Well after the success at Yamba we went back to the vet for a check-up yesterday; mostly as Zoom's alopecia is not improving and she has an antibiotic-resistant rash on her back. Below is the medical history of Zoom.
Now we are in April, and the positives are her staph infection has cleared and she is regrowing thick black hair where the infection had been. A skin scraping has cleared her of demodectic mites, though she did lose another tooth over Easter. But generally she is more happy and active again and has recommenced agility training and competing (and is enjoying it!). The negatives are (as depicted in these photos) that she has a new, or at least more noticeable, rash on her back and the alopecia is continuing or at least not improving in areas other than where the staph had been; her hair feels dry and brittle and breaks easily. 
She has some mottled black pigmentation in some areas of the alopecia. The rash is hard and raised, not puss-like, but rather dry and crusty.
Zoom was diagnosed with Discoid Lupus in October 2005 and has been on 10mg of Prednosone per day since then; she is 500mm tall and weighs 16kg; her DOB was 22/5/03; she is a tricolour Border Collie.
Around August 2006 I noticed Zoom had a pimple-like skin rash over her back towards her tail and had started to get a redish tinge to her coat and it was thinning in the areas of the rash. By October she had started to get more lethargic and less active on hikes and at training. A routine CBC at this time showed a low White Blood Count at 3.21, low Albumin at 22 g/l and elevated glucose at 6.5. Otherwise everything was within the normal ranges. We treated the skin rash with anibiotics and monitored her. She started increasing her water intake dramatically and was also wetting her bed during the night. Back to the vet who placed her on Hormone Replacement Therapy.
Her condition worsened over Christmas with discenable coat colour changes (people thought she was a chocolate tri) and dramatic thinning of the hair; she was also drinking and urinating lots; was continually hungry and had started guarding food sources (the fridge, food plates etc). The pimple-like rash was still present and spreading.
In January she had an eye ulcer and a tooth infection at the same time. Whilst treating for these we tested her bloods again, this time including thyroid and found her T4 was very low. Hypothyroidism was diagnosed and she commenced on Thyroxine; 0.4mg tablet twice daily. It seemed that many of her ailments fitted this disease and I was looking forward to having an improvement in her condition. Her t4 had stabilised in the normal range in February. Though as my previous blogs tell, she then got a staph infection across her back and neck and we started her on cephlexin antibiotics; she is still on this. Two weeks later Demedex was also diagnosed and she commenced 7 weeks of ivermectin treatment. It was apparent she had no immunity.
Now we are in April, and the positives are her staph infection has cleared and she is regrowing thick black hair where the infection had been. A skin scraping has cleared her of demodectic mites, though she did lose another tooth over Easter. But generally she is more happy and active again and has recommenced agility training and competing (and is enjoying it!). The negatives are (as depicted in these photos) that she has a new, or at least more noticeable, rash on her back and the alopecia is continuing or at least not improving in areas other than where the staph had been; her hair feels dry and brittle and breaks easily. 
She has some mottled black pigmentation in some areas of the alopecia. The rash is hard and raised, not puss-like, but rather dry and crusty. My vet believes this rash to be calcinosis cutis (though says he has only seen it once before) and based on that, her varied symptoms and long-term medicating with 10mg per day of pred has tentatively diagnosed Iatrogenic Cushing's disease. He is having me wean her off the Pred slowly over the next month. No discussion of how to manage the lupus without the Pred yet.
Since this tentative diagnosis I have had time to read more about Cushings and concur that her symptoms do match this disease; but then the symptoms are quite similar to those for Hypothyroidism. She seems young to have Cushings, but I am wondering if the average age I am reading about (10 yo) is for pituitary and adrenal based cushings rather than the veterinary-induced version, which I'd guess from its nature could occur at any age. Her bloods do not really seem to be indicating Cushings from this description, no increase in specific liver enzymes. She also does not have the distended abdomen. I have been having problems with rebuilding her muscle tone though she has had no weight gain since 2005, but I am very careful with monitoring all my dogs weights for agility which was why thyroidism took a while to diagnose also.
I guess this diagnosis raises questions for me surrounding the doseage levels of cortisone that is likely to induce Iatrogenic cushings. Most of what I am reading on veterinary sites is suggesting that it is brought on by overdosing. I would not have thought that 10mg per day in a 16kg dog was an overadministration; though another site has given me another view by suggesting it is more the length of time she has been exposed to that doseage, than the doseage itself. This site at Newman Veterinary suggests anything longer than 3 weeks is prolonged use and may affect the dog's "HPA"....the Hypothalamic-Pituitary-Adrenal axis; which means the adrenal glands, in turn, may "shrink" (atrophy) due to lack of stimulation.
I'm really stuggling with getting my girl stable and healthy again, and want to be sure that I'm "crossing the t's and dotting the i's" in sorting out what her problems are. We had a great weekend over Easter and I had thought we were well on the road to recovery, but was still concerned that her rash had not cleared after 8 weeks of antibiotics and that the alopecia was not reversing after 9 weeks on the Thyroxine. Now I am just plain worried that she may have the Pituitary Dependent Cushings which accounts for 85% of cases and has a far from positive prognosis; or that she does indeed have Iatrogenic Cushings but her adrenal glands have atrophied to an unreversible point.
For more information on Cushings Disease:
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