Medication and Your Dog


Warning: Rimadyl will cause liver damage in some dogs. There have been some deaths in dogs with this reaction. This effects 0.02% of dogs and 70% of those are geriatric. More information can be found by consulting the Small Animal Clinics of Pharmacology's latest edition.. This is a remarkable drug for many dogs. Blood work however should be done prior to beginning treatment and one or two weeks into treatment to monitor liver values.

Deramax (Rx) is Deracoxib

Q: Dear Dr. Mike,

Do you know anything about a new pain reliever called Duramax for animals? Is there a website that has a write up on it or other information? Thanks and still a great newletter! Sincerely, Debbie

A: Debbie- Deramax (Rx) is deracoxib. This is a medication in the same category as Celebrex (Rx) and Vioxx (Rx) for humans. It was originally approved for post-surgical pain but has recently been approved for chronic use for arthritis, although I have not received dosing information from the company for this use, yet. It is manufactured by Novartis and there probably is a web site for it, but I have not seen it. We have used this medication for post-surgical pain and for pain associated with pelvic fractures in a number of patients. It appears to work very well and based on our initial impressions, I think it is the most potent of the non-steroidal anti-inflammatory medications that we have used. While I have no experience with long term use, at this point, I suspect it will be a good choice based on the use of Celebrex and Vioxx in people. At this time, there are no alerts for problems such as liver injury or kidney damage but it is still early in the use of this medication and it would be prudent to keep in mind that new medications do sometimes have effects that won't show up until they are used in large numbers of patients.

Mike Richards, DVM

Faxing and Regulations Regarding Prescriptions

Q: I recently tied to order heartgard med. for my dogs. The pharmacy faxed my vet a form to be faxed back. The vet then gave me a written prescription for me to mail in. My dogs are all up to date on tests vaccines etc. My vet sells interceptor which I do not like. Two of my dogs are also on elavil for aggression. Now I'm afraid he won't give me a renewal form for that either. I just don't know what to do and I don't know what my rights are. I just want to be able to get what I need for my dogs without having to feel uncomfortable asking for it. Do you have any suggestions? Thank you, Irene (a subscriber)

A: Irene-

In many states (probably most and perhaps all) it is illegal for a veterinarian to refuse to write a prescription for a product that they would dispense. It is not illegal for your vet to refuse to write a prescription if there is a legitimate reason for not doing so, such as not seeing the patient within a year, no heartworm examination on file, heartworm examination that is beyond the term that the vet hospital routinely uses -- for many vets still a yearly procedure but may be longer if there is reasonable evidence that you have been giving the medication. At the present time, in Virginia, the Board of Veterinary Medicine is suggesting that veterinarians do not fax prescriptions to pharmacies that call and request them, because there has been some abuse of this. Their suggestion is that the client be given a written prescription that they can take, or send, to the pharmacy of their choice.

I am not sure how or when this issue will be resolved to everyone's satisfaction so I suspect that for a while, at least, you will have to pick up written prescriptions if the Board in your state has made a similar suggestion to veterinarians. We do sometimes call in prescriptions to pharmacies and the Boards suggestion on this was to be sure we were talking to a pharmacist when we call in a prescription for the first time and to renew prescriptions from the same pharmacy only. In Virginia, veterinarians are required to post their license, which has the Board of Veterinary Medicine phone number printed on it. If some question about the prescriptions arises in the future you can get the phone number for the Board in this manner or from the state government web site or other information source. It is a little more trouble to have to pick up the prescription but the fraudulent practices of some Internet and mail order pharmacies have troubled the veterinary boards and pharmacy boards in many states and resorting to requiring a written prescription, which is hopefully harder to alter, is the current stop gap measure they are suggesting to combat fraudulent practices.

Mike Richards, DVM

Cosequin Effects and Pain Management for Hip Dysplasia

Q: Dr. Mike, My 8 yo GSD has been diagnosed with mild hip dysplasia. She has been given Rimadyl in the past for a flare but suffered from bloody diarrhea and vomiting after 4 days of treatment. At the same time she was also started on Cosequin DS. Obviously she should not be given Rimadyl again but I'm have a couple questions regarding treatment:

1. Could the Cosequin DS have also contributed to her adverse reaction? I'm not sure about the side effect profile of this product.

2. What are her future options for treatment for acute pain? I'm not sure I'd be comfortable with even a short course of steroids given her reaction to the NSAID.

3. If she truly needs steroids do you have any information about the addition of a drug like ranitidine or omeprazole to prevent GI problems?

Thanks. Pat

A: Pat-

I have not heard of bloody diarrhea associated with the use of Cosequin (tm) or other glucosamine/chondroitin products. However, we have had at least one dog in our practice who developed diarrhea without blood when given glucosamine/chondroitin products that was a repeatable circumstance and I have talked with other vets who have had similar experiences. So I suspect that there are a few dogs who develop diarrhea as the result of the use of glucosamine and/or chondroitin use. In general these are pretty safe products, though. We have had some clients who reported vomiting associated with the administration of glucosamine and chondroitin and there are anecdotal reports of disturbances in glucose levels in diabetic patients when using glucosamines. There is some concern about exacerbation of pre-existing bleeding disorders due to the similarity in chemical structure between glucosamines and heparin. Since shepherds are somewhat prone to bleeding disorders this may be something to think about due to the bleeding that occurred in association with the diarrhea when Rimadyl (tm) was administered, even though it isn't highly likely to be a problem.

I would not rule out the use of all non-steroidal anti-inflammatory (NSAID) medications based on a reaction to one of them. Individual patients seem to react differently to the various NSAIDs and it is often possible to use a different one without problems. Among the NSAIDs it seems reasonably safe to use aspirin, carprofen (Rimadyl Rx), etodolac (Etogesic Rx), ketoprofen (Orudis tm - 1mg/kg/day, may be best to use intermittently) and meloxicam (not yet available in the U.S., in in Canada). All of the NSAIDs do have some potential to cause problems, usually gastrointestinal, liver or kidney related. This risk has to be weighed against the potential for pain relief and improvement in the quality of life. Based on our practice experience the quality of life improvement can be dramatic and justifies taking small risks, however your experience with carprofen does give rise to higher worries than exists in most cases. I wouldn't totally rule out the possibility of trying a different NSAID in the future if the arthritic pain associated with hip dysplasia becomes more severe.

It is acceptable to use cimetidine (Tagamet tm), famotidine ( Pepcid AC tm), ranitidine ( Zantac tm) and misoprostol (Cytotec Rx) to lessen the gastrointestinal effects of NSAIDs in cases in which they are irritating but it still seems necessary to consider their use.

For pain relief associated with hip dysplasia there are several additional options. Narcotics can be used with good success in some dogs. We use hydrocodone/acetaminophen (Vicodin Rx) combination medications in our practice for chronic pain fairly frequently and it seems to be beneficial to many patients. This combination can't be used in cats due to the acetaminophen and rarely acetaminophen causes liver damage in dogs, as well. Hydrocodone is available without acetaminophen and it is acceptable to use codeine (0.5 to 2mg/kg every 8 to 12 hours). Amitriptyline (Elavil Rx), seems to help in chronic pain when used alone or in conjunction with narcotics. While I think it works better when used with narcotics, we do have one patient on amitriptyline alone for chronic hip dysplasia because it seems to do well with amitriptyline as the sole drug. Morphine ( 0.5mg/kg every 4 to 6 hours) works well for chronic pain relief as well but we usually try to reserve this use to really difficult cases when all other medications fail. Fentanyl patches (Duragesic Rx) are an effective short term solution for moderate to severe pain in dogs and some veterinarians use these more chronically but we have not tried this approach, yet. Corticosteroids are very effective anti-inflammatory medications. They have wider ranging systemic side effects than most of the other medications used in veterinary medicine, though. For this reason, most veterinarians prefer to avoid the chronic use of corticosteroids for conditions that can be treated with other medications. However, there is a time in the course of hip dysplasia when the risk/benefit balance begins to favor the use of corticosteroids, as well. While corticosteroids can cause gastrointestinal problems, including ulcers, this effect is less common with cortisones than with non-steroidal anti-inflammatory medications. Misoprotol doesn't seem to help much with cortisone induced ulcers but the H2 blockers (famotidine, ranitidine, cimetidine) might be helpful. In general, though, I don't think that it is really necessary to use these medications in conjunction with steroids unless the dosage is high or daily use (as opposed to every other day use) has to be continued for long periods of time.

Using anti-oxidants, such as Vitamin E (up to 2000U/day) and marine fish oils (3V Capsules tm) may be beneficial to some patients with chronic inflammatory disorders. Glucosamine (500mg/25lbs body weight/day) and chondroitin (400mg/25 lbs body weight/day) are widely used for chronic anti-inflammatory effects and there are now some better studies that do support their use.

I wouldn't rule out hip replacement surgery, either. This works really well in 90% of the patients who have surgery and the relief post surgically is sometimes really dramatic. It is more costly initially but I suspect that many of our clients spend more money in the long run treating the chronic pain and the dog gets the benefit of not having the pain that has to be treated. While it is probably overkill for most dogs with mild pain I don't see any reason not to consider it for a patient who has reactions to pain medications.

I hope that this is helpful. I think that there will be additional choices in non-steroidal medications for dogs, including one or more of the newer C0X-2 inhibitors (a human example would be celecoxib (Celebrex Rx)) being approved for use in dogs. That may be helpful for dogs like yours who have stronger gastrointestinal reactions to the medications that have more of a COX-1 or mixed COX-1/COX-2 effect.

Mike Richards, DVM


Q: Dr. Mike,

I have a nine year old female Pekinese who recently has had some eye problems. Somehow she damaged her right eye and scratched it causing an indentation on her eye. I noticed that her eye didn't look right and immediately took her to my vet. My vet placed dye in her eye so that she could evaluate the damage and started her on antibiotics. My vet also prescribed atripine and gentocin ointment for her eye. My vet continued to check her eye every two to three weeks and changed the dosage of the medicine accordingly.

Three weeks ago I added artificial tears as well as continuing to put the ointment in her eyes. Now the eye looks better, but there is some scar tissue. My vet is ordering cyclosporin and explained that it would take at least a week before she got it. I'm to use it four times a day to start and then the dose will taper off. My vet wants me to keep the dog on this medication for her eyes for the rest of her life. It was explained to me that the scar tissue in the eye would go away and the cyclosporin would help to lubricate the eye since my dog never fully closes her eyes even when asleep. Have you had any experience with this drug called cyclosporin? Thanks again for the great service that you provide.


A: Vicky-

Cyclosporin is the medication that is used in humans to prevent rejection of organ transplants. It stimulates tear production in dogs for some reason. It doesn't seem to have this effect in cats. It is far and away the best medication for the problem of tear deficiency in dogs. Since tear deficiency is the most common cause of excessive mucous formation in the eyes of older dogs and since tear deficiency leads to keratoconjunctivitis sicca, in which eye ulceration can occur, it is likely that this is why your vet is using this medication.

We use cyclosporin on a twice daily basis most of the time. It is available in an ointment with the brand name Optimmune (Rx). If the ointment doesn't work, it can also be formulated in a eye drop, although this is not an approved formulation.

I do not know how well cyclosporin might work if the problem is that the lids do not close sufficiently. Usually, when this problem is present we refer our patients to an ophthalmologist for a procedure referred to as nasal reconstructive blepharoplasty, in which part of the eyelid margin is closed surgically in order to allow the rest of the eyelid margin to successfully close over the eye. This seems to work well for most of the dogs with problems closing their eyelids completely.

Once in a while we see reactions to cyclosporin, usually when we are using the formulated eye drops and this is usually due to the oil that the medication is mixed with. I can't remember a reaction to the Optimmune ointment. Cyclosporin probably helps about 80% of the dogs with tear deficiency. It is OK to supplement the cyclosporin with artificial tears or other medications to stimulate tear production, if necessary.

It is really important to do something that is effective when tear deficiency is present, so keep working with your vet until you find a solution to this problem.

Mike Richards, DVM

Tums (for Calcium Carbonate Requirements)

Q: I need to include calcium carbonate in my dogs home cooked diet, but have yet to find it except in the form of Tums. I have read that Tums can be detrimental to pets. Is this true?

A: To the best of my knowledge, there is no problem with using unflavored Tums (tm) in dogs for calcium carbonate requirements. One Tums tablet contains 0.5gm of calcium carbonate. It is also possible to find calcium carbonate as the calcium ingredient in some human calcium supplements. I don't know the names but you could probably pick them out by reading the ingredients.

Mike Richards, DVM

Aluminum Hydroxide and Phosphorus Binders

Q: Dr. Richards,

Princess is suppose to take 2-3 times a day Alternagel as a phosphorus binder because she is now on Calcitriol I just finished reading the information about aluminym hydroxide on From what I have read, it seems that prolonged use of aluminum (hydroxide) has a number of very undesireable side effects. Princess also does not like the taste of the stuff and vigorously opposes having to take it. The problem with this situation is that she has laryngeal paralysis. I think you get the idea. I guess my questions are these:

  1. Can this product be compounded so that it goes down better?
  2. If the product can be compounded, can it just contain the aluminum hydroxide only or would there be other ingredients other than calcium?
  3. She also has to take ursodiol (Actigall). The problem is that Aluminum hydroxide negates the effectiveness of the Actigall
  4. Are there better phosphate binder alternatives? It seems prolonged use of the aluminum hydroixde has very bad effects.


A: Tony-

The information on side effects of aluminum hydroxide is gathered mostly from human medicine. The specialists who work with kidney failure patients in veterinary medicine do not report these effects. It is likely that the shorter durations of therapy with aluminum hydroxide ( perhaps 2 to 3 years for pets and 10 to 15 years for humans due to the use of dialysis) makes this compound safer for pets. I read the information on the Foster and Smith web site and these warnings do match those listed in some veterinary formularies but these usually mention that the reports are from the human literature, making it reasonable to be cautious. Despite this, there are no reports that I can find of these effects occurring in animals.

Our compounding pharmacy makes aluminum hydroxide products for us because we were having a hard time finding the medications for a while.

Phosphate binders containing aluminum do bind with ursodiol (Actigall Rx), so it is possible that they would interfere with its action. It may be reasonable to increase the dosage of the ursodiol to compensate for the loss.

An alternative phosphate binder containing neither aluminum or calcium would be sevelamer hydrochloride (Renalgel Rx). It supposedly has worked well for some pets but I have not seen published data with dosages and an evaluation of how well it works.

Mike Richards, DVM

Acetaminophen (Tylenol™) Safety in Dogs and Cats

Q: Hi Dr Mike:

I have a question about Acetaminophen (Tylenol™). The Receptionist at our local veterinarian told us that in case of fever, it was ok to give our dogs a Tylenol™ and NOT to give them ASPIRIN, or IBUPROFEN.

According to the AVMA Pet Poison Guide ratings scale, it appears to me that the Acetaminophen (Tylenol™) is more dangerous then the ASPIRIN, or IBUPROFEN. Is this true or am I misunderstanding what I am reading or was this by chance a misprint?

What would you recommend be given to a dog in case of a fever ASPIRIN, IBUPROFEN, Acetaminophen (Tylenol™) or something else?

Thank you for your time. I hope to hear from you soon, David

A: David-

Based on reactions in our canine patients, this is the ranking I would give these medications: safest = acetaminophen (Tylenol tm), also safe = aspirin, less safe = ibuprofen (Advil tm, Motrin Rx). However, this is the ranking that I would give them based on the reports in the literature and factoring in the likelihood of a bad reaction causing death: safest = aspirin, also safe but less so = acetaminophen and less safe = ibuprofen.

The reason for these rankings include these things. Aspirin is reasonably likely to cause gastric ulcers, which can be life threatening if ignored but which respond to withdrawal of the medication. Acetaminophen doesn't seem to cause ulcers but there are uncommon reactions to it in which liver failure occurs and this may not respond to therapy, so death is a possibility. Ibuprofen is very likely to cause ulcers, with 100% of dogs developing ulcers with the use of ibuprofen in at least one study. On the other hand, lots of my clients come in and tell me "I gave my dog an ibuprofen last night" and I have only had to treat one or two cases of ulcers and I can't recall a dog dying from this medication, yet.

My personal preference for pain and fever in dogs is aspirin but we do warn our clients to discontinue the medication if the dog stops eating and to call us or come in for a recheck if that happens.

In cats the situation is different. Acetaminophen is very toxic to cats and this medication should simply never be used to treat a cat. Aspirin has a long half life in cats, at least 24 to 48 hours, so it will reach toxic levels pretty quickly if it is given more frequently than once every 48 hours and the dosage is 10mg/lb so a baby aspirin (81mg) is a much more appropriate dosage for a cat than an adult aspirin. I have not seen much information on ibuprofen and cats but it is a good idea to avoid all non-steroidal anti-inflammatory medications in cats, at least until one of them does prove to be safe in someone's clinical trials.

Mike Richards, DVM

P.S. to the previous note. My guess is that the AVMA figures that it is safer not to confuse people with the difference between the effects of acetaminophen in dogs and in cats. I have several pain control references which state that acetaminophen is generally safe in dogs and it is used frequently because hydrocodone/codeine + acetaminophen combinations are pretty effective for post-surgical pain and for chronic pain from arthritis in dogs. The general feeling is the the narcotic provides the pain relief in this combination, though.

Stanozolol (Winstrol-V tm) and Poor Appetite with Renal Failure

Q: Dr. Richards,

Princess is a 16-year old Pom weighing in at 11 lbs. She is somewhere in the end stage of kidney failure. These are my questions:

  1. She is given a weekly injection of 25 mg. of winstrol. At what level is this dosage? And is one of the side effects heightened activity? Princess kept me awake for a goodly portion of last night when her constant rearranging of her blankets and pillows. What are some of the potentially serious side effects of this drug?
  2. Princess currently receives 250 ml. daily of LRS. Would upping the volume help to improve her appetite? Inappetance continues to be a major problem.


A: Tony-

The recommended dosage of stanozolol (Winstrol-V tm) for small dogs by injection is 25mg once a week. No dose range is suggested. For large dogs it is recommended that Winstrol-V be given at a dose rate of 50mg once a week by injection. It is available in an oral form, as well. When using the oral tablets the dose for small dogs is 1 to 2mg per dog per day and for large dogs it is 2 to 4mg per dog, per day. There is surprisingly little information on the effects and side effects of stanozolol in the veterinary literature considering that it has been around a long time. In cats there are reported cases of liver damage that appear to be related to use of the medication. In dogs the only side effects that are reported are "androgenic effects", which might include increased aggression, increased activity, weight gain and mood alterations. We do not use this medication in our practice so I do not have much personal familiarity with it.

Increasing the fluid dosage will only increase Princess' appetite if she is dehydrated or uremic (has toxins in the blood stream that should be removed by the kidneys but that is not happening). A poor appetite may very well be due to the presence of either of these conditions, though. If so, increasing the fluid dosage might help with the situation.

Mike Richards, DVM

Medication Interference - [Aluminum Hydroxide and Ursodiol (Actigall Rx)]

Q: Dr. Richards,

Alternajel contains aluminum hydroxide which Princess needs to take in order to control the phosphorus level. She is also on actigall at least for now. Does not aluminum hydroxide negate the effectiveness of the actigall?


A: Tony-

It is possible that aluminum hydroxide, or any aluminum containing compound could reduce the effectiveness of ursodiol (Actigall Rx). Magnesium based phosphate binding compounds should not be used in patients with kidney failure so there is not a safe alternative.

Since both medications work best if given at mealtimes it may be necessary to consider increasing the dosage of ursodiol in order to compensate for the binding of the medication by the aluminum hydroxide, or to choose which one is more necessary right at the present time. You should ask your vet about this, too.

Mike Richards, DVM

On-line PDR, Chronic Infection and Long Term Antibiotics

Q: Dr. Richards,

Thank you for this service, the web site and this service are an invaluable resource. I have several questions.

  1. Chow 12yrs. of age. Male not neutered. Normal wgt. 65-70lbs.
    • Has had a chronic thermal cycle problem (2-3yrs. extant), seemingly an Enteric condition of unknown cause. Perhaps E. coli based. Symptoms are: elevated temperature, increased water ingestion, minor to moderate bloat, general lethargy. Usually runs 5-6 days followed by a period of 3-6 days absence of all the listed symptoms, one would use the word "normal"! Aspirin is the agent that best helps and near the end of the cycle using electrolyte replacement supplementation in the water. I mention E. coli because of a fiendishly difficult bout of anal infection fought 3-4 years ago. There was only one antibiotic that culture sensitivity tests found to work, unfortunately our Vet. forgot to record the name, which will I think become important later.
    • Currently we are fighting a systemic infection that first (we think) started as an external testicle infection. This was most likely caused from dried fecal material caught in underbelly hair. We were unaware that an infection was present I am supposing for several weeks. At the time the situation was found the application of Bactine followed with application of Neosporin ointment twice daily. This course was continued for 7-12 days, during which a marked increase in body weight and abdominal bloat accompanied by dry cough and attendant heavy respiration. At this juncture we went to our Vet. His orders were to administer 1@ Amoxicillin (500 mg.) twice per day for 10 days continue with an antibiotic creme and cleaning as before.
    • --10 days later-- continued bloat and respiratory distress this time administer Primor 600 3@ tabs the first day continuing with 1.5@tabs daily for 7 days, and 2@ Medrol (4 mg.) twice daily for 5 days then gradually reduce to nothing by day 10. This worked the bloat came down. However by the 4th day off the Primor 600 the dry cough was returning and the bloat was coming back. Vet. again: An injection of a diuretic, and a synthetic Penicillin, instructions to administer 1@ Amoxi. (500 mg.) 2 times daily, discontinue use of antibiotic creme situation is one of moist eczema use Gold Bond medicated powder and continued cleaning multiple times daily.
    • ---10 days later-- Marked turn for the worse, dog unable to walk, massive bloat, raging fever, testicles very inflamed, diarrhea, breathing very labored, very little willingness to eat or drink. I insisted on a change of medication, back to the Primor 600 this time dosage to reflect the total weight of now 97.5lbs- 3@tabs first day then 2@tabs once daily for 10 days. The result is markedly positive, but we lost a lot of valuable time and the series will run out before the infection has been completely defeated. The external infection is very slowly easing, but the internal mucus/stuff will take a long time to be reabsorbed through the intestines as defecant to completely reduce the bloat. The Vet. has basically written us off, as he is convinced that there is a "growth" substance causing the edema. His dictum is that an ultra-sonic scan is need before further consideration is given. My 'take' on it is that the ultra-sound procedure will show important things, and I am not unwilling to have it performed, BUT, if there is a growth of any sort this symmetrically arrayed there is nothing that is possible to be done. Additionally, the infection if untreated will make moot the whole debate, therefore, I espouse eradicating the infection first, then look at ultra-sonigrams.
      • Now the question: Given that the Primor 600 is working, also given that this class of pharmaceutical is not safe at high dose levels for extended periods, what suggestions do you have? As with several of the bladder infection queries posted on the web site this will be a protracted recovery.
  2. Is there a Veterinary P. D. R. on the web that one may peruse?

Thank You in advance, Matthew

A: Matthew-

The disease that popped into my mind with the symptoms that you are seeing is brucellosis. This is usually caused by Brucella canis in dogs but can occur due to Brucella abortus or other species of Brucella. The periodic fever problem is more common in humans infected with Brucella abortus than with dogs infected with Brucella canis but it is a possible problem and testicular inflammation/infection is very common with this infection. It seems like it would be worth checking into this, if it has not already been ruled out. There are serum tests available and the organism can be cultured from blood samples in some patients. It is treated with streptomycin (an aminoglycoside injectable antibiotic not available in the United States at the current time), doxycycline and enrofloxacin (Baytril Rx). The other aminoglycosides might work (amikacin, gentamicin) but these are injectables and pretty toxic for long term use and antibiotics usually have to be used for some time. A compromise is to use streptomycin, amikacin, gentamicin for a week and then change to one of the oral medications.

The second thing that came to mind, which is probably more likely in a twelve year old chow, was metastatic cancer. This is the most common cause of fever of unknown origin in older patients, probably. It can lead to enough immune suppression that secondary infections occur easily, which confuses the issue.

The Compendium of Veterinary Products is available on the Network of Animal Health (NOAH), run by the AVMA but I am not sure what the policy is on non-member use of the site (I don't know if there is any public access allowed at all). You can purchase Dr. Plumb's "Veterinary Drug Handbook" for the PalmOS from This is a very good reference but does not contain all of the commonly used drugs in veterinary medicine, just a big percentage of them.

I do think that I would switch away from sulfadimethoxine/ormetoprim (Primor Rx) after three weeks of use and that is in the package insert direction as well. This medication does seem safer than the trimethoprim-sulfa combinations and if it is the only antibiotic that is helpful, you might have to consider using it longer and monitoring for problems, such as low platelet counts, anemia and liver problems.

It does sound like it might be a good idea to consult an internal medicine specialist. If your vet refers patients for ultrasound examination to an internal medicine specialist it would be possible to get a second opinion as well as the ultrasound results.

Mike Richards, DVM

Doxycycline for Urinary Tract Infection in Irish Setter

Q: Dear Dr. Richards:

Recently my other Irish Setter of 10 yrs died (who had several problems of her own) and Rubi was not eating like she usually does. I attributed it to the loss of my other dog for a few days, but it did not get better and we found upon bringing her to the vet she has a urinary tract infection.

She is now taking 400mg doxycycline.

I could not find much info on this tetracycline and I wondered if you thought it would be effective in treating a uti.

Thanks, Tina

A: Tina-

Doxycycline is used for urinary tract infections but not as commonly as other antibiotics. Doxycycline is usually dosed at 5mg/kg of body weight every 12 hours. If this antibiotic doesn't work, choosing the next antibiotic based on culture of the urine and sensitivity testing may be a good idea.

Hope this helps some.

Mike Richards, DVM

Anxiety Medication for Phobias- [Buspirone (Buspar Rx) and Diazepam (Valium Rx)]

Q: If an 11 month old (Rough) Collie has been successfully obedience trained, and showed eagerness and a desire to please during the training process, but developed phobias of certain objects (that a dog needs to be able to encounter daily without displaying objectional behavior), would you entertain the thought of medicating the dog (perhaps with a drug like Buspar), to help it overcome it's fears? The dog was alpha in it's litter, unusually strong willed (for a Collie), typically highly intelligent, and learned rapidly. However, the same dog has a few phobias that no trainer, including myself, has been able to help the dog completely overcome -- not even in time or with persistence, praise or patience.

Answer: I think that there are times when the anti-anxiety medications like buspirone (Buspar Rx) and diazepam (Valium Rx) are helpful with fearfulness or anxiety. If these are not helpful, some dogs do respond to the SSRIs mentioned earlier for anxiety related behaviors, as well. It is worth trying these after behavioral modification techniques have failed when used alone. Mike Richards, DVM 1/3/2001

Ketoconazole (Nizoral Rx) for Malassezia (yeast) dermatitis in Pug

Question: Hi there.. I have an older rescue (8 yo) with a severe yeast overgrowth. He is on antibiotic therapy (cephlaxin, ketoconazole, and hydroxizine) with topical Dermapet spray, and when we remove the antibiotic his skin begins to "weep" again. This was an extremely severe case, and I am concerned about long term side effects of the ketoconazole and cannot seem to find drug information. He is starting to cough...and I am concerned about effects on the lungs. He is HW-. there any diet that possibly could help retard the growth of this horrid yeast? His worst spots have been neck/stomach/nose folds and naturally ears.

If you can point me in the right direction..I am an avid amateur researcher...

Thank you!!!!! Pam

Answer: Pam-

Ketoconazole (Nizoral Rx) is considered to be a fairly safe medication. It has a couple of known serious side effects but they affect only a small number of patients. It can definitely cause birth defects if given to a pregnant female, which obviously is not going to be a problem in this case. It will decrease the fertility of male dogs while on the medication by lowering testosterone levels but this is a reversible effect. A small number of patients will develop liver problems. This appears to be an idiosyncratic reaction, rather than a toxicity due to the dose or duration of treatment. These reactions are the serious ones that are seen with ketaconazole that affect small groups of patients (since the testosterone effect is really only important in dogs used for breeding). I can not find any mention of ketoconazole causing coughing.

More commonly, some dogs and cats will have gastrointestinal irritation leading to lack of appetite, vomiting or diarrhea. Ketoconazole lowers the serum cortisol levels in most patients during administration, which may make it necessary to give corticosteroids if highly stressful situations occur while the medication is being administered. This can be a serious side effect if the client or veterinarian are unaware of it and surgery is necessary or a severely stressful event does occur.

For Malassezia (yeast) dermatitis in dogs, ketaconazole usually has to be given for at least 30 days. If it doesn't work, itraconazole (Sporonax Rx) may be helpful, given for the same length of time. It is also important to use topical therapy. Using a shampoo that can help remove the greasiness, such as a tar and sulfur shampoo or other anti-seborrheic shampoo can be helpful. Using white vinegar mixed 1:1 with water as the rinse to get the last of the shampoo off can be very helpful, as well. Dogs should be bathed at least twice a week during the time they are being treated for Malassezia. Many dogs have both yeast infections and bacterial infections, so it is often necessary to treat for the Malassezia and bacterial infection at the same time.

Unless there is an underlying food allergy, I do not know of a diet that is helpful in the treatment of yeast skin infections.

Mike Richards, DVM 11/29/2000 Metamucil

Question: Dear Dr Mike,

I have a 40 pound 12 year old lab mix who has a number of food and inhalant allergies. She is on a food that works well for her allergies but her stools are very soft. At her last checkup, the vet had to express her anal glands. I want to add more fiber to her diet and she does not like pumpkin. When she did eat the pumpkin, her stools were normal. My questions are:

  1. If I use Metamucil, what would be the dosage? Do most dogs like it just sprinkled over their dry food? The package states that a human should drink 8 ounces of water with it. How does that work for a dog?
  2. Another product for fiber comes in a tablet and contains calcium polycarbophil (625 mg). This might be easier to administer. Do you know if that would be safe for a dog? If so, what would be the dosage? Has anyone in your practice used it?
  3. Are there any other products that I could use to increase fiber that are safe for dogs?
  4. She is also on Atarax (2x day), Cosequin (2x day), 3V caps (1x day), and etogesic (1x day) long term. She is on Cephalexin (2x day) short term (bacterial skin infection). Would giving her the fiber supplement cause any problems with absorption of these other additives/medicines?

Thanks for your help. I really look forward to your newsletter. Please do not use my name if you use these questions on your website.

Answer: D- We usually recommend using 1/4th teaspoonful of Metamucil per 20 lbs of body weight twice a day but there is a wide variation in recommended dosages and it is probably safe to use slightly more than this. It probably doesn't work as well when water isn't added but this doesn't seem to be enough to affect the use.

I don't know what the dosage would be for other products but for a 40 lb dog it is probably reasonable to give about one-third to one-half of the recommended dosage for humans.

Green beans are a good source of fiber and many dogs like them. There are lots of psyllium containing products on the market and all would be acceptable substitutes.

None of the other medications are listed among the medications that can be affected by fiber in the diet.

Mike Richards, DVM 11/6/2000

Heart disease drugs, Cushing's and Medication

Q: Dear Dr. Mike:

I have a few questions:

1. Would 500mg per day of Lysodren (for Cushing's) cause heart disease or heart failure in a 30 pound Lhasa Apso?

2. If he already has heart disease, would that dosage of Lysodren make his heart disease worse?

3. Does Rimadyl reduce the ability of Vasotec (aka Enalapril) to treat heart disease or heart failure?

4. Are there any circumstances under which diuretic furosemide should not be used with Vasotec to treat heart disease or heart failure?

5. Under which circumstances should any of the following drugs be used, either alone or with any other drug or drugs, to treat either heart disease or heart failure: Amrinone Captopril Digitalis Glycosides Digoxin Dobutamine Hydralazine Intravenous Furosemide Milrinone Morphine Nitroglycerine Nitroprusside Procainamide Propranolol Quinidine Theophylline

What ever advice you can offer will be much appreciated, because, as a layman, I cannot understand the veterinary articles on this subject.


A: Gregory-

Lysodren is the brand name for a mitotane. This is a medication chemically related to DDT (the insecticide). It is useful in the treatment of hyperadrenocorticism (Cushing's disease) because it selectively kills adrenal tissue. Most of the adverse effects of mitotane are related to its effect on the adrenal gland because it can cause signs of hypoadrenocorticism (Addison's disease) if it is overdosed. It is very easy for small dogs to be overdosed with mitotane because it is only available in 300mg tablets. Initially dogs are given about 25mg/lb of bodyweight twice a day. (so about 1 tablet per 12 lbs). This dosage is continued until the symptoms of Cushings disease subside or for 10 days to 2 weeks. At that time the medication is usually used on a once per week or twice per week schedule, using somewhere between 10 and 30mg/lb of body weight, based on the clinician's evaluation of the initial response to treatment.

When Lysodren is overdosed most of the problems seen are due to the medication causing hypoadrenocorticism. The signs of this are vomiting, diarrhea, weakness, depression, shock and even death. Once in a while these symptoms will appear really rapidly with Lysodren use but usually they are seen after a week to 10 days. Since the object of using Lysodren is to kill adrenal cells and decrease production of adrenal hormones the effects of the medication must be closely monitored, especially during the period when it is being used everyday. Lysodren can cause liver damage that is unrelated to its effect on the adrenal gland and hypersensitivity (allergy) reactions have been reported to it, as well. I am not aware of any reported effects on the heart function. Addison's disease can lead to heart failure due to high potassium levels that occur as a result of the disease and inhibit cardiac function but this effect is supposed to be uncommon with the use of mitotane because it isn't as effective at killing the adrenal cells that control potassium levels as it is at killing adrenal cells that are involved in corticosteroid production. So there would be a small chance of heart effects due to overdosage of Lysodren but they would be an indirect effect.

I have written the word "overdosage" in relation to the use of Lysodren several times in this note and I think that it needs to be explained a little. Many medications are used according to specific guidelines, such as 5mg/lb of bodyweight. Lysodren is used "to effect", which means that it is dosed daily until it has done its job and then a guess is made as to how much is needed on a maintenance basis. There are no easy guidelines for Lysodren use and it is very very easy to overdose the medication despite doing a good job of monitoring its use.

Question 2: A lot of dogs with Cushing's disease have some degree of heart failure, because Cushing's disease causes muscular weakness and the heart is basically a specialized muscle group and because most dogs with Cushing's disease are older animals likely to have heart failure independently of the Cushing's disease. Lysodren should help this situation in most cases. As far as I know heart failure as a specific reaction to Lysodren is not reported to be a problem.

Question 3: It is very likely that carprofen (Rimadyl Rx) will decrease the effectiveness of enalapril (Enacard Rx, Vasotec Rx) because other non-steroidal anti-inflammatory medications are reported to have this effect. I do not have a package insert from Rimadyl with me (I'm on the road this weekend) but I will try to check and see if this effect was studied during the drug approval process for carprofen.

Question 4: Furosemide is a diuretic which has some effect on blood pressure (lowering it). Enalapril also lowers blood pressure. Using both medications at the same time may cause the blood pressure to get too low (hypotension). If this happens it is probably better to reduce the amount of furosemide being given than to reduce the amount of enalapril. It is a good idea to be very cautious when using either furosemide or enalapril in patients with low sodium levels. Enalapril and potassium sparing diuretics, such as spironolactone, can be a bad combination, leading to excessively high potassium levels.

Question 5: There are a lot of different causes of heart failure and different medications are used based on they type of problem present. I will try to give you an idea of the circumstances medications are used in but not in great detail. If you need more information on any of these, let me know.

Amrinone: This medication is used in low output heart failure. I have not ever used it and have no personal experience with it but low output heart failures are situations in which the heart is too weak or too damaged to pump blood effectively or when blood volume is too low for the heart to work properly.

Captopril: Captopril is closely related to enalapril and it is used in the same circumstances. Both are in the "ACE inhibitor" class of medications which are used to treat chronic heart failure. Prior to the availability of enalapril (Enacard Rx) as an approved medication for use in dogs captopril was commonly prescribed.

Digitalis Glycosides: this is a group of medications which include digoxin and digitoxin. In humans digoxin is the digitalis glycoside of choice. In dogs digitoxin may be safer and more effective. These medications increase the strength of the heart beat and help to control arrythmias. There has always been a lot of controversy over the effectiveness of digitalis glycosides but currently they seem to be in favor again.

Digoxin: see above

Dobutamine: Dobutamine is supposed to be a heart strengthening medication (positive ionotrope) but I haven't seen much written on its use in veterinary medicine.

Hydralazine: Hydralazine is a rapidly acting venous dilator. It can be used in an emergency situation to reduce the workload on the heart prior to initiating therapy with enalapril or other ACE inhibitors since they are slower to exert their beneficial effects.

Intravenous Furosemide: Intravenous furosemide is used when it seems unlikely that a pet would be able to properly absorb oral furosemide (severe heart failure symptoms) or when oral administration is not advisable (gastro-intestinal disease).

Milrinone: I have not used milrinone but it is supposed to be helpful in low output heart failure, which is when the heart is too weak or the valve function too poor for the heart to pump enough blood.

Morphine: Low dose morphine usage is supposed to be helpful in controlling anxiety associated with severe heart failure. It may also be useful if pain is the cause of an arrythmia, such as might occur with trauma or difficulty delivering puppies.

Nitroglycerine: Nitroglycerine is used in situations in which rapid lowering of pulmonary venous pressure may be beneficial. This situation doesn't arise as often in the dog as it does in cats. It also has the advantage of being absorbed across intact skin which means that it can be applied to cats in severe respiratory or cardiac distress without hassling the cat too much.

Nitroprusside: I think that nitroprusside is also probably used more in the cat than in the dog but am not certain of this. It is also a potent vasodilator, affecting both arterial and venous blood pressure. It is possible to lower the blood pressure beyond what is good for the patient using this medication so it is best to monitor its use carefully. In cats this medication is sometimes credited with real life-saving ability in severely ill cats and it is possible that it may be similarly effective in dogs.

Procainamide: This medication is used to control ventricular (large heart chamber) arrhythmias. It is sometimes associated with sudden death, which may be an effect of the medication or might just be due to the situations it is used in, since these dysrhythmias seem to occur in stressful situations.

Propranolol: Propranolol is used to treat ventricular arrhythmias and atrial tachycardia (too rapid beating of the atrium). It is a "beta blocker" and has a rapid but short-lived effect. Despite this it may be recommended for long term use in atrial tachycardia in some cases

Quinidine: Quinidine is an antiarrhythmia medication that is similar in effect to procainamide. It enhances the effect of digitalis glycosides and must be used with caution when also using those medications.

Theophylline: Theophylline is used in dogs with heart failure because it is has a slightly positive effect on heart strength and because it is a bronchodilator, which may make it easier for a pet to breathe if it has pulmonary congestion secondary to the heart failure. Personally, I don't think this medication works well enough to make much use of it. It can be hard to distinguish lung problems from heart problems early in either disease and theophylline may benefit either one, so I think it is used sometimes in an effort to cover all possibilities.

In chronic heart failure in dogs, there are three commonly used groups of medications: "ACE Inhibitors" which decrease blood pressure and make it easier for the heart to work; diuretics which also lower blood pressure and make it easier for the heart to work; digoxin or digitoxin, which increase the strength of the heart muscle and control arrythmias. Cough suppressants can be beneficial in dogs in which cough persists despite medications for the heart problems.

Mike Richards, DVM


Question: My 9 year old golden retriever has very stiff back legs. He has trouble getting up and down. He does not tolerate the Rimadyl , loose stools. My vet here in N.C. said he could take Celebrex the human drug 100mg. twice a day. Just wanted a second opinion. The vet. clinic here is very busy and sometimes they get their information confused. Do you remember I am the one who has the little corgi girl with the excessive bleeding after bladder stone surgey. Your advice at that time was correct, there was something else wrong. She had a major kidney infection. So I would like to know if Charlie can take the celebrex. I love him very much, and I want him to be pain free and move a little better. He eats good and seems happy. He is just very stiff in the back legs. Like me , getting up and down is very hard for him. I have Ankylosing Spondylitis and I take methotrexate. I wonder have they ever used that medication in dogs?

Answer: C-

Unfortunately the best answer I can give is "I don't know". There is not a published dosage for this medication, yet, that I can find for dogs or cats. Your vet might know of a validated dosage, that I don't, though.

Anecdotally, I know that some vets are using Celebrex, but I don't know

how they are calculating the dosage to use. I have not heard of any problems but there were no reports of problems with carprofen in Europe and then when it was approved in the US for dogs (a much larger market) a few dogs did develop liver problems as a result of the medication.

I use hydrocodone with acetaminophen (Vicodin Rx) for my patients who don't tolerate carprofen (Rimadyl Rx) or etodolac (Etogesic Rx) well. There is a small risk of liver problems due to acetaminophen, too --- but so far we

have not had a problem with this. I can't say this is a better option but it is another option -- and for chronic arthritis problems in older dogs it is nice to have options.

Methotrexate is used in dogs but not commonly for arthritis, since rheumatoid arthritis is not a common problem in dogs and the immunosuppressive effect of methotrexate isn't as beneficial in other forms of arthritis.

Another option is glucosamine, chodroitin or glucosamine/chondroitin combination products. These are very safe and seem to help a fair number of dogs with chronic arthritis problems.

Hope this helps some.

Mike Richards, DVM 9/29/2000


Question: Dear Dr. Mike, I read that Kaopectate can be used to treat digestive upset in dogs. When is it appropriate and how would I determine dosage? Can it be used to treat diarrhea? Thanks again,

Answer: T-

The recommended dosage for kaopectate is 1 to 2 ml/kg of body weight, every 2 to 6 hours (recommendations vary a lot on this product). This works out to about about a teaspoonful per 10 lbs of body weight for the low end of the dosage and about a teaspoonful per 5 lbs of bodyweight for the high end of the dosage. Our personal experience has been that it is hard to get this much kaopectate into a patient and that the protective action of the kaopectate is pretty minimal, so we don't use it. It is usually used for the treatment of diarrhea or suspected toxin ingestion, where its purpose is the absorption of the toxic agent. We use activated charcoal when we think absorption of a toxin might be helpful and we usually use loperamide ( Immodium AD tm) for symptomatic control of diarrhea when that seems appropriate.

If you have heard of another use and want me to check into it, I will be glad to do that.

Mike Richards, DVM 5/4/2000


Question:1. I have a slight fungal infection in a toe nail which I sometimes treat with a tioconazole solution (28% w/w) which is painted on the nail like nail polish and allowed to dry. Blue likes to apply his tongue to everything. If I see he is about to go for my toes I usually stop him, but occasionally his tongue has touched this nail.

Any idea of risks? Would there be long term risks of cancer from ingesting fungi? I believe tioconazole can affect the liver.

Answer: I could not find any information on the use of tioconazole in dogs or cats, except one study on the PubMed web site that discussed susceptibility of ringworm cultures to the medication but I couldn't tell if any of it was actually administered to cats based on the abstract of the study. Tioconazole is considered safe for treating diaper rash in babies, though. Presumably, babies are likely to ingest it, too. So I think that minor exposure such as Blue is getting, would present no problems. Tioconazole can induce increases in some liver enzymes but it is not clear that this is actually a problem, since there isn't an association with decreases in liver function or other problems and the induction (increased activity) of the liver enzyme. Contact allergy appears to be the most common serious problem associated with tioconazole in humans.

Mike Richards, DVM 4/23/2000

Clomicalm Rx (clomipramine)

Question: My dog is a female Lab X who is spayed and about 13 years old. In September, she had a seizure which lasted about 2 minutes. The emergency vet kept her overnight and ran tests on her. Her regular vet ran additional tests on her.

All tests came back in the normal range and/or negative. She has not had a MRI as it is cost prohibitive at this time so we do not know if my dog may have a brain tumor or something similar. My dog had a second seizure in October about 5 weeks after the first seizure. This second seizure lasted less than a minute. My dog seemed more cognizant than the first time around. As the seizures are more than one month apart at this time, our vet does not want to put my dog on anti-seizure medication.

At the time


Michael Richards, D.V.M. co-owns a small animal general veterinary practice in rural tidewater Virginia. Dr. Richards graduated from Iowa State University's College of Veterinary Medicine in 1979, and has been in private practice ever since. Dr. Richards has been the director of the PetCare Forum...