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Bone Overgrowth in Cats


Hypertrophic Osteopathy in Cats


Though rare in cats, hypertrophic osteopathy can create extreme discomfort and pain in your pet. It refers to an abnormal increase in size of bone due to new bone formation, which may cause swellings at all four limbs and is often confused with arthritis. Hypertrophic osteopathy may also cause lameness due to swelling and pain at joints and bones.


Symptoms and Types


  • Lethargy
  • Reluctance to move
  • Swellings at distal portions of limbs, especially forelimbs
  • Painful limbs
  • Edema on limbs
  • Decreased movement in joints due to swelling
  • Lameness




The exact cause of new bone formation is still unknown, but this condition has been seen in association with various diseases, including:


  • Pneumonia
  • Heartworm disease
  • Heart disease
  • Tumor of urinary bladder
  • Tumor of liver and prostate gland
  • Lung tumors metastasizing to the affected areas





Your veterinarian will take a detailed history, asking you about the duration and frequency of symptoms. He or she will then perform a complete physical examination. Routine laboratory tests including complete blood count, biochemistry profile, and urinalysis will be conducted. The results are usually normal but may vary depending on the underlying disease, if present. X-rays of the bone may reveal new bone formation and help your veterinarian in localizing the disease. He or she may also decide to take bone sample for further evaluation, including investigating for the presence of tumors.





Diagnosis of the underlying cause and treating it are major goals for the resolution of the problem. However, as exact etiology is still unknown, finding the underlying cause and treating it is not always possible. Your veterinarian will prescribe painkillers to alleviate pain and drugs to reduce swelling at affected sites. In some cases, surgery may be required to remove the tumor mass.


Living and Management


It is important to follow the guidelines and administer medication at the right dosage and time to maintain quality of life. But even after treatment of the primary cause, clinical symptoms may continue for one to two weeks. Bone(s), meanwhile, may take months to get back to its original shape, even with the correction of the underlying disorder and are not known to be fully reversible. Your cat may feel sore and may need therapy for pain management at home.


If a metastic tumor is the underlying cause of the hypertrophic osteopathy, prognosis is very poor.



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