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PHChristy: Good evening and thank you for coming to our special discussion of anesthesia risks for pregnant bitches and unborn/newborn puppies.

PHChristy: Before I begin, let me stress that I am NOT a veterinarian, and that I encourage all of you to work with qualified veterinarians with experience in canine reproduction when dealing with the issues we're discussing here tonight.

PHChristy: Also joining us tonight is Nancy Campbell RVT,VDT, who is a registered veterinary technician with special training and certification in veterinary anesthesia. She will be here a little later on in the chat.

PHChristy: In the meantime, let's begin.

Being pregnant causes a number of definite biological changes in the bitch.

PHChristy: Oxygen desaturation (lowered levels of blood oxygen) occurs much more easily in a pregnant bitch. Oxygen levels in the bitch need to be monitored carefully and constantly, and oxygen administered when needed, including before and after anesthesia.

PHChristy: HOWEVER... Both TOO MUCH OXYGEN and TOO LITTLE OXYGEN can compromise the unborn fetuses. Veterinary experience is critical here.

PHChristy: According to Drs. Pascoe and Moon, both professors of anesthesiology at UC Davis, diplomates of the American College of Veterinary Anesthesiologists, and co-authors of the chapter on anesthesia in "Clinical Theriogenology," "Pregnancy causes an apparent sensitivity to anesthetics."

PHChristy: High levels of progesterone have a sedative effect, decreasing the amount of anesthesia or sedation needed to get the same result as in a non-pregnant canine.

PHChristy: The University of Missouri's John R. Dodam, DVM, PhD, Diplomate of the American College of Veterinary Anesthesiologists, writes:

PHChristy: "Potency of inhaled and epidural/spinal anesthetics is increased in pregnant animals, partially because of elevated maternal progesterone concentrations.

PHChristy: "For inhaled anesthetics, a 25-40% increase in anesthetic potency is observed and persists for about five days postpartum.

PHChristy: "Besides increased potency, the spread of epidural and spinal local anesthetics is also increased in pregnant animals. Thus, induction and maintenance doses of inhalant anesthetics should be decreased.

PHChristy: "The dose of epidural anesthetics may be reduced by 25-33% in pregnant animals."

PHChristy: The cardiovascular system (heart, lungs, circulation) is also affected by pregnancy.

PHChristy: "Systemic blood pressure and right and left atrial pressures decrease, although heart rate increases slightly. Cardiac output and blood volume are increased to provide adequate blood flow to the fetus."

PHChristy: Plasma volume increases more than blood cell volume, which produces a condition of "pregnancy anemia." The more puppies the bitch is carrying, the more pronounced this is.

PHChristy: The amount of blood going to the uterus and placenta is dependent on blood pressure, and automatic regulation of blood pressure by the bitch's system does NOT work to control blood pressure in the fetuses.

PHChristy: Hello, Nancy! Welcome!

NancyRVT: *wave* G'd evenin'

PHChristy: Nancy is our special guest, she's going to catch me in any errors I've made

PHChristy: hopefully I got them all out of the way before she got here

PHChristy: I'll go back to the presentation, but Nancy or anyone, feel free to jump in with comments, questions, or corrections

PHChristy: Both high and low blood pressure can negatively effect the fetuses.

NancyRVT: Will do

PHChristy: Because of these and other changes, management of blood pressure and oxygen levels during trauma as well as anesthesia is critical to ensure the survival of the fetuses.

PHChristy: This typically involves the use of IV fluids before, during, and after anesthesia, and oxygen before and after.

PHChristy: I mentioned trauma as well as anesthesia, because pain and stress cause a sympathetic nervous system response in the bitch that shunts blood away from the fetuses.

PHChristy: It's urgent to manage pain and stress aggressively in a pregnant bitch.

PHChristy: It's also important to note that certain drug choices tend to have better effects on cardiac and respiratory function.

PHChristy: If you need to use a vet who isn't familiar with reproduction, it may be a good idea to print out and take the information from the VASG website that will be included at the end of this chat, or insist that they contact a veterinary college and consult an anesthesiologist prior to doing a procedure on your bitch, if time allows.

PHChristy: Surprisingly, pregnancy also produces a number of changes in the gastrointestinal system, and this does have an effect on anesthesia. Esophageal sphincter tone is decreased, which means the bitch can regurgitate more easily, which increases the chance that she'll aspirate and develop pneumonia.

PHChristy: In addition, gastric contents are more acidic in pregnant animals. Combined with increased gastric emptying time and increased fluid volume in pregnancy, according to Dr. Dodam:

PHChristy: "This implies that regurgitation and aspiration would be both more likely and more dangerous during anesthesia in pregnant animals. Rapid and proper placement of a cuffed endotracheal tube is the most effective method to prevent aspiration of gastric contents."

PHChristy: It was long known in human obstetrics that that patients undergoing a c-section have an increased risk of aspiration pneumonia, and research has now shown this to be the case with dogs too.

PHChristy: In one study, 56 percent of maternal deaths after c-section were from pneumonia, which is a much higher percentage than the general population of anesthetized patients.

PHChristy: And now the part that we as breeders and owners need to know....

PHChristy: For this reason, the breeder MUST know when the bitch last ate and how much food may be in her stomach before she undergoes anesthesia.

PHChristy: If an xray is being taken for some other reason, the vet should try to include the stomach, to assist in evaluating how much food is present.

PHChristy: If there is food in the stomach, Drs. Pascoe and Moon suggest:

PHChristy: "Any radiographic evidence of a full stomach would be an indication to use a technique that would allow rapid control of the airway to prevent asiration during induction. Vomiting and regurgitation during recovery are also possible; thus, the endotracheal tube should remain in place until adequate control of the airway is regained by the patient."

PHChristy: They also recommend antibiotics be administered if "there is any stained mucus in the endotracheal tube at extubation."

PHMowgli: hello

PHChristy: OK, does anyone have any questions or comments so far? :)

PHChristy: LOL Morgan, are you kicking them out instead of greeting them?

PHChristy: if no one has questions, let me go on to one of my personal favorite topics....

PHChristy: Some breeders and even some vets like to use gas-only anesthesia, believing it is easier on the bitch and puppies, and that it is safer, because fewer drugs are given. NOTHING COULD BE FURTHER FROM THE TRUTH.

NancyRVT: One of mine too. :-)

PHChristy: Gas-only, also known as "masking down" or "mask induction" presents substantially INCREASED risk, not decreased.

PHChristy: First, you have to use a LOT higher dose of anesthesia to induce with gas than to maintain anesthesia, which increases the risk.

PHChristy: Isoflurane, which is a wonderful gas anesthetic generally, is a very potent vasodilator, which means that you can send blood pressure plummeting, more so with the high doses needed to induce with it.

PHChristy: You also get more severe cardiovascular depression, with its obvious risks.

PHChristy: Furthermore, when you gas induce, you have no control over stage 2 anesthesia, which is the stage of involuntary excitement.

PHChristy: You HAVE TO go through stage 2 to get to full surgical anesthesia (stage 3), but with gas inductions it lasts much longer as well as having no control over it.

PHMorgan: (been there, seen that)

PHChristy: Stage 2 anesthesia is accompanied by catechol release, which is very hard on the heart; this effect is dose dependent, so again, the increased dosage substantially increases the risk.

Arrythmias in particular are more likely to occur.

PHMorgan: Will explain later...

PHChristy: Lastly from the animal's point of view, you have no way to get rapid control of the airway during the procedure. This increases risk, once more, especially for aspiration-prone pregnant bitches.

PHChristy: From the vet/staff's points of view, gas inductions expose THEM to waste gases and are hazardous.

NancyRVT: Good induction protocol and the excitory stage appears bypassed. :-)

PHMorgan: ::::Duct-taping Mow into her chair:::::

PHChristy: See, Nancy, we do love ya

PHMowgli: Whew I tried this once before and was not really here

PHChristy: Morgan, please go ahead and share your experience with a gas induction....

PHChristy: I think at least once a week someone tells me their vet uses this because it's "safer"

PHMorgan: Well, I'm not sure if I’m understanding what you said about the stage 2 part correctly.....

NancyRVT: *grumble* I wish it were so.

PHMorgan: But the last section I had my vet used Iso on my bitch and it took FOREVER to get her completely under

PHChristy: just iso?

PHChristy: nothing to induce?

PHMorgan: They did give her some kind of injection - I forget what it was.... She was making a LOT of involuntary movements (looked like protesting)

PHMorgan: And it took nearly 5 minutes for him to be able to make an incision safely

PHChristy: hmmm, if he gave her an injection, then he did induce her... Nancy, what do you think?

NancyRVT: Do you remember if the injection was intravenous or not?

PHChristy: unless it was just ace or something

PHMorgan: It was not

NancyRVT: Then it was not an induction agent

PHMorgan: I think it was ACE - but not 100% sure

PHChristy: oh man

PHChristy: that's not good

PHMorgan: He didn't think so either

PHChristy: good thing you came to this chat

PHMorgan: He was muttering about the anesthesia - he apparently wants to use something else

PHChristy: I have one more thing to say about csections, let me whip through that and then we'll talk about unborn/newborn pups

PHChristy: Nearly all human c-sections are done using epidural anesthesia rather than general anesthesia, and this is becoming more common in canine pain control too.

PHChristy: However, unless you are working with a vet with extensive experience with epidurals in pregnant bitches and c-sections, this can be risky.

PHChristy: And obviously a bitch is not likely to just lie there, numb but awake, while you section her - so other forms of anesthesia will still be necessary.

PHChristy: Research this subject well with your vet before deciding whether to give it a try or not.

PHChristy: Now, on to the topic of the effects of anesthesia on puppies, both unborn and newborn (neonates).

PHChristy: Obviously if a bitch has to be anesthetized for a c-section, her puppies will also be anesthetized.

PHChristy: This is because most drugs will cross the placental barrier. All the sedatives, tranquilizers, anesthetics, and centrally acting analgesics will do so. They will affect the puppies.

NancyRVT: Always.

PHChristy: absolutely. ALWAYS

PHChristy: During pregnancy, the bitch will re-absorb the drugs from the fetuses as they wear off on her. However, after birth, the puppies will have to metabolize the drugs themselves, and their ability to do so is not well-developed at this stage.

PHChristy: So, what can you do?

PHChristy: To protect puppies as much as possible from the effects of anesthetic drugs, Drs. Pascoe and Moon suggest:

PHChristy: -Use local anesthetics when possible

PHChristy: -Use the smallest dose possible to get the desired effect on the bitch. They indicate that one-eighth to one quarter of the dose in a non-pregnant animal might be considered.

PHChristy: -Use drugs with a short duration of action that are rapidly metabolized by the dam, to increase the chances the dam will clear the drug from the puppies before they are delivered. They offer propofol as an example of such a drug.

PHChristy: -Use drugs that are reversible, so an antagonist can be given to the newborn puppies to reverse its effects.

PHMorgan: ?

PHChristy: Morgan ga

PHMorgan: OK - so clearly we want to use a lesser anesthesia on pregnant bitches....

PHChristy: we want to CONSIDER, or START WITH, lesser amounts

PHChristy: but you still have to evaluate the plane of anesthesia

PHMorgan: But how to we KNOW we are using ENOUGH? That the bitch is sufficiently anesthetized to safely (and comfortably for momdog) do surgery??????

PHChristy: you still need to fully anesthetize her, but you don't want to go right to the full dose

NancyRVT: :-)

PHChristy: Morgan, you don't decide if an animal is anesthetized based on how much drug they had.... you decide it based on their physical state

NancyRVT: A technician that is trained in anesthesia can tell.

PHChristy: and we also hope the VET can tell

NancyRVT: There are certain reflexes that are not present during specific planes and stages of anesthesia.

NancyRVT: Yes, LOL

PHChristy: trained staff and the right monitoring equipment are essential

PHMorgan: Which are?

PHMorgan: Reflexes, not equipment

PHChristy: this is a good thing to focus on, because when the mother is in stress because her anesthesia is wrong, it puts her unborn puppies into distress as well, and causes blood to be taken from the fetuses and given to the bitch

NancyRVT: If you pinch the toes and the dog pulls back they are not ready/under. If you tap the corner of their eye and they blink, they are not ready/under.

PHMorgan: OK GA

NancyRVT: That's just an example

NancyRVT: You can also tell by the heart rate, blood pressure and respiration.

PHChristy: ok, back to the tips.... -Minimize the time the bitch is exposed to inhalant anesthesia

PHChristy: They also recommend not using dissociative drugs, such as ketamine, and against the tranquilizer ace promazine, due to the fact that it is metabolized through the liver, and hepatic metabolism in neonates is very undeveloped.

PHChristy: They also state:

“The most comprehensive study of cesarean section in dogs to date ... analyzed data from 809 operations. The only two drugs associated with a lower puppy mortality rate were isoflurane and propofol, and the only two drugs with a negative effect on puppy survival were zylazine and methoxyflurane."

PHChristy: That means that iso and propofol were associated with BETTER survival, while xylazine and methoxyflurane with WORSE

PHChristy: Like pregnant bitches, newborn puppies have some biochemical differences from adult dogs.

PHChristy: All these things make it difficult to successfully anesthetize newborn puppies, or for puppies delivered by cesarean.

PHChristy: Drs. Pascoe and Moon caution once again against dissociatives like ketamine in the first three weeks of life, as well as many of the usually-safe injectable drugs. They cautiously support the use of propofol or etomidate to induce anesthesia in neonates.

PHChristy: They even go so far as to suggest that if neonates need to be anesthetized, the vet might want to consider mask induction, because the risk of laryngeal damage is so great in very small animals when they are entubated.

PHChristy: It's one of those "damned if you do, damned if you don't" scenarios :(

PHChristy: Monitoring post-anesthesia of neonates is critical, including cardiac function, respiration, oxygenation, and doppler sonagraphy to check blood pressure if available.

PHChristy: MANY VET PRACTICES DO NOT HAVE THE ABILITY TO MONITOR THESE THINGS IN NEONATES - so try to locate a practice you can reach in an emergency, or for a planned section, that does.

PHChristy: As for managing pain in neonates, Drs. Pascoe and Moon are very clear that modern research finds that newborns absolutely have a well-developed ability to sense painful stimuli from birth, and that many procedures such as dew claw removal or tail docking that we traditionally have viewed as "not so painful" have been found to cause physiological signs of pain in young puppies - even when no pain was observed by the owner or vet staff.

PHChristy: Thus, we have an obligation to use pain control when doing these procedures. Unfortunately, the state of research on idea pain management protocols for dew claw removal and tail docking is not advanced, and they do not make any specific recommendations.

NancyRVT: :-(

PHChristy: In conclusion, the single most important thing you can do, whether dealing with a non-obstectric emergency in a pregnant bitch, a planned section, an emergency section, or a need to anesthetize a newborn puppy, is to use a vet with extensive experience in canine reproduction, neonatal care, and anesthesia.

PHChristy: Using a vet who is very experienced in managing anesthesia in pregnant bitches, with a long history of good outcomes, is essential. Many vets who do not have an extensive reproductive practice may be less able to easily manage anesthesia in a pregnant bitch.

PHChristy: Unfortunately, in most parts of the country, that's easier said than done.

PHChristy: For those interested in additional resources, for their own benefit or to share with emergency vets:

PHChristy: Much of the information presented here tonight came from the chapter on anesthesia in "Clinical Theriogenology," Autumn P. Davidson, DVM, Dipl. ACVIM, Editor.

PHChristy: The chapter was authored by Peter J. Pascoe, BVSc, Diplomate, American College of Veterinary Anesthesiologists, and Paula F. Moon, DVM, Diplomate, American College of Veterinary Anesthesiologists. Both Dr. Moon and Dr. Pascoe are professors of anesthesiology at UC Davis.

PHChristy: Two excellent resources on the web are:

C-Sections and Anesthesia, Veterinary Anesthesia Support Group website

Neonatal and Pediatric Management, Veterinary Anesthesia Support Group website

PHChristy: That concludes my prepared remarks, Nancy, did you have anything to add or any suggestions for those looking for better anesthesia for their bitches and puppies?

NancyRVT: I think the only thing I want to stress is to not be afraid to ask questions

PHChristy: and hope someone in the practice has the answer or knows how to get it... fast

NancyRVT: Knowing how to get the answers fast is important

NancyRVT: I work in a small animal practice in a small town...

NancyRVT: So you can imagine that we don't see as much as someone somewhere like Seattle

NancyRVT: it's important that the vet I work for has a "lifeline" to emergency and specialty hospitals for that reason.

PHChristy: OK, we'll open up the discussion now for general discussion of the topic of anesthesia risks in pregnant bitches and unborn/newborn pups.... questions, comments, experiences....

PHMowgli: I have a comment

bulldogs_nr: my mom breeds english bulldogs

PHChristy: and vets who belong to VIN also have instant access to a world of information as well as not-as-instant access to a whole staff of veterinary specialists

PHMowgli: my vet uses innovar and narcan and he claims they do not reach through the placental wall and mom is awake very quickly and the pups never seem to be affected

PHChristy: and most small practices do have relationships with nearby vet schools, and they should be able to call on them as needed

PHChristy: they DO reach through the placental wall, but the narcan simply antagonizes the anesthestic

PHMowgli: he also injects a local into the abdominal wall prior to incision

bulldogs_nr: can you breed a bulldog female if it has a wry jaw

PHChristy: reverses it

PHChristy: bulldogs, our topic tonight is anesthesia... we might have time for some general breeding discussion at the end

PHMowgli: yes I know the narcan is a reversal

PHChristy: so his saying the drug doesn't go through the placental barrier is incorrect

PHMowgli: my comment was mostly about the local

PHMowgli: it seems unusual to me

PHChristy: I don't know what "innovar" is

PHMowgli: well if it does it never seems to affect the pups

PHChristy: the local just numbs the incision site, it's very low risk to the mom and the pups but doesn't have any effect on her overall pain

PHMowgli: ketamine I believe

PHChristy: Hi, SamsSammy! Welcome to Dog Breeding Chat! Our topic tonight is Anesthesia Risks for Pregnant Bitches and Unborn/newborn Puppies

SamsSammy: Hi all.

PHChristy: Mowgli, I don't think so, narcan won't reverse ketamine

PHChristy: narcan reverses narcotic drugs, opioids, that type of drug

PHChristy: ketamine is a dissociative drug, and it absolutely does cross the placental barrier

PHMorgan: Maybe you could explain the difference between dissociative drugs and narcotic drugs???

PHMowgli: well my receipts say innovar maybe Nancy knows LOL

PHMorgan: :-D

PHChristy: narcotic drugs bind to certain types of pain receptors on our cells

NancyRVT: It's fentanyl

PHChristy: dissociative drugs interefere with how you experience pain

PHChristy: in your mind

PHMowgli: thanks nancy

NancyRVT: no problem

PHChristy: Fentanyl is a good drug

PHChristy: and is reversed by Narcan

NancyRVT: Best way to explain is a dissociative is ....you can feel pain, but you can't do anything about it.

PHChristy: Mowgli, you might not have been here, but we did discuss using reversible drugs - it's a good thing :)

PHMorgan: THat doesn't sound too pleasant for the dog

PHChristy: your vet is doing one of the things these guys recommended

PHChristy: ketamine is bad news IMO

NancyRVT: Ketamine should never be used alone

PHMowgli: well it seemed to work great for my 3 sections I was happy with the results

PHChristy: but they do usually give it with other drugs, such as valium, as a premed

PHChristy: not as an anesthestic which it's not - it's more a sedative

PHMorgan: OK - maybe I'm dense, but I'm getting confused with inducers, anesthetics and which is which

PHMorgan: How can I find out specifically which is which and what they do?

NancyRVT: Induction agents are used to relax the patient so that they can be intubated.

NancyRVT: They are fast but short acting

PHChristy: once you get the tube in, they turn on the gas anesthesia, such as isoflurane

NancyRVT: Anesthesia is usually a gas...it's used to maintain anesthesia

PHChristy: exactly

NancyRVT: Propofol is lightning fast for instance.

PHChristy: vets also sometimes give a sedative even before the induction agent

NancyRVT: Exactly

PHChristy: and often (and I think this is a good idea) give pre-emptive pain medication

PHChristy: trying to prevent the pain, rather than treat it

NancyRVT: Sedative/preanesthetic then induction, then maintenance.

PHChristy: this makes me wonder about Mowgli's vet - Fentanyl isn't an anesthestic, it's a pain med....

PHChristy: I'm going to assume he is using something on top of that fentanyl

NancyRVT: must be

PHChristy: a local plus fentanyl, the bitch would go insane on the table

PHChristy: he HAS TO be using some kind of gas with that

PHMowgli: probably christie he gives two injections no gas

PHChristy: or an epidural

PHMowgli: then he uses local on table

PHChristy: does he give an injection in her back?

PHChristy: the local won't kill her pain, it just numbs the skin

PHMowgli: not in back no both iv

PHChristy: no way would it allow him to cut into her abdominal wall, she'd go NUTS

PHMowgli: no epi's

NancyRVT: Have you been in there when it is done?

PHChristy: a barbituate?

PHMowgli: yes

NancyRVT: Is it white?

PHMowgli: all three times

PHChristy: I find this very hard to understand or figure out what he's doing

PHMorgan: Mine gives a sedative, then a local then gas....

PHMowgli: first injection is white

NancyRVT: That's propofol

PHMowgli: then he said the innovar

NancyRVT: He's using propofol to effect it sounds like

PHChristy: if innovar is fentanyl, it's just for pain

PHChristy: and it takes up to 14 hours to take effect

PHMowgli: then he ties her and uses local in abdominal area

PHMowgli: then he cuts

PHChristy: I don't know, Mowgli... what do you think, Nancy? is it enough?

PHMowgli: after he closes he injects narcan

NancyRVT: Fentanyl Citrate is an opiate, it's white also

PHChristy: so the pups are OUT.... so the narcan is after delivery, so they don't benefit, and he's REVERSING the fentanyl?

PHChristy: anyway, I'm not trying to attack a vet who isn't here, just don't understand. I really shouldn’t comment without knowing for sure what his protocol is, rather than a second-hand account of it. I’m commenting not on what he actually does, but on what you are describing to me

PHMowgli: pups are up and moving and doing wonderful

PHMowgli: but he has never used a gas

PHChristy: you should ask him what his exact protocol is

PHChristy: he might do it, he might like the results, but it might not be enough for your bitches, they might still be feeling this

PHMowgli: I know christie and my receipt just says injections of innovar and narcan

NancyRVT: It is a neuroleptanalgesia.

PHMowgli: I know they blink during the procedure but never even move and he did 2 girls with ruptures this way

PHMowgli: so they seem awake

PHMorgan: I know my vet often doesn't put all the drugs on my receipt

PHMorgan: Some things he just doesn't charge for

NancyRVT: it is only used as an analgesic/tranquilizer for MINOR surgical procedures

PHChristy: well, Mow, you should ask him for the full protocol

PHMowgli: yeah morgan that is possible but only 3 injections I know that for a fact

PHChristy: because honestly, what you're describing sounds cruel

NancyRVT: it's also used as a chemical restraint in aggressive dogs

PHChristy: it also BIG TIME lowers blood pressure, which could put pups at risk

PHChristy: just ask him to spell the whole protocol out

NancyRVT: I'm curious what the protocol is.

PHChristy: yeah

PHChristy: me too

NancyRVT: From beginning to end.

PHChristy: well folks, that's the end of our time for Dog Breeding Chat, thank you so much for coming, especially to Nancy for sharing her expertise with us! Now let me turn things over to PHMowgli for Showdog Chat!