The occurrence and treatment of keratitis in pet dogs

Keratitis is a general term for inflammation of corneal tissue. It is characterized by corneal opacity (nebula), corneal neoplasia, corneal ulcer, corneal perforation and corneal macula, which can occur in all kinds of dogs, but it is common in small dogs with long hair. The etiology and therapeutic effect of 68 cases of keratitis in dogs diagnosed and treated since May 2005 were analyzed. Most of them were caused by trauma, foreign bodies, improper drugs and infection, and some of the causes were unknown. After treatment, 66 cases were cured, with a cure rate of 97.06%. Corneal ulcers cause perforations that are difficult to cure.

1 Analysis of cases

1.1 among the 68 cases of keratitis, Jingba dogs accounted for the majority (28 cases), followed by lion dogs (15 cases), small mixed dogs (11 cases), cocker spaniel (5 cases), small hounds (5 cases), eight pigeon dogs (2 cases) and Pomeranian dogs (2 cases).

1.2 causes of the disease

1.2.1 traumatic injuries are most common in dogs biting each other, accidentally kicking, bumping and scratching each other. The cornea is inflamed after being injured, and most of these cases are in serious condition.

1.2.2 when foreign bodies are stimulated, sand and ash fall into the eye to stimulate the cornea, abnormal eyelashes stimulate the cornea, and sticky substances such as chewing gum stick to the cornea to stimulate the cornea.

1.2.3 Drug factors use expired eye drops or eye ointment to treat corneal inflammation caused by tears. There are also conjunctivitis and corneal inflammation caused by discomfort with certain ophthalmic drugs.

1.2.4 bacterial and viral infections were found in canine distemper, canine infectious hepatitis, canine herpesvirus and Staphylococcus aureus. This kind of situation is more common, and the condition is more serious.

1.2.5 unknown causes may be caused by allergic reactions or corneal dystrophy.

2 clinical symptoms

Among the 68 cases of keratitis, unilateral eyes accounted for 36 cases, accounting for 52.9%, and bilateral eyes accounted for 32 cases, accounting for 47.1%. There were 34 cases of corneal opacity and neoplasia, accounting for 50%, 23 cases of corneal ulcer, accounting for 33.8%, and 11 cases of corneal perforation, accounting for 16.2%.

The common symptoms of keratitis are shyness, tears, pain, conjunctival flushing, eyelid closure, followed by corneal opacity, ulcers, serous or purulent eye secretions, and severe visual impairment. Traumatic keratitis can be seen corneal injury, bleeding, infection, suppuration, ulceration. Canine distemper often occurs in both eyes at the same time, in addition to eye symptoms, systemic symptoms are also obvious, such as mental depression, body temperature rising to 39.5 ℃ ~ 40.0 ℃ and so on. Corneal opacity is the formation of opaque white clouds on the corneal surface, opacity may be localized or diffuse, the new state of corneal opacity is not obvious, the surface is rough and bulging, there are symptoms of inflammation. Old corneal opacity has no inflammatory symptoms, and the boundary is obvious. When the deep cornea is opaque, it is often in the shape of light blue cloud. Corneal neoplasia is an obvious local hyperplasia and thickening of the cornea. Corneal ulcer is an irregular defect on the surface or deep layer of the cornea. When the cornea is perforated, the cornea breaks, and aqueous humor and viscous exudates flow from the rupture, and even capillaries are exposed. Corneal pannus is an opaque gray-white scar formed in the later stage of corneal opacity and ulcer.

3 treatment

Based on the principle of eliminating etiology, eliminating inflammation and relieving pain, and promoting absorption, the method of local drug treatment and systemic treatment is combined.

Rinse the eyes with normal saline to remove foreign bodies and secretions. In the acute stage, when there is no suppuration, ulceration or perforation of the cornea, chloramphenicol eye drops and cortisone acetate eye drops are used alternately, 3 to 5 times a day. At the same time, systemic treatment was performed with ampicillin sodium injection, compound ampicillin injection and dexamethasone sodium phosphate injection intramuscularly or subcutaneously, once or twice a day for 2 to 7 days. Viral keratitis was treated with polymyocyte injection or immune serum at the same time, once a day or every day for 3 to 5 days. In addition, there should be symptomatic treatment and, if necessary, intravenous infusion of 5% glucose saline to improve systemic symptoms and animal resistance. Such as keratitis secondary to bacterial infection, suppuration, ulceration, or even perforation, with penicillin 80000 units, plus 0.5 ml of normal saline mixed eye drops, 3-5 times a day, while systemic treatment. If the corneal perforation is serious, eyelid conjunctival covering surgery can be performed to make an autologous eye bandage to the affected eye, which can effectively prevent the outflow of aqueous humor and prevent the invasion of pathogenic microorganisms, which is beneficial to the repair of corneal injury. With inosine, vitamin C, vitamin B1, vitamin B2, the curative effect is better. Strengthen the care of sick dogs, reduce their outdoor activities as much as possible, avoid strong light stimulation and gray sand falling into the eyes, avoid fighting with other dogs, and feed them nutritious and digestible food.

4 summary and experience

68 sick dogs were treated, 66 cases were cured, and the cure rate was 97.06%. Two cases were not cured, one of which had been treated elsewhere for many days, corneal fester and suppuration, lens prolapse, complete blindness after the elimination of inflammation, and the other case was traumatic keratitis, which was seriously injured and the host gave up treatment after 3 days of treatment. If the condition is mild, it can be cured after systemic treatment for 1-2 days and local treatment for 3-5 days; for severe cases, systemic treatment takes 3-7 days, and local treatment for more than 7 days; corneal ulcers and perforations often have small dotted defects or grayish pannus in the cornea after treatment, but it has little effect on vision.

In the treatment of canine keratitis, the choice of eye drops is very important, because there are many kinds of eye drops used by people, but not all of them are suitable for dogs. Clinically, it is common that some livestock owners only pay attention to buy expensive eye drops for treatment, but delay the disease because of poor results. In the treatment of canine keratitis, systemic adjuvant therapy is also very important, especially for those with severe systemic symptoms. In the treatment of keratitis caused by unknown causes, the author uses, on the one hand, to treat ophthalmopathy, on the other hand, to clean up intestinal feces and change food types, which can often get twice the result with half the effort, because this kind of dogs often eat meat, animal liver and other viscera as staple food, and develop eye disease due to malnutrition or exuberant liver fire. In the treatment of canine ophthalmopathy, the author does not advocate the use of eye ointment, because eye ointment sticky, so that dogs feel uncomfortable, will continue to scratch the eyes, so that the eyes aggravate the injury. However, it is also advisable to use it once when you go to bed at night to prolong the action time.

The causes of the above analysis are commonly seen by the author in clinical practice, but the 68 cases of keratitis diagnosed and treated statistically do not include keratitis caused by canine distemper, because the cure rate of canine distemper is low, so emphasis is placed on the treatment of other diseases.

The causes of eye diseases such as corneal opacity and ulcers in dogs are complex, including external causes (physical, chemical and microbial), internal causes (allergies and nutrition), and some unknown causes. It has been reported abroad that one of the causes of corneal opacity is that collagenase produced by epithelial cells destroys the formation of collagen, which results in turbidity through the light scattering of the cornea; collagen is a very strong protein, in normal pH conditions, except collagenase, collagen is generally impossible to be broken down. However, under the stimulation of microbial infection, physical and chemical factors, a large amount of collagenase is produced in corneal epithelial cells, which destroys collagen and leads to corneal opacity and ulcer. 3% N-acetylcysteine eye drops is effective, safe, reliable and stable in the treatment of canine eye diseases, because 3% N-acetylcysteine eye drops can inhibit excessive collagenase activity in the early stage of inflammation, remove damaged corneas and contribute to corneal regeneration, improve corneal ulcers, inhibit the development of depth, and promote the repair of corneal epithelial cells. In addition, there are reports of using their own blood to treat canine keratitis.