Subcutaneous Fluid Administration in Animals

In veterinary medicine, fluid therapy is given in four ways,

  1. Oral – by mouth
  2. Intravenous – through an intravenous catheter
  3. Intramedullary – within the medullary canal of bones
  4. Subcutaneous – under the skin

Subcutaneous administration means fluids are injected under the skin using a needle. The fluids accumulate into a large pouch between the shoulder blades.  This gives the patient a ‘hunchback’ look. Overtime, the fluids are absorbed into the animal’s bloodstream. Because it takes time for the absorption to take effect, the subcutaneous route is not appropriate for animals who need fluids immediately. The intravenous or intramedullary route is used for these cases.

To perform subcutaneous fluid therapy, I recommend cleaning the skin where the needle will be placed with an antiseptic solution to prevent infection. Next, the skin is pulled up off the animal’s body making a ‘tent’. A sterile needle is inserted into the base of the tent and the fluids are injected. A new needle is used for every treatment. Needles should not be reused under any circumstances as they become dull and contaminated.

Only sterile, non antigenic fluid can be injected under the skin. Examples of appropriate fluids include lactated ringers solution, Normasol, Plasmalyte or saline. Fluids that contain any form of sugar (glucose or dextrose), high osmolality and/or unsterilized fluids should never be used for subcutaneous administration. Sugar causes a horrific reaction that often causes abscess formation and sloughing of the skin.  The sugar placed in the warm subcutaneous space creates a perfect incubator for bacteria. I saw a dog go into septic shock after it was given Pedialyte subcutaneously. These animals are in extreme pain. I have seen dogs and cats lose all of the skin on their backs from sugar. Even with extensive skin grafts and hospital care, some of these animals died. Here are a few examples of fluids that should never be used for subcutaneous fluids. Pedialyte, D5W, Gatorade and mannitol.

Please talk to your veterinarian before giving any medications or therapy to your pet!




Published by kristennelsondvm

Dr. Kristen Nelson grew up on a farm in Watertown, Minn., where she developed a deep love for animals of all kinds. She received a Doctor of Veterinary Medicine degree from the University of Minnesota, College of Veterinary Medicine. Kris then completed a small-animal internship at the prestigious Animal Medical Center in New York City. In addition to writing and speaking, she cares for small and exotic animals in Scottsdale, Az. Dr. Nelson is widely quoted in the media. Her credits include Ladies’ Home Journal, USA TODAY, the Los Angeles Times and numerous radio and television interviews. Dr. Nelson has written two books, Coated With Fur: A Vet’s Life and Coated With Fur: A Blind Cat’s Love. Kris and her husband Steve share their home with rescued cats, birds and a dog.

15 replies on “Subcutaneous Fluid Administration in Animals”

  1. I have been giving my dog sub cutaneous fluids (lactated ringers) for about 1 year. My vet said it was not necessary to put antiseptic on the skin before puncture so I never did. My dog was elderly and with kidney problems. I am afraid of possibly pushing him to septic shock because it is possible he had dried urine on his skin (because he would fall on his back when I was not home) and I did not have time to wash him yet. I believe I gave him sub-q fluids on Tuesday and Thursday and he passed away Friday. Is it possible for urine residue near sub-q puncture site to cause septic shock?

    1. I am so sorry to hear about the loss of your beloved pet. Most veterinarians and technicians do not apply an antiseptic before giving an injection. I am one of the old fashioned vets who likes to put some alcohol on the spot but I am definitely in the minority. Septic shock can be caused by many different things. Did the skin become inflamed about the injection site? Did it drain pus? If not, then I would look at other sources of infection. Since your dog had kidney issues, he probably excreted a dilute urine. Dilute urine is more prone to infection. I think an infection that ascended from the urinary bladder to the kidneys and then into the blood stream would be more likely. Having said that, I have had several cases where the cause was never identified. Again, please accept my condolences.

      1. Is it ok to give my dog sub q fluids (LR) as directed by my vet and also give them some pedialyte PO?


        1. Yes, the Pedialyte has important electrolytes and calories that will help your dog recover from illness. It is especially important in dogs with diarrhea.

  2. Hello. At this moment I am sick and heart broken. My 9 year old Golden Retriever, Kenzie passed away this morning from septic shock. Everything you have written above mirrors our case. My beloved pet got into 2 chocolate bars this past Sunday evening. She vomited shortly thereafter. I took her to vet on Monday am and she showed slight temp and elevated heart rate, which the vet said could be considered normal given the anxiety some dogs have when visiting the vet. They conducted no other tests but said they would give her fluids. I had never seen this subcutaneous fluid process administered before and I’ll admit it shocked/surprised me that my dog had a water balloon the size of a grapefruit like a big hump on her back. What would be the appropriate ML for a 76.5 lb Golden?

    By noon Monday Kenzie was doing well. Eating her lunch, alert and normal stools. Things started to decline by dinner where my normally enthusiastic eater didn’t want her dinner. By bedtime she was lethargic and had what I called “dead eyes” I freaked out & rushed her to emergency clinic Monday evening. This was followed by daily visits back to the vet on Tues-Wed because she was lethargic and in obvious pain. She had blood tests, ultrasounds, x-rays…they found she tested positive for Lyme disease and administered Doxycycline. The only thing that makes sense is she was contaminated by the fluids. TUFTS called me and asked me if I would consent to a necropsy. TUFTs was our emergency care provider, where she ultimately died early this morning. Please, what advice to you have for me? I strongly believe the vet was negligent and led to the death of my otherwise healthy dog within a 72 hour period from either incorrect or non-sterile fluids. Thank you for any advice you can offer.

    1. Hello Jennifer,

      First, please accept my sympathies for the loss of your beloved Kenzie. Subcutaneous fluid administration is a common procedure in veterinary medicine. A dog the size of Kenzie can handle a liter or more. The fluids usually make a large lump that feels like a water balloon as you described. Septic shock means bacteria have entered the blood stream. The big question is where did the bacteria come from? I would recommend performing a necropsy to help answer this question. If it came from contaminated fluids there should be signs of infection in the area of the fluid administration. During the necrospy, they will also check for other problems including heart disease secondary to the Lyme disease. Again, I am so sorry for you loss.

      1. Thank you for taking the time to respond to my message. The necropsy is being performed at Tufts in Grafton. I have been advised that the results can take several weeks. We will wait. Nothing can bring our baby back, but we need answers. She was HEALTHY and her health went into an unexplainable, rapid death spiral after the administration of those fluids. Thank you, again.

      2. Doxycycline is horrible I have never been so sick took it 4 days. Vet was trying to kill bacteria all right. Doxycycline killed the dog

        1. Why did your dog get fluids? My Chihuahua ate a chocolate bar at 5 yrs. I lost her sister at 8 yrs Banfield Roanoke sedated her to drain fluids. Vet said after she went into shock” she sure didn’t like that tube down her throat. It was closing time had I been in the room I would have walked out

  3. My cat had a sub q injection about 7 weeks ago and still has a bump at the injection site, below his shoulder blade. Is this normal??

    1. No, this is not normal. Many cats will have small nodules form at the site of a vaccine injection but these should be gone within a few weeks. Please contact your veterinarian right away. We need to be especially cautious with cats as vaccines related sarcomas can occur.

        1. I am glad it wasn’t a vaccine as chances of sarcoma formation are less with fluids. I would still recommend bringing your cat in for the veterinarian to check the site. They may perform a fine needle aspirate to see what kind of cells are inside. Although it sounds bad, the process involves preparing the skin and then inserting a needle into the lump. The cells are spritzed onto a slide and examined under a microscope. It takes a few seconds to perform. Most cats tolerate it well.

  4. Hey I have a cat that is getting sub -q fluids at home.. But she seems like its not enough to rehydrate her….can I do a 2snd treatment in the evening?

    1. I recommend giving a larger amount of fluids once a day instead. It would be less painful. Talk to your veterinarian to make sure you are giving the proper amount. Hopefully, we will find the cause of kidney failure in cats soon. Best of luck to your cat.

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