This is a question that I have previously pondered over. My answer before was simply “no”. I would like to say, however, that your dog may be able to eat some guava fruit as long as it does not contain any pits or seeds. So let’s take a closer look, shall we?

What is Guava?
Guava (Psidium species) belongs to the myrtle family (Myrtaceae). Guavas are generally pear-shaped and slightly elongated. The flesh of the fruit can be creamy white, yellowish pink, stains red when bruised or reddish-purple with raspberry-like juicy translucent pulp embedded with numerous small shiny black seeds.
How Can You Identify if Your Dog Ate Guava?
If your dog ate guavas it may start exhibiting some of the following signs: 2
Stomach upset. Vomiting. Diarrhea. Weakness Headache Loss of appetite Heavy breathing Seizures Coma Death.
Guava is frequently used in conventional and alternative cancer treatments. They are known to interfere with the development of tumors, metastases (secondary tumors), and tumor regrowth (tumor recurrence). The presence of antioxidants like vitamin C makes guavas an effective treatment against free radicals that can cause cancer.
The use of guava leaves as an herbal medicine has been gaining momentum due to their anti-microbial properties. Guava leaf extract inhibits the growth of many bacteria including Staphylococcus aureus. This bacterium causes food poisoning through toxins it secretes. You may find it interesting to know that other plants used for their medicinal value include carrots, parsley & cherry juice.
How Dangerous is Guava for Dogs?
Although some dogs may be able to eat guavas without too much trouble, it’s best not to feed your dog this fruit in large quantities. The reason is that guavas contain a substance called psoralens which can cause photodermatitis. This means if your dog eats the fruit and then spends time in direct sunlight, his skin will burn.
It’s not uncommon for dogs to eat plants. It is best to consult with your veterinarian before feeding your dog any fruit or vegetables, even if it’s only in small amounts.