Written and maintained by CASRAI Editorial Board
Last updated
General reference information for clinic, shelter and laboratory staff. It is not medical or veterinary advice and does not describe how to perform any procedure.
Short answer
A veterinary surgical pack is a wrapped, sterilized set of instruments and textiles assembled for one kind of procedure. A “spay pack” is not one fixed list: in a published spay/neuter clinic pack guide, the contents differ by species and sex, and every pack also carries non-instrument items such as Huck towels, gauze and a sterilization indicator strip. The same guide notes that contents may change with the surgeon’s preferences.
Definition and scope
In the sources cited on this page, a pack is a group of items wrapped together so they can be sterilized and opened as a unit. The ASPCA Pro-hosted pack-assembly guide (Source 1) says packs should ideally be assembled on a pack wrap in list order. A university animal-care guideline describes wrapping instruments in a towel or surgical drape, closing the wrap with autoclave indicator tape, and wrapping a second time.
Three related terms are easy to confuse:
- Surgical pack: the wrapped unit, listed by species and sex of the patient (female dog, female cat, male dog, male cat).
- Instrument/extras tray: a separate item meant to give the surgeons extra instruments and gauze. The guide says instrument trays and their lids should be autoclaved separately.
- Needle pack: a separate pack with a variety of needle sizes, one needle holder and one indicator strip.
“Vet surgical instruments” is the broader category of individual tools. A pack is the assembled, wrapped combination of those tools with towels, drapes and gauze.
How packs are assembled and labeled
The clinic guide lists each pack in layout order, starting with a surgical Huck towel as the base and ending with a fenestrated drape where the pack includes one. It also states that pack contents vary by species and sex and may change per the surgeon’s request or preferences.
For labeling, one university institutional animal care and use committee (IACUC) guideline, approved November 13, 2017, says to write the date autoclaved, the type of pack and your initials on the autoclave tape. That guideline is written for a rodent-surgery program, so treat its specifics as one institution’s protocol rather than a universal rule.
Pack contents by species and sex
The table below puts the four packs from the clinic guide side by side. Every entry is taken from that guide; an empty cell means the guide lists none for that pack.
| Pack | Instruments listed | Textiles and supplies listed |
|---|---|---|
| Female dog | 2 Carmalts (preferably 1 straight, 1 curved); spay hook; Crile; 1 mosquito hemostat (curved or straight); needle holder; rat tooth forceps; Metzenbaum scissors; 2-3 towel clamps | Huck towel as base; gauze stack of 5 pieces (4 in × 4 in); indicator strip; 1-2 more Huck towels depending on dog size; fenestrated drape |
| Female cat | 1 Carmalt; spay hook; Crile; 1 straight and 1 curved mosquito hemostat; Adson-Brown forceps; Metzenbaum scissors; needle holder; 2-3 towel clamps | Huck towel as base; gauze stack of 5 pieces (4 in × 4 in); indicator strip; 1 more Huck towel; fenestrated drape |
| Male dog | 1 extra large Crile or Carmalt; needle holder; Adson-Brown forceps; 2-3 towel clamps | Huck towel as base; gauze stack of 5 pieces (4 in × 4 in); indicator strip; 3 more Huck towels |
| Male cat | 8 mosquito hemostats (the pack accommodates 8 cat neuter surgeries) | Huck towel as base; 8 pieces of gauze (4 in × 4 in); indicator strip; 1 more Huck towel |
Three patterns stand out. First, only the female packs list a spay hook, and only the female dog pack lists rat tooth forceps. Second, the male cat pack is built around repeated use for eight patients, so it is mostly hemostats and gauze. Third, every one of the four lists a sterilization indicator strip, and the textiles are part of each list rather than an add-on.
Instrument names in these lists such as the Olsen-Hegar needle holder and the towel clip are covered in separate CASRAI references; the drape in the female packs is described in what is a sterile drape.
What “vet surgical instruments” listings do and do not tell you
Product listings often describe a pack by a count. One distributor listing for a “Spay Pack, Grade 1” (SKU 077888, RICA Surgical), checked November 1, 2026, gives the size as an 18-count pack and describes it as an instrument pack for spay and neuter surgery in dogs and cats. The description does not break the count down by species or sex. Compared with the clinic guide above, whose four packs list between 5 and 11 instruments each (counting towel clamps), a count by itself does not say which instruments are inside, or whether towels, gauze and an indicator strip are included. A buyer or clinic comparing listings therefore needs the item-by-item list, not the count alone.
Where it matters for labs, clinics and supply decisions
- Two packs per surgeon. The clinic guide says to prepare two of each of its specialty packs per surgeon, in case the first is contaminated.
- Trays and lids. The guide says instrument trays and their lids should be autoclaved separately.
- Shelf life under one protocol. The university guideline gives a shelf life of thirty days for a pack in a single outer wrap, three months for a double outer wrap, and three months for an individual quick-seal autoclave bag. If a pack’s sterility expires, it must be re-labeled and re-sterilized.
- Sterilization method. The same guideline says most surgical packs can be heat sterilized before surgery, and that an instrument which cannot be heat sterilized can be gas sterilized.
- Single-use or reusable. For how reusable and disposable surgical instruments compare, see autoclavable vs single-use surgical instruments. For how staged surgical supplies are organized, see case cart.
Common misunderstandings
“A spay pack is one standard list.”
The clinic guide lists separate packs for female dogs, female cats, male dogs and male cats, and says the contents may change per the surgeon’s preferences.
“A pack is only instruments.”
Each list in the guide includes a Huck towel base, gauze and an indicator strip; the female packs also include a fenestrated drape.
“The count on a listing describes the contents.”
A count such as 18 tells you how many items, not which ones.
“A wrapped pack stays sterile until it is used.”
Under the university protocol, sterility is time-limited and depends on the wrap, and an expired pack is re-labeled and re-sterilized. Another facility may set different rules; follow your own written protocol.
Frequently asked questions
What is in a spay pack?
In the clinic pack guide, a female dog pack holds eight kinds of instruments (Carmalts, spay hook, Crile, mosquito hemostat, needle holder, rat tooth forceps, Metzenbaum scissors and towel clamps) plus Huck towels, a gauze stack, an indicator strip and a fenestrated drape. The female cat pack is similar but lists Adson-Brown forceps instead of rat tooth forceps. See the table above.
Is a spay pack the same for every patient?
No. The guide builds separate packs by species and sex, and notes contents may change per surgeon.
What is the difference between a surgical pack and an instrument tray?
In the guide, the pack is the wrapped, patient-specific set, while the instrument/extras tray provides additional instruments and gauze, and is autoclaved separately from its lid.
How long does a wrapped surgical pack stay sterile?
Under one university protocol: thirty days with a single outer wrap, three months with a double outer wrap or a quick-seal bag. Your facility’s own protocol governs.
What do “vet surgical instruments” listings include?
That varies by listing. One distributor listing gives an 18-count total without a species-by-sex breakdown.
Sources
- “Sterility & Packs at Spay/Neuter Clinics,” pack assembly pages (female, male and specialty packs), hosted by ASPCA Pro: aspcapro.org pack assembly PDF. Date checked: November 1, 2026.
- SDSU IACUC Guidelines, “Instrument Cleaning, Packing and Sterilization,” approved November 13, 2017: research.sdsu.edu guideline PDF. Date checked: November 1, 2026.
- Covetrus North America, “Spay Pack, Grade 1” (SKU 077888) product details: northamerica.covetrus.com product page. Date checked: November 1, 2026. Cited for the count and description only.
