Thursday, December 31, 2009

HEALTH ALERT | Pacific Rimism

Relevant to all dog owners, especially those who own Asian breeds, particularly the spitz types (shibas, akitas, jindos, chows, etc)

A scary experience of a fellow Shiba owner led to this awareness:

Pacific Rimism in Japanese Dogs
An informal case study in the lethal misdiagnosis of Hyper-kalemia and Addison’s disease in Nihon Ken

Hi all, I wanted to write up some of what I have come to know about this recently. I believe it is essential that all Nihon Ken owners, or anybody with related Asian spitz breeds like Jindo, etc, read, understand and share this information, especially to the Veterinary community.

Following our Christmas dinner (and scraps from the relatives), my spayed 2.5 year old Shiba Inu female Beebe began to have some GI upset/gastroenteritis/colitis symptoms, mainly mucous diarrhea. This is not a new thing for her. To refresh, she was diagnosed last year with an immune deficiency and has been on interferons, allergy injections, and has required treatment for demodex, papilloma virus warts, and histiocytomas. She suffers from environmental and food allergies, and thus we made the transition to a home prepared raw diet for 6 months now to help with her GI issues. It works well, except when she eats grain and table scraps, and for the fact that she is not a healthy dog to begin with.

Her most recent bought of diarrhea went on for 2 days, but it wasn’t severe to cause me to panic. I made her NPO and then fed her a bland diet of rice and chicken which resolved the diarrhea. On top of the GI disturbance, she also seemed to just not be herself, seemed more tired, had some trembling episodes during the night, and appeared to be developing some rear limb weakness in conjunction with hesitance when rising, getting on the couch or jumping into the backseat of the auto. She occasionally regurgitates her food (prior to starting raw). These symptoms are suggestive of Addison’s, and are symptoms sometime seen with conditions like hip dysplasia, LP, hypothyroid, mega-esophagus, cauda equina, colitis, and pancreatitis. I took her in to my Vet to do bloodwork and x-rays.

Of note, the spun serum had blood stranding and a pinkish hue, even though it was allowed the standard time to clot and set prior to being spun. This suggested cellular lysis (hemolysis). When this happens, electrolytes in the cells can be released, giving falsely elevated electrolyte levels, and in certain breeds, it can appear that the electrolytes are at lethal levels as their cells are naturally more prone to this condition, and contain higher levels of K naturally which is not a detriment to the animal.

These were her aberrant labs, which Dr. told me was scary to see.

K: 8.1, reference range 4.0-5.7
Repeat K level the following day was 8.4. We performed an EKG which was normal.
As a human nurse for 5 years and an animal nurse for 15 years, I can tell you that I have never known an animal with K that elevated, and if it was a human they would be dead in an ICU. Hyper-kalemia (elevated K), can result in fatal heart arrhythmias if not treated. K can be elevated in renal failure, adrenal insufficiency, and hemolysis, secondary to leakage of cellular material in platelets and RBCs during the clotting process and is influenced by lag time in blood collection. In Addison’s (hypo-adrenocorticism), K is elevated and sodium (Na) is reduced (hyponatremia). Her Na/K ratio was also low (18, with a reference range of 27-40). Following this, the definitive diagnostic rule-out is an ACTH stimulation test. Her sodium was normal, so I was encouraged to have her undergo an ACTH stim test as the pieces didn’t fit into the larger picture. All other significant labs were normal, including glucose, and renal/liver values (which are often abnormal in Addison’s).

In addition to the abnormal labs, the blood cells themselves exhibited slight hypochromasia (most commonly related to iron deficiency anemia in dogs, vitamin deficiency, or celiac disease) and poikilocytosis (a misshapen and distorted RBC seen as a result of hemolysis, immune mediated injury, or by a congenital process).

Unlike the Vet in the instance below, my Vet had heard of Pseudo-hyperkalemia in Akita, and wondered if it wasn’t the same for my Shibas, given that Addison’s is NOT known in Shibas and the generally unknown instance of Pseudo-hyperkalemia can easily be mistaken for it. I decided to phone some breeders, this is what they had to say:

This paragraph on Pacific Rimism is listed further down in this article.
I have seen a number of Shibas over the years with elevated potassium levels and this is entirely NORMAL for Shibas, as well as a number of other Asian breeds. A vet in Seattle actually treated a 6 month old Shiba puppy for Addison’s with only the elevated potassium levels. The dog came in with a gastrointestinal problem and vomiting. What was probably just a bug, was treated totally improperly and led to this dog's demise. I am absolutely dumbfounded at the number of vets over the years that have no knowledge of Pacific Rimism. I really feel that the information should be given in written form to the new Shiba owners to give to their Vets along with the health record. I am sure that some vets would see this as insulting, but it has cost me entirely too much time and effort over the years to educate the uneducated.

-Leslie, of San Jo Shibas

“What is Pacific Rimism?
Dog breeds originating in the Pacific Rim, such as the Akita and Shiba inu, commonly have elevated potassium levels on blood tests. This can be very confusing when a patient has symptoms that suggest Addison's disease. These patients will have normal ACTH Stimulation test results if they do not have Addison's disease.”

The Vet feels it is likely this syndrome, so the next step for Beebe is an ACTH stim test just to be sure. I am obviously hoping that it is normal. I am so thankful to the knowledgeable people who pointed me in the right direction as had we undergone steroid treatment for Addison’s when it is likely not, the result could be lethal. Here is the Dogster page and journal entries for the Shiba pup who died from misdiagnosis:

Fujise, Hiroshi; Higa, Kazunari; Nakayama, Takahiro; Wada, Kayoko; Ochiai, Hideharu and Yuichi Tanabe. Incidence of Dogs Possessing Red Blood Cells with High K in Japan and East Asia. The Journal of veterinary medical science. 59( 6): 495-497. (Jun 1997)

ABSTRACT: The phenotype of high K (HK) red blood cells, which is an autosomal recessive, was found in dog groups from 10 of 13 breeds or populations in Japan. The incidence of HK was 26 to 38% in the San-in-Shiba, Shinshu-Shiba and Akita breeds, and the gene frequencies of HK ranged from 0.513 to 0.612. The highest incidence (42%) was found in the Jindo breed from Korea, and the gene frequency was 0.652. Two other groups from Korea also possessed this HK variation. However, although HK cells were not found in dogs from Taiwan, Mongolia and Sakhalin, Russian, the HK phenotype is clearly distributed now throughout Japan and Korea.

COMMENTS: Very interesting article for the researcher and layman. It gives evidence on the flow of dogs from Korea to Japan. The following quotes are what I consider crucial conclusions that every Jindo owner should be aware of::

"There are a couple of clinical problems related with high K (potassium) cells or hyperkalemia. The first is pseudohyperkalemia where cellular K may leak out from red blood cells into the serum during separation procedures confusing diagnosis. The second possibility is life-threatening hyperkalemia resulting from transfusion. In this instance, the availability of fresh blood as well as stored blood is critical
because K may move from plasma when the recipient is acidotic or the hemolysis may result from improper transfusion."

"HK cells also exhibit high sensitivity to onion extracts and aromatic sulfide and have a tendency to hemolyze."

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