Of limping and ringworm

Dear Dr. Forsythe: Our six-month-old lab puppy has started limping in his front legs after we play with him. At first it was after we played, but now he is doing it more often.  He favors one leg one day and then another leg the next day.  We can’t really tell which leg he’s doing it on.  We don’t think he fell or was injured so we aren’t sure what is happening, and we don’t think it is in his hips since it seems worse in the front most of the time.  He has been suffering in pain for two weeks now so we are starting to think about taking him back to the breeder where we got him.  Do you think we bought a bum dog? – Waiting for advice in Sonoma

Dear Waiting: While I can’t really tell you if your dog is a bum, I can tell you that what you are describing sounds a lot like a rather common disease of the long bones in large breeds of young dogs (most commonly the German shepherd).  It is called Eosinophilic panosteitis. The problem you’ve described is also called osteomyelitis, enostosis, fibrous osteodystrophy, juvenile osteomelitis, and “Eo Pan” by breeders.

Although the disease causes severe lameness, you’ll be glad to know that the problem is self-limiting which means that it will go away by itself.  It’s terrible to see your big, sweet puppy limping and whining in pain, and I know you worry you got a bum dog, but if this is pan osteitis – and there is a good chance it is – it may not be as terrible as it seems. Little is known about what causes this disease, although infection, metabolic disease, endocrine problems and hereditary factors are thought to be involved.

I suggest you have a good set of X-rays taken to confirm a diagnosis and to rule out something more significant, such as a traumatic injury, a fracture, and hip or elbow dysplasia. Treating the pain and inflammation are important, and many veterinarians recommend curbing the amount of groceries you feed to quickly growing large breed dogs and reduce the chance of growth spurts. Reduce vigorous exercise to eliminate sudden stress on the long bones.  These cautionary actions will allow for a slower lengthening of the bones and help reduce the severity of the disease.  A bum dog?  I say nay!   Labs are a mainstay in the American home.  I’m sure your pet is not a “bum” dog, but a wonderful chum.  It would be wise to inform the breeder as to the outcome of this medical problem since there is a good possibility that other puppies in the line are affected as well.  Thanks for your question and I hope your Lab is well soon. – Dr. F

Dear Dr. Forsythe: My 14-year-old son recently got a severe skin sore that was diagnosed as ringworm by his pediatrician.  The doctor asked me if we had a family dog and I told him about our Jack Russell “Rusty.”  I also informed him that Rusty is current on all his vaccines and even had been tested for ringworm recently in order to get his prescription for the monthly Heartgard he takes, so there is no way the dog could have given ringworm to my son.  Where do you think my son could have gotten ringworm? – Rusty’s owner

Dear Rusty’s owner:  First of all, I want to clear up the confusion that ringworm is not a worm at all, but a zoonotic infectious fungal infection.  You seem to be confusing it with Heartworm infection, a parasitic worm which is spread from mosquitoes and infects their hearts with long skinny worms.

Your dog Rusty most likely received an annual heartworm test while he was at the veterinarian to check his blood for heartworm disease – a routine test done as part of good preventative care to make sure a dog is free from the life threatening parasite. Vets do not routinely check for ringworm (dermatophytes) unless a pet presents with a pink raised skin sore or an owner says that someone close to the pet has developed sores that fit the description of ringworm.  In that case the DVM would want to check the dog over with an ultra-violet “Black Light” for the presence of ringworm.

The ringworm your son was diagnosed with, however, is really a misnomer since it is purely a fungal infection and no worms are involved.  Although it is quite a nuisance, your son should respond to the medication he received.  It’s quite possible that your son was exposed to ringworm from gym clothes or a wrestling mat.  A common source for dermatophyte infection in high school age kids is gym class.  So the saying “Cleanliness is next to Godliness” is appropriate in this case. – Dr. F.