For those who have never experienced the tragedy of spinocerebellar (late onset) ataxia, I would like to tell my experiences.
My litter (of 3) were born healthy with no whelping problems, but at 9 wks of age I began to notice that one of the pups was moving like each leg was a different length. I showed him to my breeder friends and they thought he just looked like an uncoordinated “big” puppy. As the days went by I became more and more aware that he was not normal. I searched the internet and came up with a disease called ataxia… what is this? I wondered. Could a test be given to determine if he had this illness? I found out that only a MRI or a necropsy could give a diagnosis. But, I also found out that with an MRI the pup would have to be anesthetized AND if you anesthetize a dog with ataxia it might make the disease worsen at a greater rate of speed. A necropsy would be only if the pup were euthanized or had died. So, I didn’t have much choice. I found a veterinarian that had studied ataxia and made an appointment. He confirmed what I had thought – ataxia. Of course, his diagnosis was not proven without a necropsy.
How did this happen? I bred both the sire and dam several times but not together and never had ataxia in my other crosses. I then learned that you can breed carrier to carrier and not produce it… so to say, you have never produced it… but have the lines that have… well, your guess is as good as mine… maybe you will and maybe you won’t.
As the months rolled by, I noticed this pup stood in a tri-pod stance, and progressively became so wobbly in his hindquarters that you could push him over with one finger. His gait was a pace (right legs forward, left legs back); and when running, he would leap in the air and “throw” himself forward. I noticed a head bob and the worst of all, he had seizures. The seizures were different. When having one, his muscles would quiver like hundreds of worms under his skin – he would fall down, his eyes were normal, he was panting and extremely hot. One time, we offered him water and was surprised that he could drink (unlike other types of seizures) and when we immersed him in lukewarm water the seizure stopped. I’m not saying that to immerse a dog in water helps a seizure but it helped this dog. We found that if he became excited and/or stressed that this caused a seizure. So, our goal was to keep him from getting too excited or stressed – almost an impossibility with a Jack Russell Terrier. I have since learned that he had Myokymia (a type of seizure disorder that can appear with late onset ataxia).
MacTu had normal intelligence and drive and the same intense personality that his sire and dam had. He was lovable, not aggressive and was obedient. We always thought that he knew he was at a disadvantage when interacting with the other terriers and, surprisingly, they never attacked him. One day we had company, he became very excited at seeing unfamiliar terriers and had a fatal seizure.
It is said that late onset dogs don’t live beyond 24 months – MacTu was 23 months. Since MacTu did not show any signs of this disease until 9 weeks it is a good thing that I did not sell him. Can you imagine how upset the family of this terrier would be?
Not long after that, a person contacted me who had an ataxia pup, they had purchased this pup at 15 weeks and he appeared normal at the time of purchase. But, they began to notice that he would NOT go down the stairs but would go up. Then, they saw he wasn’t traveling correctly with his hind legs and appeared to be weaker behind. I said I would take this terrier and keep him for however long he might live. Throughout the months, I paid attention to his movements and his health. He began to have seizures at 12 months… the same type MacTu had. He exhibited the same type of gait and the same wonderful personality. Again, my terriers treated him as normal. He and my lab became buddies and when he’d have a seizure, my lab would lick him until it went away.
At 21 months I had to put Bolt down. His necropsy just came back… he had spinocerebellar ataxia.
My experience with the ataxia terriers has been uplifting and at the same time very devastating. They try to be all they can be despite their affliction.
If you think you may have a puppy or terrier that exhibits signs of ataxia, please contact the Jack Russell Terrier Research Foundation (Debbie Johnson, firstname.lastname@example.org).
I also want to thank all the people who have submitted DNA allowing for the research and gene isolation for SCA.