10 Deadly Diseases in Dogs

Written and verified by the biologist Samuel Sanchez

Last update: 22 December, 2022

Although the average life expectancy of a domestic canine is 10 to 13 years, there are certain deadly diseases in dogs that greatly accelerate their demise. Some types of cancer, certain congenital defects, and various metabolic disorders can become lethal in these pets, and much more so if not addressed in time.

In this article, we’re going to tell you briefly about the 10 most common deadly diseases in dogs and how to detect them in time. Don’t miss it, because the speed of diagnosis often means the difference between life and death in these animals.

1. Rabies

As indicated by the portal VCA Hospitals, rabies is the most lethal viral disease in wild and domestic mammals, including dogs. The pathogen is transmitted by biting and the symptoms appear in 3 different phases (prodromal, neurological, and comatose). It’s a fatal disease in all cases and causes death within 5 days after the onset of signs.

Gradually, the affected dog loses psychomotor skills, and paralysis of the limbs, facial distortion, and difficulty in swallowing can be observed. Unfortunately, once symptoms set in, death is inevitable.

As there’s no treatment once the disease is contracted, the rabies vaccine is always the best prevention.

2. Distemper

Distemper is another deadly viral infectious disease in dogs. The pathogen affects animals of all ages, but puppies and the elderly are the most vulnerable groups. General symptoms in the affected canine are fever, loss of appetite, dehydration, coughing, and respiratory distress. There’s no specific treatment for distemper, so supportive therapy is preferred.

The death rate of canine distemper is 50% of those affected. Fortunately, a vaccine is available.

3. Cancer

It’s estimated that 1 in 4 dogs will suffer from some type of cancer in their lifetime, a probability that increases to 50% in the senior stage. All the diseases included in the term “cancer” have something in common: the mutation of a cell lineage that causes its unbridled growth. The tumor appears sooner or later and can spread throughout the body by metastasis.

There are many types of cancer in dogs, as tumors can appear in almost any part of the body. In the following lines, some of the most serious and deadly cancers are described in detail.

3.1 Mast cell tumors

These cancers represent the most common neoplasms in dogs and manifest themselves in the form of cutaneous nodules under the skin of the dog. Mast cell derivatives account for more than 20% of superficial malignancies in the species and only 50% of affected dogs live for 6 months after diagnosis.

3.2 Osteosarcoma

Osteosarcoma is the most common type of bone cancer in canines (and young children). The tumor almost always arises in the bony material of the limbs and therefore usually manifests with lameness, difficulty walking, and severe pain in one leg. Treatment almost always involves amputation of the limb, but only 2% of dogs live for 2 years after surgery.

3.3 Lymphoma

Lymphomas are atypical cancers, as they result from an excessive proliferation of white blood cells in the bloodstream and associated organs. Swollen lymph nodes represent the most common symptom of the disease, but the affected dog also often shows apathy, a lack of appetite, and clear weight loss.

The average patient survival after diagnosis of canine lymphoma is usually no more than a year and a half.

3.4 Liver cancer

This type of malignancy is almost exclusive to older dogs, with the average age of diagnosis at 10 years of age. It manifests with nonspecific symptoms, although jaundice (yellowing of the eyes and mucous membranes) differentiates it from other cancers. In its diffuse and aggressive variants, the dog doesn’t live much longer than 3 months after the discovery of the tumor.

Cancers represent one of the most deadly diseases in dogs, as the symptoms usually appear when the tumor has already metastasized to other parts of the body. In addition to the complexity of the treatment, most canines that suffer from them are already quite old.

Up to 50% of dogs will have at least one type of cancer if they reach the age limit for their breed.

4. Gastric torsion

This condition occurs when the canine’s stomach fills with gas and “twists” on itself. It occurs mostly in large breeds with deep chests, as indicated by the American Kennel Club (AKC). The cumulative incidence of this condition is 5.7% of all dogs and the risk increases with age.

Anxiety, breathing problems, hypersalivation, and abdominal bloating are the most common symptoms of this condition. If not treated soon, the twisting of the stomach will make the blood unable to flow properly in this organ and the tissue will die irreversibly.

In this condition, the patient must remain in the clinic for at least 48 hours.

5. Kidney failure

Kidney failure in dogs isn’t a fatal disease per se, but represents a very serious underlying condition that can take the life of the dog at any time. This kidney dysfunction is either acute or chronic and manifests with symptoms such as vomiting, diarrhea, weight loss, loss of appetite, and changes in urinary frequency.

Acute conditions are more easily treated, but chronic kidney damage is irreversible. Over time, kidney tissue is destroyed and scarred, which prevents proper organ functioning in all cases. At this point, palliative care is the only option.

6. Lyme disease

Lyme disease is transmitted by vectors, specifically certain species of ticks. Once infected with the causative bacteria, dogs develop fever, numbness of the extremities, clumsiness, and swollen lymph nodes. This pathology is treated with long-term antibiotics and anti-inflammatory drugs.

If not treated in time, Lyme disease can lead to severe kidney failure and death.

7. Parvovirus

Canine parvovirus is the leading viral killer of dogs, ahead of rabies and distemper. It mainly affects puppies, producing a characteristic alteration of the intestinal villi. This results in lethal diarrhea, vomiting, dehydration, dehydration, and even heart problems.

Without proper supportive treatment in the clinic, 90% of infected dogs will die within hours after the onset of symptoms. Fortunately, the survival rate is greatly increased if the animal is placed in the hands of an emergency veterinarian.

As with all other viral illnesses, Lyme disease can be prevented by early vaccination.

The most deadly diseases in dogs and their prevention

As you have seen, in this article we have shown you a total of 10 deadly diseases in dogs, with special emphasis on cancer and citing the most prevalent types in the species. Malignant neoplasms occupy one of the first positions as far as veterinary emergencies are concerned.

Apart from malignant tumors, viral diseases are usually prevented with proper vaccination, while systemic problems can be alleviated with early detection and intervention. Undoubtedly, taking your dog to the vet for any atypical signs will always be the best approach.