Why is my dog eating grass and vomiting? Causes & advice

Many dogs eat grass from time to time, and some may vomit afterwards. This common behaviour can confuse owners who worry it signals illness. Understanding why your dog eats grass and vomits can help you respond calmly and responsibly.

Why Do Dogs Eat Grass?

Grass eating in dogs, sometimes called pica when it involves non-food items, is generally considered normal behaviour by veterinarians. Dogs are natural omnivores descended from wild canids, such as wolves, which have been found to consume plant matter as part of their diet. Many dogs may simply enjoy the taste or texture of fresh grass, and young dogs especially may explore their environment this way as part of learning and foraging instincts.

There are several reasons a dog may eat grass:

• To satisfy a natural craving for fibre which helps digestion and bowel movements.
• As a response to mild digestive upset or nausea, where eating grass may irritate the stomach lining causing vomiting to relieve discomfort.
• Out of curiosity or habit, with no illness involved.

Importantly, only about 25% of dogs vomit after eating grass, and most grass-eating is not a direct attempt to induce vomiting but rather a side effect of the grass irritating the throat or stomach.

Causes of Vomiting in Dogs That Eat Grass

Vomiting in dogs can stem from many causes, such as infections, sudden diet changes, food sensitivities, or ingestion of foreign material. If your dog vomits after eating grass, this may be due to irritation caused by the grass blades, especially if they have an upset stomach.

Another cause to consider is Bilious Vomiting Syndrome (BVS), which occurs when digestive fluids reflux into the stomach, commonly causing vomiting first thing in the morning or after long periods without eating. Feeding smaller, more frequent meals or offering a small bedtime snack of easily digestible food may help manage BVS.

When Is Grass Eating a Concern?

While eating grass occasionally is generally harmless, it is important to watch for warning signs that indicate an underlying problem, such as:

• Frequent or persistent grass eating and vomiting.
• Repetitive vomiting or vomiting that contains blood.
• Signs of illness like lethargy, fever, or refusal to eat.

If you notice these symptoms, it is advisable to consult your veterinarian promptly to identify any serious issues and develop an appropriate treatment plan.

Precautions for Safe Grass Eating

If your dog eats grass, ensure it is from areas free of harmful pesticides, herbicides, or chemicals that could poison your pet. Also, maintain up-to-date parasite prevention, including regular treatments against lungworm, which dogs can contract by accidentally ingesting slugs, snails, or their slime trails while grazing on lawns or gardens.

Always supervise your dog during outdoor time to minimise exposure to dangerous substances.

Management Tips for Vomiting Dogs

To support a dog prone to vomiting or grass-eating caused upset stomach, consider the following:

• Feed a balanced diet rich in fibre to promote healthy digestion.
• Offer small, frequent meals rather than large ones.
• Use high-quality, easily digestible foods such as Purina Pro Plan Veterinary Diets Gastrointestinal, or simple home-cooked options like rice with chicken, white fish, turkey, or egg.
• Keep fresh water available to ensure hydration.

When to Visit Your Vet

Seek veterinary advice if:

• Your dog eats grass repeatedly or compulsively.
• Vomiting is frequent, severe, or includes blood.
• Your dog shows signs of illness such as lethargy, fever, inappetence, or diarrhoea.

Early veterinary assessment helps rule out underlying causes like gastrointestinal infections, pancreatitis, or other digestive conditions.

Frequently Asked Question: Why Do Dogs Eat Grass?

Quick Answer: Dogs may eat grass for fibre intake, to soothe an upset stomach, or simply because they enjoy the taste and texture. Vomiting afterward is often an accidental side effect rather than intentional self-inducing vomiting.

Many veterinarians agree that grass eating is a normal instinctive behaviour rather than a sign of serious illness. Grass provides dietary roughage and may trigger vomiting if the dog has an irritated stomach. However, not all dogs vomit after grass consumption. If vomiting becomes frequent or your dog shows other health changes, a vet consultation is recommended.

Frequently Asked Question: What Is Bilious Vomiting Syndrome in Dogs?

Quick Answer: Bilious Vomiting Syndrome happens when bile irritates the stomach lining, usually after a long fasting period, causing dogs to vomit bile, often in the morning.

Dogs affected by BVS often benefit from feeding small, frequent meals or a late-night snack to reduce stomach irritation. A diet with easily digestible food helps soothe their digestive tract and may prevent the bile reflux that triggers vomiting episodes.

Frequently Asked Question: How Can I Prevent Lungworm in My Dog?

Quick Answer: Regular parasite preventatives that protect against lungworm, plus avoiding areas with slugs and snails, help prevent lungworm in dogs.

Lungworm is transmitted when dogs ingest intermediate hosts like slugs or snails accidentally while exploring grassy areas. Using vet-recommended lungworm preventatives as part of a parasite control plan is the best defence. Keep your dog away from wetlands or heavily slug-infested areas and ensure they do not eat slugs or snails to reduce risk.

Key Takeaways

• Occasional grass eating and vomiting is usually normal and linked to mild digestive upset or fibre needs.
• Vomiting after grass eating is often caused by the physical irritation of grass blades, not intentional vomiting.
• Ensure your dog is fed a balanced diet with adequate fibre and parasite preventatives are up to date.
• Avoid letting dogs eat grass sprayed with chemicals or in unsafe areas.
• Persistent vomiting or signs of illness require prompt veterinary attention.

For additional reliable information on dog vomiting, visit Vomiting and diarrhoea in dogs.

If you remain concerned about your dog's health, you can book a video appointment to chat with a qualified vet from your home.