Hypertrophic Osteopathy in Dogs

Old Dog

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Hypertrophic osteopathy is a perplexing condition where new bone formation arises off existing bones, causing painful, swollen limbs. While hypertrophic osteopathy can be resolved entirely, its treatment only comes from identifying and successfully treating a larger, underlying disease.  

What Is Hypertrophic Osteopathy?

Hypertrophic osteopathy is a condition where new bone formation occurs in the limbs of a dog. The disease causes periosteal proliferation, rapid new bone growth, on bones starting in the paw and working its way up the leg of a dog. Interestingly, the abnormal bone growth is a response from a primary, underlying disease. The primary disease can vary, but can often be malignant in nature.  The primary disease causes a disruption in nerve signals which alters blood supply, and promotes growth of new bone on top of existing bone surfaces. Large breed dogs, such as the Labrador retriever, Rottweiler, and Doberman pinscher, over eight and a half years old are more often affected.

Signs of Hypertrophic Osteopathy in Dogs

Signs of Hypertrophic Osteopathy in Dogs

  • Lethargy and reluctance to move
  • Swollen paws or limbs which are painful when examined
  • Lameness 
  • Decreased appetite 
  • Coughing
  • Blood in urine
  • Weight loss

Causes of Hypertrophic Osteopathy

Frustratingly these signs may happen gradually or acutely depending on the severity of the primary disease. The primary disease can vary widely but typically dogs have a tumor of the lung that is cancerous. Certain bacterial or viral infections, bone cancers, or other masses effecting internal organs can also trigger this cascade of new bone growth.

Diagnosing Hypertrophic Osteopathy

If you are concerned your dog may have hypertrophic osteopathy, or if you notice any limb swelling, it’s important to see a veterinarian.

Your veterinarian will start by obtaining a thorough history on your dog. Being able to supply your veterinarian with as much information as possible with regards to the timeline of when symptoms started, activity levels, travel history, and if your pet takes any medications or supplements. When providing an accurate history of your pet, be sure to include if you have given your them any medications at home in an attempt to decrease pain. Some medications, even ones previously prescribed by your veterinarian for pain, can have reactions if taken with newly prescribed medications. 

A thorough physical examination will be performed on your dog. While it can be difficult to see your pet in pain, the vet must carefully palpate, or put pressure, on all the limbs that appear to be swollen. This first step helps to determine any subsequent steps that need to be taken as well as allowing the vet to determine your pet’s level of pain. Understandably, pain medications can be necessary when evaluating swollen limbs. 

Your vet will need to take x-rays of the limbs to diagnose hypertrophic osteopathy. In addition to evaluating the affected bones, your vet will also take X-rays of the chest and abdomen to check for any masses or signs of cancer. An ultrasound may be recommended in evaluating organ structure as it can be more accurate and sensitive with viewing specific organ and soft tissue detail. 

Depending on the initial lab work and diagnostic results, your vet may need to collect additional samples for more specialized testing and evaluation at a larger laboratory.

Treatment of Hypertrophic Osteopathy 

The results of your pet’s history, physical examination, images from x-rays, and lab work will all aid in your veterinarian’s ability to formulate a diagnosis of the primary disease. Successful treatment of the primary disease is the only way to resolve hypertrophic osteopathy. Examples of successful outcomes can include removing a mass through surgery where there was no evidence of cancer spreading or identifying and treating an underlying diagnosed bacterial or fungal infection. Unfortunately, many times a diseased has advanced to the point where treatment is not realistic or a positive outcome is unattainable. 

Early detection and evaluation are key to resolving hypertrophic osteopathy in dogs. Any changes to a pet’s mobility, limb size, swelling, or pain associated with any limbs should be addressed immediately. While it is impractical to suggest you can prevent this disease, there are steps you can take to be proactive with disease detection in general.

Wellness care for dogs requires you to plan a vet visit at least once a year even when no vaccines are due. At every vet exam make sure you give a detailed history and let your vet know if you have noticed any new changes with your pet’s personality, behaviors, eating, drinking, and bathroom habits.  Make sure to inform your vet of any medications or supplements, including alternative treatments, which you are using with your dog. No matter how insignificant they may seem to you, all of these details help your vet to create a health care plan that is designed just for your pup. 

Bi-annual vet visits and routine screening lab work can be helpful for dogs starting around seven years old. Screening lab work checks basic organ function, red blood and white blood cell counts, and is a helpful indicator of internal health. It is helpful to have annual lab work done as it establishes a timeline of your pet’s health and wellbeing. If your pet was ever to become sick suddenly, it can serve as a helpful comparison of their wellness as they age. This history can often provide insight into potential changes you and your vet can make to keep your family member happy and healthy. Some veterinary hospitals offer screening X-rays with their senior pet examinations. X-rays on middle aged and senior pets allow the vet to recognize any changes that are happening internally, making sure heart and lung health, bone changes, and internal organs all appear normal or if there are any changes they can be addressed immediately. 

Making sure your pet can go to the vet at least once a year and bringing them to be examined sooner if a problem arises keeps even the oldest pups in top shape. Like the old saying goes, an ounce of prevention is worth a pound of cure!

The Spruce Pets uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Withers, S S et al. Paraneoplastic hypertrophic osteopathy in 30 dogsVeterinary and comparative oncology vol. 13, no. 3, 2015, pp. 157-65. doi:10.1111/vco.12026

  2. Bone Disorders in Dogs. Merck Veterinary Manual.