Why do dogs eat grass?

There can be several reasons why a dog may eat grass, as shown below. Some reasons are harmless while others may be an indication of something more serious, thus requiring veterinary assistance.

1.    Vomiting after eating grass. Sometimes dogs will eat grass if they are not feeling well. The small hairs on the grass are said to tickle the dog’s throat causing them to regurgitate their food. This may have been a behaviour that dogs learned as a survival mechanism. Dogs have spent many years around humans –scavenging off scraps and rubbish in many societies – possibly eating undesirable foods that make them feel unwell, which may prompt them to make themselves vomit. While it is true some dogs have more sensitive stomachs than others, if the grass eating-vomiting behaviour seems to be occurring frequently or it is accompanied by any other symptoms, such as diarrhoea, decreased appetite and lethargy, veterinary assistance should be sought.     

2.    Compulsive grass eating. This may be an indication that a dog suffers from anxiety and has developed compulsive grass eating as way of trying to cope with this anxiety. A veterinary behaviourist may need to be consulted.

3.    Deficiency. Another theory is that grass eating may be an indicator of a deficiency in a nutrient or in fibre etc.  This requires a close look at the dog’s diet to see if a supplement or increase in fibre is required. A veterinarian may need to be consulted if this is the case.

Grass eating is a very common behaviour in dogs, it is can really only become a problem if it is associated with nausea or anxiety.