Larynx and Throat Problems in Dogs

Paroxysmal Respiration

Pneumonia

Laryngeal scarring with debarking

Question: Dr. Richards,

When laryngeal scarring occurs, as in debarking, is it possible that the scarring could grow larger over time? Punkin had her teeth done and the vets had to use a 2.5 bore esophogeal tube for the anesthesia.

Tony A.

Answer: Tony-

I have corresponded with veterinarians who felt that the laryngeal scarring that can occur with debarking was progressive in one or more patients that they dealt with. Based on our patients who have had problems after debarking procedures were done I can't say that I have seen progression. However, I have seen these patients when they were having symptoms related to the laryngeal scarring and if I remember correctly one of these dogs was eight years old and had been debarked when it was young, with no prior history of complications from the procedure. So it seems logical to me that there was a worsening of the scarring to lead to the clinical signs.

I have been reading some testimonials about using laser surgery to open up the larynx when scarring occurs (from trauma, cancer or debarking). It appears to be pretty important to have a very experienced operator for the laser but there seems to be some success in treating this problem using lasers. Hopefully, if Punkin does have a further decrease in the largyneal lumen size it will be possible to help her in this manner, or with another procedure your vet is comfortable with. A 2.5 fr endotracheal tube is very small for just about any canine patient. We rarely have to use a tube smaller than 3.5 or 4.0 fr. tube and we do have some very small canine patients. If you see signs of respiratory distress in Punkin, such as holding her head extended to breath, having audible respiratory sounds, rapid respiration's (like 40 breaths per minute or more at rest), then it would be a good idea to have her examined as soon as possible. Hopefully, that will never occur.

Mike Richards, DVM 8/27/2001

Debarked dog problems - stenosis in poodle

Questions: Hello Dr. Mike, We recently adopted a two yr old miniature poodle (retired show dog). The previous owner had her debarked. Could you please tell me if there is any way that this procedure can be safely reversed or its effect lessened. She is unable to make any sound at all which causes her great frustration when trying to express herself and communicate with our other dogs. Even the basic motions of asking to be let outside or for more attention are left to subtle face expressions. We are also concerned about possible airway problems as she gets older. Is there anything that we can do to help her have a better life? Any help or suggestions would be greatly appreciated.

Thank you very much. Betty

Answer: Betty-

Most dogs that have been "debarked" still vocalize, they just make a lower pitched sound that is quieter. So it seems a little odd that your poodle doesn't make any sound at all. There are two surgical approaches to debarking that I know of. In one approach, the surgery is done by reaching down through the mouth to the larynx and removing a portion of the vocal folds with a biopsy punch or scissor. When this surgery is done it isn't too unusual for dogs to regain the ability to bark, often at near normal pitch and volume, over time. If an attempt is made to remove the entire vocal fold using this approach there is sometimes stenosis (blockage) of the larynx from scar tissue and it is possible that this condition may be occurring and leading to the reluctance of your poodle to vocalize at all. The other approach to debarking is to make an incision over the larynx and then through the larynx to approach the vocal folds. It is usually possible to remove more of the fold with less risk of secondary complications using this approach. There is less chance of a dog regaining near normal barking volume and pitch using this approach.

It is hard to deal with stenosis problems. I have heard that removal of built up scar tissue using a laser is sometimes possible to do without causing even more scarring but we do not do debarking procedures and so I do not have any practical experience with dealing with complications of the surgery except for one or two patients who came to the practice debarked. We sent one of these patients to a veterinary school for surgery due to complications from debarking but they were not able to help much with the problem that dog had.

I am reasonably certain that the answer to your question is that not much can be done to change the current situation but that it might improve with time. However, it may be a good idea to ask your vet if there is a surgical specialist in your area who could examine your poodle to determine if there is something that can be done to help the situation, unless your vet is experienced in dealing with laryngeal surgeries and can help without the aid of a specialist.

Mike Richards, DVM 9/25/2000

Laryngeal Paralysis and surgical risks in older dog

Question: My 13.5 year old golden retriever/irish setter mix has been diagnosed with Laryngeal paralysis. She does not have hyperthyroidism and has a strong heart and is in otherwise pretty good health. The surgeon also found a growth on her vocal chords. The surgeon has recommended surgery, but has warned me of potential complications such as pneumonia due to water/saliva etc. going down into her lungs. My questions are as follows:

1) What is the danger of surgery and general anesthesia for a 13.5 year old dog? Statistically, how many come through fine? 2) Given her general good health, would she be expected to recover fully? Or how long would it take for full recovery? 3) What is the statistical chance of her getting pneumonia from this surgery? 4) What are the dangers associated with removing the growth on the vocal chords? 5) Is there anything else I should consider or know about to help make my decision? 6) What would be your recommendation?

Thank you very much for your help! L and N John-

Answer: Most your questions are difficult to answer directly with the information available to veterinarians. There are few statistics kept on surgical or anesthetic succcess in veterinary medicine since there are few insured patients and few regulatory agencies collecting data directly from practicing veterinarians.

1) I can not remember losing a geriatric patient due to anesthesia, ever, in 18 years of practice. I have had older patients die during surgery but these have been deaths due to complications of the surgical procedure as far as I could tell. The risk of this depends on the surgery being contemplated. The risks associated with largyngeal surgery generally occur in the post-surgery time period so in this case the surgical time is not that risky.

2)Older dogs recover at approximately the same rate as younger animals except that they are a little more likely to be sensible and take it easy for a few days post-operatively.

3) I searched the databases I have access to and it appears that the rate of unacceptable post-surgical complications runs about 10% but there was a not a breakdown to indicate what percentage of dogs had pneumonia. Complications included post-operative hemorrhage, scarring causing obstruction of the airway, aspiration pneumonia and progression of neurologic signs despite surgical correction. In one study (the smallest) the complication rate was 30% but this was the only one with results even close to this bad.

4)Scarring would seem to be more likely with the removal of a tumor since there is less control over how much tissue is removed and which tissue is removed.

5)Hypothyroidism is a common complication in laryngeal paralysis cases. Even low normal thyroid values should be suspect when laryngeal paralysis is present.

6)If the tumor is already causing respiratory difficulty it seems to me you have little to lose by trying surgery, except the cost. If you can afford to have this surgery done without harming the care of other family members it seems to me that it is worth a try.

Good luck with this.

Mike Richards, DVM

Sore throat in dog

Question: Mike,

About a month ago I noticed the following symptom in Zeus two or three times. He would swallow about 20 times in a row, even though he had had nothing to eat. This usually happened first thing in the morning.

We took him to the vet. The vet said Zeus had a sore throat and gave him a five day course of antibiotics. The vet said it was nothing to worry about. We took Zeus for a further appointment on Monday 7 August. The vet then said he was fine.

However in the intervening 11 days since the 7th August there have been two or three further episodes where Zeus swallowed about 20 times in a row even though though he had had nothing to eat. On one occasion or more he rubbed his neck against the bed for maybe 10 or 20 seconds--I am not quite sure how long. I think these episodes happened first thing in the morning.

Zeus looks fine. His appetite is OK. There are no other behavioural changes. No weight loss. He is about seven years old.

Is there anything to worry about?

It should be said that for the past several weeks I have woken up with a slight sore throat which I put down to a minor viral infection. Zeus sleeps on my bed.

John

Answer: John-

Dogs can get sore throats, pharyngitis, laryngitis and all of the other things that people get. These problems usually clear up within a few days to a few weeks. There are some things to worry about if this behavior continues, though.

Repetitive swallowing sometimes occurs with megaesophagus. This is weakness of the esophageal muscles, leading to dilation of the esophagus and difficulty moving food through it. It can occur due to myasthenia gravis, hypothyroidism, esophageal injuries, immune system disorders, polyradiculoneuritis, muscular dystrophy and several other conditions.

Masticatory myositis can cause this symptom early in the disease. Later on, there is usually swelling of the muscles of the head and then muscle loss.

This can occur in some dogs as a form of seizure disorder.

Dental problems, such as gingivitis or periodontal disease, can sometimes cause increased swallowing.

There are probably other conditions that I can't think of off the top of my head that can do this, as well. If this condition is still present it would be a good idea to have your vet re-examine Zeus. Sometimes, it is not possible to find the cause for a behavior and once in a while these are problems like obsessive-compulsive disorders, that are hard to conclusively prove to be present, in a dog. Still, it is worth at least some effort to rule out possible causes before giving up and treating it as a psychological problem.

Mike Richards, DVM 8/22/2000

Laryngeal paralysis in older Lab

Question: Dear Dr. Richards:

We have a 13 year old black Lab x, a spayed female named Shadow. She is currently on Lysodren for Cushing's Disease, and is well controlled. However, she recently has been quite short of breath and is coughing....a short, dry little cough. We took her to the same doggy internist who is treating the Cushing's. An echo-cardiogram showed a slight enlargement of the left side of the heart and a heart murmur, graded 3/6. However, our vet feels that Shadow's respiratory difficulties and cough may well not be related to her heart condition, but rather to what she called larynx paralysis. I gather that this condition results in a periodic narrowing of the airway and makes it difficult for the dog to breathe. In fact, the harder the dog tries to breathe, and can't, then the more frightened the dog becomes and it sets up a vicious cycle. Apparently, this condition is treatable by surgery on the throat. I have been able to find out very little infomation about paralysis of the larynx and would appreciate anything that you could tell me. We are very hesitant to subject a 13 year old dog to major surgery, but if we could expect a good outcome, we would certainly consider it. We are very concerned with the "quality of life" issue and don't want to artificially prolong Shadow's life, if all she can expect is more distress.

Thank you for your attention. I'll look forward to hearing from you.

Patricia

Answer: Patricia-

Laryngeal paralysis is a reasonably common problem in older Labrador retrievers, so your vet's instincts are likely to be correct in this case. The only way to be sure is careful evaluation of laryngeal function while the dog is anesthetized. This is something that most vets don't do on a frequent basis so it may be worth having this evaluation done by a surgical or internal medicine specialist. Laryngeal paralysis can lead to secondary problems pretty rapidly and it does appear to be frightening to the patient in many cases, so when it is possible, we do recommend repair of this condition.

I do not know why laryngeal paralysis develops in most dogs that are affected with this problem. There is some feeling that it might be part of a larger neurologic syndrome in big older dogs but I don't know if this theory is widely accepted. There has been a link to hypothyroidism in past literature but this is a weak link if it is a problem at all.

The larynx works sort of like a pair of sliding doors that cover the tracheal opening. The doors slide closed all by themselves and prefer to stay that way. It takes muscular action to open them so that air can enter the trachea. This is a good system most of the time, since it is very important that liquids and food don't enter the trachea, making it better if the body has to open up the laryngeal folds in order for breathing to occur. When the nerves that control the muscles that open the larynx don't work, the "sliding doors" or laryngeal folds, don't open and the dog has to force air through the closed larynx in order to breathe.

Unfortunately, repair is not yet a perfect option, as there are complications from surgical repair with more frequency than with most surgical procedures. So it is also important to have a surgical specialist, or at least a vet with a lot of experience in repairing this problem, do the surgery. I am not aware of a really effective medical treatment for this problem, if it is present, so surgery is the best option, despite the potential for complications.

Since this problem occurs most commonly in older dogs, it is always hard to decide if it is beneficial to do surgery since many patients have other problems and since there is a small chance of surgery making things worse instead of better. I still think it is the best choice in most cases, but it is important to evaluate the overall situation in making this decision, especially with complicating factors like Cushing's disease also being present. Your vet can often really help in giving you an evaluation of expected complications and present problems and how all of that affects decision making regarding surgery. Don't be afraid to discuss your reservations and your idea of what a successful outcome would be as openly as possible. Your vet will understand how hard a choice this is.

Mike Richards, DVM 6/20/2000

Laryngeal paralysis

Q: Hi, Dr. Mike, I feed my aging black labrador pink or red salmon from the can. It rejuvenates her to a point that if I skip more than a day or two she becomes listless and somewhat depressed-acting. My veternarian just prescribed Rimadyl for her arthritis and it seems to be a real source of relief for her. Try has a real problem when she awakens with her throat. She coughs weakly until her throat starts working for her again. Is there something for this problem? I was told that some older labs get a paralysis of some sort in their throats. Also, I am concerned about grieving her loss, when the time comes. Thank you

A: Older big dogs do sometimes develop laryngeal paralysis. This can occur spontaneously and it also can occur as a secondary effect when hypothyroidism is present, I think. Usually, I don't think of this as a common cause of coughing but that is one sign reported to occur with laryngeal paralysis. More commonly, dogs have a "hoarse" bark or do not bark, raspy or noisy breathing and may seem to tire more easily or be more sensitive to heat. Some dogs even faint from difficult breathing.

Other possible problems include heart disease, chronic bronchitis, tracheal collapse and cancers of the trachea or lungs, as well as other less common problems.

I'm sure your vet has considered these other options and it sounds like he or she has seen your dog recently (since Rimadyl Rx is pretty new). If you didn't mention the cough you might want to set up an appointment to discuss it with your vet, though.

It is always hard to deal with grief over loss of a pet. A friend is a friend, whether they have four feet or two. Everyone handles the grief differently. I have to work my way through it and take a while to try again with a new dog after I can get it all in perspective and finally appreciate all the good memories instead of all the empty feelings. Other people need to let themselves start the process of loving a new pet right away. Once in a while, we see pet owners who are so upset they do decide not to get another pet. We do have to accept that most of the time we will outlive our pets and have to deal with the grief of losing them. I continue to believe the time we do get to spend together is worth it, though. It sounds to me like you probably believe that too. Mike Richards, DVM P.S. - I forgot -- most of the causes of coughing do have some medications that relieve symptoms or even cure them in some cases. It is just that you have to identify which problem is present before any real recommendations can be made. Laryngeal paralysis may require surgical correction if it is severely affecting a dog. I don't know of a medication that helps unless it is from hypothyroidism and is caught pretty early.

Mike Richards, DVM