Vomiting is not a disease or disorder in itself; it is a clinical sign of some type of digestive disturbance or as a result of another disease or disorder. Occasional bouts of vomiting can be considered normal but if the vomiting persists and is accompanied by severe or bloody diarrhoea, lethargy, weakness, depression, pain or fever then this is a sign that something is seriously wrong and veterinary attention is required. Vomiting can be caused by something the dog has eaten (e.g. rotten food), ingestion of toxins, adverse reactions to drugs or an allergic reaction to something in the environment.
Giardia intestinalis and Giardia duodenalis are single celled protozoan parasites, which inhabit the affected dog’s small intestine, causing clinical signs of Gardiasis. The protozoa attach themselves to the intestines and multiply. They may be directly swept through the intestines and appear in the infected dog’s faeces or they may develop into a tougher more durable ‘cyst’ form, which is again passed in the dogs faeces but is able to survive for long periods in the external environment. Dogs are infected by ingesting the cysts from contaminated water and the environment. Infected dogs may not show any clinical signs of Gardiasis, but they can still shed the protozoa from their systems, spreading the infection to other healthy animals. Infection and subsequent illness is more commonly seen in younger animals. Signs of infection include: chronic or intermittent diarrhoea that may appear ‘fatty’ and slimy, accompanied by a very foul smell. Weight loss is also possible if left untreated.