Can a Blind Diabetic Dog be Happy? - Part Two
Blind dogs with diabetes can certainly live happy and fun-filled lives and there are things you want to know. As we discussed in Part One of this series, dogs respond differently to blindness based on a number factors, including rate of vision loss, age at onset of vision loss, concurrent comorbities (A comorbidity is defined as the simultaneous presence of two or more diseases in one patient. For example, a patient with both heart disease and arthritis.), and hearing loss. For helpful information on these topics, please refer to Can a blind dog be happy? - Part One
Part two of the three part series is about blind dogs with vision loss as it relates specifically to diabetes mellitus.
The focus of this article is:
- To discuss the role of cortisol in managing diabetes in dogs with extra attention on how factors such as elevated endogenous cortisol and vision loss impact the ability to regulate a diabetic patient.
- To educate families that cataract removal surgery to restore vision is an elective treatment option with a window of opportunity for the highest success rate for life-long vision and comfort.
- To share an excellent resource for families with diabetic dogs. That resource is our team. Call us (720-810-5480) to speak with a doctor to get answers to your questions about your diabetic dog. We are here to help people and pets live their best lives.
Diabetes mellitus is the number one cause of cataracts in dogs. Almost 90% of dogs diagnosed with diabetes will develop cataracts.
Cataract is the term used to described when the normally clear lens inside the eye becomes opaque (white). This change from a clear lens (used for improving focus) to a white lens (that impairs or prevents vision) is the reason that patients with cataracts cannot see.
The rate of cataract formation in a diabetic dog can be very fast. For example, a diabetic dog may be playing ball with their family in the morning and be blind, due to rapid onset cataract progression, later that same day. The faster the onset of the cataract, the more likely the patient will have secondary swelling and discomfort from the cataract. Keep reading to learn how cataracts cause swelling and pain.
When a dog is newly diagnosed with diabetes, the first goal is to get their blood sugar levels stable. This is also referred to as “getting a patient regulated”.Regulating blood sugar for diabetic patients means supplementing them with insulin after meals to keep their own blood sugar in a safe range. When blood sugar levels are too high this impacts other internal organ systems, like the liver and kidney, in a negative way. High blood sugar also increases a patient’s risk for urinary tract infections (UTIs). Having elevated blood sugar, with or without a UTI, can leave patients feeling lethargic and nauseous, which will impact their appetite. When a diabetic patient’s eating becomes erratic, it is difficult to know how much insulin they need and a cycle of being poorly regulated begins, with blood sugar running too high or getting dangerously too low.
Your primary care veterinary team will work to find the right brand of insulin and the right dose of insulin for your pet.
Other factors that impact regulating diabetic patients are the type of food they eat and the ability of the family to provide meals according to a fairly set schedule. When a patient continues to be difficult to regulate despite receiving their insulin at regular intervals throughout the day, your primary care team will rule out other causes, such as disease processes, that can make a patient resistant to their insulin. The classic example of a disease process that makes a patient resistant to their insulin is hyperadrenocorticism, also called Cushing’s syndrome.
In Cushing’s syndrome, a patient has increased internal cortisol production from one or both of their adrenal glands. Cortisol is an internally produced steroid and steroids cause resistance to insulin. For example, a patient with Cushing’s syndrome, receiving 6U of insulin at home, may only feel like they are receiving 3U of insulin with one dosing and 4U of insulin at another dosing and 6U of insulin at another dosing, depending on their internal cortisol levels at the time the insulin is administered. This bouncing around in insulin levels due to insulin resistance created by elevated internal cortisol levels due to Cushing's syndrome can make it difficult to regulate a patient. Your primary care team can determine if Cushing's syndrome is a concern when diabetes is diagnosed.
In addition to Cushing's syndrome, sources of pain and stress can make it difficult to regulate a diabetic patient. For example, pain from dental disease will cause a fluctuation in internal cortisol levels and the stress of vision loss from cataracts due to diabetes can also make it difficult to regulate some diabetic patients due to high internal cortisol levels secondary to stress. At Apex Veterinary Ophthalmology, our ophthalmologists see many cases where a poorly regulated diabetic patient is referred to an internal medicine specialist who rules out all causes of insulin resistance, only to land on vision loss as a cause of stress for the dog and cataract removal surgery is recommended. Helping these patients, stressed by vision loss, see again is a win:win for an improved quality of life and diabetic regulation.
Meet Angel, a 9-yo, female spayed Schnauzer. Angel was diagnosed with diabetes and cataracts due to diabetes at the same exam on a Friday afternoon with her primary care veterinary team. She did not stop barking for the following 72 hours. When I met her on Monday morning, both Angel and her family were exhausted. After completing her exam, with Angel barking the entire time, I agreed to fast track her surgery to the following day. Angel started pre-surgical eye drops. Underwent cataract removal surgery on Tuesday morning and Angel woke up from surgery looking around, and wagging her tail. Personally, I will never forget seeing her waiting in her recovery area quiet as a mouse and looking pleased with life. The reunion with her family was joy filled. Angel was the most stressed blind canine patient I have ever met and she appeared visibly relieved after her vision was restored with cataract removal surgery. Angel stands out because she underscored how stressed a patient can be secondary to cataract formation with vision loss which impairs the ability to regulate diabetes. After surgery removal surgery, Angel had on-going diabetic control.
Going beyond their regulation, it is important to understand that cataract formation, especially in diabetic dogs, is frequently associated with swelling and pain. Like us, a dog is born with a clear lens comprised of constantly growing clear proteins. Though the lens is constantly growing, it is not increasing in size, but rather the lens is increasing in density throughout the patients life-time.
In diabetic dogs, clear lens protein is exposed to excess sugar inside the eye and this exposure changes the protein in the lens from normally clear protein to white protein, which we call a cataract. The new, sugar-induced white protein (cataract) in the eye is foreign to the immune-system. So when the ever-scanning immune-system comes in contact with the cataract it mounts an immune-response against the perceived foreign material. The incited immune-response causes swelling, also called inflammation in the eye. The term for inflammation in the eye is uveitis. So cataracts, secondary to diabetes, in dogs, cause swelling in the eye which is a source of pain. From swelling and pain, more problems can ensue because inflammation (acute or chronic) in the eye can lead to elevated intraocular pressure, called glaucoma.
Having elevated intraocular pressure (glaucoma) can also be painful. The key to helping dogs with diabetic-induced cataracts is starting preventative medications, typically eye drops, to decrease the risk for painful inflammation and eventual glaucoma. In worst case scenario, a dog with cataracts secondary to diabetes never receives an exam with a veterinary ophthalmologist, develops inflammation and/or glaucoma, is painful and eventually is best served with eye removal surgery to become a pain-free, blind and happy diabetic dog.
At Apex Veterinary Ophthalmology, we are committed to helping clients make informed decisions for their pet's ocular health and we never want to hear the phrase, “I wish I would have known that my diabetic dog needed eye drops” ever again.
Managing vision loss due to cataracts in diabetic dogs is centered around maintaining comfort. While there is no eye drop available to slow, halt, or reverse the progression of cataracts in dogs, there are topical aspirin-like drugs that can decrease the risk for swelling and pain, and, if families are interested, cataract surgery is a commonly performed at our surgical center which can permanently restore vision. Though a patient will remain a diabetic after cataract removal surgery, surgery only needs to be performed once to have a life-long vision and comfort.
In summary, dogs with vision loss due to diabetes can have wonderful, happy, long lives. Awareness of factors causing stress is important for regulating diabetic patients. Vision loss due to cataracts can be a source both pain and stress. There are topical medications that can decrease the risk for pain secondary to cataracts even when cataract removal surgery is never elected. For the best chance for comfortable eyes, with or without cataract removal surgery, diabetic dogs will benefit from an eye exam with a veterinary ophthalmologist. We recommend this exam is performed as soon as the patient diagnosed with diabetes. This exam is even helpful prior to cataract formation and vision loss.
If you are the pet parent of a diabetic dog, your next step is simply to call Apex Veterinary Ophthalmology (720-810-5480) and talk to us over the phone. Let our board-certified eye doctors answer your questions. We want to provide you with valuable information specific to your pet and with peace of mind.
Dr. Nuhsbaum is the owner of Apex Veterinary Ophthalmology and board-certified, veterinary ophthalmologist. She works to improve the ocular comfort, vision, and quality of life of animals. Dr. Nuhsbaum is part of the team of experts at Apex Veterinary Ophthalmology Specialists.