Q34: Is human disease also treated with doxycycline?

C: I am not sure if doxycycline is used in all cases, but I was once treated preventively with doxycycline myself (I got the flu shortly after being in contact with a dog with leptospirosis, so I was treated while test results were pending, which came back negative).

Q35: Can dogs be treated initially with amoxicillin-clavulanate injections, then amoxicillin-clavulanate orally for one week then doxycycline for two to three weeks?

C: Yes, this would be appropriate, although I would usually change to doxycycline as soon as the dog can tolerate oral medication. See questions 12 and 19 for more discussion about treatment and antibiotic doses.

Q36: Any views on IFA screening?

C: see question 33.

Q38: Can vaccine-induced immunity against leptospirosis be boosted by exposure to wild-type leptospires?

C: I don’t think that any studies have looked at this, but we know that some dogs become exposed to Leptospira species in nature and develop antibodies without becoming ill, so I would suspect that exposure to vaccinal serovars of Leptospira may increase immunity.

Q39: Is it OK to use the Nobivac L4 vaccine at the same time than the intranasal parainfluenza vaccine?

C: See question 25 for more advice on vaccination in puppies.

Q40: You said that 10% bleach kills leptospires. Do you mean final concentration or 1:10 dilution? Because there is no commercial solution of 10% bleach.

C: Hi, industrial bleach seems to be around 10% and can be bought (here on Amazon: http://www.amazon.co.uk/gp/product/B00915WEEK/ref=pd_lpo_sbs_dp_ss_1?pf_rd_p=479289247&pf_rd_s=lpo-top-stripe&pf_rd_t=201&pf_rd_i=024500906X&pf_rd_m=A3P5ROKL5A1OLE&pf_rd_r=1PKXXCHR4TNX5PT8DXAS).

One review article mentioned that 10% bleach could be used to treat outdoor areas where dogs urinate. A 1:1 dilution of 10% bleach with water could be used to inactivate urine collected via a urinary catheter. Iodine-based disinfectants, accelerated hydrogen peroxide and quaternary ammonium solutions are also effective (reference: Sykes et al., 2010 ACVIM Small animal consensus statement on leptospirosis: diagnosis, epidemiology, treatment and prevention. J Vet Intern Med 2011, 25:1-13).

Q41: For how long do vaccines protect from urinary shedding?

C: It depends on the vaccine. Only some vaccines have been proven to protect against renal carriage in dogs. For Nobivac L4:

–       Study 3 weeks after vaccination: in one study, dogs (a group of vaccinated dogs and a control group) were experimentally challenged 3 weeks after the second vaccination. The results demonstrated that Nobivac L4 vaccine induced sterile immunity against leptospiraemia and renal infection with strains of serogroups Canicola, Icterohaemorrhagiae and Grippotyphosa, and induced sterile immunity against leptospiraemia with a strain of serogroup Australis. This led to the claim that Nobivac L4 protects against renal carriage from Canicola, Icterohaemorrhagiae and Grippotyphosa serogroups. Nobivac L4 has not been approved to reduce renal carriage by the serogroup Australis (including serovar bratislava), so although vaccinated dogs should be protected against developing disease from this serogroup, asymptomatic renal carriage cannot be excluded (reference: Klaasen et al. A novel tetravalent Leptospira bacterin protects against infection and shedding following challenge in dogs. Vet Rec. 2013 Feb 16;172(7):181).

–       Study 12 months after vaccination: in one study, dogs (a group of vaccinated dogs and a control group) were experimentally challenged twelve months after the second vaccination. The vaccine was able to either prevent or significantly reduce infection following challenge with the strains of all four serogroups. The vaccine was also able to prevent or significantly reduce renal infection following Canicola and Icterohaemorrhagiae challenge, and there was a trend of reduction of renal infection with Australis (serovar bratislava). In the case of the Grippotyphosa study, challenge led to no detectable renal infection in any dog of the control group, so protection against renal carriage by this serogroup could not be assessed (reference: Klaasen et al. A new tetravalent canine leptospirosis vaccine provides at least 12 months immunity against infection. Vet Immunol Immunopathol. 2014 Mar 15;158(1-2):26-9).

Q42: If an adult dog has missed its leptospirosis booster, say by one year, does it then need a single dose to re-establish immunity, or does it need to start the course again?

C: As immunity probably doesn’t last much longer than a year (contrary to vaccination against parvovirosis, distemper or hepatitis), a dog having missed a booster would need two injections of leptospirosis vaccination again, at 2-4 weeks interval depending on the vaccine used.

Q43: what are the most common clinical signs of leptospirosis in cats?

C: The reported clinical cases were all cats with renal disease. Cats infected experimentally develop renal and hepatic inflammation.

Q44: How do you know how often the vaccine should be given if you can’t test for protection with serology?

C: Serum agglutinating antibodies, as measured by the MAT, usually only persist for 12-16 weeks after accination and are most of the time only present at a low level. However in experimental challenges, it was found that vaccinated dogs can be protected against leptospirosis even when they have no or very low detectable serum antibodies as measured by MAT. The duration of immunity for a vaccine is based on experimental studies: dogs vaccinated then challenged with pathogenic strains of Leptospira a while after vaccination, to see if they remain protected. I am aware of published studies demonstrating a one year duration of immunity for Nobivac Lepto 2 , Nobivac L4 (both MSD Animal Health) and Eurican L (Merial):

–       Nobivac Lepto 2: Klaasen et al. Duration of immunity in dogs vaccinated against leptospirosis with a bivalent inactivated vaccine. Vet Microbiol. 2003 Aug 29;95(1-2):121-32.

–       Nobivac L4: Klaasen et al. A new tetravalent canine leptospirosis vaccine provides at least 12 months immunity against infection. Vet Immunol Immunopathol. 2014 Mar 15;158(1-2):26-9.

–       Eurican L: Minke et al. Onset and duration of protective immunity against clinical disease and renal carriage in dogs provided by a bi-valent inactivated leptospirosis vaccine. Vet Microbiol. 2009 May 28;137(1-2):137-45.

C: and to all the people who thought the webinar was good: thank you very much!