The risk for heartworm disease, giardiasis and leptospirosis rise after a strong storm or hurricane has saturated the soil and left pools of standing water. Avoid contact with these areas whenever possible. Giardia is an intestinal parasite that causes diarrhea. Heartworm disease symptoms may take months to years to be seen- be sure to remember to keep your pet current on this preventative. Symptoms of Leptospirosis most noticed by owners are lethargy, fever and inappetence. The effect on the kidneys or liver usually result in prolonged hospitalization or even death. Although vaccination is never a guarantee, dogs current on their leptospirosis vaccination have a very high degree of protection.