It’s not uncommon for a dog, or ourselves for that matter, to be a little stiff and sore for a few days after a hard run this is often described a delayed onset muscle soreness or DOMS. DOMS is fairly predictable and not usually to serious a problem that is in all likelyhood due to inflammation of the muscles from damage to a small proportion of muscle fibers and the resulting pain this causes. More worrying are recently a couple of instances where owners of lurchers have noticed their dogs showing signs of severe muscle soreness and or cramps with urinating what appears to be blood the day after a hard session. This is often followed by a drop in condition for a time after wards to a greater or lesser degree. A common suggestion as to the cause of this seems to be a build up of lactic acid but in light of modern thinking, discounting lactic acid as the bad boy and high-lighting its role as an important energy source, this theory doesn’t seem to hold water. So what could be going on?
One idea is that the dark brown/red urine is not due just to blood alone but also the contents of damaged muscle cells, myoglobin and creatine kinase, that are released into the blood stream and this is known as rhabdomyolysis (RMS). When the released myoglobin is excreted by the kidneys it gives the urine a dark brown colour. The difference between DOMS and RMS is the extent of the muscle damage involved and the effect this has on the kidneys. High levels of myoglobin can cause kidney failure to the extent that long term damage or even death is a possibility.
So why does this happen? RMS was first described in the blitz when people trapped under fallen buildings suffered extensive crush type injuries which lead to major muscle damage; this led to the release of large amounts of the muscle cell contents. Since then it has been described in a variety of species with a genetic link in some breeds of both horses and dogs. But these lurchers had not suffered any such injuries and sight hounds are rarely prone to genetic faults so how had they come to cause so much damage to their bodies? A strong possibility is suggested by looking at the background. In both cases the hounds had had long hard runs at the beginning of the season when they were at less than optimum preparedness and in truth they were both weekend warriors who may lack true working fitness even when at their best. This lack of fitness may have resulted in over exertion of some off the largest muscles in the body leading to extensive damage/breakdown and so exertional rhabdomyolysis.
Conditioned muscles in both humans and dogs are usually able to cope with exercise, unless there is a genetic variance, and the body has a variety of methods to protect itself against over exertion but sight hounds have been bred for generations to push the boundaries of the possible so bringing them nearer to the red line than most breeds. This ability to push the limits may mean that, if the incentive is right, they can cross the line when unfit to the extent that DOMS is extremely likely but also doing serious harm to their own bodies is a possibility. So what can we do to recognise treat and avoids these problems.
The main symptoms are severe muscle pain, cramping and altered gait with blood/very dark urine. Early recognition is important in the long term outcome. Your vet can check for chemicals in the urine and blood to confirm the diagnosis. And the vet is the best person to lead the treatment as depending on the extent of the problem intravenous fluids with powerful pain killers may be required. Appropriate management of renal function is the major concern but also the causative muscle breakdown needs to be addressed and a regime to rehabilitation and conditioning the dog to prevent future occurrences should be instigated. Good hydration is always of great importance as dehydration may increases the risk of muscle damage and post exercise will increase the strain on the kidneys. Also concentrated urine may well be very dark in the absence of any illness so muddying the waters some what.
Any dog that seems to be suffering exercise intolerance should always have a thorough check out with your veterinary surgeon to exclude any underlying heart, lung or systemic illness and check for any structural problems. A genetic predisposition to RMS may mean an animal needs special consideration as to it’s working ability but for normally fit and healthy dogs without any underlying problems then prevention is so much better than cure. Prevention means good preparation before work after a seasonal or injury enforced lay off plus regular top ups for the weekend warriors.
Edited by sandymere, 13 February 2009 - 10:59 am.