launched NSG to provide the service.

Dr. Taylor Spangler, who works full-time at VDx Veterinary Diagnostics in Davis, said he occasionally speaks with pet owners immediately after their pet has passed away. This is especially true when they discover NSG through a Google search or a reference from the university. It’s not unusual for us to answer the phone and ask, “Necropsy Services Group, how can I help you?,” before hanging up for 15 or 20 minutes as the owner unloads.

The majority of cases at NSG involve sudden, unexpected deaths in young animals. Death can be brought on by illness or being hit by a car. In addition to other situations, NSG receives calls from veterinarians when cats or dogs pass away unexpectedly during or immediately following general anesthesia. A necropsy may reveal underlying reasons or indicate an issue with anesthesia.

The NSG veterinary pathologists spend a lot of time on the phone with pet owners, discussing the results. According to Dr. Spangler, they have perfected their abilities to discuss a pet’s passing and provide owners with logical reasons as to what might have happened and why.

Although a diagnosis of purposeful poisoning is relatively rare at NSG, clients sometimes call with the concern that their neighbor has poisoned their animal companion. NSG does get involved in situations of animal abuse and neglect that are prosecuted as crimes as well as those involving chronically ill animals whose conditions were never properly diagnosed by the vet.

Dr. Spangler remarked, “I believe clinicians can undervalue pet owners’ need to comprehend why their companion has passed away.

The ability to discuss what happened with a qualified pathologist and to be aware of the intricacies of what occurred is often really appreciated by our clients. These animals were cherished family members, and the necropsy and the information it offers appear to significantly aid in the grieving process. It helps them reach a resolution.

Do dogs realize when they are dying?

We are aware of how frightening this inquiry might be, but Dr. Ann Brandenburg-Schroeder want to bring some comfort to pet owners going through a trying period. After seeing the gentle loss of her own cherished canines, she realized it was her calling to offer an at-home euthanasia service to help other animals experience the same blessing. She reassures owners on her website, Beside Still Water, “Animals know when they are dying. At least not in the same way that we are. They do not fear death. They reach a point of acceptance as they draw closer to death and make an effort to convey it to us.

If you want to know how a dog can express that they are ready to die, continue reading.

How do dogs behave before passing away?

Many of these symptoms are also signals of diseases that can be treated. A trip to the vet is necessary to have your dog inspected if he exhibits even one unsettling change, especially if he has been doing well up until that time. Your veterinarian can advise you as to whether your dog’s condition is treatable or whether he faces more serious difficulties based on the examination and any diagnostics that are conducted.

Senior dogs frequently suffer from diseases like diabetes mellitus, liver failure, renal failure, cancer, and heart failure. When these illnesses are detected early, they are frequently treatable, but as your dog ages and his sickness worsens, his condition may get worse. When several diseases are present at once, it can be more painful and challenging to treat them.

Extreme Weight Loss

Senior dogs frequently lose weight, and it usually begins well before death. The dog loses muscular mass as he ages because his body is less effective at digesting protein, which is a normal part of the aging process. Increased protein in the diet that is simple to digest can slow this process.

Weight loss can also result from illness, either as a result of decreased hunger brought on by illness or as a result of the body being under more stress. Cancer patients who lose a significant amount of weight are said to have cachexia. Cancer cells need a lot of energy as they perpetually divide and spread, and this need for energy can cause your dog’s muscles and fat reserves to break down.

Even if the dog is still eating substantial meals, weight loss frequently quickens as the dog gets older or sicker.

Lethargy and Fatigue

Older dogs snooze a lot. Your dog will start to sleep more and become more easily worn out as his life draws to a close. Instead of going on walks and other trips like he used to, he could decide to stay at home on his dog bed.

Poor Coordination

Your dog’s muscles and nerves lose some of their former functionality as his body matures. His coordination will deteriorate due to the decrease of muscular mass and the dysfunction of proprioceptive neurons. He might have trouble climbing stairs, getting around barriers, or slipping on non-carpeted floors. Some dogs stutter or have problems putting their feet in the right places when they walk. These symptoms are typically progressive, starting out as infrequent, minor bumbles that gradually increase in frequency and severity. Additionally, some dogs may twitch their muscles without meaning to.

By giving your dog non-slip surfaces to walk on and supporting him when walking and going outside to relieve himself, you can help your dog. Ramps are useful for climbing up and down stairs and onto and off of furniture, but they also serve as a spotter in case the user loses balance and falls off a narrow ramp.


Senior dogs often experience incontinence, or loss of control over the urine and/or intestines. There are numerous causes for this that may all be fully treated (for example, urinary incontinence due to a urinary tract infection).

Some dogs may urinate or defecate while they are asleep, while others may dribble urine or even urinate while moving around seemingly unaffected. Considering that our dogs naturally don’t want to soil the house, incontinence can be irritating to them. Never chastise your dog for having these mishaps; doing so will simply make him feel worse. Medication and more regular outside excursions can both be beneficial. As your dog gets closer to the end of his life, incontinence frequently gets worse.

Decreased Mobility

Reduced mobility is a typical aging sign that will only get worse over time. This could be as a result of discomfort brought on by arthritis or other old injuries, a loss of muscle mass that reduces strength, or confusion brought on by deteriorating vision. Changes in mobility frequently begin quietly, with the dog trotting after a ball rather than running, and then steadily worsen to the point where the dog can no longer jump onto furniture or into a car, struggle with stairs, or have difficulty getting up after a nap.

Making ensuring the food and water bowls are simple to reach and using a sling or harness to help your dog enter and exit the house are both helpful ways to assist your dog. He could require assistance standing up. Eventually, he might not be able to stand still at all and might have trouble walking.


Canine cognitive dysfunction (CCD) and human dementia share many similarities. Early indications of CCD include fussiness, irritability, and nighttime pacing. As time goes on, your dog could act as though they are strangers or that they are becoming lost around the house and yard. When rousing a sleeping dog with CCD, exercise extra caution since they may nip or snap if they get confused about their surroundings or what is happening.

Behavior Changes

When a dog is dying, they may exhibit a range of behavioral changes. From dog to dog, the specific alterations will differ, but the important thing is that they are changes.

Some dogs will become agitated and start to pace around the house, appearing unable to settle or find comfort. Others will be unusually quiet and possibly even silent. The sleeping habits of your dog may alter. He can become irritable and challenging to manage as a result of discomfort or confusion.

Some dogs become overly dependent on their owners’ comfort and company, while others become more lonely and seek out peaceful places to be by themselves. Some dogs seem to be able to sense when they are going to pass away and will wander off to a quiet spot in the house or yard to spend their last moments.

Dehydration and Not Drinking

Water is crucial for the health of your dog. He can become less interested in his water bowl as he aged or gets worse. To improve his intake of moisture, try adding water to his meal or feeding him a canned diet.

In some circumstances, it may be permissible to administer water using an oral syringe or squirt bottle (always use a fresh container that has never contained cleaning agents), but proceed with caution. Only squirt a small amount of water into your dog’s mouth at a time while aiming his muzzle downward. Too much water forced into his mouth runs the risk of entering his lungs and trachea, leading to aspiration pneumonia and choking. The moment your dog feels water on his tongue, he ought immediately begin to automatically swallow. Sucking reflex loss is a very serious indicator.

Poor Response to Treatments

Your dog may stop responding to treatments and medications that used to keep him happy and healthy as his body ages. A dog with diabetes may need apparently unending insulin dose adjustments, while a dog with arthritis may need more painkillers. Even with medication and appetite stimulants to keep him eating, a dog with cancer may continue to lose weight and worsen.

Dull Eyes

The eyes of dogs towards the end of their lives frequently change. Your dog’s eyes could appear dull or glassy to you. When combined with other symptoms, changes in the appearance of the eye(s) can signal the end of life, albeit these changes are frequently just a sign of an eye disease on their own.

Poor Temperature Regulation

Aging and sickly dogs frequently struggle to control their body temperature, easily becoming overheated or chilly. Provide your dog with a shaded, well-ventilated spot to rest if you live in a warm region. Make sure your dog has access to a warm, snug bed in colder climates, as well as a pleasant warm space to lie in the sun or next to a radiator.

Lack of Appetite and Not Eating

At the end of life, nausea is a regular occurrence. Dogs who are ill frequently don’t want to eat, and some drugs may make food less enticing to your dog by causing him to lose his sense of taste or smell. Try giving your dog foods with a strong aroma so he can smell them better to improve his interest in food. You may also warm his food to make it smell better.

To increase your dog’s appetite, your vet may also recommend an appetite stimulant. A prescription for an antiemetic like Cerenia may be given if it is thought that your dog might be queasy.

Lack of Interest and Depression

Dogs frequently lose interest in their favorite things near the end of their life, including walks, toys, food, and even their devoted owners. When you pay closer attention, you’ll see that your dog no longer does things like meet you at the entrance or wag his tail when you tease him with a favorite toy. At first, it could just seem like your dog is sleeping more.

Dogs with mobility issues could get depressed because they can’t do the things they once enjoyed, which can cause frustration.

Abnormal Breathing

The muscles and nerves in your dog’s body that control breathing are not immune to the body’s progressive decomposition. Your dog may begin to exhibit aberrant breathing patterns, with ups and downs in his respiratory rate even while he is at rest. Periodically, he may stop breathing, then start again.

Open-mouth breathing, straightening out his head and neck while keeping the rest of his body steady, or moving his abdomen in and out while breathing are all indications of trouble breathing. It is urgent that this situation be handled right away.


Towards the end of their life, some dogs may start having seizures. This may be brought on by metabolic disturbances brought on by illnesses like kidney failure or by issues with the brain itself. These seizures may or may not respond to treatment, depending on the underlying reason and their severity. Emergency situations include seizures that last longer than 10 minutes or that happen in a series of clusters.