VETINUITY
Doxycycline is dosed at 5 mg/kg PO every 12 hours or 10 mg/kg once daily in dogs and cats, and every oral dose in a cat must be followed by water or food to prevent esophageal stricture.
Cats: chase every tablet or capsule with at least 6 mL of water or a small meal.
Doxycycline for dogs and cats is 5 mg/kg by mouth every 12 hours or 10 mg/kg once daily, per Vetinuity’s doxycycline dose calculator above, with one rule that changes how it is given rather than how much: in cats, every tablet or capsule is followed by water or a bite of food. Heartworm-positive dogs receive a higher course, 10 mg/kg twice daily for 28 days, to clear Wolbachia before adulticide treatment.
| Indication | Dog | Cat | Route and frequency |
|---|---|---|---|
| Feline upper respiratory infection (Chlamydia, Mycoplasma) | not applicable | 5 mg/kg q12h or 10 mg/kg q24h | PO, 7-10 days (Chlamydia 28 days) |
| Canine infectious respiratory disease complex | 5 mg/kg q12h or 10 mg/kg q24h | not applicable | PO, 7-10 days |
| Ehrlichia, Anaplasma, Rocky Mountain spotted fever | 5 mg/kg q12h or 10 mg/kg q24h | 5 mg/kg q12h | PO, 28 days for Ehrlichia |
| Heartworm disease, Wolbachia reduction | 10 mg/kg q12h | not applicable | PO, 28 days before melarsomine |
The 2017 ISCAID respiratory guidelines name doxycycline the first-line empirical drug for feline upper respiratory infection when an antimicrobial is indicated, because it reaches Chlamydia felis and Mycoplasma, and a first choice for canine infectious respiratory disease complex with bacterial involvement. The guidelines recommend 7 to 10 days for most cases and a longer course for feline chlamydiosis.
German and colleagues reported cats that developed esophageal strictures after doxycycline tablets, some needing repeated balloon dilation. Use a liquid formulation, a pill treat or butter, or chase the pill with about 6 mL of water. Compounded doxycycline suspensions have shown poor stability, so check the pharmacy’s beyond-use date.
Nausea and vomiting are common on an empty stomach; give with food. Elevated liver enzymes are reported in dogs. Doxycycline binds polyvalent cations, so separate it from sucralfate and antacids by 2 hours. Avoid it in pregnancy and in very young animals because of effects on bone and teeth. Vetinuity, built by Brian Toncray, DVM, an emergency veterinarian, puts the feline chaser rule in its dose table, not in a footnote.
Related: amoxicillin-clavulanate, sucralfate, enrofloxacin and IMHA.
The label dose of amoxicillin-clavulanate is 13.75 mg/kg PO q12h in dogs and 62.5 mg per cat q12h; ISCAID guidelines use 12.5-25 mg/kg q12h for urinary and skin infections.
Sucralfate is a fixed dose, not a per-kilogram one: 0.5-1 g per dog by mouth every 8-12 hours and 0.25 g per cat every 8-12 hours, given 2 hours apart from other oral drugs.
Enrofloxacin is dosed at 5-20 mg/kg once daily in dogs, but never more than 5 mg/kg per day in cats, the dose above which retinal degeneration and blindness have been reported.
Prednisolone is dosed at 0.5-1 mg/kg/day for inflammation and 2 mg/kg/day for immunosuppression in dogs, and 1-2 mg/kg/day and 2-4 mg/kg/day in cats, which should get prednisolone rather than prednisone.
Evidence-based canine IMHA treatment protocol from the 2019 ACVIM consensus, with antithrombotics per the ACVECC CURATIVE guidelines.
Tablets and capsules lodge in the feline esophagus when given dry, and doxycycline is irritant where it dissolves. Case series describe strictures after doxycycline pills, which is why a water or food chaser is part of the dose.
Yes. Unlike older tetracyclines, its absorption is only modestly reduced by food, but separate it from calcium, antacids, iron and sucralfate.
Vetinuity explains clinical options with journal citations.
The veterinarian diagnoses and prescribes.