Canine distemper is a highly contagious disease spread through either direct or indirect contact. The disease actually affects more than just those in the canine family, with foxes, raccoons and even bears able to develop the disease, and it is caused by a relative of the measles virus.

Canine distemper is becoming increasingly rare due to the widespread use of dog vaccinations, but it's still a good idea to know the symptoms, especially if your dog is either still in the puppy stage or not vaccinated.

Here are just four signs of canine distemper.

1. High Fever

One of the first signs that your dog might have developed canine distemper is an explained high fever. This will usually occur just 3-6 days after infection, and such a fever may be accompanied by a runny nose and discharge from the eyes. Vets diagnose a high temperature in most dogs as resting at or above 103.5 degrees Farhenheit, or 39.7 degrees Celsius. However, many dogs, especially older and healthier ones, return to normal right after the fever has passed. Be advised that this does not mean that the condition has left them; it is usually just dormant.

2. Digestive Issues

Dogs aren't exactly known for being particularly discerning eaters, so any lack of appetite is going to be a noticeable cause for concern. Many dogs who contract canine distemper will seem off their food, and eating may simply lead to vomiting or diarrhoea, and such gastrointestinal problems are often associated with increased thirst. These symptoms are also common to parvovirus, but you should see your local vet in either case.

3. Involuntary Movements

As the white blood cells in your dog's body try to fight the virus, they release enzymes as a by-product. Unfortunately, these enzymes also damage the myelin sheath which covers the nerves. Damage to the myelin sheath will mean that nerve signals aren't able to fire properly, so your dog may suddenly start to tremor or make odd jerks. In later stages, seizures or paralysis can occur.

4. Hardening and Thickening of the Pads

One of the less serious signs of canine distemper is a hardening and thickening of the footpads. This occurs when keratin formation is interrupted, and it is a symptom that tends to be associated more with growing puppies than full-grown adult dogs. Though not a serious condition in and of itself, it is not one that should be ignored.