HOD, Physitis and Epiphysitis


Hypertrophic Osteodystrophy - vitamin C controversy

Question: Hi, I read a good article on your site about Hypertrophic Osteodystrophy (HOD in puppies. In the article there is however a statement I was wondering about. It is the contrary of what I have learned. Author of the article is: Michael Richards, DVM. It says: "There is a persistent rumor that vitamin C supplementation is beneficial in dogs with HOD. This appears to be a false rumor and there is some evidence that vitamin C may actually promote abnormal calcification in these puppies. It is not a good idea to supplement vitamin C." Could you please give me the references to where I might read more about this? Thank you very much. I really enjoyed your site! Best wishes from Annegry

Answer: Annegry- This is a reference that is available at the PubMed site online: Ascorbic acid deficiency and hypertrophic osteodystrophy in the dog: a rebuttal Teare JA, Krook L, Kallfelz FA, Hintz HF It is easiest to search on the author name -- just use Teare JA as the search term. There are a couple of other references to this but I couldn't find any of them online. This information is consistent with research on cats who are being fed diets meant to acidify urine as they often have increases in calcium concentrations in the blood stream, as well. Mike Richards, DVM 7/7/2002

Hypertrophic Osteodystrophy

Question: Dr. Richards, please help. I have a 3 1/2 year old Dalmatian bitch named Sage. She's been plagued by a variety of health problems stemming, we believe, from vaccine reactions. Most recently, she has developed swelling in the 2nd inside toe of ALL four paws. The same toe on each paw. At first our vet thougt it was an infection as only 1 toe was affected and she's been on antibiotics since then for 5 weeks with one week off (she is currently taking them). However, when we went back most recently she x-rayed all 4 paws and found the same swelling. After researching the matter she found it might be something called HYPERTROPIC OSTEOPATHY. I found your site and the Q&A regarding HYPERTROPIC OSTEODYSTROPHY which seemed the same type of thing. Also, the right front toe is gradually increasing its swelling.

Her paws ache, she doesn't like to walk much, and we don't know what to do. She's taking Rimadyl 100mg but that hasn't seemed to help the last couple of days. Also, even if it gets its efficacy back, she can't stay on it indefinately due to the liver damage it causes. What are our options?

You mention in your web response that some cases spontaneously heal. If that happens, what are the chances for recurrance? If we have the toes surgically repaired (if that become an option) what are the chances that they will revert to their current state? What is the long-term prognosis? will the illness spead to the rest of her limbs/joints or will it stay localized? what are the degenerative possibilities of the illness?

General background: Sage has a heart murmur, grade 1-2; vaccination history: 6 months - severe uninary tract infection; 1 1/2 year - severe prolonged case of felliculitus; year 2 1/2 - noticable enlargment of all muscles (i.e. her jowls bulged out and have remained so); 3 1/2 - hypertrophic osteopathy?. Each vaccination accompanied by successive weight gain which was never lost. She is 24" at shoulder & 85 lbs w/no excess fat. All reactions occured within 2-5 weeks of vaccination. At other times she's very healthy.

In addition to any information you can give us, do you know of any specialists in this area who might be able to help us?

Thanks very much, Jason

Answer: Jason-

I do think that you need to seek the help of a specialist, if possible. I do not know the names of specialists in your area, though. Your vet should be able to help you locate an internal medicine specialist who is not too far away. If that is not feasible, it is possible that a dermatologist might be able to provide assistance in this case, as well.

It would be odd for an adult dog to develop hypertrophic osteodystrophy. This condition primarily affects puppies and is associated with vaccine reactions, especially in Weimaraners. It is swelling around the growth plates, usually involving the carpus (wrist) of the front leg and often other growth plates, as well.

Hypertrophic osteopathy is excessive bone deposition along the long bones of the legs which often also involves the toes. This condition occurs when there is a space occupying lesion in the thorax (chest), usually a cancer or infectious disease that produces granulomas in the lungs. It does fit the clinical signs that you are seeing and it would be a really good idea to get chest X-rays taken to look for a mass in the chest, if that has not been done yet. If there is a mass there, it would make the diagnosis much more likely to be correct. The only really successful treatment is removal of the mass (or treatment that makes it go away in the case of some infections, especially fungal illnesses). It can be hard to rule out a mass in the chest so it may be necessary to consider ultrasound examination or even an MRI or CT scan if the signs are strongly suggestive of this problem but a mass is not found with X-rays and ultrasound.

Other possible problems include self inflicted trauma due to itchiness of allergies, immune mediated disease or infections (this last one does seem odd considering the distribution of the lesions). It would also be possible that vasculitis (inflammation of the blood vessels) may be occurring as a form of vaccine reaction and affecting areas with poorer circulation, such as the toes. If this is the type of problem present a dermatologist might be better to consult with than an internal medicine specialist, so starting either way seems reasonable to me.

All of these conditions could potentially get much worse but hypertrophic osteopathy will certainly get worse if the underlying cause can not be dealt with by treating the inciting wound in the chest.

I would think really hard before vaccinating Sage with the combination distemper, parvovirus, parainfluenza, adenovirus vaccines --- with or without other ingredients such as leptospirosis or coronavirus. Recent evidence points to a long duration of immunity from these vaccinations and the risk to Sage of the vaccines is almost certainly higher than the risk of the diseases for at least three years or so --- and skipping a couple of years might give you a feel for whether this is just a seasonal problem or an intermittent problem that is not related to the vaccination but has coincidentally been happening around the time of vaccination.

Good luck with this. I wish that I was familiar enough with the specialists in your area to recommend someone.

Mike Richards, DVM 1/9/2001

Hypertrophic Osteodystrophy or HOD

Q: Dr. Mike, I'm looking for information on some thing called,(please pardon my spelling) ... Hypertheradic Osteo Distrophy... has something to due with growth in puppys, seems to affect the limbs on either side of the joint. I would be forever in your debt if you could help me find some info on this very sad situation. Thank you, C.

A: I think that you are seeking information on hypertrophic osteodystrophy or HOD.

Hypertrophic osteodystrophy causes lameness and extreme pain in young growing dogs, usually of a large breed. Great danes, German shepherds, dobermans, retrievers and weimaraners are examples of breeds that may be affected by this condition. It appears to occur in weimaraners as a vaccine reaction and this may also affect mastiffs and great Danes. In this case, it usually occurs a few days after vaccination and may appear to be worse than the "average" case on radiographs.

HOD usually shows up as an acute lameness, often seeming to affect all four legs simultaneously. Affected dogs may stand in a "hunched up" stance or refuse to stand up at all. They may have a fever but this is not consistently present. They usually have painful swellings around the lower joints on the legs. Some puppies will die from this disease, some suffer permanent disablity but many recover later. The disease is so painful that many owners elect to euthanize the puppy rather than watch it suffer, despite the reasonably good chance for recovery, long term. Affected dogs may be so ill that they refuse to eat.

X-rays confirm this diagnosis in most cases. There are very typical X-ray changes, although it can look a little like bone infection from a septic condition. There is some evidence at this point that viral or bacterial infections may underlie some cases of HOD as canine distemper virus has been found in the affected areas in some dogs. There can be high white blood cell counts and the alkaline phosphatase level in the blood stream is often elevated.

There is also a theory that this condition may occur with excessive dietary levels of calcium or protein. I am not sure what the current status of this theory is.

Treatment usually consists of analgesic medications such as aspirin or carprofen (Rimadyl Rx). Since a viral or bacterial agent may be involved in this problem the use of corticosteroids is questionable. Many people try switching to a diet that is lower in calcium (the puppy foods for large dogs may be a good choice now that they are available. Previously many people switched to adult dog foods which didn't always result in lower total calcium in the diet). Even more potent pain relief medications may be indicated in some puppies. Hydrocodone and aspirin may be a more effective combination than either one alone. Antibiotics are often given for this condition. There is a persistant rumor that vitamin C supplementation is beneficial in dogs with HOD. This appears to be a false rumor and there is some evidence that vitamin C may actually promote abnormal calcification in these puppies. It is not a good idea to supplement vitamin C.

Hypertrophic osteodystrophy may resolve spontaneously in as short a time as a week or so. It can be a recurrent, cyclic infection that goes on for a long time, too. If there are severe secondary bone changes, surgical correction of these may be necessary for normal future function of the limbs.

There is no reason not to control pain as effectively as possible with this condition. That definitely needs to a primary goal of treatment.

Mike Richards, DVM

Physitis, epiphysitis or HOD and puppy food

Q: Dr. Mike: I have a 10 month old Afghan Hound (Male).. He has been diagnosed with a condition generally found in Horses called Epiphysitis, an inflamation of the growth plate. He has been placed on a Senior Diet and medication called GLYCOFLEX. Do you have any experience with this condition and are we following the right course of action? Secondly, should owners of larger breed canines stay away from the new generation puppy foods to help prevent these growth conditions? Thanks, Don

A: Don- Physitis or epiphysitis is pretty unusual in dogs but is reported to occur. It can be confused with hypertrophic osteodystrophy (HOD) which causes physeal inflammation most commonly in the front legs. I do not know if a particular cause for this condition is known, making all therapy other than pain relief, pretty theoretical.

From a dietary standpoint there are two common concerns about puppy foods. The first is that there is too much calcium and that some conditions may be related to calcium levels, such as HOD or hip dysplasia. To the best of my knowledge there is no strong evidence to support these claims except when calcium is excessive. Usually it is necessary to supplement calcium in addition to that found in dog foods in order to cause problems since most dog foods are now AAFCO approved and the maximum calcium level in approved foods is 2.5%. Dog food manufacturers are like any other business, though. If YOU think that puppy foods higher in calcium cause problems and enough people agree with you, even if they are wrong, the puppy food manufacturer (or a puppy food manufacturer) will produce a food claiming "lower in calcium" and playing on that fear-- because they want to sell you dog food. If you are restricting the total daily calories it is probably not too important whether you feed a puppy food or not but most people have a hard time cutting the food volume down so feeding an adult dog food approved for all life stages allows people to give a little more food in the bowel to achieve the same number of calories.

The other problem with puppy foods that is commonly seen as a problem is the protein level. I am pretty sure that the higher protein levels are not a problem from the standpoint of damage due to protein levels. There just isn't much proof that high protein levels cause any problems at all. The major problem with high protein levels is that the puppy will convert excessive protein into calories. Puppies usually do not need more than 22% protein in their diet and can get by with less in most instances.

The nutritional factor that doesn't seem to get much press is caloric density. High calorie foods lead to fat puppies and fat puppies have orthopedic problems more commonly than thin puppies. A growing puppy should be thin enough that your neighbors ask you, with real concern, "are you feeding that puppy enough?". If you like your dogs a little on the chunky side, wait until they are at least a year, or ideally two years old, before letting them get a little padding on their ribs and over their rumps. I am pretty certain that excessive caloric intake is the most important nutritional factor in causing orthopedic problems in puppies. Feeding a "Senior" diet may not be sufficient in some puppies for calorie reduction. Feeding a "Lite" diet of a premium brand is better if the puppy is really in need of caloric reduction. The premium foods almost always have more calories than similarly named foods from grocery stores but this is beneficial when feeding puppies.

I hope that wasn't too confusing. The truth is that I doubt your puppy's problems are nutritional in nature. I would worry about an immune mediated problem, a viral illness in which virus has "settled" in the physeal region (this can also occur post-vaccination in weimaraners and probably in other breeds) and bacterial infection doing the same thing more than I would worry about nutritional concerns as a cause.

I hope things are better. These conditions can be very very painful and I would lean towards stronger pain relief medications if your pup is not doing well. I like carprofen (Rimadyl Rx) and would consider using even stronger pain relievers such as hydrocodone or even fentanyl patches if necessary.

Mike Richards, DVM

HOD care

Q: Our 5 1/2 month old weimaraner has just been diagnosed with HOD. Fortuneatly, the condition has been caught early and the case seems mild. He was prescribed Rimadyl to help with joint swelling. We have several questions concerning his recovery: 1. What are the side effects of Rimadyl? 2. Should we limit his physical activity. If so, for how long? 3. Should we change his diet to a lower protein based product? He is currently eating Iams Eukanuba for large breeds (no less than 26% protein)? 4. What are the chances of a relapse? 5. Should we suppliment his diet with vitamin C? 6. How long can we expect HOD symptoms to be present. 7. Will this disease cause irreversable damage to his bones/joints? Thank you for your assiatance

A: P- The most common side effects of Rimadyl usage are vomiting and diarrhea, which occur in around 4% of the dogs treated with this medication. It is safe for chronic use if that should be necessary. There is no clear evidence that I know of that links HOD with high protein diets but this has been linked to HOD on an unscientific basis in the past. Using one of the large breed puppy growth foods is be a good idea, just to be sure, but you are already doing that. I don't think I would limit the activity in the sense of forcibly restricting your pup from exercise but I wouldn't encourage excessive exercise, such as Frisbee chasing, either. HOD symptoms can be episodic, so periods of pain may wax and wane, giving the impression of recovery and relapse. Most dogs do outgrow this condition. Some dogs have suffered permanent damage to the growth plates by the time they outgrow the problem. I know of no way to predict which ones will have these problems.

I hope the problem is works out to be relatively minor. Mike Richards, DVM


Michael Richards, D.V.M. co-owns a small animal general veterinary practice in rural tidewater Virginia. Dr. Richards graduated from Iowa State University's College of Veterinary Medicine in 1979, and has been in private practice ever since. Dr. Richards has been the director of the PetCare Forum...