The Grizzly Truth. Were Stitches Once Made From Cat Guts?


Sutures, or stitches, have been used in medicine for thousands of years. The earliest known sutures were described in ancient Egyptian texts dating back to 3000 BC. For centuries, sutures were primarily made from natural materials like linen, horsehair, hemp, silk, and catgut. Catgut specifically refers to suture material made from the intestines of animals, usually sheep, cattle, or horses. Catgut sutures were first produced in the early 1800s and remained the dominant absorbable suture material through the 1930s, thanks to their strength, flexibility, and biocompatibility. Though other suture materials like silk and cotton were sometimes preferred for non-absorbable applications, catgut dominated surgery for internal stitches that needed to be absorbed by the body over time. While catgut sutures played an invaluable role in the history of surgery, they have been largely replaced today by synthetic absorbable sutures made from purified polymers.

Origins and Early Use of Catgut for Sutures

The earliest evidence of using animal intestines as suture material dates back to the 3rd century AD. The prominent Greek physician Galen, who lived during the Roman Empire, is known to have used animal gut strings as medical sutures for wound closure (

Catgut sutures continued to be used through the Middle Ages in Europe. Surgeons would harvest and prepare the intestines of animals like sheep and horses, using them to sew up wounds after surgery or injury. The natural structure of the twisted animal fibers made catgut effective as a suture material that the body could absorb over time as the wound healed.

Catgut remained the dominant suture material for internal stitches through the early 20th century. Doctors used silk or cotton threads for external sutures that needed more strength and longer dissolution times. But catgut was valued for its combination of strength, flexibility, and absorbability when stitching up internal wounds and incisions (

Advantages of Catgut Sutures

Catgut sutures became popular in the late 19th century due to several key advantages over previous suture materials like silk or hemp:

Absorbability – Catgut sutures are absorbable, meaning they slowly dissolve over time and do not require removal. This makes them convenient for internal stitches. According to research, catgut sutures typically absorb within 60-90 days after implantation.

Strength – Catgut sutures were known for maintaining high tensile strength, especially in the first few weeks after implantation while the wound is healing. This gave them advantages for abdominal and orthopedic surgery where strength was critical.

Low Reactivity – Compared to silk or other materials, catgut was found to be relatively inert and did not cause much tissue reaction or inflammation. This made it well-suited for internal applications.

Overall, the absorbability, strength during critical healing periods, and low reactivity of catgut gave it significant advantages that made it the preferred suture material for many surgeons at the turn of the 20th century.

Disadvantages and Issues with Catgut Sutures

Despite their widespread historical use, catgut sutures have some important drawbacks and issues that need to be considered:

Variability in absorption time – Catgut absorption is highly variable, making it difficult to predict exactly how long the sutures will last before dissolving. Factors like tissue type, degree of tension, presence of infection, and manufacturing process all impact catgut longevity 1.

Poor knot retention – Due to its smooth, slick surface and oval shape, catgut tends to slip when tied, leading to loose knots that can unravel. Surgeons must tie extra knots or use special techniques to secure catgut sutures 2.

Inflammatory reactions – Being made of a foreign protein, catgut elicits a moderate inflammatory response during absorption. This leads to more scar tissue compared to synthetic absorbable sutures 3.

Modern Manufacturing of Catgut Sutures

The manufacturing process of catgut sutures has evolved over time but still relies on the use of animal intestines as the raw material. The intestines, typically from sheep, cattle, or horses, are thoroughly cleaned and then split open into long strips. These strips are scraped to remove the mucous membrane layer. The remaining tissue, which is primarily collagen, is then twisted or braided into strings and polished to create smooth, uniform threads.

To improve strength and duration, the strands may be treated with chromium salts, which cross-link the collagen proteins. This creates “chromic catgut” sutures that resist digestion longer than untreated “plain catgut.” The exact specifications of the threads such as thickness, tensile strength, and absorption time are tightly controlled during manufacturing. The finished catgut suture strands are sterilized using gamma radiation before being packaged for use.

While the basic process remains similar, innovations in techniques like precision scaling and computer-controlled braiding have allowed modern high-volume production of consistent, medical-grade catgut suture materials. However, catgut manufacturing is still relatively labor-intensive compared to synthetic suture production. This is one factor that has led to the decline in catgut suture usage over the past 50 years.


Applications and Use Cases for Catgut Sutures

Catgut sutures were commonly used for a variety of surgical procedures, particularly those involving soft tissues that required rapidly absorbing sutures. Some of the most common applications and use cases for catgut sutures included:

Closure of the uterus after cesarean section – Catgut provided rapid absorption and tissue security in the uterine incision closure (

Bowel anastomoses – Catgut sutures were often used for securing bowel anastomoses since these tissues heal quickly. The rapid absorption prevented prolonged tissue reaction (

Ophthalmic procedures – In ophthalmic surgeries such as corneal transplantation, catgut sutures were useful for securing the conjunctiva and rectus muscles due to rapid absorption (

Oral surgeries – Catgut sutures were commonly used to close oral incisions in soft tissues like the tongue and oral mucosa that heal rapidly (

Pediatric surgeries – The use of catgut sutures was common in pediatric surgeries since they allow for rapid absorption as children’s tissues heal quickly.

The Decline of Catgut Suture Usage

Catgut sutures were once the mainstay of wound closure and surgical sutures for many centuries. However, catgut usage started to decline in the mid-20th century with the development of synthetic absorbable alternatives like polyglycolic acid (Dexon) and polyglactin 910 (Vicryl). These new synthetic sutures offered numerous advantages over catgut 1:

  • More predictable absorption and tensile strength retention profiles
  • Minimal tissue reaction and inflammation
  • Greater knot security and smoother passage through tissue
  • Standardized suture material not subject to natural variations
  • Easier handling characteristics

Additionally, synthetic absorbable sutures avoided various disadvantages of catgut such as poor knot security, variable absorption rates, and risk of infection from animal-sourced material 2. As a result, synthetic absorbable sutures largely replaced catgut in most surgical specialties by the 1970s and 80s.

Modern Alternatives to Catgut Sutures

As catgut fell out of favor, new synthetic materials emerged as alternatives for sutures. Some of the most common modern suture materials include:

Polyglactin 910 (Vicryl) – This synthetic absorbable suture was one of the first major alternatives to catgut. It provides strength for 7-14 days but is completely absorbed in 56-70 days [1]. It is commonly used for soft tissue approximation.

Polyglycolic Acid (Dexon) – This synthetic absorbable suture lasts longer than catgut, maintaining strength for 21 days and absorbing fully in 70-90 days[2]. It is often used for fascia closure.

Polydioxanone (PDS) – This monofilament synthetic absorbable suture lasts even longer, maintaining strength for 6 weeks and absorbing in 180-210 days[3]. It is a common choice for abdominal wall closure.

These stronger, more predictable synthetic sutures offered advantages over the less consistent absorption rates of catgut. They rapidly took over as the predominant suture materials used in most procedures.


Remaining Niche Uses of Catgut Sutures

While the usage of catgut sutures has declined significantly since the mid-20th century, they are still preferred for some specific applications where their natural properties provide advantages over synthetic suture materials:

Ophthalmic Surgery: Catgut is often still used for ophthalmic procedures as it is less likely to cause irritation or astigmatism in the eye compared to synthetic monofilament sutures (Wikipedia).

Plastic Surgery: Plastic surgeons may use catgut sutures on the face because they cause less scarring and are easier to tie than synthetic sutures. The natural catgut material integrates well with facial tissues (LinkedIn).

Pediatric Surgery: For pediatric patients, surgeons often prefer the flexible and soft nature of catgut sutures which are less likely to cause damage or scarring in delicate tissues.

General Surgery: Catgut continues to be used in some general surgery applications such as sewing bowel anastomoses where its absorbable nature provides wound support initially but does not require later suture removal.

Thus catgut maintains niche applications, particularly where its natural origins make it the optimal choice over synthetic suture materials.


In summary, catgut has had a long and interesting history being used for sutures and medical procedures dating back to ancient times. Made from animal intestine, catgut was valued for being absorbable and NOT requiring removal after internal tissues healed. This made catgut popular for closing deep wounds and incisions. However, catgut had drawbacks like high variability and issues with infection. The manufacturing process improved over time, shifting away from manually preparing catgut to machine-based mass production. This helped standardize quality and sterilize the material. While catgut was commonly used for many decades, modern polymers and synthetic absorbable sutures like PDS, Vicryl and Dexon eventually replaced catgut in most major surgeries. However, catgut maintains some niche uses today in ophthalmic surgery and as ligatures. The unique properties of natural catgut still lend benefits for particular applications, though most surgical settings utilize safer, more consistent modern suture materials.

Scroll to Top