Trimethoprim-sulfamethoxazole for the treatment of tear staining syndrome in dogs

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22 dogs (31 eyes) that had treated with trimedioprim-sulfamethoxazole for tear staining syndrome at Snoopy Pet Clinic from October 2000 to September 2002 were reviewed. Of the 22 dogs, 12 were female and 10 male. Their mean (± SD) age was 3.5 (± 1.3) years. The breeds of the dogs consisted of Maltese (8 dogs), Shih tzu (6 dogs), Poodle (5 dogs), Yorkshire terrier (2 dogs), and Mixed (1 dog). The dogs received 30 mg/kg trimethoprim-sulfamethoxazole perorally twice daily for two to six weeks. 26 (19 dogs) of the 31 eyes (22 dogs) recovered completely and did not show relapse at 26-30 weeks after treatment. Any complications did not observed. Five eyes of three dogs were not cured. Two eyes (one dogs) of them had not response to medicament and three eyes (two dogs) recurrence but the clinical signs decreased. It was considered that the trimethoprim-sulfamethoxazole was effective for the treatment in dogs with tear staining syndrome.

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The value of the sulfonamides as single antimicrobial agents has been greatly diminished both by widespread acquired resistance and by their relatively low potency compared to more modern antimicrobial drugs. However, when combined with antibacterial diaminopyrimidines such as trimethoprim, resistance occurs less frequently and thus their usefulness has been enhanced. This chapter discusses the chemistry, mechanism of action, antimicrobial activity, resistance, pharmacokinetic properties, drug interactions, toxicity and adverse effects, administration and dosage, and clinical applications of sulfonamides, diaminopyrimidines, and their combinations. Diaminopyrimidines interfere with folic acid production by inhibition of dihydrofolate reductase. Some diaminopyrimidines have marked specificity for bacterial dihydrofloate reductases (aditoprim, baquiloprim, ormetoprim, trimethoprim), others for protozoal enzymes (pyrimethamine), and others for mammalian enzymes (methyltrexate). Some diaminopyrimidines such as pyrimethamine have high activity against protozoa by inhibiting dihydrofolate reductase and thus preventing purine synthesis. These drugs are used in the treatment of systemic protozoal infections.
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To investigate the effects of age, weight, gender, and of time of day on tear production in normal dogs. studied One hundred ophthalmoscopically and systemically unremarkable dogs. Schirmer tear tests (STT) were performed every 2 h during the day on one randomly chosen eye of each of 100 dogs. There was a statistically significant effect of time of day and age on the STT measurement. The mean STT decreased by 0.4 mm for every 1 year that age increased (P=0.007). Mean STT values taken at 10:00 am were 0.7 mm lower than values taken at 4:00 pm (P=0.04). Tear production decreases with age in the normal dog. In this population of dogs the largest difference was between the 10:00 am and the 4:00 pm STT measurements, but this still only amounted to 0.7 mm. This value is unlikely to be of clinical significance in the diagnosis of keratoconjunctivitis sicca (KCS).
The administration of metronidazole for a short time is without apparent ill effect. No differences were observed between pretest and posttest blood chemistries or hemograms, except an unknown delayed elevation of blood lactic dehydrogenase.
A five-year-old, female, spayed beagle with a history of unilateral epiphora of several months' duration as a result of inadequacy of the lacrimal drainage system was treated successfully with a new surgical method of parotid duct transposition. Data from complete preoperative ophthalmological examination, surgical technique, postoperative treatment, contrast radiography and histological examination were recorded. Absence of complications and complete patency of the stoma at 30 days after surgery confirmed the validity of this new technique. The use of an anatomic duct may be advantageous compared with the current techniques of conjunctivorhinostomy, conjuntivobuccostomy and conjunctival maxillary sinusostomy for the treatment of epiphora in the dogs caused by inadequacy of the lacrimal drainage system.
Long-term sulfonamide therapy for a urinary tract disorder was believed to have caused toxicosis of the lacrimal gland, and subsequently, dry eyes. Initial topical treatment of the ulcers may have potentiated the dry eye condition. The dog was referred with negligible tear production and bilateral corneal ulcers. Diagnostic evaluation of the urinary tract indicated reflex dyssynergia, a neurologic disorder causing functional urinary tract obstruction. The combination of appropriate topical and surgical therapy of the eyes, discontinuation of sulfonamide treatment, and initiation of bethanechol in the treatment of reflex dyssynergia all contributed to return of a normal tear film. Any combination of systemic and/or topical therapy may affect lacrimal secretion. The clinician must be cognizant of the potential effects that systemic medication, particularly antimicrobial drugs and drugs affecting the autonomic nervous system, may have on lacrimal secretions.
The Schirmer tear test for the measurement of tear formation in the dog was done according to 2 procedures: Schirmer I (the conventional procedure) and SCHIRMER II (with topical anesthesia and drying of the ventral conjunctival fornix. Results from 97 normal dogs averaged 21.0 mm wetting/minute (standard deviation (sd) plus or minus 4.2 mm) for the Schirmer I test and 11.6 mm wetting/minute (sd plus or minus 6.1 mm) for the Schirmer II test. When atropine was injected subcutaneously in 50 dogs (0.02 mg/kg, wetting/minute averaged 9.36 mm (Schirmer I) AND 4.32 MM (Schirmer II). Two dogs in each of 3 groups had either the lacrimal gland, gland of the membrane nictitans, or both excised. Changes in tear formation were evaluated by Schirmer I and II tear tests, as well as after parenteral administration of atropine. The lacrimal gland, the gland of the membrama mocotams. amd tje accessory lacrimal glands and mucous cells were found to contribute 6.17, 35.2, and 3.1%, respectively, to tear formation.
Thirteen cases of iatrogenic and bilateral keratoconjunctivitis sicca following the administration of the sulphonamide salicylazosulphapyridine (sulphasalazine) for the treatment of colitis were studied. No breed, age or sex incidence was noted in this series, unlike in keratoconjunctivitis sicca cases due to other causes. The lacrimotoxic effect of sulphasalazine was permanent except in one case and it is suggested that dogs on this drug should be monitored for tear secretion at regular intervals. Reports of a similar association between keratoconjunctivitis sicca and this drug and between the disease and other sulphonamides and compounds are discussed.
A commercial preparation containing phenazopyridine hydrochloride was observed to cause an acute reduction of tear secretion in two dogs, resulting in severe keratoconjunctivitis sicca. Similar results were obtained experimentally by treating three dogs with pure phenazopyridine. No disturbance of tear flow was seen in two experimentally treated cats.
During a 4-year period, keratoconjunctivitis sicca developed in 14 dogs treated with sulfonamides (13, sulfasalazine; 1, sulfadiazine and trimethoprim). Diagnosis was made in 3 dogs by clinical signs and in 11 by evaluation of the Schirmer tear test. Management of the problem included discontinuance of the sulfonamide, then use of ophthalmic preparations topically and antibiotics systemically. Pilocarpine was administered orally and topically to 11 dogs, with variable success. Lacrimation remained inadequate in 10 dogs and returned to normal in 3. One dog was lost to follow-up. Parotid salivary duct transpositions were performed in 3 dogs (in 2 successfully) with severe, unresponsive keratoconjunctivitis sicca.
The effect of trimethoprim-sulfadiazinea on Schirmer tear test (STT) values was studied in a population of dogs treated with the drug for a variety of medical and postsurgical conditions. The objectives of the study were to determine the incidence of keratoconjunctivitis sicca (KCS) secondary to trimethoprim-sulfadiazine therapy; to determine if such incidence was related to dose, duration, or both; and to identify any other factors that increased patient risk. The package insert accompanying Tribrissen states that "Dogs can tolerate up to ten times the recommended therapeutic dose without exhibiting ill effects." The results of this study indicated a 15.2% (5/33) incidence of KCS in the population of treated dogs.
A 41-year-old male developed a generalized drug eruption following sulfamide therapy, with progressive albino-like generalized cutaneous depigmentation. Electron microscopy showed the absence of melanocytes, and clear cells with Langerhans cell characteristics were seen along the basal layer. The present case constitutes a unique reaction to sulfamides not previously reported in the literature.
Measurement of tear volume by phenol red thread tear test (PRT), Schirmer's tear test (STT-1) and Schirmer's tear test with topical anesthesia (STT-2), and vital staining with a combination of fluorescein and rose Bengal of the cornea were performed in dogs with normal eyes and those with epiphora. The breeds included the Shih-Tzu (n = 26), and five other breeds (n = 50). The PRT, STT-1 and STT-2 results from the five breeds of normal dogs were 26.9 +/- 3.0 mm, 17.4 +/- 4.3 mm, and 8.8 +/- 3.2 mm, respectively. The PRT, STT-1, and STT-2 results for the Shih-Tzu eyes were (mean +/- standard deviation): 28.2 +/- 4.3 mm, 19.5 +/- 4.1 mm, and 9.2 +/- 4.5 mm, respectively. In the five breeds, corneal epitheliopathy, as evidenced by the retention of topical fluorescein and rose Bengal, occurred in 97% of dogs with epiphora and in 55% of the dogs without epiphora. Also in the dogs with corneal epitheliopathy the STT-2-value was low (4.0 +/- 2.8 mm) compared with those eyes without corneal epitheliopathy (8.8 +/- 3.1 mm). In the Shih-Tzu breed the STT-2 results were not significantly different between those dogs with corneal epitheliopathy and those with normal corneas. In the non-Shih-Tzu breeds the decrease in basic tear secretion, as measured by the STT-2, is associated with the corneal epitheliopathy.
The objectives of this study were to observe the effects of trimethoprim-sulfadiazine on equine tear production and to determine normal fluctuations in Schirmer tear test (STT) values in horses. A randomized, placebo-controlled, blinded clinical trial measuring STT values in 15 horses over an 8-week period was performed. The treatment group (eight horses) received 30 mg/kg trimethoprim-sulfadiazine orally once a day and the control group (seven horses) received placebo (flour) at the same time. All horses were housed outdoors throughout the study. Schirmer tear test values were measured at 0, 2, 4, 6 and 8 weeks, and 4 weeks after discontinuation of treatment. There were no significant differences in tear production between the treated and control groups. Fluctuations in STT were observed and may result from individual and environmental variations. Trimethoprim-sulfadiazine did not decrease tear production in the horses in this study. Horses normally experience periodic fluctuations in STT values.
Keratoconjunctivitis sicca in dogs associated with sulfonamide therapy: 16 cases (1980-90)
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A new surgical approach to treat epiphora in dogs and cats: dacryocystorhinostomy with topically applied Mitomycine-C associated with eyelid correction
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Evaluation of effect of the modified medial canthoplasty (mmc) on corneal epitheliopathy of a shih-tzu dog by the lacrimal flow observation
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Saito A, Tuduki A. Evaluation of effect of the modified medial canthoplasty (mmc) on corneal epitheliopathy of a shih-tzu dog by the lacrimal flow observation. Vet ophthalmol 2004; 7: 442.
  • 남치주 Tear
  • 서 눈물생산
  • 비루관 개통성
  • 굴곡도
서강문, 남치주. Tear staining syndrome이 있는 poodle에 서 눈물생산, 비루관 개통성 및 굴곡도. 대한수의학회지 1995; 35: 383-390.
Tear staining syndrome이 있는 poodle에서 누낭비강개구술의 효과
  • 권오경 서강문
서강문, 권오경, 남치주. Tear staining syndrome이 있는 poodle에서 누낭비강개구술의 효과. 한국임상수의학회지 1995; 12: 186-193.
Tear staining syndrome이 있는 poodle에 서 눈물생산, 비루관 개통성 및 굴곡도
  • 남치주 서강문
서강문, 남치주. Tear staining syndrome이 있는 poodle에 서 눈물생산, 비루관 개통성 및 굴곡도. 대한수의학회지 1995; 35: 383-390.