What causes bleeding after a dog is given a subcutaneous injection?

When we carefully complete a subcutaneous injection for our dog, but find that blood is oozing from the injection site, the feeling of nervousness and worry spreads instantly. Looking at the innocent eyes of the dog, the owner feels both distressed and confused, and is eager to know what has caused this situation. Understanding the causes of bleeding after a dog's subcutaneous injection is not only the key to solving the current problem but also an important step in safeguarding their health and avoiding subsequent risks.

From an anatomical perspective, a dog's subcutaneous tissue is located between the skin and the muscles, and is richly distributed with capillaries, lymphatic vessels, and loose connective tissues. Under normal circumstances, during a subcutaneous injection, the needle passes through the skin and enters the subcutaneous tissue, and the drug is injected into this relatively loose space. Although the blood vessels in the subcutaneous tissue are not as dense as those in the muscles or veins, there is still a risk of bleeding. Every injection is like "dealing with" these tiny blood vessels, and bleeding is an abnormal signal they send out.

Improper injection operation is one of the common causes of bleeding after a dog's subcutaneous injection. If the angle of the needle insertion during the injection is too vertical, it may directly pierce thicker blood vessels; if the needle insertion depth is too deep, it is also likely to damage the blood vessel plexus in the deep subcutaneous tissue. Some owners, due to nervousness or lack of experience during the injection, fail to accurately grasp the force and speed of the needle insertion, resulting in the needle shaking in the subcutaneous tissue, increasing the probability of blood vessel rupture. In addition, after the injection is completed, if the injection site is not pressed correctly or the pressing time is too short, the ruptured blood vessels cannot stop bleeding in time, resulting in bleeding.

The dog's own health condition can also affect the hemostatic effect after the injection. Dogs with coagulation disorders, such as congenital thrombocytopenia, hemophilia, or vitamin K deficiency caused by accidentally ingesting rodenticides, have defects in their blood coagulation mechanism. After a subcutaneous injection, even with a minor blood vessel rupture, these dogs may experience prolonged bleeding or continuous bleeding. In addition, some systemic diseases, such as liver diseases, can affect the synthesis of coagulation factors, and kidney diseases may lead to abnormal platelet function. These will all make dogs more prone to bleeding after an injection.

Drug factors cannot be ignored either. Certain drugs themselves have an anticoagulant effect, such as heparin, warfarin, etc. After injecting these drugs into a dog, it will prolong the bleeding time and increase the risk of bleeding at the injection site. Some drugs are highly irritating. After being injected subcutaneously, they may cause a local tissue inflammatory reaction, leading to blood vessel dilation and increased permeability, thus causing bleeding. In addition, if the dosage of the injected drug is too large, a large drug mass will be formed subcutaneously, which will also compress the surrounding blood vessels and cause blood to seep out.

The choice of the injection site is also closely related to the risk of bleeding. If the injection is carried out in an area with thin skin and rich blood vessels, such as the side of the neck, the groin, etc., the possibility of bleeding will be relatively high. While injecting in an area with thicker skin and fewer blood vessels, such as the back and the outer side of the thigh, is relatively safer. In addition, if there are skin diseases, trauma, etc. at the injection site, it will also damage the integrity of the skin and subcutaneous tissue and affect the hemostasis process.

When you find that a dog is bleeding after a subcutaneous injection, the owner should first stay calm. You can use a clean cotton ball or gauze to gently press the injection site for 3 to 5 minutes to help stop the bleeding. The pressing force should be moderate to avoid causing pain to the dog due to excessive force. After stopping the bleeding, observe whether there is swelling or bruising at the injection site, and whether the dog shows signs of restlessness or pain. If the bleeding continues or abnormal conditions such as redness, swelling, heat, and purulent exudation occur at the injection site, the dog should be taken to a veterinarian immediately. The veterinarian will conduct a detailed inquiry, physical examination, and if necessary, carry out blood routine tests, coagulation function tests, etc. to find the cause of the bleeding and take corresponding treatment measures.

Bleeding after a dog's subcutaneous injection, although it seems like a minor situation, really tugs at the owner's heart. Every bit of worry and anxiety stems from the deep love for them. Understanding the reasons behind the bleeding can not only help us handle the problem correctly when it occurs but also make us more careful and cautious in daily care. Using professional knowledge and warm care to safeguard the health of dogs, and making every treatment and care full of peace of mind and love, this is our unshirkable responsibility as owners.