If you are someone who suffers from recurrent boils in this area then do please go and see you GP because it may be that you need a cause of antibiotics and an antibacterial wash. If this is a recurrent problem then we often prescribe a longer course of antibiotics to try and break the cycle.
This is because a giardia infection interferes with digestion and inhibits absorption of nutrients from the diet. It can also damage the lining of the intestine. In fact, this particular parasite is at the root of many cases of chronic GI inflammation in dogs and cats.
The most common treatment for giardiasis is metronidazole (Flagyl) for 5-10 days. It has an efficacy rate of 75% to 100%, but it often causes gastrointestinal side effects such as nausea and a metallic taste as well as dizziness and headache.