Since your pet’s eyes are front and center every time you look at them, abnormalities of the eyes are easy to notice. Below are descriptions of some of the more common eye disorders in dogs and cats.
Cataracts
Older dogs commonly have a visible cloudiness to their eyes. The cloudiness is normal aging of the lens, called nuclear sclerosis. Nuclear sclerosis does not compromise vision, and is often mistaken for cataracts. Cataracts are an abnormal cloudiness of the lens caused by a buildup of protein or pigment in the lens which interferes with normal vision. In dogs, genetics and diabetes play a role in cataract development. Canine cataracts can be removed surgically, followed by placement of an artificial lens. Cataracts are uncommon in cats.
Dry Eye
Dry eye is a decrease in tear production and occurs in dogs, especially those with bulgy eyes, like pugs. Treatment requires lifetime eye medications to stimulate tear production.
Cherry Eye
Under the third eyelid of dogs and cats is a small tear gland. In certain breeds, such as bulldogs, cocker spaniels and Burmese cats, the gland pops up and forms a red mass in the eye, colloquially known as “cherry eye.” This abnormality typically occurs in young dogs and cats. Treatment involves tacking the gland back in place with a suture.
Glaucoma
One of the most common eye abnormalities pet families recognize is a red eye. Glaucoma is one cause of a red eye. The redness results from a painful increase in pressure inside the eye. Management of glaucoma can be challenging and involves drops, ointments and even surgery.
Corneal Ulcer
Another cause of a red eye is a corneal ulcer, a sore on the clear part of the eye. Corneal ulcers are common in dogs with dry eyes, as a sequela to feline viral respiratory infections, or trauma. A dog or cat with a corneal ulcer will squint or rub their eye because ulcers are painful. Typically, application of antibiotic ointment and oral pain medication correct this condition.
Allergic Conjunctivitis
Conjunctivitis is probably the most common eye problem on the list, since allergies are common in dogs. Allergic conjunctivitis is yet another condition resulting in red, weepy eyes. Distinguishing it from red eyes due to glaucoma or a corneal ulcer requires testing the pressure inside the eye and measuring tear production. Making the correct diagnosis is critical, since the treatment for each is different. Management of allergies with antihistamines or immunotherapy, plus anti-inflammatory eye ointment usually resolves allergic conjunctivitis.
Chronic degenerative valve disease (CVD), also known as endocardiosis, is the most common type of heart disease in dogs. It occurs when the heart valves, which control blood flow between the chambers of the heart, become thickened and inflexible. Their distorted shape prevents the valves from shutting properly. Blood then leaks through the abnormal valves resulting in backflow, leading to increased pressure within the heart chambers or blood vessels. This condition commonly affects the mitral or tricuspid valves and is also known as myxomatous valve degeneration.
In some dogs, progressive degeneration of the heart valves leads to fluid buildup in and around the lungs and in the abdomen. The fluid buildup as a result of impaired heart function is known as congestive heart failure.
The term “cardiomyopathy” is used to describe diseases that affect the heart muscle. Dilated cardiomyopathy (DCM) is an acquired disease resulting in an enlarged heart due to the thinning of the heart muscle. As the heart muscle stretches and weakens, the inner chambers become dilated which decreases the heart’s ability to contract and pump blood properly. Heart valves, which control the blood flow between the chambers, may leak because the heart takes on an abnormal shape. Leaky valves plus poor heart muscle contraction cause a buildup of fluid in and around the lungs and in the abdomen. The fluid buildup as a result of impaired heart function is known as congestive heart failure.
Intervertebral disc disease (IVDD) is one of the most common spinal conditions in dogs and is especially prevalent in dogs with a long back and short legs.
Your dog’s spinal column is made up of a series of backbones (vertebrae) with disc-shaped cushions between them. These cushions, which are known as intervertebral discs, act as shock absorbers for the spine and also provide stability.
Each cushioning disc has a thick covering on the outside, with a softer, gel-like core. Over time, the outer portion of the disc breaks down while the inner portion hardens. If the outer portion breaks down too much, the hardened interior can bulge or burst into the spinal canal and put pressure on the spinal cord or nerves as they branch off the spinal cord. This is commonly referred to as a herniated disc or slipped disc, and it can cause a wobbly walk, back or neck pain, nerve damage, and even hind limb paralysis.
Generally speaking, there are two types of IVDD:
Type I primarily affects young to middle-aged dogs. It occurs mainly in chondrodystrophic breeds, which are the dogs with the long back and short legs. In these dogs, breakdown of the disc (or discs) tends to begin early in life, leaving the disc vulnerable to damage from activities that usually would be considered normal. If an at-risk dog jumps off a couch or takes a sharp turn while chasing a ball, the hardened disc may bulge against the spinal cord causing sudden pain or gait changes.
Type II primarily affects older large breed dogs such as Labrador retrievers and German shepherds, and signs tend to appear more gradually. In type II IVDD, breakdown of the disc causes it to bulge into the spinal canal over a period of weeks or months causing slow and gradual loss of the ability to walk normally.
IVDD can occur anywhere in the spine but is most common in the middle of it (between the shoulders and hips) or in the neck. When it occurs in the middle of the spine, only the hindlimbs are affected while all four limbs may be affected if the problem exists in the neck.
Limping or lameness is a condition in which an animal’s gait (walk) is affected by a pain in one or more legs. Familiarizing yourself with the way your pet moves can help you notice when something doesn’t look right.
