One of the sweetest things about pets is the adoring way they look at you. But occasionally, you can get a nasty surprise from this "look of love": your cat squints at you through puffy eyelids, or you notice a yucky discharge welling from the corners of your dog's eyes.
Conjunctivitis (an inflammation of the membranes covering the eyes, better known as "pink eye") is a common problem for dogs and cats. It may make the eyes appear red, swollen, watery, crusty, or goopy with an unpleasant-looking discharge.
There are many potential causes of conjunctivitis:
- Viral, bacterial ("pink eye"), parasitic, or fungal infection
- Dry eye (keratoconjunctivitis sicca)
- Direct irritants
- Airborne (smoke, dust, pollen, heavy perfumes, chemical air fresheners)
- Foreign body (hair, grass awns, dirt, sand, or other debris)
- Substance (shampoo, antibiotic ointment)
- Physical trauma (blow to the eye, rubbing the eye, cat scratch)
- Systemic illness (feline immunodeficiency virus), canine distemper, Lyme disease, other inflammatory diseases)
- Autoimmune disease (pemphigus, lupus, pannus)
- Eye structure disorders or malformations (rolled or droopy eyelids, blocked or absent tear ducts, tumors)
- Allergies (usually accompanied by skin symptoms; or may be due to drug or bug bite reaction)
- Other concurrent eye disease (glaucoma, corneal inflammation)
Since dogs tend to be out and about more often than most cats, foreign bodies and trauma are found more commonly in canines. This is a particular hazard for dogs that like to stick their heads out of car windows!
However, there are also a number of breed predispositions that can cause eye problems, such as droopy eyelids or excessive hair around the eyes.
Dry eye (a condition in which there is insufficient production of the watery portion of the tears) is probably the most common cause of canine conjunctivitis.
The most common cause of feline conjunctivitis is a viral infection, usually with an upper-respiratory strain of herpes virus.
It typically causes redness and a watery-to-gunky discharge. It frequently attacks only one eye, producing a lopsided squint.
Nearly all cats are exposed to the herpes virus as kittens; and it is also included in kitten vaccines as "rhinotracheitis." For most cats, no further problems occur. However, herpes can lie dormant until the immune system is off-guard due to illness, injury, or stress. Once it gets a foothold, recurrent herpes flare-ups are common.
Solid nutritional support for the immune system can ward off many eye problems, particularly infectious and allergic varieties.
- Dry food is highly processed and may be more likely to be involved in food allergies that affect the eyes. Avoid corn-based dry foods for cats, since corn is deficient in lysine. Lysine is abundant in meat, so your best option is a meat-based canned, raw, or homemade diet.
- Probiotics help keep the gut healthy and balance immune response in dogs and cats, just as they do in people. They have been shown to have beneficial effects in many pet health conditions, including upper-respiratory infections that can contribute to conjunctivitis.
- Omega-3 fatty acids are vital for skin and coat health, and the conjunctiva (the mucous membrane that covers the eye) is an extension of the skin. Marine oils, such as fish oil and cod liver oil, are ideal for pets-look for a supplement specially formulated for pets.
- For many pets, you can help relieve irritation and wash particles from the eyes using a homemade saline solution. Use ¼ tsp. of uniodized table salt (not sea salt) to ½ cup of distilled or filtered tap water (at room temperature). Three or four times a day, use a cotton ball to drizzle a small amount saline into your pet's eyes.
Be sure to make the saline fresh every time, because bacteria will grow in the solution between treatments. You can also purchase natural saline and herbal washes formulated for pets. Caution: do not use the kind of saline products made for contact lenses.
If symptoms are severe, get worse, or persist more than a day or two, a check by your veterinarian is warranted. Untreated conjunctivitis can cause painful corneal ulcers that may result in loss of vision if untreated.