Cataracts in Dogs


Cataract surgery in dogs

Question: Dear dr. mike; first i would like to thank you for your previous advice. I think my dog is still alive because of it. (it was some six months ago and i don't believe that problem relates to the current one.) My dog, king tut, a black poodle now almost 14 years old, has cataracts. I have read your very helpful output on the subject and cleared him for the qualifications you specify. notably the retina has been evaluated and is functioning. and the other conditions you mention are met. i have consulted my usual vet as well as a veterinary opthalmologist. i believe he could benefit from the operation since he clearly has a problem seeing. so what i wonder is : whether to do both eyes simultaneously or do each separately. the opthamologist informs me that to do both at once is considerably cheaper . this is not my main consideration however and i will cheerfully pay more if it is safer or better for tut. also there is the question of whether to do an ocular implant as I believe is done with people. again i am perfectly willing to do whatever is best but have heard differing opinions on whether it is best for dogs. ( i don't see how any unblurred vision is possible without a lens but who am I to say?) ,many thanks for your opinion.. also his walk is unstable but i believe this can be attributed to the fact that he can't see but his usual vet is doing further tests about this. is this instability common with blindness? again many thanks, frances Answer: Frances- Some dogs react adversely to cataract surgery. In our practice experience it has been about 10% or so of the patients who have had cataract surgery. Due to this, I tend to think that it is better to do the procedures separately when both eyes must be operated on. I am not sure that my logic is right on this one, but I think that if complications do occur it would be easier to deal with them in one eye at a time and that this would make it less likely for a complication in one eye to lead to problems in the second eye due to the increased need to handle the unaffected eye while treating the affected one. However, if there is a significant difference in cost and doing both cataract surgeries at one time would make it much more likely that both could be done, because of cost savings, I think that I'd go ahead and opt to have both done at once and take my chances. I am presently very confused about the issue of whether or not to use implants. I do think that vision has to be much better with the implants and for that reason I would tend to advocate considering them. I have been to one lecture on ophthalmology in which the presenting ophthalmologist was convinced that implanting lenses increased the complication rate and one lecture in which the ophthalmologist said that when a preliminary review of the situation for an individual patient did not show any complicating factors in advance, that implanting lenses actually reduced the long term complication rate. To be honest I think that both speakers were probably right. If every dog receives a lens the complication rate is probably higher. If the ophthalmologist makes a choice in whether to implant a lens or not based on the condition of the eye at the time of surgery, the complication rate may be lower with implanted lenses, because the higher risk patients are weeded out prior to surgery. So right now I am just telling my clients to follow the ophthalmologist's advice based on his or her evaluation of their pet. I hope that this is still helpful to you. Mike Richards, DVM 10/12/2001 Anterior capsular cataracts in Norwegian Elkhound Question: Dr. Mike: This weekend I had my female 13 month old Norwegian Elkhound looked at an eye clinic. The diagnosis was bilateral anterior suture cataracts (triangular in shape) marked also on the CERF page was the "Inter". box. They were very, very busy and I did not get a good explanation. Are these cataracts apt to rapidly change and lead to blindness or the need for cataract surgery? Also are they definitely inherited? Both parents, all grandparents and great-grandparents have been CERF certified and passed their examinations on more than 1 occasion. I've never experienced this problem before in breeding the mother or this line. She has not had any trauma to the eyes but was fed an esbilac formula for about 2 weeks to supplement mothers milk when she got colicky on her real mothers milk. If possibly inherited by what way i.e. recessive, autosomal, etc...? A 6 month revisit with an ophthalmologist was recommended. Thank You, R Answer: R- Some puppies and kittens who are fed commercial milk replacement products have developed cataracts, so this possibility has to be considered. Most commonly these are posterior capsule or equatorial cataracts but other types of cataracts have been seen with this problem. The fact that the Esbilac (tm) was used to supplement the mother's milk production and the relatively short duration of time it was used make this less likely but the bilateral nature of the cataracts is somewhat supportive of the diagnosis. The lens sort of resembles a round pillow, having convex surfaces on both sides. It is held in place behind the iris in a vertical orientation, so that one convex surface is towards to front of the eye (anterior side of the capsule) and the other surface is towards the back of the eye (posterior capsule). In some of the breeds in which there is definite evidence of heritability for cataracts there are specific orientations for the types of cataracts that are inherited. Doberman pinschers, for example, have posterior capsule cataracts as an inherited defect. In some breeds the cataracts may be either anterior or posterior capsular cataracts. I can't recall if there is a breed with primarily anterior capsular cataracts. The ophthalmologist may be able to tell you if there is a known method of inheritance for cataracts in Norwegian elkhounds and if so, where the cataracts usually occur in the breed. This could help determine the likelihood that this problem is inherited. When information is not available for a particular breed, ophthalmologists tend to be conservative in their recommendations about breeding and usually suggest not breeding an affected dog. Our experience with anterior capsular cataracts that look like those you are describing is that they don't usually progress much or progress very slowly. I am not sure if this is true in general. The ophthalmologist in our area usually asks people to come back once or twice to check for progression of the cataracts so it seems like there must be some patients who do develop more extensive problems from these cataracts, though. The exact inheritance mechanism of cataracts in most dog breeds is not known. The breeds in which the inheritance has been worked out include dobermans, cocker spaniels, German shepherds, samoyeds, miniature schnauzers and West Highland White terriers. There may be others that I am not aware of. I am on the road and do not have access to all my books and I just got a new ophthalmology book this week. When I get home, I'll check to see if there is new information on Norwegian elkhounds. Mike Richards, DVM 5/1/2001 Cataracts on detached retinas in Jack Russell Question: I have a Jack Russell Terrier, Sammy (appox. 6 years of age). Adopted him two years ago - he was blind. (Detached retinas). He started to form cataracts in both eyes. The right eye started to form earlier than the left. He has been on AK-CIDE for the past year (a pred. eyedrop). He also was recently diagnosed with diabetes insipidus and we are getting ready to switch him to another eyedrop because of this. He is on Chlorothizaide (sp?) for this. Both eyes have the typical white/bluish cast of a cataract - see attached photo. Tonight when I was giving medicine to the dogs, I noticed that the cataract in the right is gone. I am seeing his pupil as it would appear pre-cataract. Can you give me any information on how/why this would happen? Is this a normal scenario for untreated cataracts? His opthamologist has opt! ed not to operate at this point since the dog is blind (because of the detached retinas) anyhow. I am a little mystified by the "disappearance of the cataract" and will call the vet tomorrow. Ro Answer: Ro- My guess it that the lens of the eye (containing the cataract) has luxated, or moved from its normal position. It is probably best to remove the lens, if this has happened. It is possible to use medications to keep the pupil small, helping to keep the lens behind the pupil, where it won't cause problems, but this rarely works well long term and Sammy is pretty young for a Jack Russell. Sometimes cataracts are resorbed when the interior of the lens liquefies and the capsule leaks. In a dog that had normal vision prior to the formation of cataracts this can result in the return of vision but since Sammy couldn't see before the cataracts, this won't benefit him much, if it has occurred. In some cases the leakage of lens contents will cause severe inflammation in the eye and can even produce secondary glaucoma, so it isn't always a good thing when resorption of the lens occurs. You made a good choice to have Sammy re-examined by your vet. Hopefully, there has not been inflammation in the eye, regardless of the cause of the problem. Mike Richards, DVM 12/27/2000 Cataracts in puppies Q: Dear Dr. Mike: Upon talking to an ophthalmologist, it is my understanding that, in order for a puppy to have cataracts, both parents must be carriers. Is this correct? Thank you, Cathy A: Cathy- The answer to your question depends on the cause of the cataracts and the breed the cataracts are occurring in. There are hereditary cataracts. In some breeds, the mode of transmission has not been worked out, based on the sources I have. At the present time genetic information is changing very rapidly and it is probable that the information I have is not completely up to date. For dogs in which the mode of transmission has been worked out, the breeds with cataracts caused by dominant genes (meaning that only one parent has to transmit the gene for the disease) are: beagles and Chesapeake Bay retrievers Breeds with recessive genes leading to cataracts (both parents must pass on the recessive gene to the affected offspring) are: American cocker spaniel, Boston bull terrier, German shepherd, golden retriever, miniature schnauzer, old English sheepdog, Staffordshire bull terrier, Welsh springer spaniel, Afghan hound, Irish setter, Siberian husky and standard poodle. This information is from Dr. Peiffer's book "Small Animal Ophthalmology: A Problem Oriented Approach". There are a lot of non-genetic causes of cataracts, including trauma, feeding orphaned puppies milk-replacing formulas, chronic inflammation, toxins, vitamin B deficiency, diabetes and normal aging changes. If you have more information on the type of cataract you are concerned about and breed it is associated with I would be glad to see if I can find a specific mode of inheritance for you. Mike Richards, DVM 4/5/99 Cataracts Q: dear Dr. Mike We have an 8 yr old shepard-collie mixed breed diagnosed with diabetes in june 98 who has rapidly developed progressive clouding of the lens of both eyes. My question is whether there is anything we can do to prevent further progression. She has significant visual impairment already and will become completely blind in the next few months at this rate. Our vet has confirmed that she has cataracts. I have read in a veterinary text that most dogs with diabetes develop cataracts. She started on insulin immediately and was stabilized by August with sugars @ 5-18 mmol/l venous samples( I am a doctor). She is asymptomatic. She also has osteoarthritis in her hips and had a left THR last year. She was on occasionally on Stilbestrol on the advice of our vet for about a year at age 5 for intermittent leaking of urine. I don't think this would affect the lens of the eye. She is not obese. She is on Humulin ge Lente insulin 15 units twice daily. I was wondering if this may be an autoimmune response to human insulin, but she is not insulin resistant. Would vitamin A or any other supplement help ? We are giving her cod liver oil to help her dry skin. Do we have to accept that she is going to become blind? Thank-you very much. Michele (Ontario) A: Michele- I do not know of anything that will help to correct the cataracts once they have started. While it seems logical that strict control of the diabetes might arrest the progress of the cataracts that hasn't been our clinical experience, either. Most veterinary ophthalmologists are comfortable removing cataracts from diabetic patients once the diabetes is well regulated, though. That would probably be the best choice at this time, if that is possible for you to arrange (your vet can refer you to a veterinary ophthalmologist). Mike Richards, DVM Cataract surgery In the past, veterinarians waited for near blindness in both eyes before attempting cataract surgery. I am not sure of the reasoning behind this, but feel that it had a lot to do with the success rate of the surgery. In the past (prior to 1969), the success rate for cataract surgery was generally believed to be poor. Consequently, if the dog had any vision at all, its chances were just as good with or without surgery for long term vision. At this time, it is felt that the long term success rate is 90% or better for cataract surgery, if the patient is carefully selected. A cataract can be a source of visual problems in other areas of the eye if it is left alone -leakage of proteins from the lens can lead to inflammation in the eye, which can lead to glaucoma, which makes removal of the lens (cataract) much less likely to succeed. So currently, the recommendation is to remove the affected lens as soon as significant visual deficit is present. However, there are some criteria for deciding if your dog is a good surgical candidate that you might want to consider: 1. You must be willing to spend a significant amount of money AND provide a significant amount of aftercare! 2. Any inflammation present in the eye must be controlled PRIOR to surgery. 3. The retina should be evaluated prior to surgery to make sure it is functioning - the surgery may not be justified if your dog will not be able to see when it is over. 4. No other disease can be present in the eye. 5. Your dog must be cooperative about being handled and medicated. If not, the outcome of the surgery is seriously jeopardized. Be honest with yourself about this. 6. Your dog should be in good health. If your dog and you are good candidates for this surgery, it is worthwhile. 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...