The Most Horrifying Dog Diseases You’ve Never Heard of

No one wants to think about their sweet pups getting sick, but sadly there are a lot of deadly diseases that can strike your dog. But while you’ve probably heard of ailments like parvovirus and kidney failure, many other scary ailments exist that you’re most likely not even aware of.

We do all we can to keep our pups healthy, but sadly there are many things that threaten their well-being. Being informed and recognizing symptoms early is all you can do, so watch out for these scary signs.


Cute pomeranian dog sleeping on pillow on bed
Look for the warning signs. | beer5020/iStock/Getty Images

It’s true, dogs can get hypothyroidism — and just like with humans, if it’s left untreated, it can be deadly. Hypothyroidism can cause a lack of energy and an inability to recuperate from other ailments. Look out for these signs:

  • Excessive shedding
  • Excessive weight gain
  • Dull coat
  • Lethargy
  • An inability to tolerate the cold

Next: This disease is so contagious, dogs who contract it are kept in isolation. 

Chagas disease

Bichon Frise dog
It’s transmittable to humans. | Eudyptula/iStock/Getty Images

Both humans and canines can contract Chagas — in fact, it’s one of the few diseases a dog can pass on to a human. The disease is caused by an infection of Trypanosoma protozoa, a parasite that lives in blood-sucking insects. Here’s the worst part: Some dogs who are affected die suddenly before they even show any signs of illness.

Symptoms of Chagas include:

  • Fever
  • Fainting
  • Pale gums
  • An irregular pulse or heartbeat
  • General weakness

The disease can be treated with medication, although not all dogs will respond. Once your pup is diagnosed, they’ll be isolated — it’s that contagious.

Next: If your dog limps for no reason, watch out.


limping dog
It’s treatable with surgery. | CriDam/iStock/Getty Images

Also known as LCPD, Legg-Calve-Perthes is a developmental orthopedic disease that causes degeneration of the femoral head, the top portion of the femur leg bone. Terrier and toy breeds are especially susceptible, and it tends to hit them young. Signs of LCPD are:

  • Trouble walking
  • Trouble getting up
  • Difficulty going up stairs
  • Favoring one leg
  • Holding one leg up
  • Pain with manipulation of the hip joint

LCPD is treatable, and although it involves surgical removal of the affected femoral head and neck and lots of rehabilitation, dogs can make a complete recovery.

Next: Alabama what?

Alabama rot

Little dog playing on the beach mud
It’s common in muddy areas. | Sirius_clouds_fan/iStock/Getty Images

Alabama rot is most common in muddy areas, and the cause is unknown. While it can be treated, only 20-30% of dogs will respond to treatment. Worse, this deadly disease mimics other more harmful ailments, so some owners miss it.

If you live in a muddy area, pay close attention to these symptoms:

  • Lesions and sores on the skin, typically paws and legs
  • Loss of appetite
  • Lack of energy
  • Vomiting
  • Changes in the amount of urine produced

Within a week of contracting the disease, a dog can go into kidney failure, so paying close attention is critical.

Next: We really wish this disease had died out centuries ago.

The bubonic plague

Woman walk With Labrador in forest
It’s rare but possible. | monkeybusinessimages/iStock/Getty Images

If you live in a rural, heavily forested area, beware: If your dog gets fleas, they may be contaminated by plague bacteria. This is rare — there are only about 17 cases each year — but it happens. Symptoms include:

  • Swollen lymph nodes
  • Fever
  • Inflammation
  • Depression
  • Vomiting
  • Diarrhea
  • Enlarged tonsils

The sooner your dog starts antibiotics, the better their odds are of beating it.

Next: Your dog’s adrenal glands can act up just like yours.

Addison’s disease

Sad French bulldog
It causes lethargy and excess thirst. | bruev/iStock/Getty Images

Addison’s disease is very rare in dogs, but it’s caused by the adrenal glands under-functioning, leading to a decrease in the essential mineralocorticoids and glucocorticoids. Watch for these warning signs:

  • Lethargic behavior
  • Frequent thirst and urination
  • An extreme lack of appetite
  • Vomiting, diarrhea, and weight loss

If you notice these symptoms, a urinalysis, blood count test, and complete lab tests will help your vet pinpoint the problem.

Next: Here’s how to keep your dog healthy. 

Here’s what you can do

girl spending time with lovely jack Russel Terrier dog
Many dog diseases are manageable with the right support. | Artem Tryhub/iStock/Getty Images

While disease can strike any dog at any time, there are definitely things you can do to keep your pups happy and healthy. Serve them nutritious, well-balanced food, either homemade or store bought with transparency on the ingredients. Make sure they get plenty of exercise, and see your vet regularly.

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