Check out this http://jap.physiology.org/content/89/5/1766 Hope you find this useful

We always use the 17ga (white) venflon. If you break the point of the needle off, it is very easy to use.

Hi Dorela.

We use a 14G intravenous catheter/cannula without the metal stylet. The tip of the catheter must not be too sharp.

Regards,

Nkanyiso 

Thank you, I have found the two you suggested Aldo and Soren.

(1) The APS paper use BD InSyte 16 gauge with 45mm length (382657) but there is no pricie listed on the website.  http://www.bd.com/ca/safety/products/infusion/IV_access/insyte/

(2) I have also found the BD Venflon catheters 17 gauge 45mm (393228) you suggested but there is also no price listed.  http://www.bd.com/europe/safety/en/products/infusion/bdv_prosafety.asp

I will contact the company and get quotes on both.

I also contacted Braintree during my search and they offer individual catheters (ETT-16-50) for $160 for 50. The company, however, does not list it as an item for individual sales on their website. 

For my surgery today I  was able not able to purchase new catheters and had to use the Excel Safelet Catheters 14 gauge 2in (26729). In my previous attempts the catheters collapsed due to pressure from the animals weight, however, I was able to successfully intubate young rats (SD 6wk) with these catheters and complete the surgery successfully. We also do not use the metal stylet when intubating but do use a guide wire, which I find to help intubate more effectively. 

Dear Dorela, great to hear! Best of luck with the surgery. Best wishes, Søren

We have used 16th guage BD venflone cannula for intubating rates without metal stylet and it was easy to insert.

I have not been able to buy but used something like Dr. Abu-Halaweh Sami

For 25-30 g little rats I use g25-g26 abbottcaths... For 200g rats I would go to g16-g14...