Brucellosis in Chow, On-line PDR
Question: 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. (a): 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. (b): Currently. We are fighting a systemic infection that first (we think) started as a 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 late
-- 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
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 http://www.anmldr.com/. 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 2/1/2001
Q: I can't find any info on canine brucellosis, which is what my vet said is probably wrong with my Shepard cross breed. How does it spread other than breeding. Are their any precautions you can suggest to protect my other dogs? Are their any references to canine brucellosis on the internet?
A: Brucellosis is a disease caused by a bacteria, Brucella canis. It is found throughout the world. It is spread through contact with aborted fetuses and discharges from the uterus of infected bitches, during mating, through maternal milk and possibly through airborne transmission in some cases. The bacteria enters the body through mucous membranes and spreads from there to lymph nodes and the spleen. It also spreads to the uterus, placenta and prostate gland as well as other internal organs at times.
In female dogs, infection leads to abortion or early death of infected puppies. Infected females may have no other clinical signs. In some cases there may be decreased fertility rather than abortion. This may be due to resorption of fetuses early in their development.
In male dogs, infection of the testicles can lead to infertility due to anti-sperm antibodies developed as the body attempts to fight off the bacterial infection. The testes may atrophy after the initial period of swelling. Scrotal enlargement or infection of the skin over the scrotum may be seen.
In both female and male dogs there may be infection of spinal discs (diskospondylitis) which can cause back pain and rear leg weakness or even paralysis. Eye inflammation may be seen in either sex.
It is not usually possible to culture Brucella canis bacteria from the blood or affected tissues so diagnosis is usually done by titer testing. There is a kit available to veterinarians for testing in their office. It is usually best to retest any dogs found positive on this test with other testing methods since there is a fairly high rate of false positives using the in-house test kit.
Brucellosis is very difficult to treat successfully. A combination of minocycline and streptomycin is thought to be most effective but is expensive. Tetracycline can be substituted for the minocylcine to reduce costs but also lowers the effectiveness of treatment. All infected animals should be neutered or spayed to prevent sexually related transmission. All infected animals should be considered to be lifelong carriers of the disease, even if treated.
It would probably be best not to breed dogs without testing both the male and female for this disease. Breeding should be a deliberate choice -- not a random event! For breeding kennels, routine isolation of new dogs would be a very good idea. After isolation and negative tests at entry into the kennel and one month later, it should be safe to let the new dog mix with the others in the kennel. If infection is suspected at any time, quaternary ammomium (like Roccal Rx) and iodophor (Betadine Rx) disinfectants can kill Brucella organisms in the kennel to limit spread of the disease.
One last thing. It is possible that brucellosis caused by Brucella canis may be a zoonotic disease -- meaning that people could potentially be infected by this organism. It is something to think about when handling infected dogs. Wear gloves around any body fluids and be careful about contaminating yourself in any way.
Hope this helps.
Mike Richards, DVM
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...