Vomiting in Dogs: Understanding Different Colors and Knowing When to Seek Veterinary Care

1. Introduction

Vomiting is a common clinical sign in dogs. It is characterized as an explosive discharge of stomach contents via the mouth. The different forms of vomiting are numerous, but they depend on the cause or time it occurs. It can be acute, recurrent, chronic, and/or associated with other clinical signs (e.g. diarrhea). Understanding the pathophysiology of vomiting is essential. It involves the peripheral and central nervous systems as well as the autonomous (“independent”) nervous system. It also involves neurotransmitters like acetylcholine, dopamine, norepinephrine, and serotonin.

Despite the estimated prevalence of 4.3% and despite the different origins of vomiting, it is rarely explained in detail. Multiple differential diagnoses must be considered in vomiting dogs. Gastrointestinal (GI) disorders are frequently documented causes of vomiting dogs. GI disorders, such as gastroenteritis or foreign bodies, and systemic, metabolic or toxic disorders, such as uremia or intoxication, are common causes. Non-gastrointestinal abdominal disorders, such as pancreatitis or abdominal effusion, and neurological disorders, such as meningoencephalitis or intracranial lesions, are documented as etiologies as well (Holzmann et al., 2023).

2. Causes of Vomiting in Dogs

Dietary indiscretion is a very common reason for vomiting in dogs. They often consume things they should not, such as garbage, moldy food, spoiled food, unusual foods, and foreign bodies. Severe pain due to gastrointestinal (GI) obstruction can cause vomiting. Infections can result in vomiting, especially in puppies. These infections include Parvovirus, Panleukopenia, bacterial infections, and intestinal parasites such as roundworms and hookworms (K Sævik et al., 2012). Toxic ingestions can also lead to vomiting, as can poisons and medications including Ibuprofen, Acetaminophen, human antidepressants, rodenticides, pesticides, mushrooms, xylitol, certain houseplants, and cats ingesting lily plants (Holzmann et al., 2023). Conditions involving liver and kidney failure can cause vomiting, leading to pancreatitis, liver diseases, kidney failure, hyperadrenocorticism (Cushing’s disease), neoplasias, endocrine diseases, fever, and possibly cancer.

2.1. Dietary Indiscretion

Dietary indiscretion is a common reason for vomiting in dogs and is typically associated with a recent change in diet or a sudden consumption of appropriate or inappropriate foodstuffs (K Sævik et al., 2012). The consumption of indications of unusual food, especially of animal origin, is also common in hunting, herding, and terrier-type dogs, and may generate gastric foreign body (Holzmann et al., 2023). Vomiting due to dietary indiscretion may be suspicious, especially in otherwise healthy dogs that have a rapid response to symptomatic treatment or a natural resolution of clinical signs.

Dogs kept indoors and cared-for pets may show only occasional digging or scrounging behavior, but sudden changes in their behavior may be an indication of possible dietary indiscretion. A review of minimum risk pet foods and a history of sudden changes in feeding practices should be sought in such cases. In addition, normal diets that substantially deviate from instructions provided should be questioned, as these may also be responsible for vomiting in dogs. Special care should be applied in case of pets fed spoiled home-prepared food or carcasses because they may ingest clostridia, botulinum toxin, listeriosis, or physical agents responsible for vomiting. Abscessed foreign bodies and gastric foreign bodies may also originate from fresh food of animal origin.

2.2. Infections and Parasites

Infections and parasites can be a possible cause of vomiting in dogs. Canine parvovirus (CPV) or gastroenteritis is a highly contagious and deadly viral infection in unvaccinated dogs. Its most common clinical signs are vomiting, bloody diarrhea, lethargy, and fever and is often seen in 6- to 20-week-old puppies. CPV infects and destroys rapidly dividing intestinal crypt cells, which prevents the intestine from adequately absorbing nutrients and water (K Sævik et al., 2012). After recovery, the gut heals over a period of about 3 weeks, during which time the dog has a higher risk of secondary infections due to a lack of functional intestinal villi. Grossly, the intestinal lymphoid tissues may be swollen, edematous, and/or hemorrhagic. The intestine is often mottled with red and purple discoloration. Histologically, intestinal necrosis and severe lymphocyte depletion in the gut-associated lymphoid tissue are present. In a small number of dogs, the heart may also be infected, leading to sudden death due to myocarditis. Parvovirus is commonly detected through a simple fecal test looking for viral proteins.

Another possible cause of vomiting are viruses like canine distemper or canine adenovirus infections. Canine distemper virus (CDV) is a highly contagious condition caused by an airborne virus found in infected dog saliva, urine, and feces and is shed in respiratory secretions. Most dogs infected with CDV between 3 and 6 months of age have not developed mature immunity. Clinical signs include a wide range of non-specific clinical signs in the early stages of infection, such as fever, loss of appetite, lethargy, and vomiting, and signs of respiratory infection generally develop in later stages (Holzmann et al., 2023). Canine adenovirus type 1 (CAV-1) causes infectious canine hepatitis, a viral infection that affects unvaccinated dogs of all ages but is usually more severely affected in puppies. CAV-2 is a modification of CAV-1 that caused less severe illness but originated from similar viruses. Early clinical signs caused by either virus are similar, including fever, vomiting, and abdominal pain which may develop into multiple organ failure. CAV-1 is commonly detected through a serum test looking for antibodies and/or a simple PCR test looking for viral DNA.

2.3. Toxic Ingestions

Toxic ingestions are one of the top ten reasons dogs are presented to veterinary hospitals. Fortunately, most dogs do not actually ingest the toxic substance, but others either do not arouse suspicion, or if suspected, owners often aren’t aware of the consequences of the dog eating the substance. The toxin must first be ingested and then detected by monogastric species and can present a broad variety of problems from dermal irritation to liver failure depending on the toxic substance ingested. Some of the more common household problems include acetaminophen, antifreeze, chocolate, grapes/raisins, xylitol, and many more.

The problem with a toxin is that the substance must be detected, regardless of how it is administered or the clinical signs presented. Very few toxins can be detected with an assay or radiographs, and so many of the ingestions’ medical-legal problems requires experience with proper interpretation (Holzmann et al., 2023). Following ingestion, the animal may display no clinical signs initially or possibly an immediate reaction, and so a timeline is often helpful.

3. Different Colors of Vomit

When a dog vomits, the color of the vomit may provide insight into the issue at hand. Common colors of dog vomit include yellow or green, bloody vomit, and white foam or froth. Some colors of vomit signal a particular issue. The color of vomit alone will not necessarily point to a particular diagnosis. Other symptoms, such as lethargy, appetite changes, diarrhea, and dry heaving, will also be used to determine the significance (Holzmann et al., 2023).

Yellow or green vomit signals an issue with the dog’s digestion or that it is vomiting bile. Bile is a digestive fluid produced by the liver and stored in the gallbladder. It is typically yellow or green. Dogs tend to vomit bile when they have an empty stomach, so this color vomit is common if a dog has not eaten recently. This issue may or may not require a trip to the vet. If the dog vomits yellow bile sporadically but otherwise seems normal, it can be monitored and given a meal to see if that resolves the issue. It may also be worthwhile to mention the vomiting to the vet during a regular visit. However, a dog should be taken to the vet immediately if it vomits yellow or green bile frequently or with excessive drooling or signs of pain.

Bloody vomit can be bright red (called hematemesis) or have a coffee-ground appearance. Bloody vomit points to a more serious issue. Vomiting bright red blood generally indicates an issue in the stomach or esophagus, while brown blood usually indicates that the blood has moved into the intestines and indicates a more serious issue. Bloody vomit, especially if accompanied by other symptoms such as lethargy or distress, requires immediate veterinary care. Other symptoms can include abdominal pain, loss of appetite, or unusual behavior.

White foam or frothy vomit may be experienced if a dog vomits after being outside and playing a lot. This type of vomit can be common after heavy drinking. However, if a dog with this type of vomit is also lethargic, has lost its appetite, or is experiencing other issues, it should talk to its vet.

3.1. Yellow or Green Vomit

If a dog vomits yellow or green after drinking water or food, it typically indicates bile contamination.

—Bile Contamination

Bile is a yellow-green fluid that contains bile acids, cholesterol, and waste byproducts. It is produced by the liver and helps digest fats in the intestines. Bile may become incorporated into the vomit if the stomach is empty. The addition of bile may also mean the dog is beginning to vomit from further down the gastrointestinal (GI) tract. Bile typically enters the GI tract at the start of the small intestine (the duodenum) and is not normally present in the stomach. Therefore, the presence of bile may indicate that something is wrong with the stomach, or that it is beginning to vomit content from the intestines. In most dogs, bile-contaminated vomit is yellow or yellow-green (Holzmann et al., 2023).

3.2. Bloody Vomit

Immediately seek veterinary attention if your dog vomits blood. If you are running out of time, consider the following questions. Seeing red (or brown) in your dog's vomit can be alarming. Here is a look at the different causes of bloody vomit and when that blood demands a trip to the veterinarian. When a dog vomits blood, you may note bright red specks, flecks, or a pink-tinged mass; you may notice a dark brown, coffee ground-appearance speck to the vomit. These two forms of blood differ in appearance and cause. That fact may help you and your veterinarian understand what is going on with your dog.

Many conditions may cause bloody vomit, including bleeding disorders, liver or kidney disorders, certain infectious diseases, pancreatitis, ingestion of poisons, ingestion of foreign bodies, intestinal obstruction, ulcers, or tumors (Holzmann et al., 2023). All of these issues require urgent veterinary care. In some cases, bloody vomit resolves on its own; in other cases, it may be a sign of a life-threatening condition. It is important to note that some other colors of vomit (i.e., yellow, green, blue) are concerning too. Most of those other colors, however, usually indicate gastrointestinal or metabolic issues that may not be an emergency. When a dog vomits blood, it usually indicates a more serious problem.

3.3. White Foam or Froth

Particularly if it happens when they've first woken up in the morning or after lounging about, white foam or froth in vomit may seem odd. This is usually nothing to worry about and might just mean that your pup has an empty stomach.

In some instances, vomit that’s white and foamy can mean something else. For example, it might mean:

- **Dietary indiscretion:** Dogs are notorious for munching down whatever food or chew item they find, be it something they shouldn't have eaten or something spoiled or moldy. If the dog is bringing up their fang-tastic snack too soon, the vomit may appear white foamy and frothy. If this is the case and they seem fine otherwise, there is usually no need to worry. The best bet is to keep a close eye on them for the next 12-24 hours to see if they are keeping their food down and feeling better.

- **Bile:** If the dog is just bringing up clear, foamy, or yellow vomit early in the morning they might have an empty stomach and low levels of bile may have built up. Again, this isn’t usually dangerous.

Occasionally, vomit that is white or foamy can mean something more severe. For example:

- **Pancreatitis:** If they’re not just vomiting bile but instead bilious vomiting (as in bringing up food or broad leafy slurries that have a history being preceded by gallbladder source bile) and if they have a stinkingly foul fishy odor which they absolutely do not otherwise always tend to smell of too and/or they are acting really sick, this may prompted gallbladder/bile duct food obstruction or, worse still, pancreatitis and a trip to the vet for an urgent investigation may be warranted.

- **Intestinal obstruction:** In some isolated cases, vomit that is white with foam and is excessive and they it instantly vomit again minutes after eating usually suggests something else such as food being unable to pass down into the intestines, either from auditioning a toy/collapsing chewing bone which is being bring up too or some infection or even worse something needing urgent foreign body obstruction investigation in the stomach region otherwise.

White foam or froth vomit is usually nothing to worry about but in some cases may need a trip to the vet (Holzmann et al., 2023).

4. When to Seek Veterinary Care

Every dog owner has, at one point or another, faced some challenging situations regarding their beloved pets. Of these, vomiting can be one of the most distressing. Vomiting in dogs is often accompanied by other symptoms like diarrhea, lethargy, loss of appetite, and other more serious symptoms. Some symptoms may require immediate care, while others may improve. However, the questions persist: when is it necessary to consult a veterinarian? Is there a need for emergency care? This essential guide aims to help dog owners identify crucial information regarding their pets’ health and assist them in making informed decisions.

There are many factors that can tell if it is necessary to seek veterinary care. If there are any signs of emergency such as suspected foreign body ingestion, persistent vomiting, bloody vomit, unusual vomit colors, or neurologic signs, seeking care quickly is crucial (Holzmann et al., 2023). If the dog is acting lethargic, weak, or showing any signs of pain, quick steps should be taken. In addition, if there is vomiting after a dog ate something unusual, consulting a vet is advisable. If there is vomiting after a new medication or supplement, it may be a good idea to seek veterinary care. If a veterinarian is not available, providing home care may be an option. At-home care usually requires withholding food and water for 12 hours, then gradually reintroducing them over 2–3 days.

4.1. Signs of Emergency

Seek emergency care for your pup if you notice any of the following: 1. Blood in vomit or stool. 2. Vomiting for more than one day. 3. A very painful abdomen. 4. Vomiting bile or yellow and foamy liquid multiple times. 5. Seeming lethargic, uninterested in life, or unresponsive. Good luck and take care (Holzmann et al., 2023).

4.2. Home Care Tips

If a dog vomits, owners usually want to know the cause. It can be difficult to know whether to be concerned, as dogs vomit for all sorts of reasons. Generally speaking, if a dog vomited once and is acting totally normal, there is little cause for concern. If a dog vomits multiple times or has other concerning clinical signs such as lethargy, loss of appetite, or diarrhea, further investigation should be considered (Holzmann et al., 2023).

A number of things can be done at home to help a dog who has vomited. First, make sure that there is no access to any poisons, such as medications or chocolate, that could cause this clinical sign. If a dog is not LETHARGIC, it is reasonable to withhold food and treats for approximately 12-24 hours to settle the stomach. Ice cubes or small amounts of water can be offered so a dog does not become dehydrated. If the vomiting has not recurred during this period, a small amount of a bland diet or boiled rice and ground turkey can be offered. If vomiting does not recur, gradually increase food quantity over the next several meals. If vomiting recurs, contact the veterinarian. In addition, if blood is found in vomit or any vomit is green or yellow (bile), this could be a sign of a more serious problem and the owner should contact the veterinary clinic.

5. Conclusion

Signs of distress are hard to ignore when it comes to pets. Owners like to be aware of what their pets may need and what can be expected in those situations. As with any living creature, health and wellness must be monitored regularly as some events are warnings of more severe happenings. Similarly, dogs can experience a change in condition or health, and this can be indicated through a change in behavior. Being proactive and aware of any visible alterations is important for the well-being of the animal. Common occurrences with pets, especially dogs, that are noticeable include vomiting, coughing, and seizures. The occurrence of any of these should be assessed, and the possible cause should be briefed. In regard to vomiting, it is important to know what to look for when assessing a dog’s conditions, such as the possible implications of different colors of vomit, the presence of foaming, and when to seek veterinary care.

A simple yet complex act, vomiting can often be misleading. This may appear to be a straightforward process; however, it may indicate a significant event that can be life-threatening. This is a regurgitation of the contents of the stomach and, less frequently, the upper intestine. This act may be accidental in nature and can stem from several causes. Some of these causes may be inconsequential, but others may heavily impact the well-being and safety of the dog. Nonetheless, it is important to note that although the behavior appears straightforward, determining the causal factors may be complicated and challenging; however, owners should be aware of the distinct colors of vomit and what they may imply (Holzmann et al., 2023).

References:

Holzmann, B., Werner, M., Unterer, S., & Dörfelt, R., 2023. Utility of diagnostic tests in vomiting dogs presented to an internal medicine emergency service. ncbi.nlm.nih.gov

K Sævik, B., M Skancke, E., & Trangerud, C., 2012. A longitudinal study on diarrhoea and vomiting in young dogs of four large breeds. ncbi.nlm.nih.gov