Help!! Vet can't diagnose Dog

[waffle211]

Hello I have a 1 and a half year old Chow Mix Dog. I brought him to the vet after he started losing his bark he became very hoarse. Then one day his back legs seamed to get weak but after resting recovered from it and was fine again. Now his legs become very weak right before and during a bowel movement to the point he sometimes has to sit to have a bowel movement. He also will get real weak if he runs too much or gets very excited sometimes I actually have to carry him in the house. It's only his back legs that are weak. The Vet tested him for many things including a full blood work up, he's also been tested for heart worms and disease, hyperthyroidism, myasthenia gravis, lyme disease and a few others I can't think of top of my head. but all the tests have come back negative. I also forgot to mention during one of these episodes where his back legs become weak. He shows no signs of pain and his tail is going a mile a minute. Happy as can be. The Vet has put him on Mestinon. Thinking the Myasthenia Gravis test came back with a false negative. With in 6 hrs of his first dose his bark had returned but with in four days he was back to a hoarse bark etc. We've even highered the dose and nothing seams to work. As long as he stays come he only has the leg weakness with the bowel movement. But its so said for such a young dog to not be able to run and play. Could someone please give me there thought, opinions advice something I've spoken to 3 Vets and have gotten no where.
PLEASE HELP!!!!!!!!

[TheSkeptic]

IF the local vet cannot find the problem, you may ask him to refer your case to the local vet school. They have resources not often available to the working vets for unusual problems and diagnosis. Of course this can be VERY expensive.

Mr. Dawg is going in for an MRI and it will cost us $1200, but he has save my wife's life twice and is worth the expense.

[Traci]

Did any of the three vets take x-rays? Rule out hip displaysia? Find inflammatory causes? Suggest an MRI or rule out spinal/disc problems? Was there any recent traumatic injury?

If not, please see a specialist, your vet should be able to refer you to one (and is obligated to do so if he cannot accurately diagnose)

[k9Karen]

You say the dog was tested for hyperthyroidism (over-active thyroid). Was he also tested for hypothyroidism (underactive thyroid)? If only a T4 was run, you might want to get a TSH (thyroid stimulating hormone) done. The T4 is produced by the thyroid gland itself, and can remain 'normal' even though the thyroid is begining to fail. The pituitary will put out increasing amounts of TSH in an atempt to stimulate the thyroid to produce enough T4. Eventually, the thyroid isn't able to do this, but in early disease, it may be able to keep up, at least for a while or intermittently. During this phase, the TSH will be high, but the T4 may be 'normal'. If the thyroid is enlarged or diseased, that could account for the hoarseness, and the muscle weakness could be due to the hypothyroidism itself. A different hypothyroid condition, hypothyroid myopathy, could account for both symptoms, although I do not know if this condition occurs in canines (it does in humans). This condition, I believe, is diagnosed by muscle biopsy.

Also, did your vet consider that the two symptoms may be coincidental, though not related at all? Is your dog on any medications other than the new one you mentioned?

[jdf]

I feel I would be remiss if I didn't add something here...I agree with k9Karen about the possibility of hypothyroidism. When Roxy was about nine years old, she began having episodes of hind quarters collapse. She would be fine one minute and then her rear legs would give out. These episodes usually lasted 15 to 30 minutes after which time she recovered to a normal condition. Coincidentally with the leg problem, she was having bouts of vestibular disease and her voice was very hoarse at times.

Our vet at the time did a "shoot from the hip" diagnosis, saying she had epilepsy. This diagnosis was one without any tests of any kind , BTW...we were naive and didn't question his opinion and as a result Roxy had to take phenobarbital for the rest of her sixteen years. About a year after that time, we found another vet who didn't think Roxy had epilepsy and tested her for hypothyroidism. She was found to be slightly hypothyroid "in the grey area" and was started on thyroid replacement therapy. Within a year or so after starting thyroid meds, the vestibular condition stopped and her voice became normal all the time ( except when she apparently had a reaction to inhalant allergens, which could be controlled with benadryl as needed). Our vet was concerned that her voice problem might be related to a low thyroid, BTW, he said that laryngeal paralysis is oft times associated with a hypothyroidism.

Her leg problem is not so easy to link to her slight hypothyroidism because she suffered an unrelated Fibrocartilaginous Embolism ( FCE ) when she was ten years old, The FCE paralyzed her hind quarters so it was impossible to know from that point on if her problem of hind quarters collapse was helped by the thyroid meds or not. I guess what I'm trying to get to is that it seems to me that hypothyroidism , even when only a slight problem, can affect individual dogs in sometimes mysterious but often dramatic ways - it can affect any of the bodies' many functions. I agree with k9Karen that it would be a good idea to pursue this possiblity further.

Best of luck....I hope there is improvement with your pup.

[Athena's Mom]

Hope you have a vet school near your home. Many vets don't have the expensive equiment to diagnose unusual problems. You might end up spending more on lots of tests costing a moderate amount and telling you nothing than on one expensive MRI, which is what you likely need.

Best wishes.