Dog leg cramps are a lot like the human kind. If you've experienced leg cramps yourself, you know how suddenly they can occur, without warning, and how painful they can be. As a loving and responsible pet owner, you want to keep your dog from experiencing that kind of pain if you can. To keep them from happening, it helps to know what the causes of leg cramps in dogs are in the first place.
Occasional leg cramps in dogs can be caused by overexertion, but if they occur often or don't go away the cause could be something more serious.
Identifying dog leg cramps
Although dogs can't tell you exactly what hurts, in the case of dog leg cramps, you'll probably be alerted by the dog's cries of pain. You may be able to see the stiffened leg or other muscle twitching or held rigidly in an unnatural way. Other signs are limping, lying down suddenly, or difficulty getting up and down when the dog doesn't typically have these problems. Leg cramps usually occur in only one leg at a time and may happen more frequently in one leg.
Consider overexercise and muscle fatigue
Exercise is good for dogs, but sometimes it's too much of a good thing. When the exercise is too vigorous, lasts too long, or is at a high level for days in a row, the muscles can become weak, depleted of oxygen, and unable to work. It's part of the body's safety mechanism that the muscle ceases to function so that it won't be injured further. Think about the last few days: Could your dog have overexerted during exercise? Did she exercise in a new way, or for a longer period of time? A fatigued muscle may cramp suddenly.
Note symptoms of dog viruses
Leg cramps typically go away on their own within an hour or so, but if they don't go away, or they keep recurring, a virus that causes lethargy or difficulty moving could cause the dog's muscles to cramp. Viruses usually have additional symptoms, so look for ways in which your dog is behaving abnormally. Write all the symptoms down so you can call and report them to your vet.
For example, dogs are susceptible to both H3N2 and H3N8 canine influenza, or dog flu. Symptoms of dog flu include lethargy, coughing, sneezing, difficulty breathing, nasal discharge, and runny eyes. If your dog has any of these symptoms, consider that flu might be the cause. Persistent coughing could cause a dog to have a muscle cramp. Other common viruses that cause vomiting or diarrhea could cause leg cramps from holding the body rigid in unnatural ways or for long periods of time.
Consider environmental and food toxins
If dogs ingest or inhale a toxic substance, it could affect them neurologically and cause muscle cramps. Pesticides like bait traps for insects and rodents are very toxic to dogs and cats and should always be placed out of their reach. Sprayed insecticides could be inhaled by the dog, or travel through the air into their food, or be licked when it remains on surfaces. Toxins that affect the nervous system can cause dogs to act disoriented and move in different ways, or the toxin could cause the muscles to stiffen and cramp.
Certain foods that are toxic to dogs can cause neurological issues, digestive problems, and, in severe cases, even death. Such foods, which should never be given to dogs, include chocolate, grapes, raisins, currants, plums, pomegranates, lemons, limes, avocado, rhubarb, kale, taro, chard, watercress, mushrooms, horseradish, and anything from the allium family such as onions, shallots, leeks, chives, and garlic. They should also avoid spicy foods, and the green parts of plants. For example, dogs can eat ripe tomatoes, but not green tomatoes or the green stems or leaves.
If you know you didn't give your dog any of these foods or toxic substances, or leave them within your dog's reach, consider whether you or someone else took your dog to visit a neighbor and found these no-nos there. Or, if your dog goes outside of your yard, whether as routine or as an escape, he could have found such toxic edibles and nonedibles anywhere. Standard English ivy, for instance, which looks so commonplace and benign, is toxic to dogs and can cause muscle weakness, which could lead to muscle cramps.
Consult your vet
When dog leg cramps don't go away, recur often, or are accompanied by other worrisome symptoms, it's always safest to contact your dog's vet. Have your notes handy to relay what you've observed, and follow the vet's advice. They'll know whether the leg cramps have an easy explanation or are cause for bringing your pet in for an appointment.
Always check with your veterinarian before changing your pet’s diet, medication, or physical activity routines. This information is not a substitute for a vet’s opinion.