Can Dogs Get Leprosy?

The very word "leprosy" probably brings movie images of people covered in what look like festering boils who are missing fingers, toes, limbs, and other body parts. Since the first time a case of leprosy was diagnosed we have feared this terrible disease and, in many cases, misunderstood it.

Can Dogs Get Leprosy?

YES!

It may be technically possible for dogs to contract leprosy as we know it. While the vast majority of people (including medical professionals) have never seen a case of leprosy, it has been prevalent in many societies throughout history. Even today, there are carriers such as the lowly armadillo who have the bacillus Mycobacterium leprae in their bodies that can be passed on to humans and, possibly, other animals.

However,  dogs are vulnerable to a different strain of bacterium than humans, so their ‘leprosy’ is more likely the result of exposure to the bacterium, Mycobacterium simiae. Infection can lead to a case of  “canine leprosy”, or canine leproid granuloma syndrome (CLGS). This condition is very similar to leprosy in humans in that it does cause nodules or skin lesions to form, but it is believed to be spread via biting insects, rather than exposure to infected body fluids.

Also, dogs are vulnerable to a condition with a similar name known as leptospirosis. This is a potentially dangerous bacterial infection that can be spread between species and cause liver and kidney damage.

Does My Dog Have Canine Leprosy?

Signs of canine leprosy, or CLGS, generally include skin lesions or raised masses. These skin issues are generally painless, and may appear on any part of your dog’s body, though they are most common on the head, ears, and forelegs. In order to diagnose the condition, your vet will likely make a visual examination of your dog’s lesions and may take skin samples (biopsy) for analysis.

To learn more, visit our guide to Canine Leproid Granuloma Syndrome.

How Do I Treat My Dog's Canine Leprosy?

A bit of good news regarding canine leprosy is that it is relatively easy to treat. In fact, the condition often resolves on its own without treatment. If necessary, though, your vet may prescribe an antibiotic for your dog, and recovery can usually be expected within a few months. In some cases, surgical removal of the lesions may be recommended, but recovery should be uncomplicated.

How is Leprosy Similar in Dogs and Humans?

There are a few ways in which canine leprosy and human leprosy are similar. These include:

• The formation of hard granules or nodules under the skin

• Causes skin damage

• Can be easily treated with modern medicines

How is Leprosy Different in Dogs and Humans?

There are a few key differences between canine leprosy and human leprosy: 

• Leprosy and canine leproid granuloma syndrome are caused by different bacteria

• Canine leproid granuloma syndrome is believed to be transmitted by biting insects, rather than contact with infected body fluids

Case Study

An 8-year-old male German Shepherd was taken to his vet with firm raised masses on his ears. The vet took several biopsy samples and the dog was treated using cephalexin and then enrofloxacin. Within 3 months, all of the lesions had completely regressed, leaving behind areas of depigmented skin. The dog made an otherwise full recovery.