The Chihuahua is one of the breeds predisposed to this type of hernia. This can be congenital (present at birth) or acquired. This can affect both genders and dogs of any age, but it is seen a bit more often with females that have not been spayed, tending to develop during heat or pregnancy. Note that neutered males can develop an inguinal hernia, though it is rare.
This is a hernia located in the abdominal wall of the inguinal canal through which fatty tissue and/or intestines protrude through the tear. For both genders, the groin has a small opening, which is called the inguinal canal. With males, the inguinal canal contains blood vessels and the spermatic cord which leads to the testicles. With females, the inguinal canal contains a cord of fat that runs down.
Inguinal hernias can appear just on one side (unilateral) or both sides (bilateral). In most cases, the inguinal canal is a small enough structure that only fatty tissue can protrude through a hernia. However, in some cases, intestines will spill through as well.
There are two types: With a reducible hernia, the protrusion can be pushed back into the abdominal cavity. This is a sign that only fatty tissue is involved. With an irreducible hernia, it cannot be pushed back in; this is a red flag of the intestines being involved and is a serious issue that can threaten the blood supply to the area (known as a strangulated hernia or complicated hernia).
Signs:
With males, the most obvious sign is swelling of the scrotum (skin surrounding the testicles) and/or inner thigh area. With females, the most obvious sign is a soft protrusion in the groin area and/or inner thigh area. Moderate to severe cases are painful; other signs may include lack of appetite, bloody urine, frequent urination, and/or vomiting.
Diagnosis:
Contrast study and x-rays.
Treatment:
Small inguinal hernias that do not involve the intestines, but rather just fatty tissue, can resolve on their own. If so, this will usually be by the 4 to 6-month mark. Those that do not close or those that are larger or involve the intestines protruding require surgical correction. This involves stitches to close the tear or reinforce the strength of the muscle. If a puppy is due to be spayed or neutered, surgical repair of the hernia is performed at the same time so that anesthesia is only given once.
If a Chihuahua has an inguinal hernia that involves the intestines (which can threaten the blood supply to the area), this is considered an emergency and will require immediate surgery.
If your puppy has an inguinal hernia and the veterinarian has recommended to wait and see if it resolves on its own or you are waiting for it to be repaired during the spay or neuter procedure, the vet may prescribe antacids and/or medication to help prevent straining during bowel movements, and/or recommend dietary changes.
These types of hernias are not overly common with Chihuahuas. They can be congenital, meaning present at birth; however, most cases are acquired, often due to severe trauma. With a diaphragmatic hernia, there is an internal tear the diaphragm which leads to abdominal organs (liver or stomach) spilling into the chest area. With a hiatal hernia, there is an internal tear the diaphragm which leads to the stomach spilling into the diaphragm and the esophagus spilling into the stomach.
In mild cases, signs include slight breathing difficulties and/or gastrointestinal upset. With hernias due to injury, there are typical signs of trauma including bruising, shock (severe lethargy, hyperventilation, etc.), and/or abnormal heart rate. These types of hernias are corrected with surgery.